Mediation of acute but not chronic rejection of MHC-incompatible rat kidney grafts by alloreactive CD4 T cells activated by the direct pathway of sensitization.
It has been previously postulated that there are two pathways of sensitization of MHC-incompatible kidney allografts: a direct pathway in which the host responder T cells are activated by MHC-incompatible passenger dendritic cells of the graft, and an indirect pathway, in which graft alloantigens are processed like "nominal" T cell antigens by host accessory cells, and presented as self-MHC restricted moieties. We show here that a rat AS anti-August alloreactive CD4+ T cell line, and a presumptive clone, activated through the direct pathway are capable in an adoptive transfer model of initiating rejection of normal August kidney grafts. However, neither the T cell line nor the presumptive clone initiates rejection of passenger cell-depleted August kidneys. The results support the hypothesis that direct pathway--sensitized T cells play a dominant role in early acute rejection, but not in chronic rejection.
Braun
M Y
MY
Department of Immunology, Royal Postgraduate Medical School, Hammersmith Hospital, London, United Kingdom.
McCormack
A
A
Webb
G
G
Batchelor
J R
JR
D000208:Acute Disease; D000818:Animals; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology*; D002460:Cell Line; D002908:Chronic Disease; D006084:Graft Rejection / Q000276:immunology*; D006648:Histocompatibility; D007680:Kidney Neoplasms / Q000276:immunology*; D008213:Lymphocyte Activation / Q000276:immunology*; D008297:Male; D051381:Rats; D014183:Transplantation, Heterologous / Q000276:immunology