The presence of an anti-erythrocyte autoantibody in C3HeB/FeJ mice after lymphocytic choriomeningitis virus infection.
Lymphocytic Choriomeningitis (LCM) virus, substrain Docile, causes a chronic infection in adult C3HeB/FeJ mice. The virus also induces a severe anemia which, unlike the viremia, eventually resolves. Initially, there is frank bone marrow deficit, but the anemia persists well beyond a strong erythroid compensatory response. An immune-mediated basis for the hemolytic anemia was suggested by its abrogation in cyclophosphamide-treated mice, as well as an abnormal number of spherocytes in the circulation. We now show by ELISA assay, using either anti-mouse Ig or RBC membrane ghosts as catching antigen, that unusually high quantities of antibodies can be eluted from the RBCs of virus-infected mice. Furthermore, the high transient antibody concentration correlates with the severity of the anemia. With no evidence for complement playing a role in the anemia, these data indicate that erythrophagocytosis (via macrophage FcRs) may be the mechanism for RBC elimination. The possibility of molecular mimicry (antibody cross-reactivity between LCM and RBC membrane epitopes) was considered but appeared unlikely since the RBC antibody eluates gave no signal in an LCM-specific ELISA (which showed an ever increasing serum titer of virus-specific antibody). Isotype determination of the RBC eluates revealed the following: IgG2a much greater than IgG1 greater than IgG2b greater than IgG3 greater than IgM. The precise role, if any, of LCM-virus induced polyclonal activation (most strikingly in the IgG2a subclass) has yet to be determined.
Vella
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Department of Biology, Rensselaer Polytechnic Institute, Troy, New York 12180.
Pfau
C J
CJ
D000740:Anemia / Q000209:etiology / Q000276:immunology; D000818:Animals; D000918:Antibody Specificity; D001323:Autoantibodies / Q000145:classification; D003429:Cross Reactions; D004912:Erythrocytes / Q000276:immunology*; D005260:Female; D007132:Immunoglobulin Isotypes; D008216:Lymphocytic Choriomeningitis / Q000150:complications / Q000276:immunology*; D008297:Male; D051379:Mice; D008809:Mice, Inbred C3H
D001323:Autoantibodies; D007132:Immunoglobulin Isotypes