241 results about "Xenotransplantation" patented technology

Human breast tumors contain hetrogeneous cancer cells. using an animal xenograft model in which human breast cancer cells were grown in immunocompromised mice we found that only a small minority of breast cancer cells had capacity to form new tumors. The ability to form new tumors was not a slochastic property, rather certain populations of cancer cells were depleted for the ability to form new tumors, while other populations were enriched for the ability to form new tumors. Tumorigenic cells could be distinguished from non-tumorigenic cancer cells based on surface marker expression. We prospectively identified and isolated the tumorigenic cells as CD44³⁰CD24^−/lowLINEAGE A few as 100 cells from this population were able to form tumors the animal xenograft model, while tens of thousands of cells from non-tumorigenic populations failed to form tumors. The tumorigenic cells could be serially passaged, each time generating new tumors containing and expanded numbers of CD44^+CD24 Lineage tumorigenic cells as well as phenotypically mixed populations of non-tumorigenic cancer cells. This is reminiscent of the ability of normal stem cells to self-renew and differentiate. The expression of potential therapeutic targets also differed between the tumorigenic and non-tumorigenic populations. Notch activation promoted the survival of the tumorigenic cells, and a blocking antibody against Notch 4 induced tumorigenic breast cancer cells to undergo apoptosis.

The invention relates to the inhibition of blood coagulation, especially during organ rejection, and in particular the inhibition of delayed vascular rejection. The invention provides anticoagulant proteins which are anchored to cell membranes. The anticoagulant function preferably provided by heparin, antithrombin, hirudin, TFPI, tick anticoagulant peptide, or a snake venom factor. These anticoagulant proteins are preferably prevented from being constitutively expressed at the cell surface. In particular, expression at the cell surface is regulated according to cell activation, for instance by targeting the protein to a suitable secretory granule. Expression of these proteins renders cells, tissues and organs less vulnerable to rejection after transplantation (e.g. after xenotransplantation).

PCT No. PCT/US94/05844 Sec. 371 Date Jun. 6, 1995 Sec. 102(e) Date Jun. 6, 1995 PCT Filed May 24, 1994 PCT Pub. No. WO94/27622 PCT Pub. Date Dec. 8, 1993This invention provides a method for developing immune tolerance in xenogeneic organ graft recipients, in which lympho-hematopoietic cells from an intended organ graft recipient are differentiated within a xenogeneic surrogate, such as a fetal animal. After birth of the surrogate, the matured lympho-hematopoietic cells containing antigen specific regulatory cells, including suppressor cells, veto cells, select B cells, anti-idiotype antibodies, and other related factors responsible for antigen specific tolerance in a surrogate animal are reintroduced into the intended organ graft recipient, in conjunction with an organ transplant or a tissue transplant from the xenograft surrogate. The invention also provides an organ graft repopulated with cells from the intended organ graft recipient produced in a surrogate animal.

The invention relates to the genetic manipulation of non-human animals. More particularly, the invention relates to genetic manipulation of non-human animals to be used for xenotransplantation. The invention provides viable gene knockout swine including swine in which the α(1,3)-galactosyltransferase gene has been disrupted, methods for making such swine, and methods of using the tissues and organs of such swine for xenotransplantation.

The present invention provides certain animals, and in particular porcine animals, tissue and cells derived from these, which lack any expression of functional alpha 1,3 galactosyltransferase (αGT) and express one or more additional transgenes which make them suitable donors for pancreatic islet xenotransplantation. Methods of treatment and prevention of diabetes using cells derived from such animals are also provided.

The present invention relates to an antigenic fusionprotein, which carries multiple Galα1,3Gal epitopes. The fusion protein according to the invention may also be comprised of a heavily glycosylated mucin part, which mediates binding to selectins, such as PSGL-1, and a part, which exhibits immunoglobulin properties, such as the Fc part of IgG. The fusionprotein according to the invention is preferably used as an absorber to prevent a hyperacute rejection of a xenotransplant, such as a pig tissue or organ transplanted into a human patient. In addition, the invention relates to a method for the prevention of hyperacute rejection reaction in a patient who is to receive a xenotransplant.

The present invention is a porcine animal, tissue, organ, cells and cell lines, which lack any expression of functional alpha 1,3 galactosyltransferase (alpha1,3GT). These animals, tissues, organs and cells can be used in xenotransplantation and for other medical purposes.

The present invention is directed to a composition comprising high mannuronic acid-containing alginate and a polycation having a polydispersity index of less than 1.5. The composition is particularly useful for making biocompatible microcapsules containing living cells for allo- or xeno-transplantation. Such microcapsules have enhanced durability and can maintain their structural and functional integrity over long periods of time compared to prior art alginate microcapsules.

Biologically engineered stents are provided, some having novel double-walled and hybrid composition constructions that are suitable for multi-drug delivery. Some embodiments of biologically engineered stents (BES) in accordance with the invention can deliver drugs in the form of gene therapy vectors to cells in the walls of stented vessels, thereby promoting local production of therapeutic factors that attract and enhance the formation of endothelium in the stented vessel. Other embodiments of BES include xenografts, allografts or isografts comprising sleeve-like natural matrices derived from vessels of animal and human subjects including postmortem human donors.

