Sentences with phrase «allograft rejection»

Bartlett MR, Warren HS, Cowden WB, Parish DR. Effects of the anti-inflammatory compounds castanospermine, mannose -6-phosphate and fucoidan on allograft rejection and elicited peritoneal exudates.

Until recently, the dogma in transplantation immunology held that allograft rejection was a Th1 CD4 + cell - mediated process.

Development of DTH responses to donor alloantigens has been correlated with corneal allograft rejection.

These findings also demonstrate the remarkable plasticity and redundancy in the immune mechanisms that mediate allograft rejection.

This study examined the role of CD4 + T cell - independent mechanisms of corneal allograft rejection.

The results reported here reaffirm previous findings indicating that T cells are absolutely required for corneal allograft rejection in the mouse (3).

Insufficient or excess complement activation has been shown to be important in a wide range of disease states, such as multiple sclerosis, myasthenia gravis, systemic lupus erythematosus, rheumatoid arthritis, and age - related macular degeneration, as well as in allograft rejection.

Both CD8 − and CD8 + T cells from CD4 KO corneal allograft rejector mice mediated corneal allograft rejection following adoptive transfer to nude mice.

In their study, DN T cells displayed allospecific cytotoxicity in vitro and mediated tumor allograft rejection in vivo.

The capacity of CD8 + T cells to mediate corneal allograft rejection could have been due to the CTL population that might have been present in the CD8 + T cell suspensions used in the adoptive transfer inocula.

The role of DN T cells in corneal allograft rejection was confirmed in two separate in vitro assays in which CD8 − cells were isolated from CD4 KO donors that had rejected corneal allografts and were found to induce apoptosis of donor - specific corneal cells.

The present findings are derived from studies using CD4KO mice and thus, raise the question as to whether the CD4 + T cell - independent immune mechanisms in CD4 KO mice differ from those involved in corneal allograft rejection in wild - type mice whose CD4 + T cells population have been depleted with monoclonal antibodies.

Although the immune basis for corneal allograft rejection was formally established in experimental animals by Maumenee (33) over 50 years ago, the exact immune mechanisms that lead to the corneal graft failure remain poorly understood.

The results of a typical experiment are shown in Figure 3 and demonstrate that even though spleen cells from CD4 KO mice could adoptively transfer corneal allograft rejection, they did not display conventional CTL activity against either BALB / c corneal epithelial or endothelial cells.

Removing one immune effector element only reveals the presence of an ancillary pathway for allograft rejection.

An adoptive transfer experiment was performed to confirm that the high incidence of corneal allograft rejection was immune - mediated.

Either of these effector mechanisms might contribute to corneal allograft rejection.

The capacity of CD8 − T cells from CD4 KO donors to mediate corneal allograft rejection is puzzling and on the surface, counterintuitive, since these cells are presumably double negative (DN) T cells.

Research Interests: Immunologic memory; memory T - cells; allograft rejection; transplantation; therapies for transplant recipients

Tissue - cultured corneal cells were used for in vitro studies rather than the usual lymphoid cells since corneal cells are the relevant target cells in vivo during corneal allograft rejection.

Several mTOR inhibitors have already been approved for therapeutic use, in particular in the treatment of cancer and allograft rejection.

«Long - term prevention of organ rejection: Biologists use immunoproteasome inhibition to prevent chronic antibody - mediated allograft rejection.»

Not exact matches

In the present study we sought to determine the role and mechanisms of CD4 - independent rejection of corneal allografts.

However, closer scrutiny of these studies raises questions about the role of CD4 + T cells as the sole mediators of corneal graft rejection, as corneal allografts undergo immune rejection in 33 % of the mice and 64 % of the rats treated with anti-CD4 monoclonal antibody (12, 13) and in 45 % of the CD4 KO mice (14).

Allospecific CTL and DTH responses have been associated with the immune rejection of various categories of allografts.

BALB / c corneal allografts underwent rejection in 46 % (6/13; MST = 46 days) of the recipients of CD8 − T lymphocytes and in 95 % (19/20; MST = 15 days) of the recipients of CD8 + T lymphocytes (Figure 2B).

T lymphocytes are required for the rejection of corneal allografts, as athymic, T cell - deficient nude mice do not reject corneal allografts (3).

Indeed, our results indicate that adoptive transfer of CD8 + T cells from CD4 KO mice that had rejected corneal allografts resulted in the rejection of 95 % of the corneal allografts transplanted to athymic recipients.

Several studies suggest that a significant number of corneal allografts undergo rejection in the absence of CD4 + T cells.

CD8 + and CD8 − T cells were collected from either C57BL / 6 mice or adoptive cell transfer recipients one week after the rejection of BALB / c corneal allografts.

Current projects are investigating: 1) the expression of inflammatory genes during ischemia and reperfusion of kidneys during urology transplantation and in mouse models; 2) the expression of inflammatory genes and proteins in urine as markers indicating the presence of rejection in renal allografts; and 3) the role of adhesion molecules and chemokines in directing leukocyte infiltration into organ allografts.

The results indicated that 54 % (38/70) of the BALB / c corneal allografts underwent rejection in the CD4 KO hosts, while 100 % of the grafts were rejected in wild - type C57BL / 6 mice (Figure 1).

By contrast, adoptive transfer of CD8 − spleens cells from similar donors resulted in the rejection of corneal allografts in almost half of the hosts.

However, some studies have demonstrated a role for CD8 + T cell - mediated rejection of skin and cardiac allografts (16, 17).

Additional adoptive transfer experiments were performed to ascertain the role of CD8 + and CD8 − T lymphocytes in CD4 - independent rejection of corneal allografts.

Studies in CD8 knockout (KO) and perforin KO mice demonstrated that CD8 + cytotoxic T lymphocytes (CTL) are unnecessary for the rejection of corneal allografts in mice (8, 9).

Experiments were performed to confirm that a significant number of corneal allografts underwent rejection in the absence of CD4 + T cells.

However there are notable exceptions to these allorejection processes; the fetal allograft evades rejection by the mother through a complex series of actions, similarly tissue which has limited lymphatic drainage is less prone to allorejection 74, 75.

MSC - induced Tregs were donor - specific since adoptive transfer of splenocytes from tolerant mice prevented the rejection of fully MHC - mismatched donor - specific secondary allografts but not of third - party grafts.

- Urinary - Cell mRNA Profile and Acute Cellular Rejection in Kidney Allografts; Manikkam Suthanthiran, MD, Weill Cornell Medical College.

Urinary - Cell mRNA Profile and Acute Cellular Rejection in Kidney Allografts; Manikkam Suthanthiran, MD, Weill Cornell Medical College.

More importantly, chimeric animals were protected from rejection of donor - type cardiac allografts.

Our data show, for the first time, the efficacy of ES - derived CD45 + HPCs to engraft in allogenic recipients without the use of immunosuppressive agents, there by protecting cardiac allografts from rejection.