T lymphocytes infiltrating the bladder wall of patients with carcinoma of urinary bladder are in vivo activated.

Abstract

This paper studies the phenotypical characteristics of the lymphocytes present in mononuclear cell (MNC) preparations from peripheral blood (PBMNC), lymph nodes (LNMNC), tumor bladder (TBMNC), and tumor-free bladder (TFBMNC) from patients with infiltrated transitional cell carcinoma (TCC) of the bladder and PBMNC of healthy controls. Eight patients diagnosed with TCC of the bladder, according to UICC criteria, and 10 healthy controls were studied. For immunofluorescence staining, T lymphocytes were incubated with combinations of fluorescein (FITC, green)- and phycoerytrin (PE, red)-labelled monoclonal antibodies. The percentage of NK cells in the LNMNC and TFBMNC was significantly decreased in comparison to that found in the PBMNC from these patients (p < 0.05). A significant enhancement of the expression of class II molecules of the major histocompatibility complex (MHC) by CD3+ T lymphocytes from TBMNC and TFBMNC specimens from bladder walls was found with respect to those quantified in CD3+ T lymphocytes from PBMNC (p < 0.05). In addition, the percentage of CD3+CD25+ T lymphocytes was significantly higher in PBMNC in TCC patients than in healthy controls (p < 0.05). Our data clearly demonstrate that the presence of infiltrative TCC of the bladder is associated to an infiltration of in vivo activated T lymphocytes of the urinary bladder wall. This in vivo T lymphocyte activation has been considered an expression of the immune response against the tumor cells.