USE OF HDL FOR THE PROPHYLAXIS OF GRAFTS-VERSUS-HOST DISEASE

Description

[0001] The present invention relates to the prevention and / or treatment of graft versus host disease.

[0002] The curative efficacy of allogeneic hematopoietic cell transplantation (BMT) is significantly diminished by graft-versus-host disease (GvHD), which leads to significant mortality and morbidity.

[0003] GvHD represents a pathology for which corticosteroid therapy remains the first line of treatment to date. However, on the one hand, corticosteroid therapy is associated with numerous iatrogenic complications (diabetes, disturbances in bone metabolism with risk of aseptic bone necrosis, arterial hypertension, dyslipidemia, etc.), and on the other hand, the prognosis is poor in case of resistance to this treatment. There is no treatment consensus in these serious situations and the available tools remain immunosuppression approaches interfering with the cell cycle of T lymphocytes.

[0004] There is therefore a significant need for alternative treatments for GvHD that avoid such side effects.

[0005] The present invention aims to meet this need.

[0006] Donor T cell subsets are recognized as the primary cellular mediators and effectors of acute GvHD. T cell interactions with host and donor-originating antigen-presenting cells (APCs) are required to achieve the “alloreactive activated T cell” status generating the cytotoxic attack against target organs. However, preliminary awakening of APCs by exogenous or endogenous alarm signals from injured or “distressed” cells is critical to recruit and conduct effective T cell activation. Exogenous signals are a group of widespread natural microbial profiles called “pathogen-associated molecular patterns” (PAMPs) and are thought to be translocated from the microbiota when the body’s physical barriers, particularly the intestinal mucosa, are weak.Among these PAMPs, lipopolysaccharide (LPS) is the most extensively studied in the pathophysiology of GvHD.

[0007] The inventors identified an increase in free active plasma LPS after allogeneic transplantation, and then explored its metabolism to identify the critical step altered during allogeneic hematopoietic cell transplantation. In healthy individuals, LPS is typically transported by HDL to the liver, where LPS is then eliminated via the bile. Several plasma transporters are involved in loading LPS onto HDL. The inventors here demonstrated that the limiting factor explaining the increase in free active LPS was a drop in circulating HDL.

[0008] The present invention results from the unexpected discovery by the inventors that repeated administration of HDL lipoproteins neutralizes LPS in the context of GvHD, reducing the maturation of antigen-presenting cells and decreasing the activation of GvHD effector cells, Tc1 T lymphocytes, and decreasing the occurrence and severity of acute GvHD.

[0009] Thus, for the first time, the treatment proposed here by the inventors, the administration of HDL, makes it possible to prevent and treat GvHD, without relying on toxic immunosuppressive treatment, but on a modulation of lipid metabolism without impacting the quality of post-transplant immune reconstitution and with minimal toxicity expected on other organs.

[0010] This is particularly true in the liver, where the inventors demonstrated a reduced infiltrate of CD8 + T cells, as well as limited activation of resident and non-resident inflammatory macrophages, after treatment with HDL in an experimental model of GvHD.

[0011] Cooke et al. (2001) J. Clin. Invest. 107:1581 investigated the use of a competitive inhibitor of LPS, compound B975, in a mouse model of bone marrow transplantation. Unlike compound B975, HDL is not a competitive inhibitor of LPS but neutralizes and eliminates it.

[0012] In addition, HDLs exhibit an anti-inflammatory effect, independent of LPS, further reinforcing their interest in preventing and / or treating GvHD, characterized on a pathophysiological level by a strong inflammatory component.

[0013] The present invention thus relates to a high-density lipoprotein (HDL) or an HDL mimetic for use in the prevention and / or treatment of graft-versus-host disease (GvHD) or cytokine release syndrome, in a subject, wherein the HDL mimetic is: (i) a gold nanoparticle coated with phospholipids and ApoA1 or ApoA1 mimetics, or (ii) an HDL reconstituted from ApoA1 mimetics. Detailed description of the invention

[0014] The present invention is defined in the claims. HDL and HDL mimetics

[0015] High-density lipoprotein or HDL refers to the smallest and densest group of lipoprotein particles.

[0016] HDLs are well known to those skilled in the art and are typically cholesterol-rich, phospholipid-rich lipoproteins comprising apolipoproteins A1, A-II, A-IV, CI, C-II, C-III, and E, with a density between 1.063 and 1.210 and a diameter varying between 5 and 12 nm.

[0017] Typically, the HDLs used in the context of the invention are isolated from healthy donor blood, in particular from healthy donor plasma, for example by ultracentrifugation separation techniques.

[0018] Alternatively, the HDLs used in the context of the invention are reconstituted from purified or recombinant apoliproprotein A1, as defined below, and selected lipids, in particular soybean phospholipids.

[0019] Thus, examples of HDL that may be used in the context of the invention include CSL111 as described in Tardif et al. (2007) JAMA 297:1675-1682, CSL112 as described in Diditechenko et al. (2013) Arterioscler. Thromb. Vasc. Biol. 33:2202-211, CER-001 as described in Tardif et al. (2014) Eur. Heart J. 35:3277-3286, ETC-216 (also called MDCO-216, an HDL reconstituted from ApoA1 Milano).

