Responsiveness of T Cells to Mutant Major Histocompatibility Complex Class I Antigen

Abstract

Proliferative response of splenic T cells of C57BL/6 mice to mutant major histocompatibility complex (MHC) class I antigen (H‐2K^bm1) was examined with regard to the role of accessory cells. T cell proliferation in mixed lymphocyte culture (MLC) was not induced when accessory cells were removed from stimulator spleen cells by passage through Sephadex G‐10 or nylon‐wool column. Anti‐Ia^b antibodies did not inhibit the proliferative response to class I antigen, whereas the same antibodies completely blocked the response to class II antigen (Ia^bm12). Accessory cells may not be mere presenters of MHC class I antigen because stimulator cells fixed with 0.05% paraformaldehyde lost the stimulating function. The proliferative response was partially recovered by the addition of recombinant interleukin 1 (IL‐1) and/or IL‐2 to MLC devoid of stimulator type accessory cells. It is concluded that stimulatory type accessory cells were obligatorily involved in the T cell proliferation, and the production of IL‐1 by accessory cells is thought to play a critical role in this process