Natural killer cells in inflammatory lesions and transplanted tumors in mouse skin.

The mode of natural killer (NK) cell migration to the sites of inflammation and transplanted tumors was investigated by using dry ice for physical irritation and 1-fluoro-2,4 dinitrobenzene (DNFB) for chemical irritation in mouse ear. In experiments with transplanted tumors, NK cell sensitive tumor cells (RL male 1) and insensitive tumor cells (p815) were transplanted into the ears of C3H and BALB/c mice, respectively. Employing a polyclonal rabbit antiserum against asialoGM1 (GA1), and a monoclonal rat antiserum against Thy-1 in an immunohistochemical double-staining technique, we enumerated the number of Thy-1-positive and asialoGM1-positive (Thy-1+ GA1+) cells and Thy-1-negative and asialoGM1-positive (Thy-1-GA1+) cells at various times of irritation. Following physical irritation, Thy-1-GA1+ cells (108.8 +/- 4.5/mm2 at 24 h and 71.2 +/- 3.8/mm2 at 48 h) were found in the epidermis, whereas Thy-1+GA1+ cells were not found. In delayed-type skin reaction by DNFB, Thy-1-GA1+ cells (87.1 +/- 5.8/mm2 at 24 h and 60.7 +/- 2.9/mm2 at 48 h) and Thy-1+GA1+ cells (26.4 +/- 3.6/mm2 at 24 h and 15.3 +/- 4.3/mm2 at 48 h) were found in the dermis. Since it was reported by previous investigators that Thy-1+GA1+ cells are NK cells, we assumed that NK cells infiltrated nonspecifically in the dermis in delayed-type skin reaction by DNFB. In the tumor transplant experiments, the GA1+ cells were found near both types of tumors, but they were in contact with RL male 1 and not with p815. Because it was reported that GA1+ monocytes do not have cytotoxicity against tumor cells, our findings suggest that GA1+ cells migrate nonspecifically to the sites of inflammation, and that the NK cells among them may make direct contact with the tumor cells when they encounter NK cell sensitive tumors.