[0020] By "HDL mimetics" we mean molecules that mimic the function of HDL.

[0021] Examples of HDL mimetics include gold nanoparticles coated with phospholipids and ApoA1 or ApoA1 mimetics, and HDL reconstituted from ApoA1 mimetics such as the ETC-642 molecule described in Di Bartolo et al. (2011) Lipids Health 10:224. Medical applications

[0022] The present invention relates to a high density lipoprotein (HDL) as defined in the section " HDL and HDL mimetics » above or an HDL mimetic as defined in section “ HDL and HDL mimetics » above, for its use in the prevention and / or treatment of graft versus host disease (GvHD) or cytokine release syndrome, in a subject.

[0023] The present invention also relates to the use of a high density lipoprotein (HDL) as defined in the section " HDL and HDL mimetics » above or an HDL mimetic as defined in section “ HDL and HDL mimetics » above, for the manufacture of a medicament intended for the prevention and / or treatment of graft versus host disease (GvHD) or cytokine release syndrome, in a subject.

[0024] Another subject matter of the invention relates to a method for preventing and / or treating graft versus host disease (GvHD) or cytokine release syndrome, comprising administering a therapeutically effective amount of a high-density lipoprotein (HDL) as defined in the section " HDL and HDL mimetics » above or an HDL mimetic as defined in section “ HDL and HDL mimetics » above, in a subject who needs it.

[0025] By "treatment" or "treat" is meant herein the achievement, partially or substantially, of one or more of the following results: partially or totally reducing the extent of the disease, improving a clinical symptom or indicator associated with the disease, delaying, inhibiting or preventing the progression of the disease, or partially or totally delaying, inhibiting or preventing the occurrence of a relapse of the disease.

[0026] As used herein, the term "prevention" or "prevent" refers to any indication of success in protecting a subject or patient (e.g., a subject or patient at risk of developing a disease) from developing, contracting, or having a disease, including preventing one or more symptoms of the disease.

[0027] By "subject" is meant herein a mammal, preferably a human. Preferably, the subject treated within the scope of the invention suffers from cancer, in particular a malignant hematological disease (such as leukemia, lymphoma or myeloma), or from a non-malignant hematological disorder such as primary immunodeficiency, bone marrow suppression or myelodysplasia.

[0028] By "graft-versus-host disease" or "GvHD" or "GvH" or "graft-versus-host disease" is meant any T-cell-mediated immune response in which donor lymphocytes react to host antigens, typically after bone marrow transplantation or allogeneic hematopoietic cell transplantation.

[0029] GvHD is defined by its "acute" or "chronic" nature depending on its time of onset and especially the type of clinical manifestations which respectively include inflammatory or fibrosing semiology. A form called " overlap syndrome » characterizes a GvHD that combines features of acute and chronic GvHD. The severity of acute GvHD can vary from mild to very severe. Usually, the severity of chronic GvHD is defined by its “limited or extensive” nature.

[0030] Acute GvHD most commonly occurs within the first 100 days after allograft surgery. It often affects the skin, liver, and intestine, but can also affect other organs. Acute GvHD can be classified according to the severity of symptoms: grade 1: mild symptoms, grade 2: moderate symptoms, grade 3: severe symptoms, grade 4: very severe symptoms.

[0031] Symptoms of acute GvHD typically include the following: burning sensation and redness of the skin on the palms of the hands or soles of the feet, rashes that may spread to the whole body, blisters and peeling, anorexia, nausea, vomiting, abdominal pain, diarrhea associated with malabsorption, hepatic cytolysis associated with jaundice, liver abnormalities that may progress to hepatocellular failure.

[0032] Chronic GvHD typically appears from the 3rd month after allograft. It can last a few months or a lifetime. Chronic GvHD can occur immediately after acute GvHD or a symptom-free period. Symptoms of chronic GvHD typically include the following: skin disorders such as dryness, rashes, itching, scaling, poikiloderma, loss of elastic properties of the skin resulting in a more or less extensive scleroderma picture. A dry mucosal and / or ophthalmic syndrome is often present and manifests as a burning / foreign body sensation in the eyes, xerostomia (dry mouth) with or without lichen planus or oral ulcers. On the digestive level, chronic GvHD is manifested by anorexia, abdominal pain, diarrhea, malabsorption, nausea / vomiting.Many other organs can be affected, such as the lungs (pulmonary fibrosis) or the musculoskeletal system (polyarthritis, cramps). It should be noted that extensive chronic GvHD is frequently associated with a failure of immune reconstitution, exposing the patient to opportunistic infectious complications.

[0033] In a particular embodiment, the GvHD prevented or treated within the scope of the invention is acute GvHD.

[0034] In a particularly preferred embodiment, the GvHD prevented or treated within the scope of the invention is acute hepatic GvHD.

[0035] As noted above, GvHD typically occurs after hematopoietic cell transplantation.

[0036] Thus, in a particular embodiment, to prevent or treat GvHD, in particular acute GvHD, the subject to be treated has undergone or will undergo a transplant, in particular an allogeneic transplant, of hematopoietic cells.

