Rheumatoid factor-like IgM in Plasmodium berghei (Apicomplexa: Haemosporida) infections of BALB/c mice.
Groups of female BALB/c mice infected by intravenous injection with 50 erythrocytes containing Plasmodium berghei Vincke et Lips, 1948 were sacrificed on days 3 through 12 after infection. Rheumatoid factor-like IgM (RF-IgM) and parasite-specific IgG levels were determined by enzyme-linked immunosorbent assay in serum specimens and in culture medium removed from spleen cell cultures established at sacrifice. All four mouse IgG subisotypes were recognized by RF-IgM molecules induced by Plasmodium berghei infection, and in this regard, the parasite-induced RF-IgM response resembled that induced by lipopolysaccharide polyclonal activation. Plasmodium berghei infection resulted in a biphasic RF-IgM response, with infected animals demonstrating significantly increased levels of RF-IgM early in the infection and significantly decreased levels late in the infection, compared to uninfected control mice. The decreased levels of RF-IgM observed late in infection correlated with increasing parasitaemia levels, and were primarily due to a decrease in RF-IgM specific for mouse IgG2a. Late infection levels of RF-IgM specific for IgGI, IgG2b, and IgG3 were not significantly different from those of control animals.
Hook
Reuel Robert
RR
Department of Veterinary Pathobiology, College of Veterinary Medicine, University of Missouri, Columbia, Missouri 65211, USA.
Green
Theodore J
TJ
Stuart
Melissa K
MK
D000818:Animals; D000913:Antibodies, Protozoan / Q000097:blood / Q000378:metabolism; D001402:B-Lymphocytes / Q000276:immunology; D005260:Female; D007074:Immunoglobulin G / Q000097:blood / Q000145:classification / Q000378:metabolism; D007075:Immunoglobulin M / Q000097:blood / Q000378:metabolism*; D008288:Malaria / Q000276:immunology*; D051379:Mice; D008807:Mice, Inbred BALB C; D018512:Parasitemia / Q000276:immunology; D010962:Plasmodium berghei / Q000276:immunology; D012217:Rheumatoid Factor / Q000097:blood / Q000378:metabolism; D013154:Spleen / Q000276:immunology; D013997:Time Factors
D000913:Antibodies, Protozoan; D007074:Immunoglobulin G; D007075:Immunoglobulin M; D012217:Rheumatoid Factor