Parasite burden predicts disease severity in malaria and risk of death in cerebral malaria patients. In murine experimental cerebral malaria (ECM), parasite burden and CD8(+) T cells promote disease by mechanisms that are not fully understood. We found that the majority of brain-recruited CD8(+) T cells expressed granzyme B (GzmB). Furthermore, gzmB(-/-) mice harbored reduced parasite numbers in the brain as a consequence of enhanced antiparasitic CD4(+) T cell responses and were protected from ECM. We showed in these ECM-resistant mice that adoptively transferred, Ag-specific CD8(+) T cells migrated to the brain, but did not induce ECM until a critical Ag threshold was reached. ECM induction was exquisitely dependent on Ag-specific CD8(+) T cell-derived perforin and GzmB, but not IFN-γ. In wild-type mice, full activation of brain-recruited CD8(+) T cells also depended on a critical number of parasites in this tissue, which in turn, was sustained by these tissue-recruited cells. Thus, an interdependent relationship between parasite burden and CD8(+) T cells dictates the onset of perforin/GzmB-mediated ECM.

Item Type:	Refereed Article
Keywords:	Malaria, granzyme B, CD8 T lymphocytes, protection
Research Division:	Medical and Health Sciences
Research Group:	Immunology
Research Field:	Cellular Immunology
Objective Division:	Health
Objective Group:	Clinical Health (Organs, Diseases and Abnormal Conditions)
Objective Field:	Infectious Diseases
UTAS Author:	Karupiah, G (Associate Professor Guna Karupiah)
ID Code:	107815
Year Published:	2011
Web of Science® Times Cited:	108
Deposited By:	Medicine
Deposited On:	2016-03-24
Last Modified:	2017-11-07
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