GAL-1 variant polypeptide molecule exhibiting resistance to acidic conditions of an inflammatory microenvironment and nucleic acid molecule encoding it

Abstract

Variants of the Galectin-1 polypeptide include a mutation of the histidine residue at position 52 of the complete amino acid sequence of native human Gal-1, as shown in SEQ ID No. 1. The mutation is a substitution of histidine to tyrosine or asparagine, providing resistance to acidosis that otherwise results in the inactivation of native human Gal-1. Variants of the Galectin-1 polypeptide may also include one or more additional mutations of the cysteine ​​residue at a selected position from 2, 16, 88, or combinations thereof, of the complete amino acid sequence of native human Gal-1, as shown in SEQ ID No. 1. The additional mutation is a substitution of cysteine ​​to serine, providing resistance to oxidation.

Description

FIELD OF INVENTION The description refers generally to new variants of Gal-1, and to the use of such variants in methods to modulate an immune response and methods of treatment for conditions that could benefit from negative regulation of the immune response. BACKGROUND The immune system has evolved as a complex network of mechanisms to discriminate between 'self and non-self,' and homeostasis is achieved through strict control that leads to the recognition and elimination of foreign antigens and / or the development of tolerance. T lymphocytes are key players in cell-mediated immunity, as maintaining the balance between pro-inflammatory (Thl / Thl7) and anti-inflammatory (Th2 / Treg) cell populations is essential for resolving inflammation and keeping autoimmune and chronic inflammatory diseases under control. Among the various regulatory circuits that maintain this balance (immune homeostasis) are cell surface glycosylation and lectin-glycan signaling. Lectins are carbohydrate-binding proteins that induce specific response cascades, thereby modulating the immune response. This regulation appears to be context-dependent; that is, on the glycan side, different outcomes are achieved through the programmed remodeling of the cell surface glycome by sequential actions of glycosidases and glycosyltransferases; and on the lectin side, microenvironmental conditions can alter the lectin's affinity and binding capacity. Galectins are members of a family of multifunctional lectins defined by their specificity for β-galactoside-containing glycans and by a carbohydrate recognition domain (CRD). Cooper, DNW, “Galectinomics: finding themes in complexity,” et Biophysica Acta, General Subjects, 1572:209-231 (2002). In humans, CRDs have been identified for approximately 16 different galectins, a prime example being Galectin-1 (Gal-1), a lectin that specifically binds terminal N-acetyl-lactosamine residues exposed on cell surfaces and cross-links with a group of preferred glycosylated receptors to transduce signals that directly lead to Thl and Thl7 apoptosis and termination of the inflammatory response.Human Gal-1 is a small lectin composed of 135 amino acids, which folds into a three-dimensional β-sandwich structure of two slightly folded sheets with long, variable connecting loops. A notable feature of Gal-1 is the high proportion of cysteine ​​residues (Pe'er et al., “Proteomic signatures: Amino acid and oligopeptide compositions differentiate among phyla,” Proteins, 54:20-40 (2004)), with each Gal-1 monomer containing 6 cisternae: Cys2, Cysl, Cysl0, Cys88, and Cysl30. The binding of Gal-1 depends on the activity of glycosyltransferases, including the activity of N-acetylglucosaminyltransferase 5 (GnT5), an enzyme responsible for generating branched structures of β-I,ό-V-glycan and a core of 2 β-1,6 N-acetylglucosaminyltransferase (GCNT1) that elongates the 2-O-glycans of the core. While Thl and Thl 7 cells express the repertoire of cell surface glycans critical for Gal-1 binding and cell death, Th2 cells are protected against Gal-1 binding through α-2,6 sialylation of cell surface glycoproteins (Toscano et al., “Differential glycosylation of Th1, Th2 and Th-17 effector cells selectively regulates susceptibility to cell death,” Nat. Immunol., 8:825-34 (2007)), a modification involving ot(2,6) sialyltransferase (ST6) and thus preventing Gal-1 binding by masking galactose residues in LacNAc units.The anti-inflammatory activity of Gal-1 is not limited to T cell apoptosis; it has also been found to promote the differentiation of tolerogenic dendritic cells (Ilarregui et al., “TOLEROGENIC SIGNALS DELIVERED BY DENDRITIC CELLS TO T CELLS THROUGH A GALECTIN-1DRIVEN IMMUNOREGULATORY CIRCUIT INVOLVING INTERLEUKIN 27 AND INTERLEUKIN 10,” Nat. Immunol., 10:981-991 (2009)), and to favor the conversion of macrophages to an M2-type phenotype (Starossom et al., “Gal-1 deactivates classically activated microglia and PROTECTS FROM INFLAMMATION-INDUCED NEURODEGENERATION,” Immunity, 37(2):249-63 (2002)). In fact, administration of recombinant Gal-1 has been found to improve disease severity in many autoimmune models of arthritis, uveitis, and TNBS-induced colitis. See Toscano et al., Journal of Immunology, 176:6323-32 (2006); and Santucci et al., “Galectin-1 suppresses experimental colitis in mice,” Gastroenterology, 124(5):1381-94 (2003). However, the therapeutic potential of Gal-1 is limited by intrinsic biochemical factors, including its sensitivity to oxidation and acidic pH, both of which are typically involved in inflammatory microenvironments. Furthermore, since most studies to date addressing Gal-1 function have been conducted under normal physiological conditions (i.e., at pH around 7.4), most of the available physicochemical data characterizing Gal-1 activity and affinity do not reflect its role in an inflammatory site where extracellular acidosis can cause the pH to fall below 5.5. This high proton concentration is usually attributed to the infiltration and activation of inflammatory cells, leading to increased oxygen and energy demands, accelerated glycolysis, and increased lactic acid secretion. (Menkin, Science, 1956)Furthermore, although lactic acid (i.e., extracellular acidosis) has been shown to influence many processes related to immune metabolism ((Geffner et al., (1993); Jancic et al., (2012); Kraus & Wolf, (1996); Martínez et al., (2007); Trevani et al., (1999); Vermeulen et al., (2004)), little is known about the mechanisms through which these conditions influence cell communication. One purpose of the invention is therefore to investigate the effect of altered extracellular pH, particularly that of an acidic microenvironment, on immune cells and their function. More specifically, one purpose of the invention is to investigate how Gal-1 affects immune cells and their function. SUMMARY OF THE INVENTION This summary is provided to present a selection of concepts that are described herein in more detail with respect to various embodiments of the invention. This summary is not intended to identify key or essential features of the invention, nor is it intended to limit the scope of the invention. This description relates generally to novel variants of the Gal-1 polypeptide that are resistant to adverse conditions typically found in inflammatory microenvironments, which otherwise result in the inactivation of native human Gal-1. Specifically, rationally engineered or mutant novel variants of the Gal-1 polypeptide are provided, which have certain amino acid modifications that confer resistance against the acid and oxidative inactivation observed in native human Gal-1. By eliminating susceptibility to inactivation in inflammatory microenvironments, the novel Gal-1 variants can be used in various methods of the invention as highly effective immunomodulatory agents. Embodiments of the invention relate to variants of the Gal-1 polypeptide resistant to acidic conditions that otherwise result in the inactivation of native human Gal-1. The Gal-1 polypeptide variants comprise a mutation of the histidine residue at position 52 of the complete amino acid sequence of native human Gal-1, as shown in SEQ ID NO: 1, the mutation being a substitution of histidine to tyrosine or asparagine. The polypeptide variants are resistant to acidic conditions that generally result in an extracellular pH falling below 7.0. In certain embodiments, variants of the Gal-1 polypeptide may include an additional mutation at the cysteine ​​residue corresponding to a selected position from among 2, 16, 88, or combinations thereof, of the complete amino acid sequence of native human Gal-1 as shown in SEQ ID NO: 1, this additional mutation being a substitution of at least one cysteine ​​to a serine. Specifically, variants of the Gal-1 polypeptide may include one or more additional mutations at the cysteine ​​residue, such as mutations corresponding to positions 2 and 16, or 2 and 88 of the complete amino acid sequence of native human Gal-1, as shown in SEQ ID NO: 1. Such mutants exhibit resistance to both acidic and oxidative conditions of an inflammatory microenvironment that would otherwise result in the inactivation of native human Gal-1. In certain embodiments, the polypeptide variants include: (a) a mutation corresponding to position 52 of the complete amino acid sequence of native human Gal-1 as shown in SEQ ID NO: 1, where the mutation is a substitution of histidine to tyrosine or asparagine; and (b) a mutation of the cysteine ​​residue corresponding to positions 2 and 16 of the complete amino acid sequence of native human Gal-1. Such polypeptide variants exhibit a synergistic effect under physiological pH conditions with respect to resistance to both acidic and oxidative conditions, as well as pro-apoptotic activity, compared to native human Gal-1. The polypeptide variants can also induce IL-10 secretion at least 16 times greater than the IL-10 secretion induced by native human Gal-1. Forms of embodiment of the invention also relate to nucleic acids encoding a variant of the Gal-1 polypeptide having a mutation corresponding to position 52 of the complete amino acid sequence of native human Gal-1 as shown in SEQ ID NO: 1, wherein the mutation is a substitution of histidine to tyrosine or asparagine.In certain embodiments, the nucleic acids described herein encode a variant of the Gal-1 polypeptide having: (a) a mutation corresponding to position 52 of the complete amino acid sequence of native human Gal-1 as shown in SEQ ID NO:1, wherein the mutation is a substitution of histidine to tyrosine or asparagine; and (b) at least one other mutation of the cistern residue corresponding to positions 2, 16, 88, or combinations thereof of the complete amino acid sequence of native human Gal-1 as shown in SEQ ID NO: 1, wherein the mutation is a substitution of cysteine ​​to serine. In other embodiments, the invention also relates to pharmaceutical compositions comprising the Gal-1 polypeptide variant(s), or a fragment thereof, and a pharmaceutically acceptable carrier. Methods for modulating an immune response are also provided, which may consist of contacting an immune cell with a variant of the Gal-1 polypeptide as described herein, wherein the mutation in the Gal-1 polypeptide variant modulates the immune response by upregulating the binding of the Gal-1 polypeptide or a fragment thereof to its natural binding partner(s) under acidic conditions of an inflammatory microenvironment that otherwise inhibits the binding of native human Gal-1 or a fragment thereof to its natural binding partner(s). In some embodiments, the methods for modulating an immune response may comprise contacting an immune cell with the Gal-1 variant in vivo. In other embodiments, the methods for modulating an immune response may comprise contacting an immune cell with the Gal-1 variant in vitro.In several respects, the immune cell can be an animal cell, such as a mammalian cell, such as a human cell. According to various embodiments of the invention, acidic conditions of an inflammatory microenvironment refer to acidic conditions that result in an extracellular pH falling below 6.0, such as below 5.7, or below 5.5, below 5.3, or below 5.0. Such inflammatory microenvironments typically result in acidic pH conditions falling below 6.0 and oxidative conditions that reduce the lactose binding of native human Gal-1. Certain embodiments also relate to methods for treating a subject having a disease requiring the negative regulation of an immune response. Specifically, methods according to embodiments of the invention may comprise administering to a subject having a disease requiring the negative regulation of an immune response a therapeutically effective amount of a Gal-1 polypeptide mutant that binds to the natural binding partner(s) of native human Gal-1 under inflammatory conditions, wherein the Gal-1 polypeptide variant comprises: (a) a first mutation of the histidine residue corresponding to position 52 of the complete amino acid sequence of native human Gal-1 as shown in SEQ ID NO: 1, the mutation consisting of a substitution of histidine to tyrosine or asparagine;and (b) at least a second mutation of the cysteine ​​residue corresponding to a selected position from among 2, 16, 88 or combinations thereof of the complete amino acid sequence of native human Gal-1 as shown in SEQ ID NO: 1, the at least second mutation constituting a substitution of a cysteine ​​to a serine.; In the treatment methods covered by the invention, the administration of a variant of the Gal-1 polypeptide described herein negatively regulates the subject's immune response by inducing the secretion of the anti-inflammatory cytokines IL-10 and IL-27. Furthermore, the administration of variants of the Gal-1 polypeptide can negatively regulate the subject's immune response by inducing T-cell apoptosis without increasing the secretion of the anti-inflammatory cytokines IL-10 and IL-27. With respect to the treatment methods described herein, the subject may be a human, and the disease may be an immune disorder selected from the group consisting of acute or chronic inflammatory diseases, autoimmune diseases, allergic disorders, arthritis, hepatitis, asthma, multiple sclerosis, transplant rejection, graft-versus-host disease (GVHD), inflammatory