CD40/CD154 Interactions Are Required for the Optimal Maturation of Skin-derived APCs and the Induction of Helminth-specific IFN-gamma but Not IL-4
Overview
Affiliations
The mechanisms through which Schistosoma mansoni larvae induce Th1 rather than Th2 immune responses are not well understood. In this study, using CD154-/- mice exposed to radiation-attenuated S. mansoni larvae, we demonstrate roles for CD154/CD40 in the activation of skin-derived APCs and the development of Th1 cells in the skin-draining lymph nodes (sdLN). The presence of CD154 was important for optimal IL-12p40 and essential for Ag-specific IFN-gamma, but CD154 expression by wild-type CD4- cells was insufficient to rescue recall responses of CD4+ cells from CD154-/- mice. This defect is probably due to impaired CD40-dependent IL-12 production in vivo, because administration of anti-CD40 Ab, or rIL-12, restored IFN-gamma production by sdLN cells from CD154-/- mice. CD154 ligation of CD40 was not required for the migration of skin-derived APCs, but did have a limited role in their maturation (increased MHC II and CD86). Unexpectedly, although CD4 cells from CD154-/- mice were deficient in their ability to produce IFN-gamma, they produced significant amounts of IL-4 and IL-5 in the presence of skin-derived APCs from wild-type and CD154-/- mice. Thus, in contrast to IFN-gamma, the production of Th2-associated cytokines is (in this model) independent of CD154. We conclude that whereas the priming of Th1 responses soon after exposure to schistosome larvae is completely CD40/CD154 dependent, IL-4, IL-5, and IL-13 are independent of CD154, suggesting a dichotomy in the specific mechanisms that induce these cytokines by CD4+ cells in the sdLN.
Prendergast C, Sanin D, Mountford A Parasite Immunol. 2015; 38(2):81-92.
PMID: 26679416 PMC: 4744672. DOI: 10.1111/pim.12300.
Prendergast C, Sanin D, Cook P, Mountford A Infect Immun. 2015; 83(4):1418-30.
PMID: 25624353 PMC: 4363412. DOI: 10.1128/IAI.02831-14.
Cook P, Aynsley S, Turner J, Jenkins G, van Rooijen N, Leeto M PLoS Pathog. 2011; 7(3):e1001323.
PMID: 21445234 PMC: 3060168. DOI: 10.1371/journal.ppat.1001323.
CD40 and the immune response to parasitic infections.
Subauste C Semin Immunol. 2009; 21(5):273-82.
PMID: 19616968 PMC: 2758065. DOI: 10.1016/j.smim.2009.06.003.
Hewitson J, Hamblin P, Mountford A Infect Immun. 2007; 75(7):3539-47.
PMID: 17485453 PMC: 1932915. DOI: 10.1128/IAI.00252-07.