Regulation of the contact sensitivity reaction by suppression of T gamma delta lymphocytes
Szczepanik, M.
Folia Medica Cracoviensia 39(1-2): 5-33
1998
ISSN/ISBN: 0015-5616 PMID: 10481375 Document Number: 491597
Contact sensitivity (CS) is a classical example of in vivo T cell mediated immune response that is under regulation. It is well known that in normal mice suppression of CS can be mediated by T alpha beta cells tolerized by prior exposure to high dose of antigen (Ag). In this paper it was shown that treatment of defective TCR alpha -/- or TCR beta -/- mice with high dose of Ag may result in induction of T gamma delta suppressor cells, that are able to inhibit both adoptive cell transfer of CS in vivo and IFN-gamma production in vitro. These suppressor cells are characterized as: TCR gamma delta+, CD3+, CD4-, CD8-, CD28+, CD40L+, CD95 (Fas)+, Fc gamma R+ and NK1.1-. Suppression mediated by T gamma delta cells showed antigen specificity, but was not restricted by the MHC. T gamma delta suppressor cells express very strong down-regulatory activity where even 2.5 x 10(3) T gamma delta cells could suppress 7 x 10(7) CS-effector cells. Presented data may suggest that IL-4 released by T gamma delta suppressor cells is involved in the mechanism of their down-regulatory function.