Microbial Adjuvant and Autoimmunity

Abstract

AbstractThe target organs of mice immunized with the respective syngeneic tissue extracts together with the capsular polysaccharide of Klebsiella pneumoniae (CPS‐K) as a powerful adjuvant were examined for production of lesions. In 15 out of 24 mice injected three times or more with syngeneic eyeball extracts and CPS‐K adjuvant at intervals approximately 30 days, severe eyeball lesions developed in which the normal structure was almost completely lost. A large part of the eyeball tissue of these mice was replaced by infiltration with cells such as lymphocytes, plasma cells and other mononuclear cells and by connective tissue. No definite eye lesions developed in mice injected with CPS‐K alone, eyeball extracts alone or eyeball extracts emulsified in complete Freund's adjuvant (CFA). In all of mice injected four times with thyroid gland extracts and CPS‐K at intervals of approximately 30 days, definite thyroid gland lesions were produced. In three out of five mice of this group, the thyroid lesions were so severe that the normal thyroid follicular structure was almost completely lost, and a large part of the thyroid gland was replaced by infiltration with lymphocytes, plasma cells and other mononuclear cells and in part by connective tissue. In only one out of five mice injected with thyroid gland extracts emulsified in CFA, definite but milder thyroid gland lesions developed. No definite thyroid lesions developed in the remaining four mice of this group and also in any of the mice injected with thyroid gland extracts alone or CPS‐K alone. Repeated injections of lymphoid tissue extracts and CPS‐K also induced pathological changes in the spleen and lymph nodes, although less marked than those in the cases of the eyes and thyroid gland. The most remarkable change was a decrease in numbers of small lymphocytes at the areas surrounding the central arterioles in the white pulp of the spleen and the post‐capillary venules in the cortex of the lymph nodes. From these results it has been concluded that our system can provide new and useful models for autoimmune diseases in man.