bowel diseases, Parkinson's disease, Alzheimer's disease, and any organ-specific autoimmune disease. In some embodiments, the Gal-1 polypeptide variant may be administered to a subject in a pharmaceutical composition comprising the Gal-1 variant in a therapeutically effective amount and a pharmaceutically acceptable carrier. The pharmaceutical compositions described herein may be administered to the subject in a dosage form selected from the group consisting of tablets, capsules, pills, powders, granules, parenteral solutions or suspensions, oral solutions or suspensions, oil-water emulsions, intravenous injections, and gene therapy. These and other features, aspects and advantages of the invention will be better understood by referring to the accompanying description, examples, figures and claims that follow. BRIEF DESCRIPTION OF THE DRAWINGS The manner in which the objectives of the present description and other desirable characteristics can be obtained will become evident from the descriptions of the attached drawings that follow. Figure IA shows the amino acid sequence of human Gal-1 (corresponding to SEQ ID NO: 1), with secondary annotations and numbering below the sequence corresponding to the Gal-1 residues, and arrows representing β-strands. In the primary sequence, histidine residues are highlighted in yellow scales and cysteine ​​residues are highlighted in red scales. Figure IB shows the spatial distribution of cysteine ​​and histidine residues in the monomer structure of Gal-1. Figure 2 shows the circular dichroism (CD) spectra of different redox states of Gal-1 and CXS double mutants. All reduced forms of Gal-1 and their CXS double mutants (solid line) exhibited similar CD spectra, but when oxidized in air (dashed line) or with hydrogen peroxide (composed of dots and dashes), different spectra were obtained depending on the absence of particular cysteine ​​residues. Of all the CXS mutants (not shown), only the C16S and C88S mutants generated the conformational state of the oxidized wild-type Gal-1 when oxidized in air, and they also maintained the reduced protein conformation when hydrogen peroxide was used to induce protein oxidation. Figures 3A–3E show the oxidation kinetics of Gal-1 with hydrogen peroxide (H2O2). Figure 3A shows the rate constants for the most reactive thiol in Gal-1, determined by plotting the pseudo-first-order rate constants (k') as a function of the H2O2 concentration. To determine the pseudo-first-order rate constants, Gal-1 (67 μM) was incubated with H2O2 at concentrations of 2.81 mM (squares), 4.65 mM (circles), 5.56 mM (triangles), and 8.28 mM (diamonds) in PBS at 25°C. Figure 3B shows the reducing and non-reducing SDS-PAGE results of aliquots removed from the reaction of Gal-1 with 10 mM H2O2 (ME: 2-mercaptoethanol). Figure 3C shows the reducing and non-reducing SDS-PAGE results of Gal-1 WT (wild type), C2S mutator, and C130S mutator subjected to oxidation with 10 mM H2O2 for 2 hours. Iodoacetamide (IAM) was added after H2O2 treatment to analyze in greater detail the effect of sample manipulation on thiol-free oxidation after the reaction was complete. Figure 3D shows the emission intensity at 363 nm, recorded and adjusted for lactose, of reduced (squares) and oxidized (circles) Gal-1 (8 μM) titrated by adding 100 mM lactose. Figure 3E shows the percentage of cell death observed for each recombinant Gal-1 tested (WT, CSX, and two CSX double-mimickers), with the reduced form shown as black bars and the oxidized form as gray bars. The results shown are representative of three independent experiments (mean ± SD; *P < 0.05). Figure 4 shows the kinetic analysis of the conformational changes of Gal-1 upon oxidation with H2O2. Gal-1 (7 μM) was incubated with H2O2 at concentrations of 5 mM (squares), 10 mM (circles), 15 mM (triangles), and 20 mM (diamonds) in PBS buffer (100 mM, 0.1 mM DTP A, pH 7.4) at 25°C, and the intensity of the emission spectrum at 345 nm was recorded as a function of time. A kinetic model (line) was fitted that takes into account the consumption of reduced Gal-1, the formation of the different oxidized Gal-1 species, and the hydrogen peroxide concentration to obtain the rate of the conformational changes and reactions corresponding to the over-oxidation of cisternae. Figure 5A shows a comparison of the apoptotic effects of recombinant Gal-1 on PBMCs (peripheral blood mononuclear cells) in different pH environments that mimic the acidic conditions typically found in inflammation. Figure 5B shows the decreased binding capacity of Gal-1 under the different pH environments studied. Figure 5C shows the binding of lactose to Gal-1. Figure 5D provides a detailed view of the ligand-binding groove of Gal-1, showing key amino acids that interact directly with the ligand portion, and specifically showing the location of histidines 44 and 52. Figure 5E shows the protonation equilibrium for the histidine imidiazole ring. Figure 5F provides a detailed view derived from MD simulations of Gal-1 with histidine 52 in both the double-protonated and mono-protonated states, respectively.Figure 5G shows the calculated pKa values, plotted as a function of pH, for histidine residues in mono- and di-protonated states, respectively. Figure 5H shows the orientation of the C-Ca-Cb-Cg dihedral of the histidine 52 side chain, along the simulation production, for Gal-1 with histidine 52 in both the mono-protonated (red scale) and di-protonated (blue scale) states. Figures 6A–6D show the characterization of acid-resistant Gal-1 polypeptide variants based on solid-phase competition assays with immobilized asialofetuin / lactose for Gal-1 WT and acid-resistant Gal-1 variants, H52N (N) and H52Y (Y), at pH 7.5 (Fig. 6A), pH 6.5 (Fig. 6B), and pH 5.5 (Fig. 6C). IC50 values ​​(concentration at which 50% inhibition occurs) for each mutant variant at different pH values, based on in vivo SG2 assays in an EAE model, are shown in Fig. 6D. Fig. 6E shows the Gal-1:lactose dissociation constant values ​​determined by fluorescence spectroscopy at pH 7.5, 6.5, and 5.5, respectively. Figure 6F shows the pro-apoptotic effect of Gal-1 on T cell lines as a function of pH. The FIGS.Figures 6GI show the far-ultraviolet DC spectra of the freshly prepared reduced form (Reduced), the air-oxidized form (Oxidized), and the DTT-treated oxidized form (Oxidized + DTT) of Gal-1 WT (FIG. 6G), the H52N mutants (FIG. 6H), and the H52Y mutants (FIG. 61). FIG. 7 shows the dissociation constant (K¿) values ​​of Gal-1 dactose determined by fluorescence spectroscopy at pH = 7.5, 6.5 and 5.5. Figures 8A and 8B show the far-UV circular dichroism spectra of the air-reduced and air-oxidized variants of Gal-1 WT: the four triple mutant variants (SG1, SG2, SG3, SG4) and the two single mutants (H52Y and H52N). Specifically, Figure 8A shows the far-UV circular dichroism spectrum of a Gal-1 WT solution and the mutants H52N, H52Y, SG1, SG2, SG3, or SG4 under reducing conditions, and Figure 8B shows the far-UV circular dichroism spectrum of these solutions after 5 days of air exposure, with the ellipticity parameter plotted as a function of the excitation wavelength (λ in nm). Figure 8C shows the percentage of apoptosis of Jurkat cells after 6 hours of incubation in RPMI medium with a buffer at pH 7.5, 7.0, 6.5, 6.0 or 5.5, in the presence of vehicle (saline solution) or wild Gal-1 or the mutants SG1, SG2, SG3 or SG4, at a concentration of 5 μM.The quantified percentage of apoptosis is based on Annexin-V-FITC staining and is assessed by flow cytometry. The results are representative of 6 to 10 independent experiments. Stars indicate significant differences from the WT variant, except for those below the SG1 and SG3 values, which indicate differences between those variants and the SG2 and SG4 variants. Figure 8D is a linear regression model of the result in Figure 8C. In Figure 8D, *** indicates that the linear slope fitting the WT is significantly different from zero (p < 0.0001). Figure 8E shows quantitative percentage values ​​of apoptosis susceptibility of Jurkat cells incubated for 6 hours in RPMI medium at pH 7.5 in the presence of vehicle (saline) or Gal-1 WT or the SG1, SG2, SG3, or SG4 inhibitors, at a concentration of 5 μM. FIG.Figure 8F shows the apoptotic capacity of Gal-1 variants at pH 7.5 based on pooled data from at least three experiments that assessed (by Annexin-V-FITC staining) and analyzed (by flow cytometry) the apoptosis of mouse T cells incubated for 6 hours with 5 μM of Gal-1 WT or H52Y, H52N, SG1, SG2, SG3, or SG4 mutants. Δ% Apoptosis = [% Apoptosis with treatment - % Apoptosis with PBS]. Figure 8G shows the induction of apoptosis by Gal-1 variants under acidic conditions compared to physiological pH-based apoptosis (assessed by Annexin-V-FITC staining and analyzed by flow cytometry) of T cells incubated for 6 hours with 5 μM of Gal-1 WT or H52Y, H52N, SG1, SG2, SG3, or SG4 mutants in RPMI medium at pH 7.5 or 5.5. The percentage loss of activity was determined as 100*[(Δ% Apoptosis at pH 7.5 - Δ% Apoptosis at pH 6) / Δ% Apoptosis at pH 7.5].Figure 8H shows IL-10 secretion from splenocytes induced by Gal-1 variants; splenocytes were isolated from C57BL / 6 mice and incubated in RPMI complete with PBS and 5 μM of Gal-1 WT or SuperGal-1 variants 1, 2, 3, or 4 (SG1, SG2, SG3, or SG4). The supernatants were collected after 48 hours, and the secreted IL-10 was measured by ELISA. Figure 81 shows IL-27 secretion from dendritic cells induced by SuperGal variants. Dendritic cells were differentiated from bone marrow precursors of C57BL / 6 mice with recombinant GM-CSF for 9 days, and incubated in RPMI complete with PBS and 3 μM of Gal-1 WT, SG1, SG2, SG3, or SG4, with the supernatants being collected after 24 hours and the secreted IL-27 measured by ELISA. Figures 9A-E show the secretion levels of IL-10, IL-4, IL-17A, TNF, and IL-6, respectively, in the supernatants of spleen cells stimulated for 48 hours with anti-CD3c agonist and soluble anti-CD28 antibodies (1 pg / ml) in the presence of 3 μM of Gal-1 WT or the SG1, SG2, SG3, or SG4 variants. The results represent 3 independent experiments. Figures 10A–10C show IL-27p28 and IL-23 levels in dendritic cell supernatants incubated for 24 hours in complete medium alone or with 3 μM of Gal-1 WT or the SG1, SG2, SG3, or SG4 variants, with buffer adjusted to pH 7.5 or 5.5. Figures 10D and 10E show the determination and expression of CDllc by flow cytometry in dendritic cells cultured for 72 hours in complete medium alone or in the presence of 3 μM of Gal-1 WT or the SG1, SG2, SG3, or SG4 variants. Figure 10F shows proliferation assessed by CFSE fluorescent dye dilution by flow cytometry of spleen-purified CD4+ T lymphocytes co-cultured with LPS-induced dendritic cells for 72 hours along with anti-CD3e agonist prior to exposure to dendritic cells pre-incubated for 72 hours in complete medium only (control) or supplemented with 3 μM of Gal-1 WT or of the SG1, SG2, SG3, or SG4 variants.FIG. 10G shows the division index, FIG. 10H shows proliferation, and FIG. 101 shows the percentage of dividing cells, based on the results of FIG. 10F. Figure 11A shows the clinical scores of EAE mice treated with vehicle (PBS) or 100 pg per mouse per day of Gal-1 WT or the SG1, SG2, SG3, or SG4 variants, starting from the date of first symptoms. The results are from two independent experimental groups, with five mice per group per experiment. Figures 11B and 11C show the expression levels of IL-17A and / or IFN-γ by flow cytometry of CD4+ or CD8+ cells drained from lymph nodes at the immunization site, restimulated in vitro for 48 hours with 30 pg / ml of MOG35-55 and an anti-CD3E agonist (1 pg / ml). Figure 11D shows the Foxp3 expression levels by flow cytometry of CD4+ cells draining lymph nodes from the immunization site on day 24 post-immunization. Figure HE shows the CD69 and CD44 expression levels by flow cytometry of CD4+Foxp3+ cells as assessed by flow cytometry, and FigureFigure 11F shows the quantification of the results obtained in Figure 11E. Figure 12 shows the binding of lactose to Gal-1 under different pH conditions as a function of lactose concentration, tested by fluorescence. Trp68 was used as a probe in the ligand-binding site groove, Aexc=295nm, and Xem=345nm. Figure 13A shows the clinical score of EAE mice treated with PBS vehicle (control) or 100 pg per mouse per day of Gal-1 WT (red scale) or the SG2 variant (blue scale) from day 6 to 9 post-immunization. Figure 13B shows the quantification of CD4+ T cells producing IL-17A or IFN-γ, and CD8+ T cells producing IFN-γ in lymph node drainage obtained 27 days post-immunization and restimulated in vitro with 30 pg / L of MOG35-55, evaluated by flow cytometry. DETAILED DESCRIPTION A. Abbreviations and definitions The following definitions of several terms used herein are provided to facilitate understanding of the invention. The abbreviation “DC” stands for Circular Dichroism. The abbreviation “CRD” stands for Carbohydrate Recognition Domain. The abbreviation “CXS” stands for Gal-1 Serine-for-Cysteine ​​variants. The abbreviation “APDT” stands for diethylenetriaminepentaacetic acid. The abbreviation “EAE” stands for experimental autoimmune encephalomyelitis. The abbreviation “Gal-1” stands for Galectin-1. The abbreviation “IAM” stands for Iodoacetamide. The abbreviation “PBS” stands for Phosphate Buffered Saline Solution. The abbreviation “SDS” stands for Sodium Duodecyl Sulfate The abbreviation “SDS-PAGE” stands for Sodium Duodecyl Sulfate-Polyacrylamide Gel Electrophoresis. By presenting elements in various forms, the articles “a,” “an,” “the,” “a,” and “said” are intended to signify that there is one or more of the elements. The terms “comprising,” “including,” and “having” are intended to be inclusive and to signify that there may be additional elements other than those listed. The terms Galectin-1 or Gal-1 used herein refer to the sequence, domains, polypeptides, fragments of Gal-1, as well as variants thereof, gene products of the Gal-1 gene, and / or modulators thereof. Specifically, unless otherwise indicated (e.g., terms used in reference to a variant or mutant of Gal-1), the terms refer to native Gal-1. Sequences, structures, domains, and certain biophysical characteristics and functions of the Gal-1 genes and gene products have been described in the art. See, for example, Rabinovich et al., Trends Immunol. 