Immunological competence in Snell-Bagg pituitary dwarf mice: response to the contact-sensitizing agent oxazolone.

Snell-Bagg pituitary dwarf mice are an autosomal recessive mutant, their dwarfism being the result of an anterior pituitary defect. A number of investigators have reported that these mice, in addition to having hormonal deficiencies, have immunological defects. Dwarf mice reject allogenic skin grafts slowly, show a reduced response to contact agents and decreased graft-vs-host reactivity. Other investigators have suggested that these results indicate a thymus-cell-deficiency. Contrary to this conclusion, we have found that the thymuses in our dwarf mice have a normal cellular composition and the T-cell-dependent zones in the peripheral lymphoid tissues are not deficient in the lymphocytes. Therefore, this investigation was undertaken to study the response of dwarf mice to the hapten, oxazolone, which produces one type of T-cell-dependent response, delayed hypersensitivity, and to compare this response to that of normal littermates in animals 15 to 90 days of age.