Murine epidermal Vγ5/Vδ1-T-cell receptor⁺ T cells respond to B-cell lines and lipolpolysaccharides

The Vγ5/Vδ1⁺-T-cell receptor (TCR)-bearing T-cell clone, 2CBET-3, was generated from C57BL/6 mice. Upon stimulation, 2CBET-3 cells produce interleukin (IL)-3, granulocyte-macrophage colony-stimulating factor, and tumor necrosis factor-α, but not IL-2, IL-4, IL-5, IL-6, IL-8, IL-10, macrophage colony-stimulating factor, or interferon-γ. These cells were evaluated for their ability to be stimulated by a variety of murine cell lines, including fibroblasts, trophoblasts, melanoma cells, embryonic carcinomas, B-cell lymphomas, mastocytoma cells, and keratinocytes. The human B-lymphoma cell line, Daudi, also was included in these studies. We found that 2CBET-3 cells produced cytokines up to several hundredfold above the control levels in response to the B-cell lines, Daudi, and A20/2J, but not to the B-cell line 439.4.2. After fixation with glutaraldehyde, Daudi and A20/2J continued to stimulate this γδ T-cell line. 2CBET-3 cells also responded to the keratinocyte line PAM212, but not to another, XB-2. When lipopolysaccharides (LPS) from Escherichia coli or S. typhimurium were added to 2CBET-3 cells in the presence of A20/2J cells, 2CBET-3 cells responded with increased cytokine production compared with the cytokine production in the presence of A20/2J cells alone. 2CBET-3 cells by themselves did not respond to LPS alone or to supernatants from A20/2J cells incubated with LPS. Unlike 2CBET-3, the epidermal T-cell hybridoma 70BET-49, expressing a Vγ5/Vδ1-TCR identical to that of 2CBET-3, did not respond to A20/2J cells in the presence or absence of LPS, suggesting a requirement for molecules other than the TCR for Vγ5/Vδ1-TCR⁺ T-cell stimulation by the B-cell lines and by LPS. This unique reactivity of γδ-TCR⁺ cells is different from that of αβ-TCR⁺ cells and may reflect a functional specialization of γδTCR⁺ cells in the response to bacterial infections.