Submitted December 28, 2006
Returned for revision February 5, 2007
Accepted August 17, 2007
Immunology
Bovine Luteal Cells Stimulate Proliferation of Major Histocompatibility Nonrestricted Gamma Delta T Cells
Tracy L. Davis
and
J. L. Pate *
* To whom correspondence should be addressed. E-mail: pate.1{at}osu.edu.
Abstract
Luteal cells are potent activators of T cell proliferation in vitro. The purpose of this study was to determine which subset of T cells is stimulated by luteal cells, and whether luteal cell induced T cell activation elicits a proinflammatory or anti-inflammatory T cell response. The first objective was to determine if luteal cell stimulated T cell proliferation was mediated by class I or class II MHC molecules. T cell proliferation was inhibited by anti-MHC class I but not anti-MHC class II antibodies. The second objective was to determine which T cell subtype proliferates when cultured with luteal cells. The proportions of CD4+ and CD8+ cells were unchanged, but the number of gamma delta T cells was increased, by coculture with luteal cells. Immunohistochemistry confirmed the presence of gamma delta T cells in midcycle and regressing CL. The final objective was to characterize T cell cytokine production stimulated by luteal cells. The concentrations of interferongamma (IFNG) and interleukin 10 (IL10) were increased in luteal cell-T cell cocultures, whereas IL4 was undetectable and IL12 barely detectable in culture medium. It was concluded that coculture of luteal cells and T cells resulted in activation of a somewhat unique T cell subset, gamma delta T cells, as well as production of both pro- and anti-inflammatory cytokines. This is the first report of gamma delta T cell activation by luteal parenchymal cells of any species, raising the possibility that tissue resident gamma delta T cells may be involved in regulating the balance between tissue homeostasis or luteolysis.
Key words:
Immunology •
Ovary •
Corpus luteum
