Neospora caninum-infected cattle develop parasite-specific CD4+ cytotoxic T lymphocytes.
Cattle infected with Neospora caninum readily experience transplacental parasite transmission, presumably after maternal parasitemia, leading to abortion or birth of congenitally infected calves. Cytotoxic T lymphocytes (CTL) are important mediators of protective immunity against Toxoplasma gondii, an intracellular apicomplexan protozoan closely related to N. caninum. In this study, N. caninum-specific CTL expanded from peripheral blood mononuclear cells of two major histocompatibility complex-mismatched, experimentally infected cattle were identified by using a (51)Cr release cytotoxicity assay. Enrichment and blocking of CD4(+)- and CD8(+)-T-lymphocyte effector subsets indicated that CD4(+) CTL killed N. caninum-infected, autologous target cells and that killing was mediated through a perforin/granzyme pathway. Detection and characterization of CTL responses to N. caninum in the natural, outbred, bovine host will facilitate identification of immunogens and design of immunization strategies to induce parasite-specific CTL against transplacental N. caninum transmission in cattle.
Staska
Lauren M
LM
Department of Veterinary Microbiology and Pathology, Washington State University, Pullman 99164, USA.
McGuire
Travis C
TC
Davies
Christopher J
CJ
Lewin
Harris A
HA
Baszler
Timothy V
TV
D000818:Animals; D000911:Antibodies, Monoclonal / Q000627:therapeutic use; D015704:CD4 Antigens / Q000032:analysis*; D002417:Cattle; D003048:Coccidiosis / Q000276:immunology*; D005260:Female; D053804:Granzymes; D008562:Membrane Glycoproteins / Q000502:physiology; D018688:Neospora / Q000276:immunology*; D054353:Perforin; D052899:Pore Forming Cytotoxic Proteins; D012697:Serine Endopeptidases / Q000502:physiology; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology*
D000911:Antibodies, Monoclonal; D015704:CD4 Antigens; D008562:Membrane Glycoproteins; D052899:Pore Forming Cytotoxic Proteins; D054353:Perforin; D053804:Granzymes; D012697:Serine Endopeptidases