title: CD40-activated B cells can efficiently prime antigen-specific naïve CD8+ T cells to generate effector but not memory T cells.
abstract: BACKGROUND
  The identification of the signals that should be provided by antigen-presenting cells (APCs) to induce a CD8(+) T cell response in vivo is essential to improve vaccination strategies using antigen-loaded APCs. Although dendritic cells have been extensively studied, the ability of other APC types, such as B cells, to induce a CD8(+) T cell response have not been thoroughly evaluated.
  
  
  RESULTS
  In this manuscript, we have characterized the ability of CD40-activated B cells, stimulated or not with Toll-like receptor (TLR) agonists (CpG or lipopolysaccharide) to induce the response of mouse naïve CD8(+) T cells in vivo. Our results show that CD40-activated B cells can directly present antigen to naïve CD8(+) T cells to induce the generation of potent effectors able to secrete cytokines, kill target cells and control a Listeria monocytogenes infection. However, CD40-activated B cell immunization did not lead to the proper formation of CD8(+) memory T cells and further maturation of CD40-activated B cells with TLR agonists did not promote the development of CD8(+) memory T cells. Our results also suggest that inefficient generation of CD8(+) memory T cells with CD40-activated B cell immunization is a consequence of reduced Bcl-6 expression by effectors and enhanced contraction of the CD8(+) T cell response.
  
  
  CONCLUSIONS
  Understanding why CD40-activated B cell immunization is defective for the generation of memory T cells and gaining new insights about signals that should be provided by APCs are key steps before translating the use of CD40-B cell for therapeutic vaccination.
authors.affiliation: Maisonneuve-Rosemont Hospital Research Center, Montréal, Québec, Canada.
authors.forename: Mélissa
authors.initials: M
authors.lastname: Mathieu
authors.forename: Natacha
authors.initials: N
authors.lastname: Cotta-Grand
authors.forename: Jean-François
authors.initials: JF
authors.lastname: Daudelin
authors.forename: Salix
authors.initials: S
authors.lastname: Boulet
authors.forename: Réjean
authors.initials: R
authors.lastname: Lapointe
authors.forename: Nathalie
authors.initials: N
authors.lastname: Labrecque
mesh_terms: D000818:Animals; D017951:Antigen Presentation / Q000276:immunology*; D001402:B-Lymphocytes / Q000276:immunology* / Q000378:metabolism; D019013:CD40 Antigens / Q000378:metabolism*; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology* / Q000378:metabolism; D002478:Cells, Cultured; D007156:Immunologic Memory / Q000276:immunology*; D008089:Listeria monocytogenes / Q000276:immunology / Q000378:metabolism; D008088:Listeriosis / Q000276:immunology; D008213:Lymphocyte Activation / Q000276:immunology*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D013601:T-Lymphocytes / Q000276:immunology / Q000378:metabolism
chemical_list: D019013:CD40 Antigens