Studies on the immune response of congenitally athymic (nude) mice.

The central role of the thymus in immunity was assessed in nude mice. Nudes failed to reject allografts and xenografts and to respond to foreign erythrocytes but responded normally to endotoxin and pneumococcal polysaccharide. Thymus reconstitution was demonstrated in vivo and in vitro whereas reconstitution with thymic humoral factors or polyanions was not detected. Coliform overgrowth and depressed IgA levels in nudes appeared to contribute to wasting. These data emphasize the need for thymus participation in many immune phenomena.