title: B cells expressing IL-10 mRNA modulate memory T cells after DNA-Hsp65 immunization.
abstract: In DNA vaccines, the gene of interest is cloned into a bacterial plasmid that is engineered to induce protein production for long periods in eukaryotic cells. Previous research has shown that the intramuscular immunization of BALB/c mice with a naked plasmid DNA fragment encoding the Mycobacterium leprae 65-kDa heat-shock protein (pcDNA3-Hsp65) induces protection against M. tuberculosis challenge. A key stage in the protective immune response after immunization is the generation of memory T cells. Previously, we have shown that B cells capture plasmid DNA-Hsp65 and thereby modulate the formation of CD8+ memory T cells after M. tuberculosis challenge in mice. Therefore, clarifying how B cells act as part of the protective immune response after DNA immunization is important for the development of more-effective vaccines. The aim of this study was to investigate the mechanisms by which B cells modulate memory T cells after DNA-Hsp65 immunization. C57BL/6 and BKO mice were injected three times, at 15-day intervals, with 100 µg naked pcDNA-Hsp65 per mouse. Thirty days after immunization, the percentages of effector memory T (TEM) cells (CD4+ and CD8+/CD44high/CD62Llow) and memory CD8+ T cells (CD8+/CD44high/CD62Llow/CD127+) were measured with flow cytometry. Interferon γ, interleukin 12 (IL-12), and IL-10 mRNAs were also quantified in whole spleen cells and purified B cells (CD43-) with real-time qPCR. Our data suggest that a B-cell subpopulation expressing IL-10 downregulated proinflammatory cytokine expression in the spleen, increasing the survival of CD4+ TEM cells and CD8+ TEM/CD127+ cells.
authors.affiliation: Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP, Brasil.
authors.forename: I C
authors.initials: IC
authors.lastname: Fontoura
authors.affiliation: Universidade Sagrado Coração, Bauru, SP, Brasil.
authors.forename: A P F
authors.initials: AP
authors.lastname: Trombone
authors.affiliation: Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP, Brasil.
authors.forename: L P
authors.initials: LP
authors.lastname: Almeida
authors.affiliation: Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP, Brasil.
authors.forename: J C C
authors.initials: JC
authors.lastname: Lorenzi
authors.affiliation: Instituto de Ciências Biomédicas, Universidade de São Paulo, São Paulo, SP, Brasil.
authors.forename: R A M
authors.initials: RA
authors.lastname: Rossetti
authors.affiliation: Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP, Brasil.
authors.forename: T
authors.initials: T
authors.lastname: Malardo
authors.affiliation: Universidade Paranaense, Cascavel, PR, Brasil.
authors.forename: E
authors.initials: E
authors.lastname: Padilha
authors.affiliation: Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP, Brasil.
authors.forename: W
authors.initials: W
authors.lastname: Schluchting
authors.affiliation: Departamento de Educação em Saúde, Universidade Federal de Sergipe, Lagarto, SE, Brasil.
authors.forename: R L L
authors.initials: RL
authors.lastname: Silva
authors.affiliation: Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP, Brasil.
authors.forename: A F
authors.initials: AF
authors.lastname: Gembre
authors.affiliation: Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP, Brasil.
authors.forename: J E C
authors.initials: JE
authors.lastname: Fiuza
authors.affiliation: Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP, Brasil.
authors.forename: C L
authors.initials: CL
authors.lastname: Silva
authors.affiliation: Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP, Brasil.
authors.forename: A
authors.initials: A
authors.lastname: Panunto-Castelo
authors.affiliation: Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP, Brasil.
authors.forename: A A M
authors.initials: AA
authors.lastname: Coelho-Castelo
mesh_terms: D000818:Animals; D001402:B-Lymphocytes / Q000276:immunology* / Q000378:metabolism; D005434:Flow Cytometry; D015870:Gene Expression / Q000235:genetics; D006360:Heat-Shock Proteins / Q000276:immunology* / Q000627:therapeutic use; D007156:Immunologic Memory / Q000502:physiology; D056747:Immunomodulation / Q000235:genetics*; D016130:Immunophenotyping / Q000145:classification; D018836:Inflammation Mediators / Q000032:analysis; D007371:Interferon-gamma / Q000032:analysis; D016753:Interleukin-10 / Q000235:genetics* / Q000276:immunology; D018664:Interleukin-12 / Q000032:analysis; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D012333:RNA, Messenger / Q000235:genetics / Q000276:immunology*; D060888:Real-Time Polymerase Chain Reaction; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013154:Spleen / Q000166:cytology / Q000276:immunology; D016176:T-Lymphocyte Subsets / Q000145:classification / Q000276:immunology*; D019444:Vaccines, DNA / Q000276:immunology / Q000627:therapeutic use; D018834:Chaperonin 60; D024101:Mitochondrial Proteins
chemical_list: D006360:Heat-Shock Proteins; D018836:Inflammation Mediators; D007371:Interferon-gamma; D016753:Interleukin-10; D018664:Interleukin-12; D012333:RNA, Messenger; D019444:Vaccines, DNA; C557066:Hspd1 protein, mouse; D018834:Chaperonin 60; D024101:Mitochondrial Proteins