title: Mice lacking protein tyrosine kinase fyn develop a T helper-type 1 response and resistLeishmania major infection.
abstract: Fyn is a Src family protein tyrosine kinase associated with TCR/CD3 complex. Fyn appears to play a role in the activation of T cells based on its enzymatic activation and tyrosine phosphorylation following the ligation of TCR/CD3, and it also plays a critical role in the calcium flux and interleukin-2 (IL-2) production. The protective response against murineLeishmania major infection is associated with the T helper-type 1 (Th1) responses and the ability to modulate Th1 cytokines such as IL-2 and interferon-γ, respectively. The role of Fyn tyrosine kinasein vivo was directly examined by the response to infection withL. major in C57BL/6fyn-deficient mice. Despite the absence of Fyn, the mice remained resistant to this infection with only mild lesion development, and, they demonstrated Th1 responses as assessed by the delayed-type hyper-sensitivity response and cytokine milieu. The findings in thefyn-deficient mice failed to support a relationship between the anticipated functions of Fynin vitro and the immune response toL. major infectionin vivo. As a result, in leishmanial disease, Fyn probably plays a minor role in the protective immune response and is, therefore, not a key factor in such a response.
authors: Department of Public Health, National Defense Medical College, 3-2 Namiki, 359-8513, Tokorozawa, Saitama, Japan, yamakami@cc.ndme.ac.jp.
authors: K
authors: K
authors: Yamakami
authors: S
authors: S
authors: Akao
authors: K
authors: K
authors: Wakabayashi
authors: T
authors: T
authors: Tadakuma
authors: N
authors: N
authors: Yoshizawa