title: Effects of cryopreservation on CD4+ CD25+ T cells of HIV-1 infected individuals.
abstract: The role of T regulatory cells (Tregs) in human immunodeficiency virus (HIV)-1 infection, although not entirely clear, has recently been highlighted. Despite their lack of specificity, fluorochrome-labeled CD4 and CD25 antibodies are common flow cytometric reagents used to identify these cells with immunosuppressive potential. Cryopreservation has previously been shown to alter the proportions of lymphocytes with certain phenotypes expressed in peripheral blood mononuclear cells (PBMCs). The aim of this study was to assess the effect of cryopreservation on CD4+ CD25+ T cells in PBMCs from HIV-1+ individuals to guide the design of future studies on Tregs. We recruited 30 HIV-1+ individuals and nine healthy controls. CD25 expression in CD4+ T cells was compared between fresh and frozen/thawed PBMC samples from the same time point. In this study, cryopreservation significantly decreased the proportion of CD4+ CD25+ T cells in PBMC samples from HIV-1 infected subjects. This finding suggests that studies of CD4+ CD25+ T cells should be carried out on fresh samples to avoid bias introduced by cryopreservation.
authors.affiliation: Nuffield Department of Medicine, Oxford University, Oxford, United Kingdom.
authors.forename: Anna C
authors.initials: AC
authors.lastname: Seale
authors.forename: Bouke C
authors.initials: BC
authors.lastname: de Jong
authors.forename: Irfan
authors.initials: I
authors.lastname: Zaidi
authors.forename: Melody
authors.initials: M
authors.lastname: Duvall
authors.forename: Hilton
authors.initials: H
authors.lastname: Whittle
authors.forename: Sarah
authors.initials: S
authors.lastname: Rowland-Jones
authors.forename: Assan
authors.initials: A
authors.lastname: Jaye
mesh_terms: D000293:Adolescent; D000328:Adult; D015496:CD4-Positive T-Lymphocytes / Q000378:metabolism; D002470:Cell Survival; D002648:Child; D003080:Cold Temperature / Q000009:adverse effects*; D015925:Cryopreservation / Q000379:methods*; D005260:Female; D005434:Flow Cytometry; D015658:HIV Infections / Q000097:blood / Q000276:immunology*; D006801:Humans; D016130:Immunophenotyping; D053645:Interleukin-2 Receptor alpha Subunit / Q000378:metabolism; D007963:Leukocytes, Mononuclear / Q000166:cytology; D008297:Male; D008875:Middle Aged; D050378:T-Lymphocytes, Regulatory / Q000276:immunology
chemical_list: D053645:Interleukin-2 Receptor alpha Subunit