EFFECT OF IN-VIVO DEPLETION OF CD4(+) AND CD8(+) CELLS ON THE INDUCTION AND MAINTENANCE OF ORAL TOLERANCE

The role of CD8(+) and CD4(+) cells in the generation and maintenance of high-dose oral tolerance has been investigated. Mice depleted of CD8(+) cells prior to or subsequent to oral tolerization with OVA continued to express suppressed humoral and/or T cell proliferative responses to the homologous antigen, To assess the effect of CD4(+) cell depletion on oral tolerance, mice were depleted of CD4(+) cells prior to or subsequent to oral tolerization with OVA. After 50% regeneration of CD4(+) cells was achieved, OVA-immunized mice produced anti-OVA immune responses that were comparable to those of water-fed control mice. Thus, under our experimental conditions the presence of CD4(+) but not CD8(+) cells is required to both establish and maintain Oral tolerance. (C) 1995 Academic Press, Inc.