Expanded T cell clones and cytokines expression in human gastric carcinomas of different histological types

To study the characteristics of host immune response against human gastric carcinoma of different histological types.

The expression of 24 families of T cell receptor beta chain variable region (TCRVbeta) and cytokine profiles in isolated CD4(+) and CD8(+) subsets, as well as the cytokine profiles in purified epithelial cells from the tumor tissue and the residual benign tissue of patients with gastric carcinoma, was detected by a highly sensitive radioactivity labeled semi-quantitative RT-PCR technique.

The number of expanded T cell clones in CD8(+) subset from tumor tissue of the intestinal-type carcinoma was larger than that of diffuse-type (P = 0.046). The mRNA levels of IL-6, IL-8 in CD8(+) T subset, as well as the level of TNF-alpha in CD4(+) T subset from the tumor tissue of the diffuse type (0.61 +/- 0.29, 0.56 +/- 0.22, 0.09 +/- 0.03) were significantly higher than that from the residual benign tissue (0.14 +/- 0.05, 0.27 +/- 0.09, 0.04 +/- 0.02; P = 0.028, P = 0.043, P = 0.046). However, the mRNA level of IL-8 in CD8(+) subset and epithelial tumor cells of the intestinal-type (0.57 +/- 0.25, 0.27 +/- 0.07) was significantly higher than that from the residual benign tissue (0.21 +/- 0.07, 0.14 +/- 0.06; P = 0.028, P = 0.028).

The characteristics of host immune response against tumor are different between intestinal-type and diffuse-type gastric carcinoma. Both fewer expanded T cell clones and more suppressive cytokines suggest a more suppressive immune status in the local tumor lesion of diffuse-type than in the intestinal-type of the gastric carcinoma.