[0037] More particularly, in a particular embodiment aimed at preventing GvHD, the subject to be treated will undergo a transplant, in particular an allogeneic transplant, of hematopoietic cells.

[0038] In an alternative embodiment for treating GvHD, the subject to be treated has undergone a transplant, particularly an allogeneic transplant, of hematopoietic cells.

[0039] In a particular embodiment, the subject to be treated has a disruption of digestive permeability, said disruption typically being due to pre-transplant treatment, such as chemotherapy and / or radiation therapy. Without being bound by theory, these treatments may alter the integrity of the intestinal barrier by inducing apoptosis of intestinal epithelial cells, promoting immune cell infiltration and disrupting crypt / villus structures.

[0040] Cytokine release syndrome or CRS refers to a systematic inflammatory response that can be triggered by various factors such as infections and certain medications. CRS is typically observed as a side effect after the administration of antibody-based therapies, non-protein anticancer drugs, after the administration of chimeric antigen receptor T cells (CAR-T), but also immediately after allogeneic hematopoietic cell transplantation or GvHD. This syndrome is typically characterized by severe dyspnea, with bronchospasm and hypoxia, associated with fever, chills, tremors, urticaria and angioedema, and can lead to acute respiratory failure and death.

[0041] Thus, in a particular embodiment aimed at the prevention and / or treatment of CRS, the subject to be treated has been treated or is being treated with anticancer agents, in particular anticancer antibodies, or with CAR-T cells, or has undergone or will undergo a hematopoietic cell transplant.

[0042] In a preferred embodiment for preventing and / or treating cytokine release syndrome, the subject to be treated is treated or has been treated with CAR-T cells.

[0043] High-density lipoprotein (HDL) as defined in the section “ HDL and HDL mimetics » above or the HDL mimetic as defined in section “ HDL and HDL mimetics » above is typically administered to the subject in need in a therapeutically effective amount.

[0044] The term "therapeutically effective amount" herein means an amount of active ingredient sufficient to destroy, modify, control, or eliminate the disease. A "therapeutically effective amount" also means an amount of active ingredient sufficient to delay or minimize the extent of the disease. It also refers to the amount of active ingredient providing a therapeutic benefit in the treatment or management of the disease. Finally, the term "therapeutically effective amount" means an amount of active ingredient, alone or in combination with other therapies, that provides a therapeutic benefit in the treatment or management of the disease, including an improvement in the symptoms associated with the disease.

[0045] The therapeutically effective quantity naturally depends on the active ingredient considered, the method of administration, the therapeutic indication, the age of the patient and their condition.

[0046] Advantageously, the active compound used in the context of the invention is in the form of a pharmaceutical composition optionally further comprising a pharmaceutically acceptable excipient.

[0047] By "pharmaceutically acceptable" is meant herein compositions and molecular entities that do not produce adverse, allergic or otherwise undesired reactions when administered to a subject. A pharmaceutically acceptable excipient or vehicle is thus an encapsulating material, a diluent, a carrier, or any other non-toxic liquid, semi-solid or solid formulation aid.

[0048] The pharmaceutical compositions used in the invention are typically prepared to suit the mode of administration. Acceptable pharmaceutical excipients are typically determined in part by the composition being administered, as well as the particular technique used to administer the composition.

[0049] The dosage of the compounds to be administered depends on the individual case and, as is well known to those skilled in the art, must be adapted to the individual circumstances to obtain an effective therapeutic amount and an optimum effect. The therapeutically effective dose level is specific for any patient, and will depend in particular on a variety of factors, including the disorder being treated and the severity of the disorder, the activity of the specific compound used; the specific composition employed, the age, body weight, general health, sex and diet of the patient, the time of administration, the route of administration, and the rate of excretion of the specific compound used, the duration of treatment, the drugs used in combination with the specific compound employed, and analogous factors well known in the medical art.For example, it is well known to those skilled in the art to start doses of the compound at levels lower than those required to achieve the desired therapeutic effect and gradually increase the dosage until the desired effect is achieved.

[0050] The daily dose may be administered as a single dose or, particularly when larger amounts are administered, divided into several individual doses.

[0051] The dosage of the active substance depends particularly on the method of administration, and is easily determined by a person skilled in the art. A therapeutically effective amount (unit dose) of compound may vary from 0.01 mg / kg to 500 mg / kg, preferably from 0.1 mg / kg to 500 mg / kg, preferably from 0.1 mg / kg to 250 mg / kg, preferably from 0.1 mg / kg to 100 mg / kg, preferably from 0.1 mg / kg to 50 mg / kg, and more preferably from 1 mg / kg to 20 mg / kg, in one or more weekly administrations, for several weeks or months. The effective unit dose can therefore easily be deduced from a dose calculated for an “average” patient whose weight is 70 kg.

[0052] Typically, high-density lipoprotein (HDL) as defined in the section “ HDL and HDL mimetics » above or the HDL mimetic as defined in section “ HDL and HDL mimetics » above is administered at a dose of 20 mg / kg.

[0053] In a particular embodiment, the HDL as defined in the section “ HDL and HDL mimetics » above or the HDL mimetic as defined in section “ HDL and HDL mimetics » above is administered repeatedly, preferably every other day.

