Defective T cell response to presented antigen in autoimmune mice

The effect of the single autosomal recessive gene lpr on antigen presentation was studied. MRL/Mp-lpr/lpr, C3H/HeJ-lpr/lpr, C57BL/6J-lpr/lpr, and their normal congenic partners were investigated. Mice bearing the lpr gene were unable to respond to TNP-KLH when presented by syngeneic antigen-presenting cells. The congenic normal partners gave a brisk response. Mixing experiments demonstrated that the defect resided with the lpr responding T cell and not with the lpr antigen-presenting cell. Antigen-presenting cells from lpr mice were capable of inducing T cell proliferation in normal congenic partners, whereas antigen-presenting cells from normal mice failed to stimulate lpr T cells. This defect was intrinsic to an Lyt-1+2- cell. Pharmacologic restoration was attempted by in vivo and in vitro administration of interleukin 2. However, cells from lpr mice remained unaffected. The relationship of these findings to autoimmunity is discussed.