T lymphocyte subsets and cytokine production by graft-infiltrating cells in FSGS recurrence post-transplantation.

BACKGROUND: Focal segmental glomerulosclerosis (FSGS) aetiology remains undefined although a derangement of lymphocytes and monocytes macrophages, at least, has been strongly suspected. We report the graft-infiltrating phenotypes and their cytokine production in a case of FSGS recurrence post-transplantation. METHODS: The kidney transplant recipient suffered immediate FSGS recurrence. Aspiration biopsies were done at the first and second week post-surgery and were analysed by flow cytometry. The cytokine analysis was done on aspiration sample culture supernatants and serum by enzyme-linked immunosorbent assay. RESULTS: High expression of CD3CD69, CD3CD71 and CD4CD29 was found on infiltrating lymphocytes. Biopsy cultures pointed to a Th0/Th1 pattern of cytokine production as well as significant synthesis of transforming growth factor-beta1. Interestingly, monocyte chemokines were absent. CONCLUSION: We report evidence of intragraft lymphocyte activation in the early days of FSGS recurrence. Aspiration biopsy cultures showed failure of cyclosporin A to inhibit interleukin-2 (IL-2) production by infiltrating lymphocytes. If our findings are confirmed in similar patients, a trial with anti-IL-2-receptor antibody could be warranted.     

TIGIT regulates apoptosis of risky memory T cell subsets implicated in belatacept-resistant rejection

Belatacept confers increased patient and graft survival in renal transplant recipients relative to calcineurin inhibitors, but is associated with an increased rate of acute rejection. Recent immunophenotypic studies comparing pretransplant T cell phenotypes of patients who reject versus those who remain stable on belatacept identified three potential “risky” memory T cell subsets that potentially underlie belatacept-resistant rejection: CD4⁺ CD28⁺ T_EM, CD8⁺ CD28^null, and CD4⁺ CD57⁺ PD1⁻ subsets. Here, we compared key phenotypic and functional aspects of these human memory T cell subsets, with the goal of identifying additional potential targets to modulate them. Results demonstrate that TIGIT, an increasingly well-appreciated immune checkpoint receptor, was expressed on all three risky memory T cell subsets in vitro and in vivo in the presence of belatacept. Coculture of human memory CD4⁺ and CD8⁺ T cells with an agonistic anti-TIGIT mAb significantly increased apoptotic cell death of all three risky memory T cell subsets. Mechanistically, TIGIT-mediated apoptosis of risky memory T cells was dependent on FOXP3⁺ Treg, suggesting that agonism of the TIGIT pathway increases FOXP3⁺ Treg suppression of human memory T cell populations. Overall, these data suggest that TIGIT agonism could represent a new therapeutic target to inhibit belatacept-resistant rejection during transplantation.     

The role of TDTH and Tc populations in organ graft rejection. I. Functional analysis of graft-infiltrating T cells

To analyze the role of T cell subpopulations in the rejection of organ allografts, we developed a new model for obtaining large numbers of graft infiltrating cells (GICs). We isolated W3/25+ Th/DTH and OX8+ Ts/c from vascularized, irradiated rat spleen allografts. W3/25+ GICs obtained from spleen allografts transplanted to normal recipients were highly effective in eliciting cardiac allograft rejection when transferred to sublethally irradiated recipients, however, the OX8+ subset was incapable of eliciting rejection. On the other hand, when OX8+ GICs were obtained from spleen allografts transplanted to previously immunized recipients, they were as efficient as the W3/25+ Th/DTH subset in eliciting cardiac allograft destruction. These results indicate that the W3/25+, OX8- T cell is required for the rejection of primary organ allografts, but that the rejection of a secondary allograft by an immune recipient may be mediated, independently, by both W3/25+ and OX8+ cells.     

Skin allograft rejection by L3/T4+ and Lyt-2+ T cell subsets

The L3/T4+ and Lyt-2+ T-cell subsets can be depleted from mice, using selected monoclonal antibodies in vivo, at different times during rejection of, or priming to, allogeneic skin grafts. Although L3/T4+ cells are sufficient to reject skin grafts in naive Lyt-2-depleted mice, we show that Lyt-2+ cells can become involved, after an initial delay, in intact mice. Furthermore, these Lyt-2+ cells are primed to dominate the accelerated rejection of a normal secondary response. Mice depleted of L3/T4+ cells cannot be primed in this way, suggesting that priming of Lyt-2+ cells is dependent on help from L3/T4+ cells. However, in mice depleted of Lyt-2+ cells, priming for rapid rejection can be achieved, presumably via the L3/T4+ population. This suggests that the rejection of skin allografts in a given situation reflects different contributions of multiple effector mechanisms.     

Studies on the participation of different T cell subsets in rat liver allograft rejection

In this study, we investigated which subsets of rat T cells (CD8 + vs. CD4 + ) are involved in the rejection of liver allografts by the in vivo administration of monoclonal antibody (OX-8 or OX-38, and W3/25 MAb) into thymectomized recipient Lewis (RTI¹) rats prior to DA (RTI^a) liver transplantation. We also compared the results of allograft survival of liver and heart transplants under the same experimental conditions. In order to deplete either CD8 + T cells or CD4 + T cells from recipient animals, 0.4 ml of OX-8 (ascitic form) or a 0.8 ml cocktail of MAb W3/25 and OX-38 (0.4 ml each) was injected into thymectomized recipient rats, respectively. Untreated Lewis rats consistently rejected donor DA liver grafts between 9 and 11 days (n = 7, 9.8 days ± 1.1 days). In contrast, anti-CD8 MAb pretreatment extended the survival times of DA liver grafts for up to 40 days (n = 5, 26.8 days ± 8.4 days). Furthermore, survival of DA liver grafts was significantly prolonged in Lewis rats that had been pretreated with anti-CD4 MAb (n = 7,35.6 days ± 17.9 days). Two out of seven recipient animals survived for more than 60 days. For heart transplantation, untreated Lewis rats rejected DA heart grafts between 6 and 8 days after operation (n = 6, 6.5 days ± 1.2 days). Anti-CD4 MAb treatment prolonged heart graft survival for more than 60 days in all cases (n = 3, > 60 days). However, there was virtually no effect of anti-CD8 MAb treatment on heart graft survival (n = 4, 7.0 days ± 0.9 days). These results suggested that when whole MHC disparity prevailed between donor and recipient, both subsets of T cells were required for the rejection of liver allografts and that class II reactive T cells predominantly mediated liver graft rejection. Furthermore, CD8 + T cells played a differential role in the rejection of rat liver and heart allograft.     

