Tolerance and self-reactivity in V gamma 1.1C gamma 4 transgenic mice.

ABSTRACT

Immunological tolerance is the process of inhibiting or eliminating lymphocytes that recognize self-derived antigens. By removing potentially harmful self-reactive clones, this mechanism allows for the random generation of a diverse repertoire of T-cells capable of responding to foreign pathogens. Although all self-reactive T-cells should be removed from the repertoire, it is quite clear from many recent studies that a significant fraction of T-cells bearing gamma delta T-cell receptors (TCR) recognize self-derived antigens in normal healthy mice. The presence of self-reactive T-cells in healthy animals presents a paradox which may be explained by understanding the transient expression of the antigens (e.g., MHC class Ib, Heat Shock Proteins) that have been identified for gamma delta T-cells thus far. Data from experiments with V gamma 1.1C gamma 4 transgenic mice demonstrating the presence of self-reactive gamma delta T-cells and their influence on lymphoid development and immune surveillance will be examined in this review.