Down‐regulation of an established immune response via chemical carcinogen or UVB‐altered skin

The ability to produce antigen‐specific down‐regulation of an established immune response was investigated in 2,4,6‐trinitrochlorobenzene (TNCB)‐immune mice by delivery of antigen through chemical carcinogen‐ or ultraviolet B (UVB)‐treated skin. When TNCB‐immune mice were treated on the dorsal trunk skin with 7,12‐dimethylbenz(a)anthracene (DMBA) followed by TNCB there was an antigen‐specific reduction in both contact sensitivity and antibody production. Further, immune mice that received spleen cells from naive syngeneic donors treated with DMBA followed by TNCB also exhibited a reduction in both contact sensitivity and antibody production. In contrast, mice treated with UVB irradiation followed by TNCB had a reduction in contact sensitivity but not antibody production. These results provide evidence that an ongoing immune response can be manipulated by immunization through a modified skin immune system. This may provide a beneficial approach for the treatment of autoimmune disease.