[0054] In a particular embodiment, when the subject to be treated is going to undergo a hematopoietic cell transplant, HDL as defined in the section “ HDL and HDL mimetics » above or the HDL mimetic as defined in section “ HDL and HDL mimetics » above is administered before hematopoietic cell transplantation, preferably during the conditioning phase, typically 7 days before hematopoietic cell transplantation.

[0055] Preferably, HDL as defined in section “ HDL and HDL mimetics » above or the HDL mimetic as defined in section “ HDL and HDL mimetics» above is administered before hematopoietic cell transplantation, as defined above, and is administered again after hematopoietic cell transplantation, typically 1 to 3 days after hematopoietic cell transplantation, particularly 1 day after hematopoietic cell transplantation, more particularly repeatedly between 1 and 24 days after hematopoietic cell transplantation.

[0056] Alternatively, HDL as defined in section “ HDL and HDL mimetics » above or the HDL mimetic as defined in section “ HDL and HDL mimetics » above begins to be administered after hematopoietic cell transplantation, typically 1 to 7 days after hematopoietic cell transplantation, typically 1 day after hematopoietic cell transplantation, more particularly repeatedly between 1 and 24 days after hematopoietic cell transplantation.

[0057] The compositions used in the context of the invention may be in solid, liquid or semi-solid form, suitable for various routes of administration (oral, rectal, nasal, intraocular, local (for example, topical, transdermal, buccal, vaginal or sublingual) or parenteral (for example, subcutaneous, intramuscular, intravenous or intradermal)).

[0058] Preferably, HDL or HDL mimetic is administered intravenously.

[0059] Intravenous formulations contain the active substance dissolved, suspended or emulsified in a sterile vehicle, possibly in the presence of emulsifying agents, stabilizers, buffering agents and other conventional additives; they are normally dispensed into vials or infusion bottles, and may be stored as dry products for reconstitution with water or a suitable vehicle before use.

[0060] The solid pharmaceutical compositions may be tablets, capsules, powders, granules, pills, powders for reconstitution, etc.; they may contain conventional excipients such as binders, fillers, diluents, compressing agents, lubricants, detergents, colorants, flavoring agents, and wetting agents. The tablets may be coated according to methods well known in the art. Suitable fillers include cellulose, mannitol, lactose, and other similar agents.

[0061] Liquid compositions for oral administration may be in the form of aqueous or oily suspensions, solutions, emulsions, syrups or elixirs or may be presented as dry products for reconstitution with water or a suitable vehicle before use; They may contain conventional additives, for example, suspending agents such as sorbitol, syrup, methylcellulose, gelatin, hydroxyethylcellulose, carboxymethylcellulose, aluminum stearate gel or hydrogenated edible fats, emulsifiers such as lecithin, sorbitan monooleate or gum arabic; non-aqueous carriers (which may include edible oils) such as almond oil, fractionated coconut oil, oily esters such as esters of glycerin, propylene glycol or ethyl alcohol;preservatives such as methyl or propyl p-hydroxybenzoate or sorbic acid and, if desired, conventional flavoring or coloring agents.;

[0062] For the purposes of this application, the term "comprising" shall be interpreted as covering all of the specifically mentioned features, as well as possibly some additional unspecified ones. Furthermore, the use of the term "comprising" also describes the world of embodiment in which no features other than the specific ones mentioned are present ( ie “consisting of”).

[0063] The present invention will be described in more detail by the figures and examples below. Examples Example 1

[0064] In this example, the inventors show that intravenous administration of allogeneic T lymphocytes induces early translocation of LPS as well as lower neutralization of its inflammatory properties. This LPS is found mainly in free form in plasma after allogeneic hematopoietic cell transplantation.

[0065] In an established murine model of GvHD, which consists of lethally irradiated (8.5 Gy) BALB / c recipient mice engrafted with 5×10 6< T-cell-depleted bone marrow and 1×10 6< splenic T cells from BALB / c (syngeneic, syng) or C57Bl / 6 (allogeneic, allo) donors, 3-hydroxymyristic acid (3HM) - the most common hydroxylated fatty acid found in lipid A of LPS - was quantified in plasma and bile of recipient mice 3 and 6 days after bone marrow transplantation (BMT) using the Endoquant ®< technique based on high-performance liquid chromatography coupled to tandem mass spectrometry (Plasma: n=26-32 mice / group of 6 independent experiments, post-Kruskal-Wallis test and Dunn, *: p < 0.05, **: p < 0.01, ****: p < 0.0001: Bile: n=10-21 mice / group of 3 independent experiments, one-way ANOVA and Bonferroni post-test, *: p < 0.05, **: p < 0.01, ****: p < 0.0001) ( Figure 1 ).

