Depletion Of A Gamma Delta T Cell Subset Can Increase Host Resistance To A Bacterial Infection

gamma delta T lymphocytes have been shown to regulate immune responses in diverse experimental systems. Because distinct gamma delta T cell subsets, as defined by the usage of certain TCR V genes, preferentially respond in various diseases and disease models, we have hypothesized that the various gamma delta T cell subsets carry out different functions. To test this, we compared one particular gamma delta T cell subset, the V gamma1(+) subset, which represents a major gamma delta T cell type in the lymphoid organs and blood of mice, to other subsets and to gamma delta T cells as a whole. Using Listeria monocytogenes infection as an infectious disease model, we found that bacterial containment improves in mice depleted of V gamma1(+) gamma delta T cells, albeit mice lacking all gamma delta T cells are instead impaired in their ability to control Listeria expansion. Our findings indicate that V gamma1(+) gamma delta T cells reduce the ability of the innate immune system to destroy Listeria, even though other gamma delta T cells as a whole promote clearance of this pathogen.