Human dendritic cells respond to Porphyromonas gingivalis LPS by promoting a Th2 effector response in vitro.
Understanding how mucosal pathogens modulate the immune response may facilitate the development of vaccines for disparate human diseases. In the present study, human monocyte-derived DC (MDDC)were pulsed with LPS of the oral pathogen Porphyromonas gingivalis and Escherichia coli 25922 and analyzed for: (i) production of Th-biasing/inflammatory cytokines; (ii) maturation/costimulatory molecules; and (iii) induction of allogeneic CD4+ and naive CD45RA+ T cell proliferation and release of Th1 or Th2 cytokines. We show that E. coli LPS-pulsed MDDC released Th1-biasing cytokines - consisting of high levels of IL-12 p70, IFN-gamma-inducible protein 10 (IP-10) - but also TNF-alpha, IL-10, IL-6 and IL-1beta. In contrast, no IL-12 p70 or IP-10, and lower levels of TNF-alpha and IL-10 were induced by P. gingivalis LPS. These differences were sustained at LPS doses that yielded nearly equivalent maturation of MDDC; moreover the T cell response was consistent: E. coli LPS-pulsed MDDC induced higher T cell proliferation, and T cells released more IFN-gamma and IL-2, but less IL-5 than T cells co-cultured with P. gingivalis LPS pulsed-MDDC. IL-13 was secreted by naive CD45RA+CD45RO-CD4+ T cells in response to P. gingivalisLPS-pulsed MDDC. These results suggest that human MDDC can be polarized by LPS from the mucosal pathogen P. gingivalis to induce a Th2 effector response in vitro.
Department of Periodontics, Stony Brook University--Health Science Center, Stony Brook, NY 11794-8703, USA.
Ravi
R
Jotwani
Bali
B
Pulendran
Sudhanshu
S
Agrawal
Christopher W
CW
Cutler
D015496:CD4-Positive T-Lymphocytes; D003713:Dendritic Cells / Q000276:immunology*; D006801:Humans; D007109:Immunity / Q000187:drug effects; D008070:Lipopolysaccharides / Q000276:immunology* / Q000494:pharmacology; D016966:Porphyromonas gingivalis / Q000276:immunology*; D018417:Th1 Cells / Q000276:immunology; D018418:Th2 Cells / Q000276:immunology*
D008070:Lipopolysaccharides