Topical exposure to 2-butoxyethanol alters immune responses in female BALB/c mice

Effects on immune parameters following topical exposure to 2-butoxyethanol (BE) in mice are reported in the present study. The objective was to determine whether subacute topical exposure to BE can modulate functional immune responses and/or nonspecific immune parameters such as lymphoid organ weight and cellularity. Female BALB/c mice were topically exposed to vehicle or BE at concentrations of 100, 500, 1,000, and 1,500 mg BE/kg/day for 4 consecutive days. Assessment of immune parameters began 24 hours after the final dose. No effects were observed at any of the BE concentrations on thymus cellularity or thymus to body weight ratio. A significant increase in spleen cellularity and spleen to body weight ratio was observed at 1,500 mg BE/kg/day. Topical BE exposure significantly reduced the splenic T cell proliferative response to concanavalin A (Con A) and the mixed lymphocyte response (MLR) to allogeneic antigen. No significant effect was observed in the splenic B cell proliferative response to lipopolysaccharide (LPS), nor was there an effect on the in vitro primary antibody response to sheep red blood cells (SRBCs). No significant alteration occurred in either splenocyte cytotoxic T lymphocyte (CTL) activity or natural killer (NK) cell activity following topical BE exposure. This study suggests that topical exposure to BE may suppress some aspects of T cell immunity but does not affect B cell immunity.