Cell surface antigens of melanocytes and melanoma.

One major focus of cancer immunology is the question of tumour-specific antigens, the existence of which has yet to be proven. The prime candidates for antigens that can be considered tumour-specific are the class 1 unique antigens that have been serologically defined on human malignant melanomas by antibodies from the tumour-bearing host. In addition to these antigens, intensive immunological, biochemical and genetic analyses of melanoma have permitted a rudimentary classification of other surface antigens expressed by this tumour type. Cell-surface antigens of melanoma can be grouped into three general classes: restricted antigens (i.e. antigens which are expressed by melanomas and astrocytomas) many of which are differentiation markers characterizing cells of neuroectodermal origin; antigens with intermediate distribution (i.e. antigens which are present on some cell tumour types but not on others and which show a limited distribution on normal tissues and cells); and antigens with broad distribution (i.e. antigens expressed by most human cells either malignant or normal). The detailed knowledge of the surface antigens (i.e. differentiation antigens and class 1 unique antigens) of melanoma cells has permitted a rational and coherent approach to assessing the possibility of immunological control of malignant melanoma in the clinic.