IGA-DEPENDENT CELL-MEDIATED ACTIVITY AGAINST ENTEROPATHOGENIC BACTERIA - DISTRIBUTION, SPECIFICITY, AND CHARACTERIZATION OF THE EFFECTOR-CELLS

  • 1 January 1984
    • journal article
    • research article
    • Vol. 133  (2) , 988-992
Abstract
Antibody-dependent cellular cytotoxicity (ADCC) against murine enteropathogenic bacteria such as Salmonella typhimurium and Salmonella tel aviv or Shigella X16 was assessed by using IgG, IgA and secretory IgA (sIgA) in a 2-h in vitro assay where peripheral and intestinal lymphocytes were used as effector cells. IgG could arm splenocytes (SpL) better than IgA. However, IgG did not arm lymphocytes from Peyer''s patches (PPL) or from mesenteric lymph nodes (MnL); IgA of plasmacytoma origin against S. tel aviv and purified intestinal sIgA against Shigella X16 induced specific antibacterial ADCC with both SpL and PPL. When sIgA were tested with intestinal lymphocytes from the epithelium and the lamina propria, i.e., cells from the gut mucosa which first interact with enteric bacteria, both these lymphoid populations were able to express sIgA-dependent ADCC against Shigella X16. In parallel tests, cells from thymus and popliteal lymph nodes failed to express ADCC. Blocking studies with purified IgG and IgA of goat, rabbit and mouse origin demonstrated that the Fc-.alpha. and Fc-.gamma. receptors were specifically involved in IgA- or IgG-dependent antibacterial ADCC. At least 2 effector populations, a macrophage and a Thy-1.2- lymphocyte, were observed to exert IgA-ADCC at the splenic level; only lymphoid cells expressed this activity at the GALT [gut-associated lymphoid tissues] level. Together, these results describe a new activity of IgA against enteropathogenic bacteria.