Reduction in T lymphocyte subpopulations following acute exposure to 4 ppm XXXX .

@entity7459 @entity19 @entity56 @entity6836 @entity3414
The effect of acute exposure to @entity7459 ( @entity6836 ) on splenic T lymphocyte subpopulations was studied in C57BL/6cum @entity19 . The @entity19 were exposed to 4 ppm @entity6836 for 8 hr. Monoclonal antibodies to T lymphocyte differentiation antigens and fluorescence-activated cell sorter (FACS) analysis were used to detect changes in T lymphocyte subpopulations. Percentages of total T lymphocytes (Thy-1.2-positive), T-helper/inducer lymphocytes (L3T4-positive), and T-cytotoxic/suppressor lymphocytes ( @entity3414 -positive) were significantly lower in @entity6836 -exposed animals than in filtered-air-breathing controls. Large T-cytotoxic/suppressor cells were found to be the most susceptible subpopulation. Spleen and body weights of the @entity19 were also determined. There were no differences between body weights of control and exposed animals; however, exposed @entity19 had significantly lower spleen weights. This is the first report providing evidence linking alterations in T lymphocyte subpopulations to acute @entity6836 exposure at occupational levels. T lymphocytes play a central role in regulatory and effector immunological functions such as mediating delayed @entity56 , regulating immunoglobulin production, and lysing virus-infected and neoplastic cells. The biological significance of these findings remains to be established, but it is very likely that functional impairment occurs since an optimal immune response depends upon a proper balance of the T lymphocyte subpopulations. Detection of alterations in T lymphocyte subpopulations using monoclonal antibodies and FACS analysis may provide an extremely sensitive means of demonstrating @entity6836 -induced changes in the immune system.
