Professor Claude Daniel graduated from B.Sc. in Biology at the Université du Québec à Montréal in 1986 and his Ph.D. in Virology from the Institut Armand-Frappier in 1993. He then held a position in a research officer where he was responsible for implanting molecular typing techniques at the Histocompatibility Laboratory. He became a professor at the Center for Research in Immunology and responsible for the Histocompatibility Laboratory in the fall of 1997, after a two-year postdoctoral fellowship at Washington University in St. Louis. He is now a professor at the INRS-Institut Armand-Frappier.

Regulation of organ transplant rejection through direct and indirect alloretic pathways. Recognition of heterologous major histocompatibility complex (MHC) antigens by T-cells, a phenomenon called alloreactivity, is essential for the initiation of the immune response responsible for organ transplant rejection. These antigens can be recognized by the immune system of the recipient in two distinct ways. On the one hand, they can be recognized on cells whose origin is that of the donor, a phenomenon known as direct allureactivity. On the other hand, fragments of these antigens can be presented by the cells presenting antigens of the recipient, a phenomenon called indirect alloreactivity. Numerous studies have demonstrated the importance of direct allureactivity in the acute rejection process. However, the study of the role of the indirect alloretic pathway in the rejection process has long been neglected. Recent work suggests that the latter would be equally important, especially in the chronic rejection on which clinically used immunosuppressants have little effect. Our research program aims to determine in vivo the mechanisms of activation of direct and indirect alloretic pathways and their contributions in acute and chronic transplant rejection. We demonstrated that CD4 + T cells activated by either of these alloretic pathways recognized their antigen in different physiological sites. More importantly, we have also demonstrated that some populations of reactive effector immune cells (cytotoxic T lymphocytes, B lymphocytes) were differently regulated by direct and indirect alloretic pathways.