[0066] The inventors observed that this increase in plasma LPS after allogeneic hematopoietic cell transplantation is mainly LPS in its free form. The inventors confirmed the increase in LPS after allogeneic transplantation using the LAL test (for Limulus Amoebocyte Lysate which is based on the coagulation of the lysate of amebocytes contained in the blood of horseshoe crabs in the presence of active, i.e. free, LPS only) (n=9 mice / group of 3 independent experiments) ( Figure 2 , left). This was confirmed by separating the free form of LPS (not associated with circulating lipoproteins) and the form associated with HDL by ultracentrifugation, then quantification by the Endoquant ® technique (n=3-4 mice / group of 1 experiment, two-way ANOVA and Bonferroni post-test, ***: p < 0.001) ( Figure 2 , RIGHT).

[0067] The inventors observed that the soluble form of CD14 (sCD14) was increased in the plasma of allo-recipient mice at d+15 after transplantation (n=6-15 mice / group of 3 independent experiments, Kruskal-Wallis and Dunn post-test, **: p < 0.01) ( Figure 3 ).

[0068] The ability of plasma from recipient mice to neutralize the activity of a known concentration of LPS was studied in vitro.Briefly, HEK-Blue TLR4 / CD14 / MD-2 reporter cells were cultured in the presence of 0.5% plasma and 0.01 EU / ml standard LPS. The inventors showed that at d+3 post-transplantation, the plasma of allo-recipient mice exhibited a 21.6% decreased neutralizing activity of commercial LPS supplemented at a known concentration (0.01 EU / ml, Invivogen) compared to naive mice. At d+6, the decrease was equal to 14% (n=11-16 mice / group of 2 independent experiments, one-way ANOVA and Bonferroni post-test, **: p < 0.01) ( Figure 4 ). Example 2

[0069] In this example, the inventors show that the decreased neutralization capacity appears to be due to impaired reverse LPS transport in allo-recipient mice.

[0070] Reverse LPS transport (RLT) is a metabolic pathway analogous to reverse cholesterol transport in which lipophilic substances are transported to the liver by lipoproteins (mainly HDL) for recycling or elimination in the bile.

[0071] Phospholipid transfer protein (PLTP) is an important player in RLT capable of loading LPS onto HDL. The inventors showed that its activity, measured by a commercially available kit, was slightly decreased by total body irradiation (d+3 after transplantation) and by the administration of allogeneic T lymphocytes (d+6) (n=18-21 mice / group of 3 independent experiments, one-way ANOVA and Bonferroni post-test, ****: p < 0.0001) ( Figure 5 ).

[0072] However, the inventors demonstrated that PLTP activity was not the major effector in the context of GvHD since its total absence did not aggravate the mortality of allografted mice. In this model, lethally irradiated C57BI / 6 mice (10 Gy) Pltp + / + or Pltp - / - were grafted with 20×10 6< bone marrow and 5×10 6< splenic T lymphocytes from C57Bl / 6 (syngeneic, syng) or C3H (allogeneic, allo) donors (n=12-17 mice / group of 2 independent experiments, log-rank test, ns: not significant, p = 0.5338) ( Figure 6 ).

[0073] The inventors showed that the main limiting factor appeared to be the availability of LPS transporters as an early drop (d+6) in plasma HDL concentration was observed in two GvHD mouse models. figure 7shows the results obtained with the C57Bl / 6→BALB / c model (n=3-11 mice / group of 2 independent experiments, Kruskal-Wallis and Dunn post-test, **: p < 0.01). Example 3

[0074] In this example, the inventors show that loss of apolipoprotein A1 (ApoA1) synthesis and circulating HDL increases the severity of GvHD.

[0075] To study the predominant effect of HDL in RLT in the context of GvHD, lethally irradiated (10 Gy) C57Bl / 6 mice expressing (WT) or not ( Apoa1 tm1Unc< ) the ApoA1 gene were transplanted with 20×10 6< bone marrow and 5×10 6< splenic T lymphocytes from C57Bl / 6 (syngeneic, syng) or C3H (allogeneic, allo) donors.

[0076] ApoA1 is the major apolipoprotein for HDL formation and the inventors showed that its absence aggravated the fall in HDL in recipient mice ApoA1 tm1Unc<(d+6), leading to the almost total absence of circulating HDL in the plasma (0.067 g / l) (n=6 mice / group of 2 independent experiments, Mann-Whitney test, **: p < 0.01) ( Figure 8 ).

[0077] The inventors showed that the absence of HDL in allo-recipient mice exacerbated mortality and GvHD severity after transplantation (n=9-19 mice / group of 3 independent experiments, log-rank test for survival, ***: p < 0.001 and Kruskal-Wallis and Dunn post-tests on AUC for clinical score, **: p < 0.01) ( Figure 9 ).

[0078] The inventors showed that the absence of HDL appeared to be associated with an impaired LPS neutralization capacity, as assessed by the HEK-Blue TLR4 / CD14 / MD-2 reporter cell method (preliminary data, n=3 mice / group of 1 experiment) ( Figure 10 ).

