Osteopetrotic (op/op) mice deficient in macrophages have the ability to mount a normal T-cell-dependent immune response.

The osteopetrotic (op/op) mouse possesses an inactivating mutation in the CSF-1 gene that is associated with a lack of certain mononuclear phagocyte populations. To examine the effects of these deficiencies on T-cell-dependent immune functions, the responses of op/op and normal mice to a T-cell-dependent antigen, ovalbumin, and to a foreign histocompatibility antigen were compared. The ability of op/op mice (1) to induce antigen-specific proliferation of naive T-cells, (2) to generate cytotoxic T-lymphocytes, (3) to supply spleen cells to serve as stimulators in a mixed lymphocyte reaction, and (4) to produce IgM and IgG antibodies was indistinguishable from normal mice. These data are consistent with the involvement of specific macrophages, or other cells whose development is independent of CSF-1, in these immune responses.