PBS vs. LPS stimulation of gd T cells

gd T cells recognize unprocessed or non-peptide antigens, respond rapidly to infection, and localize to mucosal surfaces. We have hypothesized that the innate functions of gd T cells may be more similar to those of cells of the myeloid lineage than to other T cells. To begin to test this assumption, we have analyzed the direct response of cultured human and peripheral blood bovine gd T cells to pathogen associated molecular patterns (PAMPs) in the absence of APCs using microarray, real time RT-PCR, proteome array, and chemotaxis assays. Our results indicate that purified gd T cells respond directly to PAMPs by increasing expression of chemokine and activation related genes. The response was distinct from that to known gd T cell antigens and different from the response of myeloid cells to PAMPs. In addition, we have analyzed the expression of a variety of PAMP receptors in gd T cells. Freshly purified bovine gd T cells responded more robustly to PAMPs than did cultured human cells and expressed measurable mRNA encoding a variety of PAMP receptors. Our results suggest that rapid response to PAMPs through the expression of PAMP receptors may be another innate role of gd T cells.

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Hedges JF, Lubick KJ, Jutila MA