title: alpha-defensins released into stimulated CD8+ T-cell supernatants are likely derived from residual granulocytes within the irradiated allogeneic peripheral blood mononuclear cells used as feeders.
abstract: We recently demonstrated the ability of human beta-defensins to inhibit HIV-1 replication in vitro and demonstrated that alpha-defensins account for the great majority of beta-chemokine independent antiretroviral activity in stimulated CD8+ T-cell culture supernatants. In a follow-up study aimed at defining specific subpopulations of CD8+ T-cells that produce alpha-defensins, we have found that in the absence of irradiated allogeneic peripheral blood mononuclear cells (PBMC), stimulated CD8+ T-cell supernatants do not contain alpha-defensins. In our present work, we define residual granulocytes within PBMC fractions as the likely source. In addition, we describe in vitro conditions that promote the internalization of alpha-defensins by cells not natively producing these proteins, thus confounding our ability to define true alpha-defensin producer cells. In light of these findings, alpha-defensins released into stimulated CD8+ T-cell supernatants are unlikely to be derived from the CD8+ T-cells themselves. Moreover, our data imply that under some experimental conditions, a soluble noncytolytic anti-HIV-1 factor other than beta-chemokines is either not produced by CD8+ T-cells or is present in too small quantity to be effective.
authors.affiliation: Aaron Diamond AIDS Research Center, New York, NY 10016, USA.
authors.forename: Gerasimos J
authors.initials: GJ
authors.lastname: Zaharatos
authors.forename: Tian
authors.initials: T
authors.lastname: He
authors.forename: Peter
authors.initials: P
authors.lastname: Lopez
authors.forename: Wenjie
authors.initials: W
authors.lastname: Yu
authors.forename: Jian
authors.initials: J
authors.lastname: Yu
authors.forename: Linqi
authors.initials: L
authors.lastname: Zhang
mesh_terms: D001483:Base Sequence; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology* / Q000821:virology*; D018920:Coculture Techniques; D018076:DNA, Complementary / Q000235:genetics; D015870:Gene Expression; D006098:Granulocytes / Q000276:immunology* / Q000528:radiation effects; D015497:HIV-1 / Q000276:immunology* / Q000502:physiology*; D018922:HL-60 Cells; D006367:HeLa Cells; D006801:Humans; D007519:Isoantigens; D007963:Leukocytes, Mononuclear / Q000276:immunology / Q000528:radiation effects; D040081:Protein Array Analysis; D014779:Virus Replication; D023084:alpha-Defensins / Q000096:biosynthesis* / Q000235:genetics
chemical_list: D018076:DNA, Complementary; D007519:Isoantigens; D023084:alpha-Defensins