title: Germinal Center T Follicular Helper Cells Are Highly Permissive to HIV-1 and Alter Their Phenotype during Virus Replication.
abstract: HIV-1 replication is concentrated within CD4(+) T cells in B cell follicles of secondary lymphoid tissues during asymptomatic disease. Limited data suggest that a subset of T follicular helper cells (TFH) within germinal centers (GC) is highly permissive to HIV-1. Whether GC TFH are the major HIV-1 virus-producing cells in vivo has not been established. In this study, we investigated TFH permissivity to HIV-1 ex vivo by spinoculating and culturing tonsil cells with HIV-1 GFP reporter viruses. Using flow cytometry, higher percentages of GC TFH (CXCR5(high)PD-1(high)) and CXCR5(+)programmed cell death-1 (PD-1)(low) cells were GFP(+) than non-GC TFH (CXCR5(+)PD-1(intermediate)) or extrafollicular (EF) (CXCR5(-)) cells. When sorted prior to spinoculation, however, GC TFH were substantially more permissive than CXCR5(+)PD-1(low) or EF cells, suggesting that many GC TFH transition to a CXCR5(+)PD-1(low) phenotype during productive infection. In situ hybridization on inguinal lymph node sections from untreated HIV-1-infected individuals without AIDS revealed higher frequencies of HIV-1 RNA(+) cells in GC than non-GC regions of follicle or EF regions. Superinfection of HIV-1-infected individuals' lymph node cells with GFP reporter virus confirmed the permissivity of follicular cells ex vivo. Lymph node immunostaining revealed 96% of CXCR5(+)CD4(+) cells were located in follicles. Within sorted lymph node cells from four HIV-infected individuals, CXCR5(+) subsets harbored 11-66-fold more HIV-1 RNA than CXCR5(-) subsets, as determined by RT PCR. Thus, GC TFH are highly permissive to HIV-1, but downregulate PD-1 and, to a lesser extent, CXCR5 during HIV-1 replication. These data further implicate GC TFH as the major HIV-1-producing cells in chronic asymptomatic HIV-1 infection.
authors.affiliation: Department of Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO 80045;
authors.forename: Stephanie L
authors.initials: SL
authors.lastname: Kohler
authors.affiliation: Department of Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO 80045;
authors.forename: Michael N
authors.initials: MN
authors.lastname: Pham
authors.affiliation: Department of Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO 80045;
authors.forename: Joy M
authors.initials: JM
authors.lastname: Folkvord
authors.affiliation: Department of Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO 80045;
authors.forename: Tessa
authors.initials: T
authors.lastname: Arends
authors.affiliation: Department of Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO 80045;
authors.forename: Shannon M
authors.initials: SM
authors.lastname: Miller
authors.affiliation: Department of Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO 80045;
authors.forename: Brodie
authors.initials: B
authors.lastname: Miles
authors.affiliation: Department of Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO 80045;
authors.forename: Amie L
authors.identifier: http://orcid.org/0000-0003-2889-8476
authors.initials: AL
authors.lastname: Meditz
authors.affiliation: Department of Surgery, University of Colorado Anschutz Medical Campus, Aurora, CO 80045; and.
authors.forename: Martin
authors.initials: M
authors.lastname: McCarter
authors.affiliation: College of Dentistry, New York University, New York, NY 10010.
authors.forename: David N
authors.identifier: http://orcid.org/0000-0001-9389-5509
authors.initials: DN
authors.lastname: Levy
authors.affiliation: Department of Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO 80045; connicke@email.arizona.edu.
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Connick
mesh_terms: D058070:Asymptomatic Diseases; D002454:Cell Differentiation; D002478:Cells, Cultured; D018858:Germinal Center / Q000276:immunology*; D015658:HIV Infections / Q000276:immunology* / Q000821:virology; D015497:HIV-1 / Q000502:physiology*; D058507:Host Specificity; D006801:Humans; D014066:Palatine Tonsil / Q000473:pathology; D010641:Phenotype; D061026:Programmed Cell Death 1 Receptor / Q000378:metabolism; D054380:Receptors, CXCR5 / Q000378:metabolism; D015163:Superinfection; D006377:T-Lymphocytes, Helper-Inducer / Q000276:immunology* / Q000821:virology; D014779:Virus Replication
chemical_list: D061026:Programmed Cell Death 1 Receptor; D054380:Receptors, CXCR5