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The magnitude of CD4 + T‐cell activation rather than TCR diversity determines the outcome of Leishmania infection in mice
Author(s) -
XIN L.,
WANDERLEY J. L.,
WANG Y.,
VARGASINCHAUSTEGUI D. A.,
SOONG L.
Publication year - 2011
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.1365-3024.2010.01268.x
Subject(s) - t cell receptor , biology , leishmania , immunology , t cell , leishmania major , cutaneous leishmaniasis , leishmania braziliensis , t lymphocyte , immune system , leishmaniasis , parasite hosting , world wide web , computer science
Summary CD4 + T cells play a critical role in determining the disease outcome in murine cutaneous leishmaniasis, and selective usage of T‐cell receptor (TCR) is implied in promoting Leishmania major infection. However, little information is available on TCR usage in Leishmania ‐specific, IFN‐γ‐producing CD4 + T cells. In this study, we investigated the TCR diversity and activation of CD4 + T cells in a nonhealing model associated with L. amazonensis ( La ) infection and a self‐healing model associated with L. braziliensis ( Lb ) infection. While marked expansion in the absolute number of several subsets was observed in Lb ‐infected mice, the percentages of TCR Vβ + CD4 + ‐cell subsets were comparable in draining LN‐ and lesion‐derived T cells in two infection models. We found that multiple TCR Vβ CD4 + T cells contributed collectively and comparably to IFN‐γ production and that the overall levels of IFN‐γ production positively correlated with the control of Lb infection. Moreover, pre‐infection with Lb parasites provided cross‐protection against secondary La infection, owing to an enhanced magnitude of T‐cell activation and IFN‐γ production. Collectively, this study suggests that the magnitude of CD4 + T‐cell activation, rather than the TCR diversity, is the major determining factor for the outcome of Leishmania infection.