Study findings from Instituto Politecnico Nacional broaden understanding of immunology
2007 NOV 20 -- A report, 'Differential CD4(+) T-cell memory responses induced by two subsets of human monocyte-derived dendritic cells,' is newly published data in Immunology. "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," researchers in Mexico report. "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," wrote S. Bajaña and colleagues, Instituto Politecnico Nacional. The researchers concluded: "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)these data might reveal new potentials in vaccination protocols with 16(+) mDC aimed at inducing strong responses on central memory T cells." Bajaña and colleagues published their study in Immunology (Differential CD4(+) T-cell memory responses induced by two subsets of human monocyte-derived dendritic cells. Immunology, 2007;122(3):381-93). For additional information, contact S. Bajaña, Seccion de Estudios de Posgrado e Investigacion, Escuela Superior de Medicina del Instituto Politecnico Nacional, Mexico City, Mexico. Publisher contact information for the journal Immunology is: Blackwell Publishing Ltd., 9600 Garsington Rd., Oxford OX4 2DG, Oxon, England. Keywords: Mexico, Immunology. This article was prepared by Life Science Weekly editors from staff and other reports. Copyright 2007, Life Science Weekly via NewsRx.com.
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