Abstract
Background: Human Cytomegalovirus (CMV), because of its ability to extensively manipulate host immunity during active infection, has been suggested to be involved in autoimmunity. However, its influence on T-cells and cytokines in systemic autoimmune diseases like systemic lupus erythematosus (SLE) and systemic sclerosis (SSc) is indistinct.
Methods: We investigated the in-vitro response of T lymphocytes from SLE and SSc patients to CMV antigen. Functional activity of T lymphocytes was determined by estimating Thl (IL-2 and IFN-gamma) and Th2 (IL-4 and IL-10) cytokines.
Results: We observed that CMV antigen stimulation in-vitro resulted in significant increase in CD4:CD8 T-cell ratio in peripheral blood mononuclear cells (PBMCs) from SLE and SSc patients; response dominated by CD4(+) than CD8(+) memory T-cells. SSc T-cell response was differentiated by aberrant increase in CD4(+) CD25(+) T-cells. CMV antigen caused elevation in IL-4 and IFN-gamma production in both patient PBMCs, whereas IL-2 was also raised in SLE PBMCs. The development of large pool of memory T-cells and overproduction of IFN-gamma may result in flare-up of autoimmunity in these patients.
Conclusion: Our study provides an insight into the immunopathological potential of CMV-reactive immune cells to develop new potential strategies for targeted therapeutic intervention.