C1.7 monoclonal antibody designates high-avidity CD4+ cytotoxic T lymphocytes involved in clinical heart rejection
van Emmerik, N.E.; Knoop, C.J.; Vaessen, L.M.; Balk, A.H.; Mochtar, B.; Claas, F.H.; Weimar, W.
Transplantation 66(1): 135-138
1998
ISSN/ISBN: 0041-1337 PMID: 9679837 Document Number: 490651
Background. It is assumed that not all donor-specific cytotoxic T lymphocytes (CTLs), but only those with a high avidity for donor antigens, can function as terminal effector cells in transplant rejection. Methods. In the present study, we searched for markers that would exclusively designate these high avidity CTL. Results. FACS analysis of donor-specific CTL clones obtained from heart transplant patients revealed that high- and low-avidity CTL varied in their expression of p38, a surface molecule involved in signal transduction, which is stained by the antibody C1.7. High- and low-avidity CD8+ CTL and high-avidity CD4+ CTL expressed p38, whereas low-avidity CD4+ CTL did not. Noncytotoxic and naive CD4+ lymphocytes also lacked p38 surface expression. Conclusion. Therefore, we conclude that p38 is a marker for CD4+ lymphocytes with the potency to damage the transplanted heart. Accordingly, p38 might be used to analyze the contribution of CD4+ CTL in immune responses, such as transplant rejection.