23:313-320 (2002); Liu and Rabinovich, Nature Reviews Cancer 5:29-41 (2005); Rubinstein et al., Cancer Cell 5:241-251 (2004); Le et al., J. Clin. Oncol. 23:8932-8941 (2005); Vasta et al., Curr. Opin. Struct. Biol. 14:617-630 (2004); Toscano et al., Cyt. Growth Fací. Rev. 18:57-71 (2007); Camby et al.Glycobiology 16;137R-157R (2006) (the disclosures of the cited references are incorporated here as a reference in full). The Gal-1 gene is also expressed in other cells, as is known in the art. See, for example, Gottschalk et al., Annu. Rev. Med. 56, 29-44 (2005); Nalesnik et al., Clin. Transplant. 13, 39-44 (1999); Toscano et al., Nat. Immunol. 8, 825-834 (2007); Ilarregui et al., Nat. Immunol. 10: 981-91 (2009); Re et al., J. Clin. Oncol. 23, 6379-6386 (2005); Marshall et al., Blood 103, 1755-1762 (2004); Gandhi et al., Blood 108, 2280-2289 (2006); Juszczynski et al., Proc. Nati. Acad. Sci. USA 104, 13134-13139 (2007); Rodig et al., Clin. Cancer Res. 14, 3338-3344 (2008); Rabinovich et al., Trends Immunol. 23:313-320 (2002); Liu and Rabinovich, Nature Reviews Cancer 5:29-41 (2005); Rubinstein et al., Cancer Cell 5:241-251 (2004); Le et al., J. Clin. Oncol. 23:89328941 (2005); Vasta et al., Curr. Opinion. Struct. Biol. 14:617-630 (2004); Toscano et al., Cyt. Growth Fact.Rev. 18:57-71 (2007); Camby et al., Glycobiology 16:137 R-157R (2006). Native human Gal-1 sequences include those provided below in the attached sequence listing. Protein sequence of human native Gal-1 (SEO ID NO: 1) ACGLVASNLNLKPGECLRVRGEVAPDAKSFVLNLGKDSNNLCLHFNPRFNAHGDAN TIVCNSKDGGAWGTEQREAVFPFQPGSVAEVCITFDQANLTVKLPDGYEFKFPNRLN LEAINYMAADGDFKIKCVAFD Nucleotide sequence of human native Gal-1 (SEO ID NO: 2) ATGGCTTGTGGTCTGGTCGCCAGCAACCTGAATCTCAAACCTGGAGAGTGCCTTC GAGTGCGAGGCGAGGTGGCTCCTGACGCTAAGAGCTTCGTGCTGAACCTGGGCA AAGACAGCAACAACCTGTGCCTGCACTTCAACCCTCGCTTCAACGCCCACGGCGA CGCCAACACCATCGTGTGCAACAGCAAGGACGGCGGGGCCTGGGGGACCGAGCA GCGGGAGGCTGTCTTTCCCTTCCAGCCTGGAAGTGTTGCAGAGGTGTGCATCACC TTCGACCAGGCCAACCTGACCGTCAAGCTGCCAGATGGATACGAATTCAAGTTCC CCAACCGCCTCAACCTGGAGGCCATCAACTACATGGCAGCTGACGGTGACTTCA AGATCAAATGTGTGGCCTTTGACTGA The term unit dosage form refers to physically discrete units suitable as unit doses for subjects to be treated; each unit containing a predetermined amount of active compound calculated to produce the desired therapeutic effect in association with the required pharmaceutical carrier. As used herein, homologs are defined as two nucleic acids or peptides that have similar, or substantially identical, nucleic acid or amino acid sequences, respectively. The term homolog further encompasses nucleic acid molecules that differ in one of their nucleotide sequences due to degeneracy of the genetic code and thus encode the same amino acid sequences. In one preferred embodiment, homologs include allelic variants, orthologs, paralogs, agonists, and antagonists of the nucleic acids encoding the peptide, or analogues thereof, of the present invention. Herein, the term orthologs refers to two nucleic acids from different species that have evolved from a common ancestral gene through speciation. Typically, orthologs encode peptides that have the same or similar functions.In particular, the orthologs of the invention will generally exhibit at least 80-85%, more preferably 85-90% or 90-95%, and most preferably 95%, 96%, 97%, 98%, or even 99% identity, or 100% sequence identity, with all or part of the amino acid sequence of the Gal-1 mutant polypeptides or analogues thereof of the present invention, preferably SEQ ID NO: 1, or mutants or variants thereof, and will exhibit a function similar to the Gal-1 mutant polypeptides. As also used herein, the term paralogs refers to two nucleic acids that are related by duplication within a genome. Paralogs usually have distinct functions, but these functions may be related. The percentage of identity between two sequences is a function of the number of identical positions shared by the sequences (i.e., % identity = number of identical positions / total number of positions x 100), taking into account the number and length of spaces that must be introduced for optimal alignment of the two sequences. Sequence comparison and the determination of the percentage of identity between two sequences can be achieved using a mathematical algorithm, as described in the following non-limiting examples. To determine the sequence identity percentage of two amino acid sequences (e.g., SEQ ID NO: 1 and a mutant form thereof), the sequences are aligned to achieve optimal comparison (e.g., spaces may be introduced into the sequence of one polypeptide to achieve optimal alignment with the other polypeptide or nucleic acid).The amino acid residues are then compared at the corresponding amino acid positions. When a position in one sequence (e.g., SEQ ID NO: 1) is occupied by the same amino acid residue as the corresponding position in the other sequence (e.g., a mutant form of the sequence selected from the peptide sequences of SEQ ID NO: 1), then the molecules are identical at that position. The same type of comparison can be made between two nucleic acid sequences. Determining the percentage of sequence identity between two nucleic acid or peptide sequences is well known in the art. For example, the Vector NTI 6.0 (PC) software package (InforMax, 7600 Wisconsin Ave., Bethesda, MD 20814) can be used to determine the percentage of sequence identity between two nucleic acid or peptide sequences. In this method, a gap opening penalty of 15 and a gap extension penalty of 6.66 are used to determine the percentage of identity between two nucleic acids. A gap opening penalty of 10 and a gap extension penalty of 0.1 are used to determine the percentage of identity between two polypeptides. All other parameters are set to their default values. For multiple alignment (Clustal W algorithm), the gap opening penalty is 10, and the gap extension penalty is 0.05 with a blosum62 array.It is understood that for the purposes of determining sequence identity when comparing a DNA sequence with an RNA sequence, a thymidine nucleotide is equivalent to a uracil nucleotide. The percentage of sequence identity between the two sequences is a function of the number of identical positions shared by the sequences (i.e., percentage of sequence identity = number of identical positions / total number of positions x 100). Preferably, the isolated homologous amino acids or nucleic acids included in the present invention are at least approximately 50 to 60%, preferably at least approximately 60 to 70%, and more preferably at least approximately 70 to 75%, 75 to 80%, 80 to 85%, 85 to 90%, or 90 to 95%, and more preferably at least approximately 96%, 97%, 98%, 99%, or more identical to the entirety of an amino acid or nucleic acid sequence of the aforementioned native human domain of Gal-1 (SEC ID NO: 1 and SEQ ID NO: 2). In a preferred embodiment, the homologous nucleic acids isolated from the present invention encode a mutant polypeptide domain of Gal-1 comprising an amino acid sequence that is at least 90%, more preferably at least 95%, identical to an amino acid sequence of SEQ ID NO: 1, and modulates the negative regulation of the immune response. As used in this document, the term inhibit includes the decrease, limitation, or blocking of, for example, a particular action, function, or interaction. As used herein, the term modulation includes both positive and negative regulation, such as increasing or inhibiting a response. For example, negatively regulating an immune response as described herein may include inducing the secretion of anti-inflammatory cytokines (IL-10 and IL-27) with or without induction of apoptosis, and / or inducing apoptosis (T cell death) without an increase in anti-inflammatory cytokines (IL-10 and IL-27). As used herein, the term nucleic acid is intended to include DNA molecules and RNA molecules. A nucleic acid molecule may be single-stranded or double-stranded, but is preferably double-stranded DNA. As used herein, the term nucleic acid molecule is intended to include DNA molecules (e.g., cDNA or genomic DNA) and RNA molecules (e.g., mRNA) and DNA or RNA analogues generated using nucleotide analogues. The term isolated nucleic acid molecule includes nucleic acid molecules that are separated from other nucleic acid molecules present in the natural source of the nucleic acid. For example, with respect to genomic DNA, the term isolated includes nucleic acid molecules that are separated from the chromosome with which the genomic DNA is naturally associated. In some embodiments, an isolated nucleic acid molecule does not contain the sequences that naturally flank the nucleic acid (i.e., sequences located at the 5' and 3' ends of the nucleic acid molecule) in the genomic DNA of the organism from which the nucleic acid is derived.For example, an isolated nucleic acid molecule, such as a cDNA molecule, may be substantially free of other cellular material or culture medium when produced by recombinant techniques, or substantially free of chemical precursors or other chemicals when chemically synthesized. In one embodiment, a nucleic acid molecule may be amplified using cDNA, mRNA, or alternatively. Genomic DNA is used as a template, and appropriate oligonucleotide primers are used according to standard PCR amplification techniques. The resulting amplified nucleic acid molecule can then be cloned into a suitable vector and characterized by DNA sequence analysis. Oligonucleotides corresponding to nucleic acid sequences can also be prepared using standard synthetic techniques, for example, with an automated DNA synthesizer. The term pharmaceutically acceptable means that it has been approved by a federal or state government regulatory agency or listed in the United States Pharmacopeia, or another generally recognized pharmacopoeia for use in animals, and more particularly for use in humans. The term polypeptide fragment refers to a polypeptide in which amino acid residues are deleted compared to the reference polypeptide, but in which the remaining amino acid sequence is usually identical to the corresponding positions in the reference polypeptide. Such deletions can occur at one or more amino-terminal ends, internally, or at the carboxy-terminal end of the reference polypeptide. Fragments are typically at least 5, 6, 8, or 10 amino acids long; at least 14 amino acids long; at least 20, 30, 40, or 50 amino acids long; at least 75 amino acids long; or at least 100, 150, 200, 300, 500, or more amino acids long.They can be, for example, at least and / or including 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 100, 120, 140, 160, 180, 200, 220, 240, 260, 280, 300, 320, 340, 360, 380, 400, 420, 440, 460, 480, 500, 520, 540, 560, 580, 600, 620, 640, 660, 680, 700, 720, 740, 760, 780, 800, 820, 840, 860, 880, 900, 920, 940, 960, 980, 1000, 1020, 1040, 1060, 1080, 1100, 1120, 1140, 1160, 1180, 1200, 1220, 1240, 1260, 1280, 1300, 1320, 1340 or more in length, provided they are shorter than the full polypeptide. Alternatively, they cannot be longer than, and / or exclude, such a range while being shorter than the full polypeptide length. A fragment may retain one or more of the biological activities of the reference polypeptide. In various embodiments, a fragment may comprise an enzymatic activity and / or an interaction site of the reference polypeptide, and may also have immunogenic properties. The term probe refers to any molecule capable of selectively binding to a specifically intended target molecule, such as a nucleotide transcript or protein encoded by or corresponding to a marker. Probes may be synthesized by a skilled scientist or derived from appropriate biological preparations. For the purpose of detecting the target molecule, probes may be specifically designed to be labeled, as described herein. Examples of molecules that may be used as probes include, but are not limited to, RNA, DNA, proteins, antibodies, and other organic molecules. As used herein, subject refers to any healthy animal, such as a mammal (e.g., human), or any animal suffering from a disease or condition that would benefit from the upregulation of an immune response. The term subject is interchangeable with patient. As used herein, the term therapeutically effective amount refers to amounts that, when administered to a particular subject in view of the nature and severity of that subject's disease or condition, will have a desired therapeutic effect, e.g., an amount that will cure, prevent, inhibit, or at least partially stop or alleviate a target disease or condition. As used herein, administration refers to various means of introducing a target composition (specifically, a variant of Gal-1 according to the invention) into a cell or tissue, or into a patient. These means are commonly known in the art, including those specifically described herein. A polynucleotide transcript or nucleotide transcript is a polynucleotide (e.g., an mRNA, hnRNA, cDNA, or an analogue of such RNA or cDNA) that is complementary to its homolog with all or a portion of mature mRNA, made by transcription of a marker and post-transcriptional processing (e.g., splicing), if any, of the RNA transcript, and reverse transcription of the RNA transcript. As used herein, the term T cells includes CD4+ T cells and CD8+ T cells. The term T cell also includes both T helper 1 and T helper 2 cells. The term antigen-presenting cell includes professional antigen-presenting cells (e.g., B lymphocytes, monocytes, dendritic cells, Langerhans cells) as well as other antigen-presenting cells (e.g., keratinocytes, endothelial cells, astrocytes, fibroblasts, oligodendrocytes). As used herein, the terms treat or treatment refer to the relief of pathological processes mediated by the binding and expression of Gal-1. In the context of the present invention, the terms mean to relieve at least one symptom associated with a condition or disease that would benefit from the negative regulation of an immune response, or to delay