[0079] The inventors finally showed that the recipient mice ApoA1 tm1Unc<have a lower capacity for LPS neutralization at day 6 after transplantation. Indeed, the recipient mice ApoA1 tm1Unc< have plasma concentrations of 3HM ( ie , total LPS) lower than wild-type (WT) recipient mice (n=6 mice / group of 2 independent experiments, Mann-Whitney test, **: p < 0.01) ( Figure 11 , left). On the other hand, these 2 groups of recipient mice present the same quantity of active LPS assessed by the LAL test (n=3 mice / group of 1 experiment) (Fig. 11, center). This results in a lower LPS neutralization capacity or activity index in the recipient mice ApoA1 tm1Unc< ( Figure 11 , RIGHT). Example 4

[0080] In this example, the inventors show that the loss of circulating apolipoprotein ApoA1 and HDL synthesis accelerates dendritic cell maturation and promotes IFN-γ production by T lymphocytes in the spleen.

[0081] Maturation of conventional dendritic cells (DC) ( Figure 12 ) and T lymphocyte polarization ( Figure 13 ) were evaluated, by flow cytometry 6 days after transplantation, in the spleen of lethally irradiated (10 Gy) C57Bl / 6 mice expressing (WT) or not ( Apoa1 tm1Unc< ) the ApoA1 gene and grafted with 20×10 6< bone marrow and 5×10 6< splenic T lymphocytes from C57Bl / 6 (syngeneic, syng) or C3H (allogeneic, allo) donors.

[0082] The inventors showed that the absolute number of live CD3 -< CD19 -< CD11c +< IA-IE +< DCs was significantly increased in the spleen of recipient mice Apoa1 tm1Unc< ( Figure 12 , left). These DCs show increased expression of maturation markers (CD80 and CD86) compared to DCs from WT allografted mice with respect to the percentage ( Figure 12 , center) and the absolute number ( Figure 12, right) of positive cells (n=11-12 mice / group of 3 independent experiments, unpaired t-test or Mann-Whitney test, *: p < 0.05, **: p < 0.01, ***: p < 0.001).

[0083] The inventors also showed that the absolute number of live splenic CD3+ T lymphocytes was increased in the recipients Apoa1 tm1Unc< ( Figure 13 , left). The proportions of IFN-γ-expressing cells among CD3 + < CD4 + < cells (Th1 lymphocytes) and CD3 + < CD8 + < cells (Tc1 lymphocytes) were higher in recipients Apoa1 tm1Unc< ( Figure 13 , center) and represented a higher absolute cell number ( Figure 13 , right) after 4 hours of phorbol-myristate-acetate / ionomycin stimulation (n = 11-12 mice / group of 3 independent experiments, unpaired t-test or Mann-Whitney test, *: p < 0.05, **: p < 0.01, ***: p < 0.001). Example 5

[0084] In this example, the inventors show that loss of apolipoprotein ApoA1 synthesis and circulating HDL could increase T cell infiltration into a target organ of graft-versus-host disease, the liver, and promotes the production of IFN-γ by these liver-infiltrating T cells.

[0085] T lymphocyte polarization ( Figure 14 ) isolated from the liver was evaluated, by flow cytometry, 6 days after transplantation of lethally irradiated (10 Gy) C57Bl / 6 mice expressing (WT) or not ( Apoa1 tm1Unc< ) the ApoA1 gene and grafted with 20×10 6< bone marrow and 5×10 6< splenic T lymphocytes from C57Bl / 6 (syngeneic, syng) or C3H (allogeneic, allo) donors.

[0086] The inventors showed that the absolute number of live CD3+ T lymphocytes present in the liver was slightly increased in the recipients Apoa1 tm1Unc<(n=5-6 mice / group of 1 experiment, Mann-Whitney test, p = 0.0628) ( Figure 14 , left). The proportions of IFN-γ-expressing cells among CD3 + < CD4 + < cells (Th1 lymphocytes) and CD3 + < CD8 + < cells (Tc1 lymphocytes) were higher in recipients Apoa1 tm1Unc< ( Figure 14 , center) and represented a higher absolute cell number ( Figure 14 , right) after 4 hours of phorbol-myristate-acetate / ionomycin stimulation (n = 5-6 mice / group of 1 experiment, Mann-Whitney test, *: p < 0.05, **: p < 0.01). Example 6

[0087] In this example, the inventors show that the loss of apolipoprotein ApoA1 synthesis and circulating HDL results in an increase in hepatic macrophages, primarily non-resident monocyte-derived macrophages. These hepatic macrophages produce increased pro-inflammatory cytokines, TNF-α and IL-6.

[0088] Cytokine production by resident (Küpffer cells) and non-resident (NRM) hepatic macrophages ( Figure 15 ) was evaluated, by flow cytometry, 6 days after transplantation of lethally irradiated (10 Gy) C57Bl / 6 mice expressing (WT) or not ( Apoa1 tm1Unc< ) the ApoA1 gene and grafted with 20×10 6< bone marrow and 5×10 6< splenic T lymphocytes from C57Bl / 6 (syngeneic, syng) or C3H (allogeneic, allo) donors.

