title: Differential CD4(+) T-cell memory responses induced by two subsets of human monocyte-derived dendritic cells.
abstract: Dendritic cells (DC) are powerful inducers of primary T-cell responses, but their role in secondary responses has not been extensively analysed. Here, we address the role of two DC subsets derived from human CD16(+) (16(+) mDC) or CD16(-) (16(-) mDC) monocytes on the reactivation of memory responses. CD4(+) CD45RA(-) memory T cells were obtained from adult blood donors, and central (T(CM)) and effector (T(EM)) memory T cells were isolated by fluorescence-activated cell sorting with anti-CCR7 antibodies. The 16(+) mDC and 16(-) mDC were cocultured with autologous lymphocytes, either unpulsed or loaded with purified protein derivatives of Mycobacterium tuberculosis (PPD) or tetanus toxoid (TT), and were analysed for up to 8 days. Over a range of doses, 16(+) mDC drove stronger T-cell proliferative responses against both antigens. Overall, antigen-specific memory cells tended to acquire a phenotype of T(EM) at later time-points in the culture, whereas cells that had completed fewer cycles of division were similar to T(CM). The 16(+) mDC induced higher rates of proliferation on both T(CM) and T(EM) lymphocytes than 16(-) mDC. This phenomenon was not related to the ability of both DC to induce CD25 expression on T cells, to lower secretion of interleukin-2, or to raise production of interleukin-10 during T-cell/16(-) mDC cocultures. The induction of T(CM) effector capacity in terms of interferon-gamma production was faster and more pronounced with 16(+) mDC, whereas both DC had similar abilities with T(EM). In conclusion, these data might reveal new potentials in vaccination protocols with 16(+) mDC aimed at inducing strong responses on central memory T cells.
authors.affiliation: Sección de Estudios de Posgrado e Investigación, Escuela Superior de Medicina del Instituto Politécnico Nacional, Mexico City, Mexico.
authors.forename: Sandra
authors.initials: S
authors.lastname: Bajaña
authors.forename: Norma
authors.initials: N
authors.lastname: Herrera-González
authors.forename: Juana
authors.initials: J
authors.lastname: Narváez
authors.forename: Honorio
authors.initials: H
authors.lastname: Torres-Aguilar
authors.forename: Amaranta
authors.initials: A
authors.lastname: Rivas-Carvalho
authors.forename: Sergio R
authors.initials: SR
authors.lastname: Aguilar
authors.forename: Carmen
authors.initials: C
authors.lastname: Sánchez-Torres
mesh_terms: D017951:Antigen Presentation / Q000276:immunology; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology*; D049109:Cell Proliferation; D002478:Cells, Cultured; D003713:Dendritic Cells / Q000276:immunology*; D004306:Dose-Response Relationship, Immunologic; D006801:Humans; D007156:Immunologic Memory; D016130:Immunophenotyping; D007371:Interferon-gamma / Q000096:biosynthesis; D008213:Lymphocyte Activation / Q000276:immunology; D013745:Tetanus Toxoid / Q000276:immunology; D014373:Tuberculin / Q000276:immunology
chemical_list: D013745:Tetanus Toxoid; D014373:Tuberculin; D007371:Interferon-gamma