Role of CD4(+) T cells in the modulation of neurotrophin production in mice exposed to low-level toluene.

To investigate the role of CD4(+) T cells in neurotrophin production following toluene exposure, male C3H mice were exposed to filtered air (control) or 9 ppm of toluene in a nose-only exposure chamber for 30 min on 3 consecutive days followed by weekly sessions for 4 weeks. All the mice were immunized with ovalbumin and some groups of mice were treated with anti-CD4 antibody. BDNF content in BAL fluid and NGF content in plasma were significantly increased in toluene-exposed mice. However, treatment with anti-CD4 mAb completely abrogated these effects. These findings suggest that the CD4(+) T cells may be involved in the toluene-induced modulation of neurotrophin production.