or reverse the progression of such condition or disease. As used herein, the term vector refers to a nucleic acid capable of carrying another nucleic acid to which it has been ligated. One type of vector is a plasmid, which refers to a circular, double-stranded DNA loop to which additional DNA segments can be ligated. Another type of vector is a viral vector, in which additional DNA segments can be ligated into the viral genome. Certain vectors are capable of autonomous replication in a host cell into which they are introduced (e.g., bacterial vectors, which have a bacterial origin of replication, and mammalian episomal vectors). Other vectors (e.g., non-episomal mammalian vectors) integrate into the genome of a host cell after introduction and thus replicate along with the host genome. In addition, certain vectors are capable of directing the expression of genes to which they are operationally linked.Such vectors are referred to here as recombinant expression vectors or simply expression vectors. In general, expression vectors useful in recombinant DNA techniques are often plasmids. The terms plasmid and vector can be used interchangeably, since the plasmid is the most commonly used form of a vector. However, this description also aims to include other forms of expression vectors that perform similar functions, such as viral vectors. B. Discussion By analyzing key features of Gal-1 inactivation, the inventors of this work have demonstrated that low pH and microenvironmental redox factors play a role in disrupting Gal-1 function. Specifically, a detailed study was conducted analyzing key features of Gal-1 inactivation due to oxidation, and other implications for immunosuppressive effects. Guardia et al., “Structural basis of redox-dependent modulation of Gal-1 Dynamics and FUNCTION,” Glycobiology, 24(5):428-41 (2014) (incorporated herein in full by reference). The results of the study established that Gal-1 activity depends on the oxidation of certain cisternae residues present in each recognition domain of Carbohydrate-resistant derivatives (CRDs) of Gal-1 were found to inhibit lactose binding and decrease apoptosis in T cell lines under redox conditions. Example 1 in this document provides a discussion of this study in detail, as well as polypeptide variants of Gal-1 that have resistance to oxidative conditions and were generated as a result of the study. As an objective of the present invention, a further study was carried out to evaluate the effects of acidosis on the structure and function of Gal-1. Example 2 hereof provides a discussion of the experiments that demonstrate how acidity impairs the anti-inflammatory activity of the glycan-binding protein Gal-1 and its intrinsic structural causes. Based on observations that adverse inflammatory microenvironment conditions (i.e., low pH and oxidative conditions) lead to the inactivation of Gal1, a further objective of the invention was to provide therapeutically suitable lectin variants that could overcome the aforementioned limitations by eliminating sensitivity to oxidation and acidic pH. Using observations from the respective studies, an additional objective achieved by the present invention was the generation of rationally designed polypeptide variants of Gal-1 (SuperGal variants) containing certain amino acid modifications that provide a solution to the observed acid and oxidative deactivations of native human Gal-1. As discussed here and in the following examples, the variants were generated by site-directed mutagenesis, replacing His52 with asparagine or tyrosine, as well as oxidation-resistant variants generated by substituting cysteine ​​residues with serine residues.The combination of both types of mutations resulted in a series of variants, called SuperGals (SGs), which not only showed resistance to both oxidation and acidic pH, but also exhibited significantly improved immunoregulatory activity (T-cell apoptosis and secretion of tolerogenic / immunosuppressive cytokines). In vivo results further demonstrated the applicability of these SuperGal variants, and particularly SG2, as therapeutic agents for the treatment and prophylaxis of autoimmune diseases. Specifically, as further discussed in Example 3 of the description, by eliminating susceptibility to inflammatory microenvironments, the novel polypeptide variants of Gal-1 serve as robust immunomodulatory agents, offering a promising option for the treatment of autoimmune diseases. Based on the observations described with respect to Examples 1 to 3 and the supporting data presented in the accompanying figures, the H52, C2, C16, and / or C88 mutations of the novel Gal-1 variants confer resistance to acidic pH and oxidative conditions that otherwise result in the inactivation of native human Gal-1, or inhibit the immune regulation of native human Gal-1. Therefore, the present description relates generally to novel Gal-1 variants that are resistant to the unfavorable conditions typically found in inflammatory microenvironments that otherwise result in the inactivation of native human Gal-1. Specifically, rationally designed novel Gal-1 variants are provided that have certain amino acid modifications that confer resistance against the observed acid and oxidative inactivation of native human Gal-1. By eliminating susceptibility to inflammatory microenvironments, the novel Gal-1 variants can be used in methods of the invention as highly effective immunomodulatory agents. In certain embodiments, the invention relates to variants of Gal-1 resistant to acidic conditions that otherwise result in the deactivation of native human Gal-1, the variants of Gal-1 comprising a Gal-1 polypeptide having a mutation of the histidine residue corresponding to position 52 of the complete amino acid sequence of native human Gal-1 as shown in SEQ ID NO: 1, the mutation being a substitution of histidine to tyrosine or asparagine. In certain embodiments, Gal-1 variants may include an additional mutation of the cysteine ​​residue corresponding to a selected position from 2, 16, 88, or combinations thereof of the complete amino acid sequence of native human Gal-1 as shown in SEQ ID NO: 1, the additional mutation being a substitution of at least one cysteine ​​to a serine. Specifically, Gal-1 variants may include one or more additional mutations of the cysteine ​​residue, such as mutations corresponding to positions 2 and 6 or 2 and 88 of the complete amino acid sequence of native human Gal-1 as shown in SEQ ID NO: 1. Such mimics exhibit resistance to acidic conditions, as well as to the oxidative conditions of an inflammatory microenvironment that would otherwise result in the inactivation of native human Gal-1. In embodiments, the Gal-1 variants comprise a Gal-1 polypeptide having at least 80% sequence homology, such as at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% sequence homology with the complete amino acid sequence of native human Gal-1. The embodiments of the invention also relate to nucleic acids encoding a Gal-1 polypeptide having a mutation at position 52 of the complete amino acid sequence of native human Gal-1 as shown in SEQ ID NO: 1, wherein the mutation is a substitution of histidine to tyrosine or asparagine. In certain embodiments, the nucleic acids described herein encode a Gal-1 polypeptide having: (a) a mutation at position 52 of the complete amino acid sequence of native human Gal-1 as shown in SEQ ID NO: 1, wherein the mutation is a substitution of histidine to tyrosine or asparagine; and (b) at least one additional mutation of the cysteine ​​residue at positions 2, 16, 88, or combinations thereof, of the complete amino acid sequence of native human Gal-1 as shown in SEQ ID NO: 1, wherein the mutation is a substitution of cysteine ​​to serine. The embodiments of the invention also relate to pharmaceutical compositions comprising a variant of the Gal-1 polypeptide of the invention, or a fragment thereof, and a pharmaceutically acceptable carrier. A pharmaceutically acceptable carrier for use in pharmaceutical compositions may include a diluent, adjuvant, excipient, or vehicle with which a compound, such as variant Gal-1, can be administered. Such carriers may be sterile liquids (such as, for example, water and oils), including those of petroleum, animal, vegetable, or synthetic origin (such as, for example, peanut oil, soybean oil, mineral oil, sesame oil, and the like); polyethylene glycols; glycerin; propylene glycol; and other synthetic solvents. Water is a preferred carrier when a compound is administered intravenously. Saline solutions and aqueous dextrose-glycerol solutions may also be used as liquid vehicles, particularly for injectable solutions. Suitable excipients for use as carriers include starch, sucrose, gelatin, rice, flour, chalk, silica gel, sodium stearate, glyceryl monostearate, talc, sodium chloride, glycerol, propylene glycol, water, ethanol, and the like. A compound or composition may also, if desired, combine minor amounts of wetting or emulsifying agents, or pH buffering agents, such as acetates, citrates, or phosphates; antibacterial agents, such as benzyl alcohol or methylparabens; antioxidants, such as ascorbic acid or sodium bisulfite; chelating agents, such as ethylenediaminetetraacetic acid; and toxicity-adjusting agents, such as sodium chloride or dextrose. Methods for producing compounds or compositions with carriers are conventionally known to those skilled in the art. In embodiments, a pharmaceutical composition may be formulated to be compatible with its intended route of administration. Administration of the composition according to the embodiments of the invention may include (but is not limited to) oral (e.g., inhalation), subcutaneous, parenteral, intraocular, intradermal, intramuscular, intraperitoneal, intratracheal, sublingual, topical, buccal, rectal, and vaginal. Pharmaceutical compositions suitable for injection generally include sterile aqueous solutions (when water-soluble) or sterile dispersions and powders for the extemporaneous preparation of sterile injectable solutions or dispersions. In all cases, the composition must be sterile and free-flowing to the extent that it allows for easy injection. Sterile injectable solutions may be prepared by incorporating the active ingredient (one of the Gal-1 variants described herein) in the required amount into a suitable solvent with one or more of the ingredients listed above, followed by sterilization by filtration. Oral compositions generally include an inert diluent or an edible carrier. For the purpose of oral therapeutic administration, the active ingredient may be incorporated with excipients and used in the form of, for example, tablets or capsules.Oral compositions can also be prepared using a fluid carrier for use as a mouthwash, in which the active compound in the fluid carrier is applied orally and shaken and either expectorated or swallowed. For inhalation administration, Gal-1 variants can be administered as an aerosol spray from a pressurized canister or dispenser. Systemic administration of the pharmaceutical compositions can also be transmucosal or transdermal, where transmucosal administration can be achieved through the use of, for example, a nasal spray or a suppository, and transdermal administration can be achieved by formulating the active compound in ointments, gels, or creams. Methods for modulating an immune response are also provided, which may include contacting an immune cell with a Gal-1 variant (or SuperGal) described herein, wherein the Gal-1 variant modulates the immune response by upregulating the binding of the Gal-1 polypeptide or a fragment thereof to its natural binding partner(s) under acidic conditions of an inflammatory microenvironment that otherwise inhibit the binding of native human Gal-1 or a fragment thereof to its natural binding partner(s). In embodiments, acidic conditions of an inflammatory microenvironment refer to acidic conditions resulting in an extracellular pH below 6.0, in some embodiments below 5.5, such as below 5.3, or below 5.0, and oxidative conditions of an inflammatory microenvironment that reduce the lactose binding of native human Gal-1. In methods for modulating an immune response, Gal-1 variants can be administered as modulating agents, for example, in the form of small molecules. Such small molecules include, but are not limited to, peptides, peptidomimetics, amino acids, amino acid analogues, polynucleotides, polynucleotide analogues, nucleotides, nucleotide analogues, organic or inorganic compounds (i.e., including hetero-organic and organometallic compounds) having a molecular weight of less than approximately 10,000 grams per mole, organic or inorganic compounds having a molecular weight of less than approximately 5,000 grams per mole, organic or inorganic compounds having a molecular weight of less than approximately 1,000 grams per mole, organic or inorganic compounds having a molecular weight of less than approximately 500 grams per mole, and salts, esters, and other pharmaceutically acceptable forms of such compounds.It is understood that the appropriate dosages of small molecule agents depend on a number of factors within the scope of the physician's, veterinarian's, or researcher's ordinary experience. The dosage(s) of the small molecule will vary, for example, depending on the identity, size, and condition of the subject or sample being treated, as well as the route of administration, if applicable, and the effect the physician intends the small molecule to have on the nucleic acid or polypeptide. Exemplary doses include quantities on the order of milligrams or micrograms of the small molecule per kilogram of subject or sample weight (e.g., approximately 1 microgram per kilogram to approximately 500 milligrams per kilogram, approximately 100 micrograms per kilogram to approximately 5 milligrams per kilogram, or approximately 1 microgram per kilogram to approximately 50 micrograms per kilogram). It is further understood that appropriate doses of a small molecule depend on the potency of the small molecule with respect to the expression or activity to be modulated. Such appropriate doses can be determined using the assays