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Theileria parva and the bovine CTL response: down but not out?
Author(s) -
MCKEEVER D. J.
Publication year - 2006
Publication title -
parasite immunology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.795
H-Index - 75
eISSN - 1365-3024
pISSN - 0141-9838
DOI - 10.1111/j.1365-3024.2006.00824.x
Subject(s) - biology , theileria parva , ctl* , east coast fever , immunity , virology , population , immunology , cytotoxic t cell , major histocompatibility complex , immune system , antigen , intracellular parasite , parasite hosting , genetics , cd8 , demography , sociology , world wide web , computer science , in vitro
SUMMARY Theileria parva is a tick‐borne intracellular protozoan of cattle, with obligate sequential differentiation stages in lymphocytes and erythrocytes. Immunity is mediated by cytotoxic T lymphocytes (CTL) that target and clear parasitized lymphocytes but allow persistence of infected erythrocytes, which are required for transmission to the tick. The life cycle of T. parva is haploid with the exception of a brief diploid stage in the tick vector during which sexual recombination occurs. There is evidence for antigenic diversity in field parasite populations, although broad immunity can be acquired following exposure to a limited number of strains. The CTL response in individual animals is tightly focused and its specificity is strongly influenced by major histocompatibility complex (MHC) phenotype. This review discusses the issue of how CTL immunity is likely to impact on parasite population structure in the light of available information on diversity of the parasite and its ability to recombine .