XXXX -specific CD4+ T-cell clones from peripheral blood and gastric biopsies.

@entity1 @entity66 @entity281 @entity3621 @entity1534 @entity356
Colonization of @entity1 @entity356 with cytotoxic strains of the bacterium @entity1534 is associated with peptic ulcer and with chronic @entity3621 . Since little is known about the T-cell response to @entity1534 , we investigated the CD4+ T-cell response both in peripheral blood mononuclear cells (PBMCs) and at the site of infection. First, we compared the bulk PBMC proliferative response to the bacterium in individuals with and without symptoms of @entity66 . We found that the PBMCs from virtually all individuals proliferate in response to heat-inactivated bacteria. Second, we cloned @entity1534 -specific CD4+ T lymphocytes from the PBMCs of three @entity1 and from both the @entity356 and PBMCs of a fourth @entity1 . We have found that CD4+ T-cell clones specific for @entity1534 from peripheral blood samples and gastric mucosae of infected @entity1 are major histocompatibility complex class II restricted and discriminate between several cytotoxic and noncytotoxic bacterial strains. Moreover, they are polyclonal in terms of T-cell receptor usage and major histocompatibility complex restriction. Our results demonstrate that the T-cell response to the whole bacterium in PBMCs does not correlate with antibody response, @entity281 . However, @entity1534 -specific CD4+ T cells are detectable, at the clonal level, in both the @entity356 @entity1 . Localization of these cells at the site of disease suggests they are effectors of the immune response to the bacteria.