described herein.When one or more of these small molecules must be administered to an animal (e.g., a human) to modulate the expression or activity of a polypeptide or nucleic acid described herein, a physician, veterinarian, or researcher may, for example, prescribe a relatively low dose initially, subsequently increasing the dose until an adequate response is obtained. Furthermore, it is understood that the specific dose level for any particular animal subject will depend on a variety of factors, including the activity of the specific compound used, the subject's age, body weight, general health, sex, and diet, the time of administration, the route of administration, the excretion rate, any drug combinations, and the degree of expression or activity to be modulated. In methods for modulating an immune response, contact between the immune cell and the Gal-1 polypeptide variant can occur in vivo or in vitro. In various respects, the immune cell can be an animal cell, such as a mammalian cell, such as a human cell. In various embodiments, Gal-1 variants can be administered as modulating agents that modulate an immune response and are prepared with carriers that will protect the active compound from rapid elimination from the body, such as a controlled-release formulation, including implants and microencapsulated delivery systems. Certain embodiments also relate to methods for treating a subject having a condition requiring the negative regulation of an immune response. Specifically, methods according to various embodiments of the invention may comprise administering to a subject having a condition requiring the negative regulation of an immune response a therapeutically effective amount of a Gal-1 variant that binds to the natural binding partner(s) of native human Gal-1 under inflammatory conditions, wherein the Gal-1 polypeptide variant comprises: (a) a first mutation of the histidine residue corresponding to position 52 of the complete amino acid sequence of native human Gal-1 as shown in SEQ ID NO: 1, this mutation consisting of a substitution of histidine to tyrosine or asparagine;and (b) at least a second mutation of the cysteine ​​residue corresponding to a selected position from among 2, 16, 88, or combinations thereof of the complete amino acid sequence of native human Gal-1 as shown in SEQ ID NO: 1, the at least second mutation constituting a substitution of cysteine ​​to serine.; With regard to the treatment methods described herein, the subject may be a human being and the condition may be an immune disorder selected from the group consisting of acute or chronic inflammatory disease, autoimmune disease, allergic disorder, arthritis, hepatitis, asthma, multiple sclerosis, transplant rejection, graft-versus-host disease (GVHD), inflammatory bowel diseases, Parkinson's disease, Alzheimer's disease, and any organ-specific autoimmune disease. In embodiments, the invention provides methods for treating, in a subject, a disease or condition associated with aberrant binding affinity of Gal-1 to β-galactosides by administering a Gal-1 as described herein that modulates the binding of the Gal-1 polypeptide to β-galactosides under acidic and oxidative conditions, wherein the disease or condition is selected from encephalomyelitis and multiple sclerosis. In some embodiments, the Gal-1 variant can be administered to a subject in a pharmaceutical composition comprising the Gal-1 variant in a therapeutically effective amount and a pharmaceutically acceptable carrier. In various respects, such pharmaceutical compositions can be administered to the subject in a dosage form selected from the group consisting of tablets, capsules, pills, powders, granules, parenteral solutions or suspensions, oral solutions or suspensions, oil-in-water emulsions, intravenous injections, and gene therapy. It is generally advantageous to formulate oral or parenteral compositions in unit dosage forms to facilitate administration and single-dose delivery. Specifications for unit dosage forms are dictated by, and directly dependent on, the unique characteristics of the active compound (e.g., the specific amino acid mutation(s) of the Gal-1 mutant), the particular therapeutic effect to be achieved, and the inherent limitations of the compounding technique for treating individuals with such active compounds. Based on the experimental results described herein, variants of the Gal-1 polypeptide were generated by site-directed mutagenesis at: (i) individual histidine residues in the native human Gal-1 sequence that confer sensitivity to low pH; and (ii) individual cistern residues responsible for the oxidative inactivation of this lectin (FIGS. 1A-1B). The results demonstrated that mutations at H52, C2, C16, and / or C88 in Gal-1 provided resistance to acidic pH and oxidative conditions. To date, the combination of these mutations in the SG2 mutant has shown (through in vitro and in vivo assays) resistance to both conditions and enhanced immunomodulatory activity. Meanwhile, SG1 exhibits an increased capacity to induce the secretion of anti-inflammatory cytokines (IL-10 and IL-27), promoting a tolerogenic environment without inducing T-cell death.SG4, on the other hand, activates T cell death programs without increasing anti-inflammatory cytokines (IL-10 and IL-27). These different SGX profiles can be exploited therapeutically to offer distinct therapeutic advantages by selectively activating one or both of these mechanisms, depending on the nature of each autoimmune disease. In summary, the present study addresses a complete scenario of the modulation of Gal-1 function by acidic or oxidative environments and its structural causes, while the robust variants of Gal-1 currently generated and described offer a promising option for the treatment of autoimmune and inflammatory diseases. EXAMPLES A. Materials and methods All experiments were performed at 25°C in 100 mM phosphate-buffered saline (PBS) containing 0.1 mM diethylenetriaminepentaacetic acid (ADTP), at pH 7.4, unless otherwise stated. Expression and purification of Recombinant Gal-1 and CXS Mutants Recombinant human galectin-1 was produced according to the procedures described in Pace et al., “Preparation of recombinant human galectin-1 and use in TCELL death assays,” Methods Enzymol. 363:499-518 (2003). A similar protocol was adopted for the production of the mutant variants. Briefly, Escherichia coli BL21 (DE3) cells were transformed with each plasmid containing different genes inserted into the pET22b expression vector (Novagen), and recombinant galectin production was induced in the logarithmic phase by adding mM isopropyl β-D-thiogalactosidol. The cells were separated by centrifugation, washed, and disrupted by sonication. The residues were removed after centrifugation at 15000 * g, and soluble fractions were obtained through subsequent purification by affinity chromatography on a lactosylSepharose column, using 0.1 M lactose in PBS supplemented with 4 mM β-ME as an elution buffer.The eluted Gal-1 was further purified using a HiPrep Sephacryl S-100 HR gel filtration column (GE Healthcare). After gel filtration, galectin-containing fractions were subjected to extensive dialysis against PBS containing 4 mM β-ME at 4°C to remove protein-bound lactose. LPS was then stripped using a Polymyxin B-Agarose column. The Gal-Ir was divided into appropriately sized aliquots and stored at -20°C in PBS containing 1 mM β-ME. Quantification of Oxidants, Protein and Thiol In the Gal-1 oxidation assays, to avoid the formation of mixed disulfide bridges between cysteine ​​residues and β-ME, β-ME was removed from the protein structure prior to any analysis by incubating the lyophilized sample in PBS with 10 mM DTT on ice for 30 min and desalting it with a NAP-5 column (GE Healthcare). This procedure removes excess DTT and β-ME. The reduced protein samples were immediately argon-purged into a sealed container, and the solution was kept on ice until use. The concentration of the H₂O₂ stock solutions (Mallinckrodt Chemicals) was measured at 240 nm (ε₂₄₀ = 43.6 × 240 M⁻¹). The protein concentration after reduction treatment was measured spectrophotometrically using an absorption coefficient at 280 nm of 8480 M'cm”1 for Gal-1 and the simple cysteine ​​mutants, according to the evaluation of their primary sequences.The flasks were determined with 5,5'-dithiobis-(2-nitrobenzoic acid) (DTNB) after incubating Gal-1 samples with an excess of DTNB in ​​PBS for 30 min in the dark at room temperature. An absorbance coefficient at 412 nm of 14150 M_1cm_1 (Riddles et al., “Ellmans reagent 5,5'-dithiobis (2-nitrobenzoic acid) - Re-examination,” Anal. Biochem., 94:75-81 (1979)) was used to quantify the 5-thio-3-nitrobenzoate anion, taking into account the absorbance of the DTNB solution and the low intrinsic absorbance of Gal-1 at this wavelength. Generation of polypeptide variants of Gal-1 Two single mutants (H52Y and H52N) and four triple mutants (C2SC16SH52Y, C2SC16SH52N, C2SC88SH52Y, and C2SC88SH52N) of Gal-1 were obtained using the reverse polymerase chain method as described in Clackson et al., “General Application of PCR to gene cloning and manipulation,” PCR, a practical approach, Oxford: IRL Press at Oxford University Press (1991). The sense primer contained a mismatch that changed the appropriate amino acid residue. These primers were used in combination with antisense primers starting at the beginning of the sense primers, as arranged in Table 1 below. The H44Q mutation was previously tested, as reported in Hiramatsu et al., “Involvement of Histidine Residues in the pH-Dependent b-Galactoside Binding Activity of Human Gal-1,” Biochemistry (2013) (whose description is incorporated herein by reference in its entirety). Table 1 Direction Mutation Cebador H52N Direction 5 ' -CA ACGCCAACGGCG ACGCCA AC-3 ' (SEQ ID NO: 3) H52N Antisense 5 '-GTTGGCGTCGCCGTTGGCGTTG-3 ' (SEQ ID NO: 4) H52Q Direction 5 '-CAACGCCC AGGGCG ACGCC AAC-3 ' (SEQ ID NO: 5) H52Q Antisense 5 '-GTTGGCGTCGCCCTGGGCGTTG-3 ' (SEQ ID NO: 6) H52Y Direction 5 ' -CA ACGCCT ATGGCG ACGCC A AC-3 ' (SEQ ID NO: 7) H52Y Antisense 5 '-GTTGGCGTCGCCATAGGCGTTG-3 ' (SEQ ID NO: 8) H44N Direction 5 '-TGTGCCTGAACTTCAACCCTCG-3 ' (SEQ ID NO: 9) H44N Antisense 5'-CGAGGGTTGAAGTTCAGGCACA-3' (SEQ ID NO: 10) H44Y Sense 5'-TGTGCCTGTACTTC A ACCCTCG-3' (SEQ ID NO: 11) H44Y Antisense 5'-CGAGGGTTGAAGTACAGGCACA-3' (SEQ ID NO: 12) The insert and vector were amplified in the same step using KOD polymerase Hot Start (Novagen), and the resulting product was ligated with T4 DNA ligase (Promega). Triple mutants were generated using the C2SC16S or C2SC88S double mutants as starting materials (Guardia et al., 2014), and mutations were introduced using the primers previously employed to generate the H52Y and H52N single mutants. Mutations were verified by DNA sequencing of the entire insert. Suitable primers may include those provided in Table 2, which correspond to the primers described in Guardia et al., “Structural basis of redox-dependent modulation of Gal-1 Dynamics and function,” Glycobiology, 24(5):428-41 (2014) (the description of which is incorporated herein by reference in its entirety). Table 2 Mutation Direction Primer C2S Sense 5 ' -ATATGGCTTCTGGTCTGG-3 ' (SEQ ID NO: 13) C2S Antisense 5 '-GTATATCTCCTTCTTAAAGTTAAAC-3 ' (SEQ ID NO: 14) C16S Sense 5 ' -CTGG AG AGTCC-GACTG-CTG-3 ' ID: NO: 13 C16S Antisense 5 '-GTTTGAG ATTCAGGTTGCTGG-3 ' (SEQ ID NO: 16) C42S Sense 5 '-C AACCTTGTCCCTGC ACTTC-3 ' (SEQ ID NO: 17) C42S Antisense 5'-TTGCTGTCTTTGCCCAGSE-GTTCQ Sentity ID NO: 16: C42S 5 '-CCATCGTGTCCAACAGCAAG-3 ' (SEQ ID NO: 19) C60S Antisense 5 '-TGTTGGCGTCGCCGTG-3 ' (SEQ ID NO: 20) C88S Sense 5 '-CAGAGGTGTCCACCACCTTC-3 ' (SEQ ID NO: 21) C88 ACTTCC-Antis Ado AGGCTGG A AG-3 ' (SEQ ID NO: 22) C130S Sense 5 ' -C AAG ATCAA ATCTGTGGCCTTTG-3 ' (SEQ ID NO: 23) C130S Antisense 5 '-AAGTCACCGTCAGCTGC-3 ' (SEQ ID NO: 24) Spectroscopic measurements Far- and near-UV DC spectra were recorded using a Jasco J-815 spectropolarimeter equipped with a Peltier temperature control. The spectra shown are averages of at least eight scans, with the background corrected by subtracting the respective buffer blanks. They were acquired within the wavelength range of 190 to 360 nm, using a colorimetrically certified 1 mm path length cell (Hellma). Deconvolution spectra were performed using DichroWeb with the CONTIN analysis software and the SP175 reference set. Intrinsic fluorescence emission spectra were measured at 25°C on a Jasco FP6500 spectrofluorometer. The excitation wavelength was set to 295 nm, and spectra were recorded between 305 and 400 nm. Excitation and emission bandwidths were set to 1 and 5 nm, respectively. An average of at least six scans was used for the final calculations.The spectra were corrected for dilution effects, and the final sample dilution was always <10%. Gal-1 to Lactose Binding The Gal-1-dactose binding constant was determined under different pH conditions (Example 2) by fitting the change in the fluorescence emission spectrum to pH = 7.5, 6.5, or 5.5, respectively. Gal-1 (5 μM) was titrated by adding aliquots of a 100 mM lactose stock solution. The intensity of the emission spectrum at 354 nm was recorded and fitted as a function of the lactose concentration. The binding constant (Kb) at 25°C was calculated by fitting the fluorescence data to a single-binding-site model. Sodium Dodecyl Sulfate-Polyacrylamide Gel Electrophoresis Sodium duodecyl sulfate-polyacrylamide gel electrophoresis (SDSPAGE) was performed using 15:1 polyacrylamide gels containing SDS, stained with silver or Coomassie blue. T Cell Death Assays T cell lines (5 × 10⁵) were cultured according to the procedures described in Lange et al., “Galectin-1 induced activation of the mitochondrial apoptotic pathway: ways in human Jurkat T lymphocytes,” Histochem. Cell Biol., 132:211–23 (2009)), and incubated with or without 3 μM of Gal-1 or its variants in Roswell Park Memorial Institute (RPMI) medium supplemented with 15% feta bovine serum (FBS), penicillin (100 mU / ml), and streptomycin (50 pg / ml) in 24-well culture plates at 37°C in 5% C₂O₅. To generate reducing conditions (in Example 1), 0.55 mM ME (final concentration) was