[PDF][PDF] Integrin subunit CD18 Is the T-lymphocyte receptor for the Helicobacter pylori vacuolating cytotoxin

X Sewald, B Gebert-Vogl, S Prassl, I Barwig, E Weiss… - Cell host & …, 2008 - cell.com
X Sewald, B Gebert-Vogl, S Prassl, I Barwig, E Weiss, M Fabbri, R Osicka, M Schiemann…
Cell host & microbe, 2008cell.com
Helicobacter pylori infection is associated with gastritis, ulcerations, and gastric
adenocarcinoma. H. pylori secretes the vacuolating cytotoxin (VacA), a major pathogenicity
factor. VacA has immunosuppressive effects, inhibiting interleukin-2 (IL-2) secretion by
interference with the T cell receptor/IL-2 signaling pathway at the level of calcineurin, the Ca
2+-calmodulin-dependent phosphatase. Here, we show that VacA efficiently enters
activated, migrating primary human T lymphocytes by binding to the β2 (CD18) integrin …
Summary
Helicobacter pylori infection is associated with gastritis, ulcerations, and gastric adenocarcinoma. H. pylori secretes the vacuolating cytotoxin (VacA), a major pathogenicity factor. VacA has immunosuppressive effects, inhibiting interleukin-2 (IL-2) secretion by interference with the T cell receptor/IL-2 signaling pathway at the level of calcineurin, the Ca2+-calmodulin-dependent phosphatase. Here, we show that VacA efficiently enters activated, migrating primary human T lymphocytes by binding to the β2 (CD18) integrin receptor subunit and exploiting the recycling of lymphocyte function-associated antigen (LFA)-1. LFA-1-deficient Jurkat T cells were resistant to vacuolation and IL-2 modulation, and genetic complementation restored sensitivity to VacA. VacA targeted human, but not murine, CD18 for cell entry, consistent with the species-specific adaptation of H. pylori. Furthermore, expression of human integrin receptors (LFA-1 or Mac-1) in murine T cells resulted in VacA-mediated cellular vacuolation. Thus, H. pylori co-opts CD18 as a VacA receptor on human T lymphocytes to subvert the host immune response.
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