T cell subsets mediating rejection of established fetal pancreas grafts and failure to observe graft adaptation

The present study has attempted to elucidate the cellular mechanisms by which long-term established fetal pancreas allografts are rejected. We used an experimental model in which H-2b nude mice were made hyperglycemic by streptozotocin treatment and then engrafted with allogeneic fetal pancreas grafts. These grafts were functional in that engrafted animals returned to near normoglycemia while all animals left unengrafted subsequently died. The fetal pancreas grafts were allowed to reside in the immunoincompetent nude host for 6-9 months prior to T cell reconstitution, at which time animals were reconstituted with either negatively selected CD4+ or CD8+ H-2b T cell subpopulations. We found that a 6-9 month residence in an immunoincompetent host did not lead to a change in the immunogenicity of fetal pancreatic grafts in that both CD4+ and CD8+ T cell subsets were capable of rejecting these long-term established fetal pancreas grafts. The finding that isolated CD8+ spleen T cell subpopulations, which are only activated by antigen-presenting cells of donor origin bearing MHC class I alloantigen, were capable of effecting graft rejection suggested that APC of donor origin persisted in these long-term fetal pancreas allografts.     

Clonality analysis of T cells mediating acute and chronic rejection in kidney allografts

The clonality of T-cell populations mediating acute and chronic rejection (AR and CR, respectively) of kidney allografts was ascertained by investigating the diversity of TCRBV genes expressed by allograft-infiltrating T cells. Both oligoclonality and polyclonality cases were found in biopsy specimens of AR as well as CR. These results indicated that the T-cell clonality in each specimen did not correlate directly with the mode of rejection. When AR and CR specimens were compared, however, the CR specimen group was significantly more polyclonal (or less oligoclonal) than the AR group. This result may reflect the higher chance of epitope spreading in the more slowly progressing CR than in AR.     

Differential diagnosis of kidney transplant rejection and cyclosporin/tacrolimus nephropathy using urine cytology

Abstract: A total of 9000 urine samples from 69 kidney transplant recipients were studied for differential diagnoses of transplant rejection and cyclosporin/tacrolimus toxicity. New–Sternheimer and Papanicolaou staining were used to differentiate cells in urine. We also employed an immunocytochemical technique for further identification of exfoliated cells. With New–Sternheimer and Papanicolaou staining, the predominance of proximal tubular cells was useful to differentiate cyclosporin/tacrolimus toxicity from acute rejection in cases of increased serum creatinine level. During rejection episodes, an increased number of mononuclear cells and renal epithelial cells were found. Immunocytochemical analysis showed a significant increase of CD2-, CD4- CD8-, CD25- and HLA-DR-positive cells with rejection. However, there was no relationship between Banff criteria rejection grade and the increase of mononuclear cells.     

Immunosuppression of graft rejection with idarubicin-monoclonal antibody conjugates by elimination of T cell subsets in vivo

Idarubicin, a more therapeutically effective derivative of daunomycin, when coupled to monoclonal antibodies that react with murine and human tumors has the ability to specifically target and eradicate tumor cell populations in vitro and in vivo. In this study the in vitro and in vivo efficacy of idarubicin coupled to monoclonal antibodies reactive with distinct subpopulations of lymphocytes (L3T4+, Ly-2+) has been characterized. Using a tumor allograft model in vivo the potential use of drug-monoclonal antibody conjugates to prevent graft rejection has been investigated. Three to five molecules of Idarubicin could be coupled to the monoclonal antibodies (anti-Ly-2.1, anti-L3T4, or anti-Thy-1) with retention of protein solubility and antibody activity. Some loss of idarubicin activity (4-10-fold) occurred upon conjugation to the monoclonal antibodies--however, selective cytotoxicity for antibody reactive cell lines was observed. All three conjugates demonstrated the capacity to significantly deplete reactive subsets of spleen cells--further evidenced by the ability of combined idarubicin-anti-L3T4 and Idarubicin-anti-Ly-2.1 treatment of idarubicin-anti-Thy-1 treatment to prolong the survival of (Ly-2-, L3T4-) P388D1 tumor grafts in CBA mice in the presence of H-2 and non H-2 antigenic differences. This form of selective immunosuppression may have relevance for the treatment of graft rejection in man.     

原发鼻腔NK/T细胞非霍奇金淋巴瘤临床分析

目的观察放化疗联合对原发鼻腔NK/T细胞淋巴瘤的临床疗效。方法回顾性分析2008年1～12月收治的12例原发性鼻腔NK/细胞淋巴瘤的疗效。结果完全缓解率33.33%,部分缓解率58.33%,疾病进展患者占8.33%。1年生存率91.67%,2年生存率58.33%。结论放化疗联合对原发鼻腔NK/T非霍奇金淋巴瘤疗效显著。