added to top up the medium before adding the cell suspension. To test the functional activity of oxidized galectins, galectins were cultured on RPMI and treated with 10 mM H2O2 for 20 minutes before the assays. Excess ROS was inactivated using catalase (100 U / mL) and the oxidation reaction was stopped.The medium was then made up with FBS, and antibiotics and cells were added to each well. After 14 hours of exposure to Gal-1 or its variants, the cells were washed with PBS. Cell death was determined by Annexin V-FITC / propidium iodide (PI) in staining buffer (HEPES 100 mM, NaCl 1.4 M, CaCl 25 mM) as previously described in Toscano et al., “Differential glycosylation of Th1, Th2 and Th-17 effector cells selectively regulates susceptibility to cell death,” Nat. Immunol., 8:825-34 (2007). Fluorescence (FITC and PI) was analyzed using a Canto FACS (BD Biosciences). Cell death was calculated as the percentage of Annexin V positive cells of the galectin-treated cells minus the percentage of position control cells treated with Annexin V. Solid-phase assays The solid-phase assays used herein were adapted from Rapaport et al. (incorporated by reference herein). First, asialofetuin (10 pg / ml) was coated in NaHCCb buffer (pH 9.6) onto a 96-well microplate and incubated at 4°C overnight. Different concentrations of lactose (0.2–8 mM) were incubated in appropriate buffer solutions (pH 7.5, 6.5, or 5.5) containing 0.3% BSA with Gal-1 (20 pg / ml, recombinantly expressed as previously described) at 37°C for 2 hours in Eppendorf tubes, and then the mixture was added to the wells of the plate containing immobilized asialofetuin. The plate was incubated at 37°C for 2 hours, washed with 0.05% PBS-Tween, and further incubated with biotinylated antibodies against Gal-1 at room temperature for 1 hour. The plate was then washed with 0.05% PBS-Tween and incubated with streptavidin-peroxidase at room temperature for 30 minutes.After the reaction was complete, the washing was repeated, and Gal-1 was detected using tetramethylbenzide (TMB). The reaction must be stopped with 2N H₂SO₄. The absorbance at 450 nm was determined using a spectrophotometer and adjusted according to the lactose concentration. The lactose concentration (in pM) required for 50% inhibition (IC₅₀ value) was calculated by adjusting the absorbance data. Individual experimental runs, with at least duplicates, were carried out independently at least four times until the saturation level of binding to the labeled protein in solution was reached. Statistical Analysis Data are expressed as mean ± SD. Prism software (GraphPad Software) was used for statistical analysis. Two groups were compared using the Student's t-test for unpaired data. P-values ​​of 0.05 or less were considered significant. B. Example 1 Oxidation-Reduction Dependent Modulation of the Gal-1 Function In a previous study using a combination of in vitro and in silico experiments, the inventors of the present work investigated the molecular mechanisms underlying the oxidation of Gal-1. A reactivity-based hierarchy was established, and the importance of each cysteine ​​residue in Gal-1 and the kinetics of oxidation with hydrogen peroxide were characterized. The first surprising result was the high degree of reversibility of the oxidation-reduction process. Since only four of the six thiols present in Gal-1 are exposed to the solvent, it was postulated that the cysteine ​​residues responsible for triggering the oxidation-induced conformational change in the protein are located among these four residues. To fully dissect the contribution of each cysteine ​​to the oxidation process, six single cysteine ​​mutants (CXS), as well as two selected double mutants, were expressed and purified and exposed to the same reduction and oxidation procedures previously used for Gal-1 WT. The apoptotic activities of reduced or oxidized Gal-1 WT and the various Cys to Ser mutants (C2S, C16S, C42S, C60S, C88S, C130S) are shown in Figure 2, demonstrating that only the C2S, C16S, and C88S mutants (i.e., those mutants lacking Cys2, Cys16, and Cys88, respectively) induced T cell apoptosis to the same extent as Gal-1 WT when exposed to oxidative conditions. In addition to the single CXS mutants, two Gal-1 double mutant variants (C2S-C16S and C2S-C88S) were generated. As shown in FIG.3, although oxidation of mutant Gal-1 resulted in the gradual loss of pro-apoptotic activity, the prevailing redox condition did not change the apoptotic effect on T cells of the double mutants. Furthermore, given their proximity and the particular acidity of one of these residues, Cys 16 and Cys 88 were also found to be good candidates for disulfide bridge formation, as supported by experimental evidence provided in Tracey et al., “Subunit MOLECULAR MASS ASSIGNMENT OF 14,654 ÜA TO THE SOLUBLE BETA-GALACTOSIDE-BINDING LECTIN FROM BOVINE HEART MUSCLE AND DEMONSTRATION OF INTRAMOLECULAR DISULFIDE BONDING ASSOCIATED WITH OXIDATIVE INACTIVATION,” J. Biol. Chem. 267: 10342-47 (1992). In this regard, the formation of three disulfide bonds, which involves the oxidation-induced conformational change when Cys 42, Cys 60, or Cys 130 were mutated, indicated that these residues have almost no relevance in the overall oxidation process. In summary, the results of the redox study demonstrated the following: - Of the six cysteine ​​residues present in Gal-1 (Cys2, Cys 16, Cys42, Cys60, Cys88, Cysl30), only three cysteine ​​residues present in each carbohydrate recognition domain of Gal-1 (Cys2, Cys 16 and Cys88) are important in protein oxidation; - the oxidized Gal-1 protein did not bind to lactose, probably due to weak interactions with Arg48 and Glu71; The oxidation was found to be slow (1.7 ± 0.2 M^s'1 at 25°C); - Oxidation was promoted by the formation of the Cysl6-Cys88 disulfide bond as well as by multimers through Cys2; and - Oxidation of Gal-1 WT did not induce apoptosis in a T cell line. C. Example 2 pH-Dependent Modulation of Gal-1 Function T cell death assays in the presence of Gal-1 were performed in different pH environments to mimic the acidosis typically found in inflammation. As previously reported (Toscano et al., Nat. Immunol., 8:825-34 (2007)) and shown in FIG. 5A, activated human CD4+ T cells exhibit susceptibility to Gal-1. However, pH was found to substantially affect its pro-apoptotic effect, with activity significantly decreasing in the pH range of 6.5 to 6. To better understand the biochemical basis of the differential susceptibility of human white blood cells to Gal-1-induced cell death, the binding of biotinylated Gal-1 was analyzed under the different pH conditions studied (FIG. 5B). Gal-1 binding was significantly lower at pH 6 than at physiological pH (pH 7.4), which is typically used in in vivo assays. To understand the interactions responsible for the change in Gal-1 affinity for lactose observed at low pH, a series of fluorescence spectroscopy experiments were performed at different pH and ligand concentrations (FIG. 5C). The results conclusively showed that Gal-1 binding to the disaccharide lactose decreases with increasing pH. Furthermore, the curves demonstrated that lectin activity was drastically reduced as the pH fell below 6. To understand the biochemical mechanisms that cause the evident loss of Gal-1 activity in acidosis, the present study was carried out to analyze the structural determinants of Gal-1, focusing on the protonation state of certain amino acids by NMR spectroscopy. Figure 5D shows a detailed view of the ligand-binding groove of Gal-1 (the region of the protein where ligand recognition and binding take place), and the presence of two histidine residues interacting with the carbohydrate moiety warrants special consideration. Histidine side chains have been shown to frequently participate in ligand recognition, providing a potential regulatory mechanism under physiological conditions given their intrinsic pKa (Figure 5E). For a solvent-exposed histidine, the expected pKa value is approximately 6.3, but this can vary depending on the protein's secondary, tertiary, and quaternary structure. NMR spectroscopy was used to assess both the tautomeric and protonated states of each histidine at pH values ​​between 5 and 8, and the corresponding pKa of His44 and His52 in the Gal-1 sequence. These studies showed that the environment of both histidines differs, as reflected by their spectra (FIG. 5G). For Histidine 52, the obtained values ​​remained close to the canonical pKa and tautomeric ratio, indicating that it is a residue fully exposed to the solvent. However, the pKa for the Gal-l-Lac complex decreased to 5.9, suggesting that the residue was involved in interactions with the lactose ring, which hinders its exposure to the solvent.On the other hand, histidine 44, located on the S4 strand, was found to be involved in hydrogen bonding with the ligand. In the free state of Gal1, this histidine showed a pKa of 5.7, with a slight decrease in the epsilon tautomer population, indicating that the residue establishes weak interactions with the tertiary structure environment, as previously reported. The pKa value and tautomeric composition of histidine 44 underwent a sudden change upon lactose binding. The pKa of Gal-1:Lactose bound to histidine 44 was 4.2, demonstrating its involvement in critical interactions with the ligand fraction that protects the residue from direct contact with the solvent environment. To better understand the relationship between structural modifications induced by pH changes and binding affinity regulation mechanisms, molecular dynamics simulations were performed on pH-dependent structural changes in the Gal-1 structure and their relationship to ligand binding of the carbohydrate recognition domain. These simulations proved stable, as shown in the root mean square deviation (RMSD) versus time plot using the X-ray initiation structure PDBid = 1GZW as a reference (not shown). A key difference between mono-protonated and di-protonated histidine 52 was observed in the loop between strands S4 and S5 using molecular dynamics simulations (FIG. 5F). Specifically, the presence of a di-protonated side chain for histidine 52 affects the loop dynamics, inducing a wider range of motion. This was demonstrated by the amplitude explored by the projection of the first essential mode with the greatest contribution to the motion, as derived from MD simulations for the protein in both states. This looser conformation was found to directly interfere with the correct positioning of the lactose ring in the ligand-binding groove. Furthermore, after deprotonation, the dihedral angle describing the orientation of the histidine 52 side chain is suitable for exploring a different configuration (FIG. 5H).Visual inspection of this new conformation, explored during the simulation, revealed that this orientation interferes with the correct stacking of the lactose rings. Therefore, the results demonstrate that at low pH, the loop containing the di-protonated state of Histidine 52 exhibits greater flexibility, and the side chain of residues rotates and moves toward the solvent, acquiring an open conformation. The outward oscillation of the Histidine 52 side chain prevents the correct positioning of the ligand in the binding groove, whereas in the mono-protonated state of Histidine 52, its configuration within the loop ensures proper ligand stacking. The results of this study revealed an interesting interaction between the pH of the environment, the conformation of the loop containing Histidine 52, and ligand binding affinity. The involvement of Histidine 52 and its protonation equilibrium in decreasing the ligand binding affinity of Gal-1 was also confirmed. D. Example 3 Generation of Gal-1 Polypeptide Variants Resistant to Deactivation by Oxidation and Acidosis Based on the results of the acidosis investigation conducted in Example 2, six mimics were generated using site-directed mutagenesis, and their pro-apoptotic activity and susceptibility to acidic conditions were subsequently tested. The mimics were as follows: H52Y, H52N, H52Q, H52R, H44Y and H44N. These six mimics were successfully produced, but the mutated variants H44X and H52R could not be properly purified, as they did not exhibit binding to the affinity column (lactosyl-sepharose). Additionally, the H52Q mutant was not used in further evaluation assays due to its recently discovered lower lactose-binding activity compared to Gal-1 WT. See Hiramatsu et al., “Involvement of Histidine Residues in the pH-Dependent β-Galactoside Binding Activity of Human Gal-1,” Biochemistry (2013). The same publication also confirmed the low lactose-binding affinity of the H44Q mutant. Of the remaining mimics, H52Y and H52N demonstrated β-galactosidase affinity comparable to Gal-1 WT. To test these Gal-1 variants and their affinity for N-glycan complexes, a solid-phase assay was performed using immobilized asialofetuin. The assay results showed that both mimics H52Y and H52N maintained their binding affinity at lower pH values ​​(FIGS. 6A-6D), and these results were further confirmed by measuring the dissociation constant (AΔd) values ​​for both mimics at pH = 7.5, 6.5, and 5.5, using intrinsic fluorescence intensity (FIG. 6E). Cell death assays were also performed to test the pro-apoptotic effect of the mutants under different pH conditions (FIG. 6F). Although Gal-1 was found to induce apoptosis of activated human T cells in all cases, this effect was substantially reduced under acidic pH conditions for Gal-1 WT and the H52N variant of Gal-1, but not for the H52Y variant of Gal-1, which supports the notion that the pro-apoptotic activity of this mutant is not affected by an acidic environment within the analyzed range. However, as expected, the His mimics (H52Y and H52N) were found not to be resistant to oxidation (FIGS. 6G-I). Therefore, further tests were performed to identify a mutant that also possessed the desired resistance to oxidative inactivation. The apoptotic activity of reduced or oxidized Gal-1 WT, as well as of the six different Cys mimics generated in Example 1 (C2S, C16S, C42S, C60S, C88S, C130S), is illustrated in FIG. 3. As shown, only the mutants lacking