Is self tolerance H-2 restricted?

An individual's immune system must be capable of responding to a wide variety of antigens, but must not react against tissues of the individual itself. The specificity of this 'self tolerance' is determined early in life and recent work has dealt with the mechanisms by which self tolerance is maintained. We report here a study designed to determine whether products of the major histocompatibility complex are involved in the induction of self tolerance; in particular, whether the induction of self tolerance in the mouse is H-2 restricted. H-2 restriction refers to the finding that mouse T cells generally recognize foreign antigens only when presented in association with the products of H-2 alleles. We questioned whether T-cell precursors are made tolerant directly by antigen alone, or whether the antigen must be associated in the cell membrane with an appropriate H-2 molecule. We find that T-cell tolerance to 'self' membrane components does not seem to be H-2 restricted and discuss the possibility that this apparent lack of H-2 restriction is due to antigen processing.