Experimental autoimmune thyroiditis in the guinea pig: characterization of infiltrating lymphocyte populations

Experimental autoimmune thyroiditis was induced in out-bred guinea pigs by isoimmunization with thyroid extract in complete Freund's adjuvant. A digestion procedure using collagenase and deoxyribonuclease was used to make viable single-cell suspensions of pooled thyroid glands from groups of animals with advanced degrees of thyroiditis. Thymus-derived or T lymphocytes, identified by their capacity to form E rosettes with rabbit erythrocytes, were found to be the predominant (75%) infiltrating lymphocyte; bone marrow-derived or B cells consitituted most of the remainder. The infiltrates of inbred animals with thyroiditis were demonstrated to contain cells capable of mediating antibody-dependent lymphoid cell-mediated cytotoxicity.