Motheaten, an Immunodeficient Mutant of the Mouse: II. Depressed Immune Competence and Elevated Serum Immunoglobulins¹

Mice homozygous for the recessive mutation motheaten (me) are deficient in capacity for immune response but show an elevated level of serum immunoglobulins. In comparison to spleen cells from normal sibs, spleen cells from me/me mice have a severely depressed 19S PFC response to SRBC. In the GVH assay, spleen and thymus cells from motheaten donors caused significantly weaker reactions than like cells from normal sibs. Serum electrophoretic patterns of motheaten mice showed increased levels of α-, β-, and γ-globulins and decreased levels of albumin. Increases in quantities of all major classes of immunoglobulins were found in serum of me/me mice 5 weeks of age and older. Elevation of serum IgM was evident by 3 weeks of age and had reached 25 times the levels in normal sibs by 6 weeks of age. Immunoelectrophoresis and Ouchterlony analysis showed motheaten serum to have both κ and λ₂ light chains. Evidence of autoimmunity was found in motheaten mice in the granular deposition of IgM and IgG in kidney glomeruli. Motheaten mice, thus, appear to have a severe immune deficiency, but the basic nature of the deficiency is not yet known.