Modulated immune responsiveness associated with experimental Encephalitozoon cuniculi infection in BALB/c mice.
Spleen cell blastogenesis to mitogens and antibody responses to sheep erythrocytes (sRBC) were tested in BALB/c mice with experimental E. cuniculi infections. Blastogenesis responses of spleen cells 1 week post-infection were significantly lower than normal to T-cell mitogens (Con A and PHA) and were unchanged in response to B-cell mitogens (LPS and PWM). After 2 weeks post-infection, the responses to T cell mitogens returned to normal. Mixing spleen cells from 1-week infected mice with cells from uninfected mice failed to reveal the presence of suppressor cells. Antibody responses to sRBC were significantly slower to develop in 1 week-infected mice compared with uninfected mice or mice infected 2 weeks earlier or at the same time as sRBC challenge. Infected mice displayed splenomegaly which was most pronounced 1 week post-infection and the differential spleen cell counts revealed the presence of lymphoblasts. Lymphohyperplasia appeared to cause the splenomegaly. No shifts in the proportion of Thy 1.2+ T cells, Ig+ B cells, or esterase-positive macrophages were detected. These results indicate that the immune system in BALB/c mice is depressed early during E. cuniculi infections.
Didier
E S
ES
Department of Veterinary Pathobiology, College of Veterinary Medicine, University of Illinois, Urbana 61801.
Shadduck
J A
JA
D000818:Animals; D000913:Antibodies, Protozoan / Q000096:biosynthesis*; D016782:Apicomplexa / Q000276:immunology*; D009670:Encephalitozoon cuniculi / Q000276:immunology*; D005260:Female; D006386:Hemagglutination Tests; D006790:Host-Parasite Interactions; D007111:Immunity, Cellular; D008213:Lymphocyte Activation; D051379:Mice; D008807:Mice, Inbred BALB C / Q000469:parasitology*; D011528:Protozoan Infections / Q000276:immunology; D011529:Protozoan Infections, Animal; D012044:Regression Analysis; D012376:Rodent Diseases / Q000276:immunology*; D013047:Specific Pathogen-Free Organisms; D013163:Splenomegaly; D050378:T-Lymphocytes, Regulatory / Q000276:immunology
D000913:Antibodies, Protozoan