OBJECTIVETo elucidate the functional status of dendritic cells (DC) in the tissue of oral squamous cell carcinoma by analyzing characteristic phenotype of them.

METHODS34 specimens from oral squamous cell carcinoma cases primarily treated with surgery were selected as test group. In addition, 30 specimens of normal mucosa from oral mucocele cases were used as control. Distribution of DC expressing CD1a+, HLA-DR+ and CD83+ in tumor tissue and normal mucous membrane was observed by immunohistochemistry. The number of DC expressing the antigens, which represented the density of DC infiltrating into tissue, was counted by microscope. The density of DC and the rate of DC expressing HLA-DR in oral carcinoma group and control were statistically compared.

RESULTSThere was no CD83+ DC in all cases, but CD1a+ DC was found in all samples. The density of CD1a+ DC in tumor tissue was significantly lower than that in normal mucous membrane (P < 0.05). HLA-DR antigen expressed on the surface of DC in tumoral epithelium of 27-case carcinoma specimens and in normal mucous epithelium of 23 cases. The rate of HLA-DR positive expression of TIDC had no statistic significance between the two groups.

CONCLUSIONThe lower density of DC infiltrating in tumor tissue might reflect the microenviromental immunodeficiency of hosts with oral squamous cell carcinoma, and the functional mature of DC might be inhibited by the immunosuppressive action of oral squamous cell carcinoma.