Cys2, Cys16, and Cys88 were able to induce T-cell apoptosis under oxidizing conditions, achieving apoptosis levels similar to reduced Gal-1 WT. Therefore, the next two double mutant variants were generated: C2S-C16S and C2S-C88S. These mutants proved resistant to oxidative inactivation, in addition to the six previously prepared single CxS mutants. In fact, the C2S-C16S and C2S-C88S mutants showed almost no change in their circular dichroism spectra after oxidation (FIG. 2), suggesting that there are no conformational changes under conditions that deactivate Gal-1 WT, due to the absence of two of the critical cisternae involved in deactivation. Further analysis was conducted to study the impact of oxidation on the structure and function of Gal-1 using T cell death assays. Specifically, as shown in Figure 3, activated T cells were exposed to different concentrations of Gal-1 under reducing or oxidizing conditions. Oxidation of Gal-1 WT resulted in the loss of pro-apoptotic activity, whereas double mutants of Gal-1 (C2SC16S and C2SC88S) did not alter the apoptotic effect on T cells, regardless of the prevailing redox conditions. Of all the Gal-1 variants studied using biophysical assays, H52N and H52Y were shown to be pH resistant. Table 3 below shows the best Gal-1 variants (acid resistant (AR) or oxidation resistant (OR)) that were designed and expressed. Table 3 rhGal-1 variant H52Y (RA) H52N (RA) C2S C16S (RO) C2S C88S (RO) Acid resistance + + Oxidation resistance E. Example 4 Generation of SuperGal Variants Resistant to Oxidative Deactivation and Acidosis with Enhanced Immunomodulatory Properties To overcome the pH dependence and oxidative inactivation of Gal-1 based on the results of Examples 1 to 3, the following additional triple mutants were generated from the combination of the two acid-resistant mutants (H52Y and H52N) and the two oxidation-resistant mutants (C2SC88S and C2SC116S): C2SC16SH52Y, C2SC16SH52N, C2SC88SH52Y, and C2SC88SH52N. These new mutants were named SuperGal-1 (SG1), SuperGal-2 (SG2), SuperGal-3 (SG3), and SuperGal-4 (SG4), respectively. These mutants were expressed and purified using lactosyl sepharose, resulting in the following yields: SGal-1 (SG1): C2S C16S H52N - yield: 42 mg SGal-2 (SG2): C2S C16S H52Y - yield: 43 mg SGal-3 (SG3): C2S C88S H52N - yield: 37 mg SGal-4 (SG4): C2S C88S H52Y - yield: 110 mg The mutants were evaluated using the same in vitro methodologies used for the previously described mutants. Starting with in vitro assays of intrinsic fluorescence intensity as a function of lactose concentration, the Gal-1-lactose dissociation constant (ATd) values ​​were determined at pH 7.5, 6.5, and 5.5. As can be seen in Figure 7, SG1 and SG3 performed poorly at pH 6.5 and 5.5, while SG2 and SG4 retained their affinity for lactose regardless of pH. To assess the additional oxidation resistance compared to Gal-1 WT, the four SGX triple mutants were exposed to air (5 days), and far-UV DC spectra were recorded. The SG1, SG2, SG3, and SG4 mutants proved to be resistant to the adverse effects of acidic pH and oxidative conditions, as summarized in Table 4 below. Table 4 Name Mutations Acid pH resistance Resistance to oxidative conditions H52Y + - H52N + - C2SC16S - + C2SC88S - + SG1 H52NC2SC16S + + SG2 H52YC2S CJ6S + + SG3 H52NC2SC88S + + SG4 H52YC2SC88S + + Once produced and purified using a lactosylsepharose affinity column, several studies were conducted. First, based on the effects of oxidation on secondary structure, previously observed in the acid-resistant variants H52N and H52Y, the effects of oxidative conditions on the new mutants were evaluated. Circular dichroism revealed that, while Gal-1 WT, H52N, and H52Y were susceptible to oxidation (10 mM H2O2), the addition of the C2SC16S or C2SC88S mutations to these variants conferred new resistance properties, as evidenced by a similar spectrum under reducing and oxidizing conditions, as shown in Figures 8A and 8B. Specifically, under physiological conditions (reducing environment), all the new variants exhibited the same circular dichroism spectrum, implying that the combination of any of the three modifications does not alter the secondary structure of Gal-1 (FIG. 8A). In particular, as shown in FIG. 8A, the four SGXs (or SuperGals) showed almost identical DC spectra for reduced and oxidized conditions. After verifying the resistance to oxidative conditions of the SuperGal variants, further studies were conducted to determine whether resistance to acidic conditions was also conserved in these variants. The induction of apoptosis in activated T cells was evaluated at different pH levels in the presence of Gal-1 WT5 μM and the SG1, SG2, SG3, or SG4 variants. Similar to the previously described H52N and H52Y mutants, the pro-apoptotic activity of the Gal-1 WT variant gradually decreased as the pH became more acidic, while the SuperGal variants were able to induce a similar percentage of apoptosis at all pH levels studied (FIG. 8C and 8D). Furthermore, the different SuperGal variants showed acidic pH activity similar to that previously observed for the H52Y variant.Conversely, the SG1 and SG2 variants—which carry the H52N mutation—showed low pro-apoptotic capacity at physiological pH, similar to that observed for the H52N variant (Figs. 8C and 8D). As further shown in Figs. 8F and 8G, H52Y and the SuperGal 2 and 4 variants (SG2 and SG4, which contain the H52Y mutation) exhibit a significantly enhanced capacity to induce T cell apoptosis compared to Gal-1 WT under physiological conditions (pH 7.5). Likewise, the single H52Y mutant and the SuperGal 2 and 4 variants were found to retain their capacity to induce T cell apoptosis under acidic conditions (pH 6) compared to physiological conditions (pH 7.5). In contrast, Gal-1 WT, H52N, SG1 and SG3 (which contains the H52N mutation) showed a considerable reduction in this biological function. In addition to high resistance to acidic pH, the combination of the H52Y variant with variants that confer oxidation resistance unexpectedly results in resistant double mutants that exhibit synergistic effects under physiological conditions. Specifically, as shown in Figure 8E, the SG2 and SG4 variants demonstrate significantly greater pro-apoptotic activity than Gal-1 WTapH 7,5. Evaluation of Immunomodulatory Properties of SuperGal Variants The synergistic effects observed for the SG2 and SG4 variants under physiological conditions with respect to Gal-1 WT prompted further research to determine if any other immune-regulating effects, besides T-cell apoptosis, can account for the superior biological effects of these novel variants. Therefore, the ability of Gal-1 to induce IL-10 secretion was evaluated, based on the previously shown modulation of this tolerogenic cytokine by Gal-1 WT in murine and human cells (Toscano et al., Galectin-1 Suppresses Autoimmune Retinal Disease by Promoting Concomitant Th2 and T Regulatory-Mediated Anti-Inflammatory Responses, J. Immunol., 176(10): 6323-32 (2006); Van der Leij et al., Dimeric Galectin-1 Induces IL-10 Production in T-Lymphocytes: an Important Tool in the Regulation of the Immune Response, J. Pathol., 204(5): 511-18 (2004); Stowell et al., Differential Roles of Galectin-1 and Galectin-3 in Regulating Leukocyte Viability and Cytokine Secretion, J. Immunol., 180(5): 3091-102 (2008); Cedeno-Laurent et al., Galectin-1 Triggers an Immunoregulatory Signature in Th Cells Functionally Defined by IL10 Expression, J. Immunol., 188(7): 3127-37 (2012); y Perone et al., SUPPRESSION OF Autoimmune Diabetes by Soluble Galectin-1, J. Immunol., 182(5): 2641-53 (2009)). In the first set of assays, each of the SuperGal variants was analyzed to evaluate its ability to induce the secretion of anti-inflammatory cytokines and activate regulatory mechanisms. As previously reported, treatment with Gal-1 can induce IL-10 secretion in both CD4 and CD8 T cells, and IL-27 secretion in dendritic cells (Ilarregui et al., Nat. Immunol., 10:981-991 (2009)). Accordingly, in this study, splenocytes were isolated from C57BL / 6 mice, and the T cells were activated with soluble anti-CD3e and anti-CD28, and then treated with either Gal-1 WT 5 μM or the SuperGal variants. IL-10 secretion levels into the culture medium were measured after 48 hours (FIG. 8H). Similarly, dendritic cells were differentiated from bone marrow precursors with recombinant GM-CSF and treated with Gal-1 WT 3 μM or SuperGal variants.IL-27 secretion levels were measured into the culture medium after 24 hours (FIG. 81). The secretion of both anti-inflammatory cytokines, IL-10 and IL-27, was significantly increased by SG1 and SG2 compared to Gal-1 WT. On the other hand, the SG3 and SG4 variants induced IL-10 and IL-27 secretion at levels comparable to Gal-1 WT. Finally, SG1 and SG2 induced a 4-fold increase in IL-10 secretion compared to Gal-1 WT induction, and a 10-fold increase in IL-27 secretion compared to Gal-1 WT induction. In further studies, splenocytes were obtained from 8-12 week old C57BL / 6 mice. To activate T cells, samples were incubated for 8 hours at physiological pH in the presence of Gal-1 WT 3 μM or the SG1, SG2, SG3, and SG4 variants, and soluble anti-CD3e and anti-CD28 agonist antibodies. After 2 days, the supernatant was collected, and IL-10 levels were measured using both conventional ELISA and CBA (cytokine bead array) flow cytometry. Table 5 Control WT SG1 SG2 SG3 SG4 Mean 155 521 2500 2512 246 289 OF 10 187 504 645 171 70 p (vs. WT) * - *** *** ns ns As shown in Table 5 above and Figure 9A, Gal-1 WT induced a 3.36-fold increase in IL-10 secretion (521 ± 10 pg / ml, WT vs. PBS), consistent with previous studies (Stowell et al., 2008), while the SG1 and SG2 variants induced IL-10 secretion that was 16.2-fold higher than the control and 4.8-fold higher than the WT variant (2500 ± 504 and 2512 ± 645 pg / ml, respectively). However, this was not observed in the SG3 and SG4 variants. Further analysis of other cytokine secretion levels by CBA flow cytometry showed no differences in IL-4 and IL-17A levels. Although no differences in TNF levels were found between Gal-1 WT and the SuperGal variants, SG2 induced a significant increase in TNF compared to the control (Fig. 9B to 9D). Furthermore, while Gal-1 WT doubled the amount of IL-6 secreted by the cells compared to the control, Fig. 9E shows that the presence of SG2 induced a significant increase in this cytokine, an effect not observed with the other variants. Aside from this particular cytokine, the main difference in cytokine secretion induced by SG2 and SG1 variants was observed for IL-10, whose secretion levels increased 2 and 4 times more than for IL-6 (2512 and 2500 vs. 1109 and 669 pg / ml, respectively). Table 6 below shows the secretion levels of the various cytokines evaluated relative to the levels induced by treatment with the wild-type variant. Of all the cytokines evaluated, IL-10 secretion was the most dramatically upregulated compared to the secretion obtained with Gal-1 WT. Table 6 Cytokine SG1 SG2 SG3 SG4 IL-10 4.80 4.82 0.47 0.55 IL-4 1.5 1.13 1.23 0.85 IL-17A 1.36 1.89 0.65 1.23 TNF 1.37 1.46 0.77 0.9 IL-6 2.54 4.21 0.49 0.83 In particular, SuperGal variants containing the H52Y mutations (SG2 and SG4) were found to induce greater apoptosis, independent of cysteine ​​mutations. Regarding IL-10 secretion by T lymphocytes, the C16S mutation (SG1 and SG2) contributed the most to the effect, independent of the mutation at position 52. Ability of SuperGal Variants to Induce Tolerogenic Dendritic Cells Galectin-1 has been shown to generate IL-27, which produces tolerogenic dendritic cells that contribute to the expansion of IL-10-producing Trl lymphocytes (Ilarregui et al., Nat. Immunol. (2009); Poncini et al., Trypanosoma Cruzi Infection IMPARTS A REGULATORY PROGRAM IN DENDRIC CELLS AND T CELLS VIA GALECTIN-1 Dependent Mechanisms, J. Immunol., 195(7): 3311-24 (2015)). Based on these findings, studies were conducted to evaluate whether acid pH- and oxidation-resistant Gal-1 variants also induce tolerogenic dendritic cells. Bone marrow precursors were obtained from 8-12 week old C57BL / 6 mice and differentiated for 9 days in the presence of recombinant GM-CSF, as described. Unlike the protocol used by Ilarregui et al., in which Gal-1 WT is present from the beginning of the differentiation process, the aim of this study was to determine whether the new variants could induce IL-27 secretion in already differentiated, immature dendritic cells. Therefore, after 9 days of fully differentiated dendritic cells, following the phenotyping of these cells (CDI le + CD86low MHC-IIlow), the immature dendritic cells were incubated in the presence of 3 μM Gal-1 WT or the SG variants. After 24 hours, the supernatant was collected and IL-27p28 was determined by ELISA. Similar to the effect observed for IL-10, treatment with the WT variant doubled baseline IL-27 levels in dendritic cells 43 (421 ± 124 vs 211 ± 44 pg / ml), while the SG1 and SG2 variants induced a more pronounced increase in the secretion levels of this cytokine, significantly higher than those generated by WT (1453 ± 120 and 2494 ± 165 pg / ml, respectively) (FIG. 10A). Furthermore, the secretion levels induced by SG2 were significantly higher than those generated by SG1. This effect was only demonstrated for variants containing the C16S mutation, as it was not observed for the SG3 and SG4 variants (FIG. 10A). The fact that the SuperGal variants induced T cell apoptosis regardless of pH variations prompted further evaluation of whether the ability of these new variants to induce IL-27 secretion was also preserved even in acidic microenvironments. For this purpose, the previous experiments were repeated, but the dendritic cells were incubated at pH 7.5 or 5.5. While Gal-1 WT lost its ability to induce IL-27 secretion in dendritic cells at acidic pH, treatment with the SG1 or SG2 variants led to similar levels of IL-27 secretion at both physiological and acidic pH, being significantly higher than the levels induced by Gal-1 WT at each respective pH (FIG. 10B). Ability of SuperGal Variants to Induce the Secretion of Pro-Inflammatory Cytokines The ability of SuperGal variants to induce the