title: The absence of lymphoid CD8+ dendritic cell maturation in L-selectin-/- respiratory compartment attenuates antiviral immunity.
abstract: Intratracheal instillation of L-selectin-deficient (L-Sel(-/-)) mice with an adenovirus 2 (Ad2) vector resulted in the lack of respiratory Ad2- or beta-galactosidase-specific CTLs with concomitant long-lived beta-galactosidase transgene expression in the lungs. The absence of Ag-specific CTLs was attributed to a deficiency in lymphoid CD11c(+)CD8(+) dendritic cells (DCs) in the lower respiratory lymph nodes (LRLNs). To enable L-Sel(-/-) CTL activity, cell-sorted L-Sel(-/-)CD8(+) T cells were cocultured with cell-sorted L-Sel(+/+)CD8(+) or CD8(-) DCs or L-Sel(-/-)CD8(-) DCs. Only the CD8(+) DCs restored CTL activity; L-Sel(-/-)CD8(-) DCs failed to support L-Sel(+/+) CTLs because these remained immature, lacking the ability to express costimulatory molecules CD40, CD80, or CD86. Although no lung CD8(+) DCs were detected, the DC environment remained suppressive in L-Sel(-/-) mice evident by the lack of CTL responses following adenoviral challenge with OVA in recipient L-Sel(-/-) adoptively transferred with OT-1 CD8(+) T cells. To assess whether the L-Sel(-/-)CD8(-) DCs could be induced into maturity, microbial stimulation studies were performed showing the failure of L-Sel(-/-) LRLN to make matured DCs. When L-Sel(-/-) mice were subjected in vivo to microbial activation before Ad2 vector dosing, CTL activity was restored stimulating the renewed presence of LRLN CD8(+) DCs in L-Sel(-/-) mice. These studies show that impairment of L-Sel(-/-) DC maturation results in insufficient mature DCs that require microbial activation to restore increases in respiratory CD8(+) DCs to support CTL responses.
authors.affiliation: Veterinary Molecular Biology, Montana State University, Bozeman, MT 59717-3610, USA. dpascual@montana.edu
authors.forename: David W
authors.initials: DW
authors.lastname: Pascual
authors.forename: Xinhai
authors.initials: X
authors.lastname: Wang
authors.forename: Irina
authors.initials: I
authors.lastname: Kochetkova
authors.forename: Gayle
authors.initials: G
authors.lastname: Callis
authors.forename: Carol
authors.initials: C
authors.lastname: Riccardi
mesh_terms: D000256:Adenoviridae / Q000235:genetics / Q000276:immunology*; D000818:Animals; D018122:B7-1 Antigen / Q000276:immunology / Q000378:metabolism; D051940:B7-2 Antigen / Q000276:immunology / Q000378:metabolism; D019013:CD40 Antigens / Q000276:immunology / Q000378:metabolism; D016827:CD8 Antigens / Q000276:immunology* / Q000378:metabolism; D045744:Cell Line, Tumor; D003713:Dendritic Cells / Q000276:immunology* / Q000378:metabolism; D005822:Genetic Vectors; D019041:L-Selectin / Q000235:genetics / Q000276:immunology*; D008070:Lipopolysaccharides / Q000276:immunology; D008168:Lung / Q000276:immunology*; D008198:Lymph Nodes / Q000276:immunology*; D016131:Lymphocyte Subsets / Q000276:immunology / Q000378:metabolism; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology* / Q000378:metabolism
chemical_list: D018122:B7-1 Antigen; D051940:B7-2 Antigen; D019013:CD40 Antigens; D016827:CD8 Antigens; D008070:Lipopolysaccharides; D019041:L-Selectin