Quantitative and functional analysis of CD69 NKG2D T regulatory cells in healthy subjects Article uri icon

abstract

  • T regulatory (Treg) cells have a key role in immune homeostasis and the pathogenesis of chronic inflammatory and autoimmune diseases. CD69 is an early leukocyte activation molecule that under steady state conditions is detected in a small proportion of lymphocytes in peripheral blood and lymphoid tissues. Although it has been reported that a subset of CD69 T cells behaves as Treg lymphocytes, the possible relationship between CD69 Treg cells and CD4 NKG2D T lymphocytes, which also exert immunosuppressive activity, has not been explored. In this study, we analyzed the expression of CD69 and NKG2D by T lymphocytes from the peripheral blood of twenty-five healthy subjects by multi-parametric flow cytometry analysis, and their suppressive activity by an assay of inhibition of lymphocyte activation (CD40L expression) and proliferation (carboxyfluorescein partition assay). We found a very small percentage of CD4 CD69 NKG2D T cells (median 0.002%25, Q1-Q3, 0.001-0.004%25), which also expressed TGF-β (Latency Associated Peptide or LAP) and IL-10, in all samples analyzed. These cells exerted an important in vitro suppressive effect on both activation and proliferation of T effector cells. Our data suggest that at very small numbers, CD4 CD69 NKG2D lymphocytes seem to exert a relevant functional immune-regulatory role in healthy subjects. © 2015 Elsevier Inc.
  • T regulatory (Treg) cells have a key role in immune homeostasis and the pathogenesis of chronic inflammatory and autoimmune diseases. CD69 is an early leukocyte activation molecule that under steady state conditions is detected in a small proportion of lymphocytes in peripheral blood and lymphoid tissues. Although it has been reported that a subset of CD69%2b T cells behaves as Treg lymphocytes, the possible relationship between CD69%2b Treg cells and CD4%2bNKG2D%2b T lymphocytes, which also exert immunosuppressive activity, has not been explored. In this study, we analyzed the expression of CD69 and NKG2D by T lymphocytes from the peripheral blood of twenty-five healthy subjects by multi-parametric flow cytometry analysis, and their suppressive activity by an assay of inhibition of lymphocyte activation (CD40L expression) and proliferation (carboxyfluorescein partition assay). We found a very small percentage of CD4%2bCD69%2bNKG2D%2b T cells (median 0.002%25, Q1-Q3, 0.001-0.004%25), which also expressed TGF-β (Latency Associated Peptide or LAP) and IL-10, in all samples analyzed. These cells exerted an important in vitro suppressive effect on both activation and proliferation of T effector cells. Our data suggest that at very small numbers, CD4%2bCD69%2bNKG2D%2b lymphocytes seem to exert a relevant functional immune-regulatory role in healthy subjects. © 2015 Elsevier Inc.

publication date

  • 2015-01-01