secretion of pro-inflammatory cytokines, such as IL-23 (which, in contrast to IL-27, favors Thl7 responses), was also evaluated. Dendritic cells were re-incubated under similar conditions. As shown in Figure 10C, the SuperGal variants did not increase IL-23 secretion compared to Gal-1 WT, which itself induced a small increase compared to the control. However, the SG1 variant induced a slight increase in IL-23 compared to Gal-1 WT, showing a significant difference from the control. Nevertheless, the levels of secreted IL-23, even after treatment with SG1, were found to be well below the IL-27 induction levels induced by SG1 (603 ± 191 vs 1453 ± 120 pg / ml, respectively). In addition to the secretion of IL-27 and IL-10, an important characteristic of tolerogenic dendritic cells is the low expression of CD11c on the cell surface (Ilarregui et al., Nat. Immunol. (2009)). To evaluate changes in this cell surface marker, dendritic cells were differentiated from bone marrow precursors and, after a 72-hour incubation period in the absence or presence of Gal-1 wt 3 μM or the SG1, SG2, SG3, or SG4 variants, CD11c expression levels were analyzed by flow cytometry. While dendritic cells showed significantly reduced CD11 levels after incubation with Gal-1 WT, cells treated with the SG1 and SG2 variants showed even lower expression of this marker on their cell surface (FIG. 10D and 10E). Likewise, although the SG3 variant induced a decrease in CD1 expression similar to that generated by the WT variant, the SG4 mutant showed inconsistent results.To confirm the tolerogenic nature of dendritic cells treated with Gal-1 WT or SG variants, purified CD4+ T cells from the spleens of C57BL / 6 mice, intracellularly loaded with the fluorescent molecule CFSE, were co-cultured with dendritic cells that had been previously pulsed with LPS (immunogenic stimulus) and soluble anti-CD38 agonist for 72 hours, in the presence of dendritic cells that had been previously treated for 72 hours with PBS or Gal-1 WT 3 μM, or SG1, SG2, SG3, or SG4. After 4 days of culture, proliferation was analyzed by flow cytometry, based on CFSE fluorescence dilution. As shown in the figures.In Figures 10F and 10G, only dendritic cells previously treated with the SG1 and SG2 variants were able to decrease CD4+ lymphocyte proliferation induced by LPS-treated dendritic cells—an effect evidenced by a significantly lower division rate. As further shown in Figures 10H and 101, these differences were not due to the ability of SG1 or SG2-treated dendritic cells to overcome T-cell activation (as evidenced by a similar percentage of dividing cells in all cases), but rather affected the further proliferation process based on the significantly lower proliferation rate observed. Moreover, only dendritic cells treated with the SG2 mutant, which also secreted higher levels of IL-27, showed significantly greater differences compared to Gal-1 WT-treated dendritic cells. The results, summarized in Table 7 below, support the conclusion that the novel SuperGal variants are not only resistant to oxidation and acidic pH conditions, but also exhibit enhanced immunoregulatory activity. The mutations introduced into these variants successfully uncoupled two different immunoregulatory activities (i.e., the induction of T-cell apoptosis versus the secretion of immunosuppressive cytokines, and the induction of tolerogenic dendritic cells). While the SG2 and SG4 variants showed increased pro-apoptotic activity, the variants SG1 and SG2 induced increased secretion of IL-10 in T lymphocytes and of IL-27 in dendritic cells. Table 7 Activity GAL-1 WT SG1 SG2 SG3 SG4 Apoptosis + - + + + - + + + IL-10 / IL-27 + + + + + + + - / + - / + Evaluation of Enhanced Immunoregulatory Activity of SuperGal Variants In Vivo EAE was induced in 8–12-week-old wild-type C57BL / 6 mice by immunization with myelin-oligodendrocyte glycoprotein 55 (MOG 55) (as described in Toscano et al., Nat. Immunol. (2007)), and Gal-1 WT or SG variants were administered according to a therapeutic protocol. When the animals showed the first signs of the disease (tail weakness), they were randomly treated with a 100 pg / day injection of Gal-1 WT or the SG1, SG2, or SG4 variants. The SG3 variant was not tested as it showed no in vitro evidence of improved immunoregulatory capacity compared to Gal-1 WT. Clinical scores were assessed daily until day 24 post-immunization. The animals were then sacrificed for ex vivo assays.While treatment with the SG1 variant produced a similar effect on the course of the disease as treatment with Gal-1 WT, mice treated with the SG4 or SG2 variants showed significantly less severe clinical signs than the group treated with Gal-1 WT. As shown in Figure 11A, the effects of treatment with the SG2 variant were even more pronounced than those observed after treatment with SG4. Interestingly, mice treated with the SG2 variant, the mutant that showed the best in vitro performance, developed a very mild and attenuated disease. Twenty-four days after immunization, lymph drainage cells were purified and re-stimulated in vitro for 48 hours in the presence of MOG35-55. As shown in Figures 11B and 11C, treatment with Gal-1 WT or the SG1, SG2, and SG4 variants decreased the percentage of Thl cells, Thl7 cells, and IFN-γ-producing CD8+ T cells in vivo compared to control mice. Both the SG4 and SG2 variants, which showed the best performance in improving clinical symptoms of the disease, were also the most successful at reducing these three pathogenic cell populations. Although SG1 was able to reduce the percentage of IFN-γ-producing CD8+ T cells and IL-17A-producing CD4+ T cells, its effects on Thl were not as pronounced. This effect could be explained by the ability of these SuperGal variants to induce high secretion of IL-27, which is an anti-Thl7 but pro-Thl cytokine. Effects of SuperGal Variants on Regulatory T Cells As can be seen from the results in FIG. 11D, all Gal1 variants induced an increase in the percentage of CD4+ Foxp3+ regulatory T cells (Tregs). However, a detailed analysis of the activation state of these cells further showed that, while the WT variant induced a higher percentage of Foxp3+ cells with an activation profile characterized by CD69 expression and high levels of CD44 (CD44hiCD69+), the SG1 and SG4 variants, as well as the SG2 variant, unexpectedly induced an even greater increase in the percentage of CD44hiCD69+ Tregs compared to Gal-1 WT, leading to a significantly higher frequency of Tregs generated in the absence of treatment. Based on an analysis of the clinical signs of the disease (clinical score) and immune correlations, SG2 appears to be the best possible candidate for achieving therapeutic responses. Based on these results, the therapeutic potential of this specific SuperGal variant was further evaluated in a short pre-clinical treatment protocol. EAE was induced in WT mice that were additionally treated with 100 pg / day of either Gal-1 WT or the SG2 variant for 1 week, starting 3–9 days post-immunization. As shown in Figure 13A, treatment with the SG2 variant for a period limited to one week before the first symptoms of the disease resulted in significantly less severe disease than treatment with Gal-1 WT. Furthermore, the disease course was substantially different, with no acute phase observed but a chronic phase similar to that seen in other groups. On day 27 post-immunization, when all groups were in the chronic phase of the disease, the mice were sacrificed, and T-cell responses were analyzed following in vitro restimulation of purified cells from draining lymph nodes.Treatment with both variants of Gal-1 induced a significant reduction in the percentage of IFN-γ-producing CD8+ T cells, as well as Thl7 and Thl cells, effects that were even more evident after treatment with the SG2 variant (FIG. 13B). Taken together, these data further demonstrate that the SuperGal-1 variants SG1, SG2, and SG4 exhibit greater immunoregulatory capacity, as evidenced by apoptosis of pathological T cells (SG2 and SG4), IL-10 secretion in T cells (SG1 and SG2), and IL-27 secretion in dendritic cells (SG1 and SG2). Taking into account all the results described above, the SG1, SG2, and SG4 variants of the invention are the Gal-1 variants with the best in vitro performance. SG2 and SG4 showed an affinity for β-galactoside residues comparable to Gal-1 WT at physiological pH (7.5), and maintained their affinity for lactose at acidic pH (6.5 and 5.5), while Gal-1 WT was not able to do so. This was further demonstrated by fluorescence intensity (FIG. 12). The immunomodulatory activity of SG2 was also evaluated in experimental autoimmune encephalomyelitis, an animal model for multiple sclerosis. As shown in FIG. 13A, treatment with the new SG2 mutant resulted in lower clinical scores compared to Gal-1 WT and control mice (FIG. 13A), further confirming that resistance to pH and oxidation results in the best biological activity. As a side note, SG1 exhibits a greater capacity to induce the secretion of anti-inflammatory cytokines (IL-10 and IL-27), thus promoting a tolerogenic environment without inducing T cell death; whereas SG4 activates T cell death programs without increasing anti-inflammatory cytokines (IL-10 and IL-27). On the other hand, SG2 triggers both immunoregulatory pathways. These distinct SGX profiles (hereinafter referred to as SuperGal mimics or variants) can be therapeutically exploited to offer different therapeutic advantages by activating one or both of these mechanisms, depending on the nature of each autoimmune disease. The results presented demonstrate that SuperGal variants of Gal-1 exhibit greater resistance to oxidative conditions when compared to Gal-1 WT, and that lactose binding in an oxidative environment shows no significant differences for any of the triple mutants. Furthermore, considering all the results (Examples 1 to 4) together, the results confirm that mutations in H52, C2, C16, and / or C88 in the Gal-1 polypeptide confer resistance to acidic pH and oxidative conditions. The SuperGal variants (SGs), which not only showed resistance to both oxidation and acidic pH, but also exhibited significantly greater immunoregulatory activity (T cell apoptosis and cytokine secretion). tolerogenic / immunosuppressive). Finally, the in vivo results demonstrate the applicability of these SuperGal variants and, particularly, SG2, as therapeutic agents for the treatment and prophylaxis of autoimmune diseases. OTHER FORMS OF REALIZATION The detailed description set forth above is provided to assist those skilled in the art in carrying out the invention. However, the invention described and claimed herein is limited in scope by the specific embodiments described above, as these embodiments are presented merely as illustrations of various aspects of the invention. Any combinations and modifications of the described methods and components, and compositions used in carrying out the methods, other than those not specifically described, will be evident to those skilled in the art based on this description and do not depart from the spirit or scope of the present invention. Such variations, modifications, and combinations are also covered by this description and fall within the scope of the appended claims. INCORPORATION BY REFERENCE All references (patent applications, proposed patents, or scientific publications) cited in this description are also incorporated herein as references in their entirety. Figures and all polynucleotide and polypeptide sequences that reference an accession number related to an entry in a public database, such as those maintained by The Institute for Genomic Research (TIGR) and / or the National Center for Biotechnology Information (NCBI), are also incorporated as references. LIST OF SEQUENCES SEQ ID NO: 1 Human native Gal-1 protein sequence ACGLVASNLNLKPGECLRVRGEVAPDAKSFVLNLGKDSNNLCLHFNPRFNAHGDAN TIVCNSKDGGAWGTEQREAVFPFQPGSVAEVCITFDQANLTVKLPDGYEFKFPNRLN LEAINYMAADGDFKIKCVAFD SEQ ID NO: 2 Human native Gal-1 nucleotide sequence ATGGCTTGTGGTCTGGTCGCCAGCAACCTGAATCTCAAACCTGGAGAGTGCCTTC GAGTGCGAGGCGAGGTGGCTCCTGACGCTAAGAGCTTCGTGCTGAACCTGGGCA AAGACAGCAACAACCTGTGCCTGCACTTCAACCCTCGCTTCAACGCCCACGGCGA CGCCAACACCATCGTGTGCAACAGCAAGGACGGCGGGGCCTGGGGGACCGAGCA GCGGGAGGCTGTCTTTCCCTTCCAGCCTGGAAGTGTTGCAGAGGTGTGCATCACC TTCGACCAGGCCAACCTGACCGTCAAGCTGCCAGATGGATACGAATTCAAGTTCC CCAACCGCCTCAACCTGGAGGCCATCAACTACATGGCAGCTGACGGTGACTTCA AGATCAAATGTGTGGCCTTTGACTGA SEQ ID NO: 3 H52N Sentido ’-CAACGCCA ACGGCG ACGCC AAC-3 ’ SEQ ID NO: 4 H52N Antisentido ’-GTTGGCGTCGCCGTTGGCGTTG-3 ’ SEQ ID NO: 5 H52Q Sentido ’-CAACGCCCAGGGCG ACGCCAAC-3 ’ SEQ ID NO: 6 H52Q Antisentido ’ -GTTGGCGTCGCCCTGGGCGTTG-3 ’ SEQ ID NO:7 H52Y Sentido '-CAACGCCTATGGCGACGCCAAC-3 ’ SEQ ID NO: 8 H44Y Antisentido '-GTTGGCGTCGCCATAGGCGTTG-3 ’ SEQ ID NO: 9 H44N Sentido '-TGTGCCTGAACTTCAACCCTCG-3' SEQ ID NO: 10 H44N Antisentido 5'-CGAGGGTTGAAGTTCAGGCACA-3' SEQ ID NO: 11 H44Y Sentido'-TGTGCCCTGTACTTCAACCCTCG-3' SEQ ID NO: 12 H44Y Antisentido '-CGAGGGTTGAAGTAC AGGCACA-3' SEQ ID NO: 13 C2S Sentido '-ATATGGCTTCTGGTCTGG-3' SEQ ID NO: 14 C2S Antisentido 5'-GTATATCTCCTTCTTAAAGTTAAAC-3' SEQ ID NO: 15 C16S Sentido '-CTGGAGAGTCCCTTCGAGTG-3' SEQ ID NO: 16 C16S Antisentido '-GTTTG AG ATTCAGGTTGCTGG-3' SEQ ID NO: 17 C42S Sentido '-CA ACCTTGTCCCTGC ACTTC-3' SEQ ID NO: 18 C42S Antisentido '-TTGCTGTCTTTGCCC AGGTTC-3' SEQ ID NO: 19 C60S Sentido '-CC ATCGTGTCC A AC AGC A AG-3' SEQ ID NO: 20 C60S Antisentido 5'-TGTTGGCGTCGCCGTG-3' SEQ ID NO: 21 C88S Sense ' -C AG AGGTGTCC ATC ACCTTC-3 ' SEQ ID NO: 22 C88S Antisense '-CAAC ACTTCCAGGCTGG AAG-3' SEQ ID NO: 23 C130S Sense '-C AAGATCAAATCTGTGGCCTTTG-3' SEQ ID NO: 24 C130S Antisense 5′-AAGTCACCGTCAGCTGC-3′

Claims

1. An isolated Gal-1 polypeptide variant molecule, characterized in that it comprises: a mutation of the histidine residue at position 52 of the complete amino acid chain of native human Gal-1 as shown in SEQ ID NO: 1, the mutation being a substitution of histidine to tyrosine or asparagine, wherein the Gal-1 polypeptide variant molecule is resistant to acidic conditions of an inflammatory microenvironment that otherwise results in the inactivation of native human Gal-1. Three claims follow.