Expression of Activation Antigens by T Cells Infiltrating Basal Cell Carcinomas

Abstract

The association of T lymphocytes and dendritic cells with the stromal mononuclear cell response to basal cell carcinomas has led to speculation that cellular immunity may, in part, regulate the growth and development of this neoplasm. It has not been established, however, whether these T cells are functionally competent, or simply coincidental bystanders. We examined the immunologic phenotypes of mononuclear cells in 32 lesions of basal cell carcinoma obtained from 26 patients. The majority of infiltrating mononuclear cells were T cells that were equally distributed between the helper/inducer (Leu 3a+) and cytotoxic/suppressor (Leu 2a+) subtypes; a minority of cells were dendritic and expressed Leu 6 antigen. Virtually all T cells and dendritic cells were HLA-DR+, and many (greater than 30%) of the T cells expressed antigens consistent with stages of ongoing activation (T9, T10). TS2/7, a novel monoclonal antibody recently documented to identify activation-specific subcomponents of 210/165/130 kD glycoprotein complex present on the surface of mitogen- or alloantigen-stimulated human T cells, was also used. Greater than 50% of the T cells observed were TS2/7+. These observations provide in situ immunomorphologic evidence of stromal T cell activation in association with basal cell carcinomas, and suggest a role for active and ongoing cellular immune mechanisms as a determinant of local biological behavior of this neoplasm.

Increased Densities of Langerhans Cells in the Epidermis of Skin Tumors

“…Guillen et al (16) reported that Leu 6-and HLA-DR-positive dendritic cells were present in normal to apparently increased numbers within the perilesional epidermis of BCE, but we could not find any LC increase in BCE. A possible reason for this discrepancy is a difference in the density of inflammatory infiltrates, for we observed fewer inflammatory cells in our BCE cases than they did in theirs.…”

Perineural spread of basal cell carcinomas treated with Mohs micrographic surgery

“…This is not surprising in light of the fact that over 60% of BCCs exhibit a moderate-to-heavy peritumoral infiltrate, consisting primarily of helper T cells, which is typically most dense at the lateral and inferior borders of the tumor and only sparsely involves the tumor islands. [32][33][34][35] In fact, a dual population of inflammatory and tumor cells may at times be seen perineurally on close examination (Figs. 2a and b).…”

Cytokine profiles in spontaneously regressing basal cell carcinomas

“…The observation that BCCs are frequently infiltrated with immune cells, including activated T lymphocytes, 20,21 suggests that these tumours are immunogenic, and that the host initiates an immune response which could potentially control tumour development. In the present study, the finding of a tendency towards elevated CD3δ expression in actively regressing BCCs is consistent with the work done by Hunt et al .…”

“…CD3d levels showed a trend towards elevation in actively regressing BCCs (an approximately 2´5-fold difference in median values), although not to a statistically significant degree. The observation that BCCs are frequently infiltrated with immune cells, including activated T lymphocytes, 20,21 suggests that these tumours are immunogenic, and that the host initiates an immune response which could potentially control tumour development.…”