The present invention provides porcine Forssman synthetase (FSM synthase) (Globoside α-N-acetylgalactosaminyltransferase) protein, cDNA, and genomic DNA sequence. Furthermore, the present invention includes porcine animals, tissue and organs as well as cells and cell lines derived from such animals, tissue and organs, which lack expression of functional FSM synthetase. Such animals, tissues, organs and cells can be used in research and in medical therapy, including in xenotransplantation. In addition, methods are provided to prepare organs, tissues, and cells lacking the porcine FSM synthetase gene for use in xenotransplantation.

The present invention provides ungulates, including pigs, expressing CTLA4-Ig, as well as tissue, organs, cells and cell lines derived from such animals. Such animals, tissues, organs and cells can be used in research and medical therapy, including xenotransplanation. In addition, methods are provided to prepare organs, tissues and cells expressing the CTLA4-Ig for use in xenotransplantation, and nucleic acid constructs and vectors useful therein.

The invention provides an article of manufacture comprising a substantially non-immunogenic bone xenograft for implantation into humans. The invention further provides a method for preparing a bone xenograft by removing at least a portion of a bone from a non-human animal to provide a xenograft (X); washing the xenograft in saline and alcohol; subjecting the xenograft to a cellular disruption treatment; and treating the xenograft with a glycosidase to remove surface carbohydrate moieties. The invention also provides an article of manufacture produced by the above identified method of invention. The invention further provides a bone xenograft for implantation into a human including a portion (10) of a bone from a nonhuman animal, wherein the portion has substantially no surface carbohydrate moieties which are susceptible to glycosidase digestion. Each xenograft of the invention has substantially the same mechanical properties as a corresponding native bone.

The present invention provides porcine CMP-N-Acetylneuraminic-Acid Hydroxylase (CMP-Neu5Ac hydroxylase) protein, cDNA, and genomic DNA regulatory sequences. Furthermore, the present invention includes porcine animals, tissues, and organs, as well as cells and cell lines derived from such animals, tissues, and organs, which lack expression of functional CMP-Neu5Ac hydroxylase. Such animals, tissues, organs, and cells can be used in research and in medical therapy, including in xenotransplantation, and in industrial livestock farming operations.

The present invention relates to methods and compositions for the reduction of xenotransplantation rejection. Specifically, the present invention relates, first, to transgenic cells, tissues, organs and animals containing transgenic nucleic acid molecules that direct the expression of gene products, including, but not limited to enzymes, capable of modifying, either directly or indirectly, cell surface carbohydrate epitopes such that the carbohydrate epitopes are no longer recognized by natural human antibodies or by the human cell-mediated immune response, thereby reducing the human immune system response elicited by the presence of such carbohydrate epitopes. In a preferred embodiment, the transgenic cells, tissues, organs and animals express nucleic acid molecules encoding functional recombinant alpha-Galactosidase A (alphaGalA) enzyme which modifies the carbohydrate epitope Galalpha(1,3)Gal. In a more preferred embodiment, the transgenic cells, tissues, organs and animals expressing the functional recombinant alphaGalA are transgenic pig cells, organs, tissues and/or animals. Second, the present invention relates to methods for xenotransplantation comprising introducing the transgenic cells, tissues and/or organs into human recipients so that a lower level of hyperacute rejection (HAR) is observed in the human recipients relative to the level of HAR observed in human recipients having received non-transgenic cells, tissues and/or organs.

In accordance with the present invention, there are provided humanized fish insulin genes. Humanized insulin the present invention encode human insulin alpha and/or beta chains while using fish-preferred codons and regulatory sequences. These humanized genes are thus expressible in fish islet cells. Also provided are transgenic fish having islet cells containing and capable of expressing humanized insulin genes. These islet cells (Brockmann Bodies) can be xenotransplanted into subjects having diabetes. In this manner normoglycemia can be achieved in the recipient of the islets.

Most human tumors find ways to resist anticancer drug monotherapy. Akt is considered a likely peptide providing such monotherapy drug resistance. Data indicates that Akt chemoresistance is induced in a p53-dependent manner and that inhibition of Akt may be an effective means of overcoming chemoresistance in cancer cells expressing wild-type p53. Breast, ovarian, lung cancer and leukemia cells lines were treated with combinations of Akt activation inhibitor Triciribine (TCN) or Triciribine phosphate (TCNP) and chemotherapeutic drugs to determine the efficiency of combination therapy. Additionally, cells were introduced into xenograft models to determine in vivo effects of combination treatment. Combining TCN or TCNP with other anticancer drugs overcame cytotoxic or treatment resistance. Thus, TCN and TCNP are shown to broaden the spectrum of human tumors that can be effectively treated.

The invention relates to the genetic manipulation of non-human animals. More particularly, the invention relates to genetic manipulation of non-human animals to be used for xenotransplantation. The invention provides a method of selecting GGTA 1 null cells, a viable GGTA 1 null swine, methods for making such swine, and methods of using cells, tissues and organs of such swine for xenotransplantation.