[0089] The inventors showed that the absolute number of resident hepatic macrophages (Küpffer cells) and non-resident hepatic macrophages (NRM) present in the liver was increased in the recipients Apoa 1tm1Unc< (n=5-6 mice / group of 1 experiment, Mann-Whitney test, *: p < 0.05) ( Figure 15 , left). The absolute number of cells expressing TNF-α ( Figure 15 , center) or IL-6 ( Figure 15 , right) among F4 / 80 int< CD11b high< cells (NRM non-resident macrophages) were higher in recipients Apoa1 tm1Unc< after 4 hours of LPS stimulation (n=5-6 mice / group of 1 experiment, Mann-Whitney test, *: p < 0.05). Regarding F4 / 80 high< CD11b high< cells (Küpffer cells) expressing these pro-inflammatory cytokines, there is a tendency to increase (n=5-6 mice / group of 1 experiment, Mann-Whitney test, p = 0.0823 and p = 0.0519, for TNF-α and IL-6 respectively). Exemple 7

[0090] In this example, the inventors show that intravenous (iv) administration of HDL reduces the intensity of GvHD and neutralizes available LPS.

[0091] To test the benefit of prophylactic use of IV HDL administration to moderate GvHD severity, lethally irradiated (8.5 Gy) BALB / c recipients transplanted with 5×10 6< T-cell-depleted bone marrow and 1×10 6< splenic T cells from BALB / c (syngeneic, syng) or C57Bl / 6 (allogeneic, allo) donors were treated with IV administration of HDL isolated from human plasma (20 mg / kg body weight) three times weekly between d-1 and d+24 post-transplant.

[0092] The inventors showed that IV administration of HDL reduced mortality ( Figure 16 , left) and gravity ( Figure 16 , right) of GvHD in allografted mice (n=19-39 mice / group of 4 independent experiments, log-rank test for survival and one-way ANOVA and Bonferroni post-test on AUC for clinical score, ****: p < 0.0001).

[0093] The inventors also showed that iv administration of isolated HDL restored the level of circulating HDL at d+6 (n=10-11 mice / group of 3 independent experiments, Mann-Whitney test, *: p < 0.05) ( Figure 17 ).

[0094] The inventors finally showed that IV administration of HDL appeared to decrease the concentration of 3HM in the plasma and bile of allografted mice (n=9-13 mice / group of 4 independent experiments, Mann-Whitney test). Plasma levels ( Figure 18 , left) and biliary ( Figure 18 , center) of 3HM were strongly correlated with the concentration of circulating HDL (respectively n=13 mice / group of 4 independent experiments, Mann-Whitney test; n=26 pairs, non-parametric Spearman correlation test and n=9-10 mice / group of 4 independent experiments, Mann-Whitney test; n=19 pairs, non-parametric Spearman correlation test, ****: p < 0.0001). The concentrations of 3HM detected by the Endoquant ® technique represent the total amount of LPS present in biological fluids. IV administration of HDL also appears to decrease the endotoxin activity of circulating LPS measured by the LAL technique (n=7-9 mice / group of 3 independent experiments) ( Figure 18 , RIGHT). Exemple 8

[0095] In this example, the inventors present preliminary data showing that intravenous (iv) administration of HDL could limit systemic inflammation associated with acute GvHD.

[0096] Preliminary data obtained by the inventors suggest that IV administration of HDL isolated from human plasma (20 mg / kg body weight) three times per week could decrease systemic inflammation caused by acute GvHD in lethally irradiated (8.5 Gy) BALB / c recipients transplanted with 5×10 6< T-cell depleted bone marrow and 1×10 6< splenic T-cells from C57Bl / 6 (allo) donors.

[0097] The inventors showed that iv administration of HDL appeared to limit the plasma level of the acute GvHD intestinal biomarker REG-3γ at d+15 post-transplantation (n=8 mice / group of 1 experiment) ( Figure 19 ).

[0098] The inventors also showed that circulating inflammatory cytokine levels tended to be decreased by iv administration of HDL: interleukin-6 (IL-6) was two times lower at d+6 (n=10 mice / group of 2 independent experiments, unpaired t-test, *: p < 0.05) ( Figure 20 , left) and tumor necrosis factor-α (TNF-α) is decreased by 30% at d+15 (n=3 mice / group of 1 experiment) ( Figure 20 , RIGHT).

[0099] The inventors finally showed that splenocytes from allografted mice treated with iv HDL administration were less able to stimulate the proliferation of allogeneic naive lymphocytes. Briefly, splenocytes from recipient mice of the C57Bl / 6 → BALB / c model were treated with mitomycin C and cultured with T lymphocytes from naive C57Bl / 6 mice and labeled with CFSE. The dilution of the CFSE labeling was analyzed by flow cytometry after 5 days of co-culture. The proportion of proliferated T lymphocytes was significantly lower when they were cultured with splenocytes isolated from mice treated with iv HDL administration ( Figure 21 , left). This lower proportion seems to be explained by a lower number of cells entering division (division index) ( Figure 21 , right) and not by a difference in division speed (proliferation index) ( Figure 21 , center) (n=6 mice / group of 1 experiment, Mann-Whitney test, ns: not significant, **: p < 0.01). Exemple 9

[0100] In this example, the inventors present preliminary data showing that intravenous (iv) administration of HDL limits the production of pro-inflammatory cytokines TNF-α and IL-12 by hepatic macrophages, and the infiltrate of CD8 T lymphocytes producing IFN-γ in the liver. This results in a reduced histological score of hepatic GvHD in mice treated with iv administration of HDL, and more particularly less cholangitis ( i.e. , inflammation of the bile ducts).

