Ultraviolet B irradiation increases endothelin-1 and endothelin receptor expression in cultured human keratinocytes

AbstractThe effect of ultraviolet B (UVB) irradiation on endothelin-1 (ET-1) and ET receptor expression was examined using cultured normal human keratinocytes. Keratinocytes secreted ET-1 in the medium at a level of 2.1 pg/day/105 cells. UVB irradiation up to 10 mJ/cm2 increased ET-1 secretion 3-fold, and potentiated expression of mRNA for ET-1. Both ETA and ETB receptor mRNAs were detected in keratinocytes, and their expression was up-regulated by 5 mJ/cm2 UVB irradiation

Beneficial effect of donor-specific blood transfusions (DST) on living-related kidney allograft survival.

The survival rate of 19 patients who underwent living-related kidney transplantation after donor-specific blood transfusions (DST) was compared with that of 32 historical controls receiving transplants without DST. The graft survival rate of the DST group was 82% after two and three years. The graft survival rate of the DST group was significantly better than the 53% rate after two years obtained with the 32 historical controls (p less than 0.05). We tested sera from 16 DST-treated recipients to study the beneficial effect of DST on kidney allograft survival using the mixed lymphocyte culture (MLC) serum inhibition test. The results demonstrated that MLC inhibitory factors were induced in the serum of the recipient after completion of DST. This inhibition of MLC was observed by treatment of responder lymphocytes with serum obtained three weeks after DST plus rabbit complement. The inhibitory effect was also specific for responder cells in anti-donor MLC. Regarding the correlation with rejection episodes, these MLC inhibitory factors were often observed in the non-rejection group (p less than 0.05). The data suggest that such factors may be anti-idiotypic antibodies and be associated with prolonged graft survival.</p

Analysis of suppressor T cells induced in long-term human allogeneic mixed lymphocyte culture

Suppressor T cells (Ts) may play an important role in the regulation of immunological responses. Ts may play a role in the long-term acceptance of an allogeneic organ graft and the beneficial effects of donor-specific blood transfusions on subsequent transplant survival. The population of Ts induced in mixed lymphocyte culture (MLC) was analyzed, and the mechanism underlying the suppressor activity was examined. The Ts generated in 10-day MLC were found to belong to the OKT8(+) subset and inhibited both mixed lymphocyte reaction (MLR) and cell-mediated lympholysis. These Ts inhibited MLR in an antigen-specific manner, but failed to alter the kinetics of the MLR. Furthermore, these Ts inhibited the production of endogenous interleukin-2 and exerted a suppressive effect only when added early in the culture. In condition, the precise target of Ts generated in 10-day MLC might be the earliest responding T helper clone