Autoimmune thyroiditis: conversion of low-responder mice to high-responders by cyclophosphamide.

Inbred strains of mice are low- or high-responders with respect to the magnitude of thyroid infiltrates that appear after immunization with mouse thyroglobulin emulsified in Freund's complete adjuvant. This aspect of the immune response to thyroglobulin is strongly controlled by the major histocompatibility complex. Low-responder strains treated with cyclophosphamide, before the antigenic challenge, were converted to high-responders. This suggests that in low-responder mice, a specific suppressor activity influences the development of the thyroid lesions characteristic for the autoimmune thyroiditis.