A RECOMBINANT FRAGMENT OF HELICOBACTER-PYLORI CAGA AFFECTS PROLIFERATION OF HUMAN-CELLS

The outcome of H. pylori infectins depends on proliferation of various host cells, including lymphocytes, monocytes and epithelial cells. In this study we showed that a recombinant fusion protein carrying an im munodominant region of H. pylori CagA antigen affected the proliferati on of human cells. The rCagA inhibited PHA-driven T cell proliferation but enhanced the growth of epithelial HeLa cells, especially in the p resence of granulocyte macrophage colony stimulating factor (GM-CSF). When THP-1 monocytes and Kato-3 epithelial cells from metastasis of ga stric carcinoma were stimulated with GM-CSF, they were also susceptibl e to the inhibitory effect of rCagA. These results confirmed our earli er suggestion on the inhibition of T cell function by H. pylori CagA p rotein. However, antiproliferative activity of CagA antigen appears to be not restricted to T lymphocytes but modulatory effect of this prot ein seems to depend on the cell type.