title: LNFPIII/LeX-stimulated macrophages activate natural killer cells via CD40-CD40L interaction.
abstract: Lacto-N-fucopentaose III (LNFPIII) is a human milk sugar containing the biologically active Lewis X (LeX) trisaccharide. LNFPIII/LeX is also expressed by immunosuppressive helminth parasites, by bacteria, and on a number of tumor/cancer cells. In this report, we first demonstrate that LNFPIII activates macrophages in vitro as indicated by upregulation of Gr-1 expression on F4/80(+) cells. Further, we investigated the effect of LNFPIII-activated macrophages on NK cell activity. We found that LNFPIII-stimulated F4/80(+) cells were able to activate NK cells, inducing upregulation of CD69 expression and gamma interferon (IFN-gamma) production. The experiments show that NK cell activation is macrophage dependent, since NK cells alone did not secrete IFN-gamma in response to LNFPIII. Furthermore, we found that activation of NK cells by glycan-stimulated macrophages required cell-cell contact. As part of the cell-cell contact mechanism, we determined that CD40-CD40L interaction was critical for IFN-gamma secretion by NK cells, as the addition of anti-CD40L antibodies to the coculture blocked IFN-gamma production. We also demonstrated that LNFPIII-stimulated macrophages secrete prostaglandin E(2), interleukin-10 (IL-10), and tumor necrosis factor alpha (TNF-alpha) but a very low level of IL-12. Interestingly, addition of anti-TNF-alpha, anti-IL-10, or anti-IL-12 monoclonal antibodies did not significantly alter NK cell activity. Our data show that these soluble mediators are not critical for LNFPIII-stimulated macrophage activation of NK cells and provide further evidence for the importance of cell-cell contact and CD40-CD40L interactions between macrophages and NK cells.
authors.affiliation: Department of Immunology and Infectious Diseases, Harvard School of Public Health, 665 Huntington Ave., Boston, MA 02115, USA. oatochin@hsph.harvard.edu
authors.forename: Olga
authors.initials: O
authors.lastname: Atochina
authors.forename: Donald
authors.initials: D
authors.lastname: Harn
mesh_terms: D000606:Amino Sugars / Q000378:metabolism / Q000494:pharmacology*; D000818:Animals; D019013:CD40 Antigens / Q000378:metabolism*; D023201:CD40 Ligand / Q000378:metabolism*; D002450:Cell Communication / Q000187:drug effects / Q000276:immunology; D005260:Female; D066298:In Vitro Techniques; D007371:Interferon-gamma / Q000378:metabolism; D016753:Interleukin-10 / Q000378:metabolism; D018664:Interleukin-12 / Q000378:metabolism; D007376:Interleukin-2 / Q000494:pharmacology; D007694:Killer Cells, Natural / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism; D016256:Lewis X Antigen / Q000031:analogs & derivatives; D017737:Macrophages, Peritoneal / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D016513:Mice, SCID; D011134:Polysaccharides / Q000378:metabolism / Q000494:pharmacology*; D014312:Trisaccharides / Q000378:metabolism / Q000494:pharmacology*; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism
chemical_list: D000606:Amino Sugars; D019013:CD40 Antigens; D007376:Interleukin-2; D016256:Lewis X Antigen; D011134:Polysaccharides; D014312:Trisaccharides; D014409:Tumor Necrosis Factor-alpha; C110530:galactosyl-(1,4)-fucopyranosyl-(1,3)-N-acetylglucosamine; C434666:lacto-N-fucopentaose III; D016753:Interleukin-10; D023201:CD40 Ligand; D018664:Interleukin-12; D007371:Interferon-gamma