ABSTRACT
<p><b>OBJECTIVE</b>To study the characteristics of host immune response against human gastric carcinoma of different histological types.</p><p><b>METHODS</b>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.</p><p><b>RESULTS</b>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).</p><p><b>CONCLUSIONS</b>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.</p>