NK cell-mediated immunopathology during an acute viral infection of the CNS.
Natural killer (NK) and cytotoxic T (Tc) cells are prime effector populations in the antiviral response of the host. Tc cells are essential for recovery from many viral diseases but may also be responsible for immunopathology. The role of NK cells in recovery from viral infections is less well established. We have studied acute virulent Semliki Forest virus (vSFV) infection of the central nervous system in C57BL/6J mice, which was mainly controlled by NK cells without marked Tc cell involvement. We show that mice with defects in the Fas and/or granule exocytosis pathways of cytotoxicity are more resistant to lethal vSFV infection than wild-type mice. On the other hand, mice defective in the IFN-gamma response are more sensitive than wild-type mice, whereas mice lacking the Tc cell compartment (beta-2 microglobulin-deficient mice) exhibit susceptibility similar to wild-type mice. The additional finding that depletion of NK cells significantly delayed the mean time to death but did not prevent mortality in SFV-infected B6 mice suggests that cytolytic activity of NK cells is detrimental, while IFN-gamma production is beneficial for recovery from SFV infection. This is the first study illustrating an NK cell-mediated immunopathological outcome to an acute viral infection.
Division of Immunology and Genetics, The John Curtin School of Medical Research, Australian National University, Canberra, Australia.
Mohammed
M
Alsharifi
Mario
M
Lobigs
Markus M
MM
Simon
Astrid
A
Kersten
Klaus
K
Müller
Aulikki
A
Koskinen
Eva
E
Lee
Arno
A
Müllbacher
D018354:Alphavirus Infections / Q000276:immunology*; D000818:Animals; D002493:Central Nervous System Diseases / Q000276:immunology / Q000473:pathology / Q000821:virology*; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D007371:Interferon-gamma / Q000276:immunology*; D007694:Killer Cells, Natural / Q000276:immunology*; D051379:Mice; D008810:Mice, Inbred C57BL; D012672:Semliki forest virus / Q000276:immunology; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology
D007371:Interferon-gamma