Factors affecting the susceptibility of the mouse pituitary gland to CD8 T-cell-mediated autoimmunity.

We have previously shown, in a transgenic mouse model, that the pituitary gland is susceptible to CD8 T-cell-mediated autoimmunity, triggered by a cell-specific model autoantigen, resulting in pan-anterior pituitary hypophysitis and dwarfism. In the present study, we now demonstrate that antigen dose, the T-cell precursor frequency, the degree of lymphopenia and the context of target antigen expression, are important parameters determining the time course and extent of the pathological consequences of CD8 T-cell-mediated autoimmunity. Furthermore, our data indicate that the pituitary gland is susceptible to CD8 autoimmunity following an inflammatory insult such as a viral infection. As lymphocytic hypophysitis may be manifest in other autoimmune conditions, and the pituitary gland may be susceptible to T-cell-mediated pathology after immunization with a virus expressing soluble pituitary antigen, it is important to consider that strategies based on vaccination against soluble pituitary gonadotrophins could have other unexpected endocrine consequences.