Alterations in T-lymphocyte sub-set profiles and cytokine secretion by PBMC of systemic lupus erythematosus patients upon in vitro exposure to organochlorine pesticides

Chronic exposure to organochlorine pesticides (OCP) has been suspected of causing immunoregulatory abnormalities that eventually lead to development and progression of systemic lupus erythematosus (SLE), but the role of these non-genetic stimuli has remained poorly understood. This study quantified the levels of different OCP residues in the blood of SLE patients to determine the effects of in vitro treatment of peripheral blood mononuclear cells (PBMC) from these patients and healthy controls with OCP. Levels of different OCP residues in the blood were measured by gas-liquid chromatography. Isolated PBMC were treated in vitro with hexachlorocyclohexane (HCH), o,p’-dichlorodiphenyltrichloroethane (DDT), or phytohemagglutinin-M (PHA-M) for 72 h, then stained with different dye-labelled monoclonal antibodies to analyse alterations in T-lymphocytes using flow cytometry. ELISA also estimated levels of different TH1 and TH2 cytokines. Significantly higher levels of p,p’-DDE and â-HCH were detected in the blood of SLE patients than in healthy controls. HCH exposure markedly increased the percentages of CD3+CD4+ T-lymphocytes and expression of CD45RO+ on CD4+ and CD8+ T-lymphocytes, but decreased CD4+-CD25+ T-lymphocytes in SLE patients. DDT exposure increased the percentages of CD3+CD4+ T-lymphocytes and decreased those of CD4+CD25+ T-lymphocytes in SLE patients as compared to healthy controls. No significant responsiveness of patient PBMC to PHA-M stimulation was observed indicating suppression of T-lymphocytes by these OCP. Further, both HCH and DDT decreased the levels of IL-2 and IFNç but had no effect on IL-4 levels in SLE patients. DDT also increased significantly the levels of IL-10 in patients. It is likely that higher levels and prolonged durations of exposure to HCH and DDT may significantly influence T-lymphocyte sub-sets and cytokine expression in vivo that could lead to the development or exacerbation of SLE.

Authors: Dar, Sajad A.; Das, Shukla; Ramachandran, Vishnampettai G.; Bhattacharya, Sambit N.; Mustafa, M. D.; Banerjee, Basu D.; Verma, Prashant ;Full Source: Journal of Immunotoxicology [fusion_builder_container hundred_percent=”yes” overflow=”visible”][fusion_builder_row][fusion_builder_column type=”1_1″ background_position=”left top” background_color=”” border_size=”” border_color=”” border_style=”solid” spacing=”yes” background_image=”” background_repeat=”no-repeat” padding=”” margin_top=”0px” margin_bottom=”0px” class=”” id=”” animation_type=”” animation_speed=”0.3″ animation_direction=”left” hide_on_mobile=”no” center_content=”no” min_height=”none”][online computer file] 2012, 9(1), 85-95 (Eng) ;