Humoral immunity is not critical for protection against experimental infection with Sarcocystis neurona in B-cell-deficient mice.
Immunodeficient B-cell-deficient mice (mmuMT) were infected with Sarcocystis neurona merozoites to determine the role of B cells and the humoral immune response in protective immunity. As expected, the mice did not seroconvert based on a direct agglutination test. Infected mice did not have significant changes in gross pathology at the time points examined. Histologic changes included mild perivascular and peribronchial infiltrate in the lungs; perivascular infiltrate and mild inflammatory sinusoidal foci in the liver; prominent high endothelial venules in the lymph nodes; and moderate cellular expansion of the periarteriolar sheaths (PALS) in the spleen. Changes resolved by day 60 postinfection. Mice developed significant CD4 and CD8 responses in lymphoid organs, including significant effector (CD45RB(high)) and memory (CD44(high)) CD4 and CD8 responses. Flow cytometry confirmed the lack of B cells. Overall, these data suggest that B cells are not critical to the protective immune response to SN infection.
Witonsky
Sharon G
SG
Department of Large Animal Clinical Sciences, Virginia Polytechnic Institute and State University (Virginia Tech), Blacksburg, Virginia 24061, USA. switonsk@vt.edu
Gogal
Robert M
RM
Duncan
Robert B
RB
Norton
Heather
H
Ward
Dan
D
Yang
Jibing
J
Lindsay
David S
DS
D000372:Agglutination Tests; D000818:Animals; D000913:Antibodies, Protozoan / Q000096:biosynthesis* / Q000276:immunology; D001402:B-Lymphocytes / Q000276:immunology*; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology; D005260:Female; D005434:Flow Cytometry; D007111:Immunity, Cellular; D007121:Immunocompetence; D007371:Interferon-gamma / Q000235:genetics; D008099:Liver / Q000473:pathology; D008168:Lung / Q000473:pathology; D008198:Lymph Nodes / Q000473:pathology; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D012522:Sarcocystis / Q000276:immunology*; D012523:Sarcocystosis / Q000276:immunology*; D013154:Spleen / Q000473:pathology
D000913:Antibodies, Protozoan; D007371:Interferon-gamma