Analysis of Antitumor Mechanism of Intravesical BCG Therapy in Tumorigenesis(II) Study about Memory T Cells and Lymphocyte Homing Receptor Positive Cells

Kim, Sun Jin

Abstract

A study was focused on the analysis of the change of the number and distribution of immunocytes during the tumorigenesis by N-buty1-N-(4-hydroxybutyl)-nitrosamine (BBN) administration to C3H/He inbred mice and intravesical BCG therapy to starch for the subclass of the T cells which could be the major elements in antitumor mechanism of BCG. The number and distribution of memory T(CD44) cells were studied immunohistochemically in the spleen and urinary bladder and those of memory T cells in peripheral lymph nodes and those of lymphocyte homing receptor(Mel-14) positive cells in thymus were studied microflowcytometrically following 4 weekly intravesical BCG instillations. In BBN administered group, changes of immunocytes were not induced by BBN only but as gross tumor developed, increase of memory T cells was observed but was not statistically significant comparing with those of control group. In BCG treated group, memory T cells in bladder and spleen, lymphocyte homing receptor positive cells in thymus and memory T cells in lymph nodes were all increased markedly and de creased with time sequence. In BBN administered and BCG treated group, as the immune cells decreased, gross tumor developed and infiltration of memory T cells to tumor tissues was observed in this group. In conclusion, memory T cells which were activated by BCG can be major element involved in antitumor activity of BCG and the change of the number and the pattern of distribution of immune cells showed us that local reaction as well as systemic cellular immunity seemed to be important in antitumor activity. Also the effect was time limited.