Impaired and imbalanced cellular immunological status assessed in advanced cancer patients and restoration of the T cell immune status by adoptive T-cell immunotherapy

Abstract

Recent progress has been made in understanding the mechanisms of antitumor immune responses, which may further clarify the immune status of cancer patients. In this study, we performed a detailed evaluation of the immunological status of 47 patients with advanced solid cancer, who had received no immunosuppressive treatment, and compared the results with 32 healthy subjects. Flow-cytometry data for peripheral blood were obtained using 19 monoclonal antibodies against various cell surface and intracellular molecules. Absolute numbers of T cells, several T cell subsets, B cells, and NK cells were significantly decreased in patients compared with healthy subjects. The percentage of CD27(+)CD45RA(+) T cells was lower and that of CD27(-)CD45RA(-) T cells was higher in patients compared with controls. Regulatory and type 2 helper T cells were elevated in patients relative to healthy subjects. The percentage of perforin(+) NK cells was significantly lower in patients than in controls. These results suggest a dysfunctional anti-tumor immune response in cancer patients. Furthermore, peripheral blood from 26 of 47 cancer patients was analyzed after adoptive T cell immunotherapy (ATI). ATI increased the number of T cell subsets, but not B and NK cells. The number and percentage of regulatory T cells decreased significantly. These results suggest that ATI can restore impaired and imbalanced T cell immune status.