Induced regional differences in cutaneous cell-mediated immunity in the mouse

Single applications of 1-fluoro-2,4-dinitrobenzene (DNFB) or oxazolone to one ear of a mouse resulted in brisk local cell-mediated immunity (CMI) upon antigenic rechallenge of the same ear. However, only a minimal CMI reaction occurred when the other ear was treated with antigen. The relative unresponsiveness of the contralateral ear persisted for periods as long as 14 weeks. The depressed CMI of the contralateral ear was eliminated when cyclophosphamide was given prior to initial antigenic exposure, and therefore, appeared to be mediated by suppressor cells. These observations indicate that regional variations in the intensity of cutaneous CMI can be induced in mice. The significance of these observations is discussed.