Heterogeneity of human natural killer cells in the spleen.

Natural killer cells have an important role in tumour and viral defence and immunoregulation. In the present study the pan-NK cell monoclonal antibody NKH1 was utilized to study the heterogeneity of NK cells in the human spleen. Using one and two colour analysis it could be demonstrated that the majority of NKH1+ NK cells are located in the red pulp and marginal zone whereas only a minor subset is found in the lymph follicles. In the red pulp, NK cells resemble those of peripheral blood in terms of function and phenotype. In contrast, the few NK cells in the lymph follicles are mostly NKH1+, CD2- and CD16- and thus express a unique phenotype. The analysis of tissue distribution provides a basis for further studies on NK cell kinetics and differentiation.