title: Toll-like receptor 4-dependent activation of dendritic cells by a retrovirus.
abstract: Mouse mammary tumor virus (MMTV) is a milk-borne retrovirus that exploits the adaptive immune system. It has recently been shown that MMTV activates B cells via Toll-like receptor 4 (TLR4), a molecule involved in innate immune responses. Here, we show that direct virus binding to TLR4 induced maturation of bone marrow-derived dendritic cells and up-regulated expression of the MMTV entry receptor (CD71) on these cells. In vivo, MMTV increased the number of dendritic cells in neonatal Peyer's patches and their expression of CD71; both these effects were dependent on TLR4. Thus, retroviral signaling through TLRs plays a critical role in dendritic-cell participation during infection.
authors.affiliation: División Medicina Experimental, Instituto de Investigaciones Hematológicas, Academia Nacional de Medicina, Buenos Aires, Argentina.
authors.forename: Dalia
authors.initials: D
authors.lastname: Burzyn
authors.forename: John C
authors.initials: JC
authors.lastname: Rassa
authors.forename: David
authors.initials: D
authors.lastname: Kim
authors.forename: Irene
authors.initials: I
authors.lastname: Nepomnaschy
authors.forename: Susan R
authors.initials: SR
authors.lastname: Ross
authors.forename: Isabel
authors.initials: I
authors.lastname: Piazzon
mesh_terms: D000818:Animals; D015703:Antigens, CD / Q000378:metabolism*; D000944:Antigens, Differentiation, B-Lymphocyte / Q000378:metabolism*; D001854:Bone Marrow Cells; D003713:Dendritic Cells / Q000276:immunology*; D008324:Mammary Tumor Virus, Mouse / Q000378:metabolism* / Q000472:pathogenicity; D008562:Membrane Glycoproteins / Q000378:metabolism*; D051379:Mice; D008807:Mice, Inbred BALB C; D008809:Mice, Inbred C3H; D011956:Receptors, Cell Surface / Q000378:metabolism*; D011990:Receptors, Transferrin; D012192:Retroviridae Infections / Q000821:virology; D051197:Toll-Like Receptor 4; D051193:Toll-Like Receptors; D014412:Tumor Virus Infections / Q000821:virology; D015854:Up-Regulation
chemical_list: D015703:Antigens, CD; D000944:Antigens, Differentiation, B-Lymphocyte; C068126:CD71 antigen; D008562:Membrane Glycoproteins; D011956:Receptors, Cell Surface; D011990:Receptors, Transferrin; D051197:Toll-Like Receptor 4; D051193:Toll-Like Receptors