Administration Of Splenocytes Research Articles

Induction of long-term graft acceptance by a combination treatment of donor splenocytes and CTLA4Ig in a high responder rat liver transplantation model

The CTLA4Ig has led to an improved survival rate in various allograft transplantation models. We investigated in a high responder rat model (Dark Agouti to Lewis) of orthotopic liver transplantation (ORLT), whether an additional adoptive cell transfer can enhance the effect of CTLA4Ig. After transplantation, recipients (n = 13/group) were treated with donor or third-party splenocytes alone or in combination with CTLA4Ig. Administration of splenocytes alone had no significant effect on survival (median 13 days, range 9-14) compared with untreated controls (median 10 days, range 8-12). CTLA4Ig monotherapy prolonged survival to a median of 30 days (range 11-150) but resulted in long-term graft rejection. The additional administration of third-party splenocytes showed no significant improvement over CTLA4Ig monotherapy. Only the combination of donor splenocytes with CTLA4Ig led to long-term graft acceptance (>150 days) without clinical and/or histological signs of rejection. A higher rate of apoptosis could be detected in livers at early time-points in long-term survivors receiving CTLA4Ig and donor splenocytes. Analysis of cytokine mRNA expression revealed a decrease of interleukin-2 at early time-points in all groups receiving CTLA4Ig; whereas, interferon-gamma was increased in long-term survivors receiving CTLA4Ig and donor cells or donor cells alone. The combination of CTLA4Ig and donor derived splenocytes is potent to induce long-term survival and graft acceptance. The mechanisms appear to involve the induction of an early inflammatory impulse and apoptosis.

SPECIFIC INFECTIOUS TOLERANCE TO AN MHC MISMATCHED KIDNEY ALLOGRAFT AFTER ANTI-DONOR CLASS II ALLOIMMUNE SERUM ADMINISTRATION INVOLVE T AND NON T-CELL REGULATORY POPULATIONS.

P952 Aims: Donor specific tolerance to a kidney allograft can be induced in the MHC mismatched LEW.1W to LEW.1A congeneic rat strain combination by anti-donor class II alloimmune serum administration on the day of transplantation. Long-term survivors accept a LEW.1W but reject a third party Brown Norway skin graft and display no sign of chronic rejection. Tolerance maintenance phenomenon and transfer (“infectious” tolerance) of cells from long term survivors (>100d) to naïve recipients have been analyzed in this model.. Methods: Phenotype and Ig deposit (immunochemistry and flowcytometry), cytokine transcripts (real time RT-PCR), in vitro proliferative response and suppression of mixed lymphocyte reaction were studied in long-term survivors (>100d). Infectious tolerance efficiency was studied following purification and administration of splenocytes, T cells or non T cells from long-term survivors. Results: T cells from long-term survivors (>100d) exhibited an increase of CD45RClow and CD62L- activated/memory cell markers without increase of CD4+CD25+ potentially regulatory T cells. Non-T cells did not present phenotype singularity compared to naïve rat. Kidney graft from long-term survivors (>100d) displayed only slight deposits of IgM/G and no evidence of Th1/Th2 cytokine shift. Whereas total splenocytes from long term survivors (>100d) transfer specific tolerance to naïve rats without histological signs of chronic rejection, pure T splenocytes or non-T cells injected alone had no effect. In addition total splenocytes from long-term survivors (>100d) displayed a decreased donor-specific response in mixed lymphocyte reaction and specifically suppress the proliferative response of pure LEW.1A T cells against donor LEW.1W APC. Purified T cells from splenocytes had no effect. Conclusions: Animal tolerant to kidney graft following peri-grafting injection of anti-donor class II alloantibody harbor potent regulatory cells. Efficient transfer requires a T/non-T cooperation.

Intravenous administration of splenocytes in early pregnancy changes the implantation window in mice.

To clarify the role of immune cells in the reproductive phenomenon during early pregnancy, we investigated the effect of splenocytes obtained from mice in early pregnancy on embryo implantation. We prepared splenocytes from 5 week old pregnant ICR mice on day 4 (pregnancy day 4 splenocytes; P4-spl) and day 8 (pregnancy day 8 splenocytes; P8-spl), from 5 week old pseudopregnant ICR mice on day 4 (pseudopregnancy day 4 splenocytes; PP4-spl) and from 5 week old di-oestrous virgin mice (di-oestrous splenocytes; Di-spl). The supernatants (P4-sup, P8-sup, PP4-sup and Di-sup) derived from the suspensions of P4-spl, P8-spl, PP4-spl and Di-spl respectively, were used in the control groups. The recipient pseudopregnant mice (6 weeks of age) were injected i.v. with splenocytes (2 x 10(7) cells) or supernatants as controls, and embryo transfer was performed on day 2. Embryo implantation was evaluated 7 days later under laparotomy. The successful implantation rate per embryo was markedly higher compared with the control groups in the P4-spl (30.5 +/- 8.55 versus 1.0 +/- 1.37%, n = 200, P < 0.01) and P8-spl (20.1 +/- 10.3 versus 1.17 +/- 1.62%, n = 200, P < 0.05) groups. On the other hand, a slight but not significant increase was observed in the PP4-spl (8.33 +/- 8.80% versus 1.5 +/- 1.37%, n = 200) and Di-spl (9.0 +/- 5.76% versus 2.3 +/- 2.28%, n = 200) groups. Among the splenocyte administration groups, the implantation rate in the P4-spl group was significantly higher than in the PP4-spl and Di-spl groups (P < 0.01). These findings indicate that i.v. administration of splenocytes can change the murine implantation window. Since the splenocytes during early pregnancy are most effective on embryo implantation, peripheral immune cells in early pregnancy may be involved in embryo implantation.

Differential immunoregulation of granulomatous inflammation, portal hypertension, and hepatic fibrosis in murine schistosomiasis mansoni.

The present study investigates the immunoregulation of hepatic fibrosis in experimental murine schistosomiasis. Disease parameters measured were portal pressure, hepatic granuloma area, hepatic interstitial collagen, and glycosaminoglycans. C57BL/6 mice were infected with 25 Schistosoma mansoni cercariae and administered splenocytes or serum derived from uninfected mice or chronically infect syngeneic mice at 6 and 7 wk of infection. Immunologically mediated modulation was noted in animals receiving splenocytes derived from chronically infected mice. Both a reduction in portal pressure and hepatic granuloma areas were noted. Hepatic collagen content but not glycosaminoglycan content was reduced by the administration of either lymphoid cells or serum from chronically infected mice. The isotypic profile of hepatic interstitial collagens was modulated by both the administration of serum or lymphoid cells. Augmented levels of type III collagen was noted on administration of serum derived from chronically infected mice, whereas type I collagen levels were relatively elevated on administration of splenocytes. The data indicate that immunomodulation of inflammation and hepatic fibrosis can occur in murine schistosomiasis but that fibrotic events and inflammatory processes are independently modulated.