[0101] Preliminary data obtained by the inventors suggest that iv administration of HDL isolated from human plasma (20 mg / kg body weight) three times per week limits hepatic GvHD in lethally irradiated (8.5 Gy) BALB / c recipients transplanted with 5×10 6< T-cell depleted bone marrow and 1×10 6< splenic T-cells from C57Bl / 6 (allo) donors.

[0102] Cytokine production by hepatic non-resident macrophages (NRMs) ( Figure 22 , left), residents (Küpffer cells) ( Figure 22 , center and right), and CD8 T lymphocytes ( Figure 23 ) was assessed by flow cytometry 6 days or 24 days after transplantation of lethally irradiated (8.5 Gy) BALB / c mice engrafted with 5×10 6< T-cell-depleted bone marrow and 1×10 6< splenic T cells from C57Bl / 6 (allo) donors receiving injections of isotonic sodium chloride (+Veh) or HDL (+HDL).

[0103] The inventors showed that the percentage of hepatic non-resident macrophages (NRM) expressing IL-12 was reduced in HDL recipients (+HDL) 6 days after transplantation and after 4 hours of stimulation in vitro by the LPS ( Figure 22 , left) (n=6 mice / group of 1 experiment, Mann-Whitney test or unpaired t test, *: p < 0.05). The percentages of resident hepatic macrophages (Küpffer cells) expressing TNF-α ( Figure 22 , right) or IL-12 ( Figure 22 , center) was reduced in HDL recipients (+HDL) 24 days after transplantation and after 4 hours of stimulation in vitro by LPS (n=6 mice / group of 1 experiment, Mann-Whitney test or unpaired test, *: p < 0.05).

[0104] The inventors also showed that the percentage of CD8 T lymphocytes in the liver of mice receiving HDL (+HDL) was reduced 6 days after transplantation ( Figure 23 , left) (n=6 mice / group of 1 experiment, Mann-Whitney test, *: p < 0.05). These liver-infiltrating CD8 T cells synthesized less IFN-γ in mice receiving HDL (+HDL) after 4 hours of phorbol-myristate-acetate / ionomycin stimulation. The absolute number of CD3 +< CD8 +< cells expressing IFN-γ (Tc1 lymphocytes) was lower in mice receiving HDL injections (+HDL) than in those receiving isotonic sodium chloride (+Veh) ( Figure 23 , right) (n=6 mice / group of 1 experiment, Mann-Whitney test, *: p < 0.05).

[0105] The inventors finally showed that the histological score ( Figure 24 ) - thin sections of liver fixed in formalin, then embedded in paraffin and stained with hematoxylin / eosin analyzed 24 days after transplantation taking into account the following 4 criteria: lobular hepatitis, portal inflammatory infiltrate (as shown in Figure 25 , top, arrows indicating immune infiltrate in the portal spaces and scale bar representing 100 µm), portal vein endotheliitis and cholangitis (as shown in Figure 25 , bottom, crosses indicating bile ducts and the scale representing 100 µm) (each parameter assessed on a scale of 0 to 3, 0 being the physiological situation) - was reduced in mice treated with HDL administration (+HDL) compared to the score of mice receiving isotonic sodium chloride (+Veh) ( Figure 24 , left) (n=6-7 mice / group of 1 experiment, Mann-Whitney test, *: p < 0.05, **: p < 0.01). The main effect of iv HDL administration was a reduction in cholangitis, i.e., inflammation of the bile ducts ( Figure 24 , RIGHT).

Claims

1. High-density lipoprotein (HDL) or HDL mimetic for use in the prevention and / or treatment of graft-versus-host disease (GvHD) or cytokine release syndrome in a subject, wherein the HDL mimetic is: (i) a gold nanoparticles covered in phospholipids and ApoA1 or ApoA1 mimetics, or (ii) a HDL reconstituted from ApoA1 mimetics.

2. HDL or HDL mimetic for use according to claim 1, wherein the HDL is isolated from the blood of a healthy donor.

3. HDL or HDL mimetic for use according to claim 1 or 2, wherein the HDL or HDL mimetic is administered intravenously.

4. HDL or HDL mimetic for use according to any of claims 1 - 3, wherein the HDL or the HDL mimetic is administered repeatedly, preferably every 2 days.

5. HDL or HDL mimetic for use according to any of claims 1 - 4, wherein the GvHD is acute GvHD.

6. HDL or HDL mimetic for use according to any of claims 1 - 5 for the prevention of GvHD, wherein the subject is to undergo a haematopoietic cell transplant.

7. HDL or HDL mimetic for use according to claim 6, wherein the HDL or the HDL mimetic is administered before and after the haematopoietic cell transplant.

8. HDL or HDL mimetic for use according to any of claims 1 - 5 for the treatment of GvHD, wherein the subject has undergone a haematopoietic cell transplant.

9. HDL or HDL mimetic for use according to any of claims 1 - 4, for the prevention and / or treatment of cytokine release syndrome, wherein the subject is treated with chimeric antigen receptor T lymphocytes (CAR-T).