Affiliation:
1. Department of Molecular Microbiology and Immunology, St. Louis University Health Sciences Center, St. Louis, Missouri 63104
Abstract
ABSTRACT
Viral encephalitis caused by neuroadapted yellow fever 17D virus (PYF) was studied in parental and gamma interferon (IFN-γ)-deficient (IFN-γ knockout [GKO]) C57BL/6 mice. The T-cell responses which enter the brain during acute fatal encephalitis of nonimmunized mice, as well as nonfatal encephalitis of immunized mice, were characterized for relative proportions of CD4
+
and CD8
+
cells, their proliferative responses, and antigen-specific expression of cytokines during stimulation in vitro. Unimmunized mice accumulated only low levels of T cells within the brain during fatal disease, whereas the brains of immunized mice contained higher levels of both T-cell subsets in response to challenge, with CD8
+
cells increased relative to the CD4
+
subset. The presence of T cells correlated with the time at which virus was cleared from the central nervous system in both parental and GKO mice. Lymphocytes isolated from the brains of challenged immunized mice failed to proliferate in vitro in response to T-cell mitogens or viral antigens; however, IFN-γ, interleukin 4 (IL-4), and, to a lesser extent, IL-2 were detectable after stimulation. The levels of IFN-γ, but not IL-2 or IL-4, were augmented in response to viral antigen, and this specificity was detectable in the CD4
+
compartment. When tested for the ability to survive both immunization and challenge with PYF virus, GKO and CD8 knockout mice did not differ from parental mice (80 to 85% survival), although GKO mice exhibited a defect in virus clearance. In contrast, CD4 knockout and Igh-6 mice were unable to resist challenge. The data implicate antibody in conjunction with CD4
+
lymphocytes bearing a Th1 phenotype as the critical factors involved in virus clearance in this model.
Publisher
American Society for Microbiology
Subject
Virology,Insect Science,Immunology,Microbiology
Reference77 articles.
1. Establishment and characterization of Japanese encephalitis virus-specific human CD4+ T-cell clones: flavivirus cross-reactivity, protein recognition, and cytotoxic activity;Ahara H.;J. Virol.,1998
2. Interleukin-4 and -5 as modulators of nerve growth factor synthesis/secretion in astrocytes;Awatsuji H.;J. Neurosci. Res.,1993
3. Comparison of neurovirulence of different strains of yellow fever virus in mice;Barrett A. D. T.;J. Gen. Virol.,1986
4. Presence of T cells with activated and memory phenotypes in inflammatory spinal cord lesions;Barten D. M.;J. Immunol.,1995
5. Benveniste
E. N.
Cytokine expression in the nervous system
Immunology of the nervous system.
Keane
R. W.
Hickey
W. F.
1997
419
459
Oxford University Press
New York N.Y
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