title: CXCR5-Dependent Entry of CD8 T Cells into Rhesus Macaque B-Cell Follicles Achieved through T-Cell Engineering.
abstract: Follicular helper CD4 T cells, TFH, residing in B-cell follicles within secondary lymphoid tissues, are readily infected by AIDS viruses and are a major source of persistent virus despite relative control of viral replication. This persistence is due at least in part to a relative exclusion of effective antiviral CD8 T cells from B-cell follicles. To determine whether CD8 T cells could be engineered to enter B-cell follicles, we genetically modified unselected CD8 T cells to express CXC chemokine receptor 5 (CXCR5), the chemokine receptor implicated in cellular entry into B-cell follicles. Engineered CD8 T cells expressing human CXCR5 (CD8hCXCR5) exhibited ligand-specific signaling and chemotaxisin vitroSix infected rhesus macaques were infused with differentially fluorescent dye-labeled autologous CD8hCXCR5and untransduced CD8 T cells and necropsied 48 h later. Flow cytometry of both spleen and lymph node samples revealed higher frequencies of CD8hCXCR5than untransduced cells, consistent with preferential trafficking to B-cell follicle-containing tissues. Confocal fluorescence microscopy of thin-sectioned lymphoid tissues demonstrated strong preferential localization of CD8hCXCR5T cells within B-cell follicles with only rare cells in extrafollicular locations. CD8hCXCR5T cells were present throughout the follicles with some observed near infected TFHIn contrast, untransduced CD8 T cells were found in the extrafollicular T-cell zone. Our ability to direct localization of unselected CD8 T cells into B-cell follicles using CXCR5 expression provides a strategy to place highly effective virus-specific CD8 T cells into these AIDS virus sanctuaries and potentially suppress residual viral replication.IMPORTANCEAIDS virus persistence in individuals under effective drug therapy or those who spontaneously control viremia remains an obstacle to definitive treatment. Infected follicular helper CD4 T cells, TFH, present inside B-cell follicles represent a major source of this residual virus. While effective CD8 T-cell responses can control viral replication in conjunction with drug therapy or in rare cases spontaneously, most antiviral CD8 T cells do not enter B-cell follicles, and those that do fail to robustly control viral replication in the TFHpopulation. Thus, these sites are a sanctuary and a reservoir for replicating AIDS viruses. Here, we demonstrate that engineering unselected CD8 T cells to express CXCR5, a chemokine receptor on TFHassociated with B-cell follicle localization, redirects them into B-cell follicles. These proof of principle results open a pathway for directing engineered antiviral T cells into these viral sanctuaries to help eliminate this source of persistent virus.
authors.affiliation: AIDS and Cancer Virus Program, Leidos Biomedical Research, Inc., Frederick National Laboratory for Cancer Research, Frederick, Maryland, USA.
authors.forename: Victor I
authors.initials: VI
authors.lastname: Ayala
authors.affiliation: AIDS and Cancer Virus Program, Leidos Biomedical Research, Inc., Frederick National Laboratory for Cancer Research, Frederick, Maryland, USA.
authors.forename: Claire
authors.initials: C
authors.lastname: Deleage
authors.affiliation: AIDS and Cancer Virus Program, Leidos Biomedical Research, Inc., Frederick National Laboratory for Cancer Research, Frederick, Maryland, USA.
authors.forename: Matthew T
authors.initials: MT
authors.lastname: Trivett
authors.affiliation: AIDS and Cancer Virus Program, Leidos Biomedical Research, Inc., Frederick National Laboratory for Cancer Research, Frederick, Maryland, USA.
authors.forename: Sumiti
authors.initials: S
authors.lastname: Jain
authors.affiliation: AIDS and Cancer Virus Program, Leidos Biomedical Research, Inc., Frederick National Laboratory for Cancer Research, Frederick, Maryland, USA.
authors.forename: Lori V
authors.initials: LV
authors.lastname: Coren
authors.affiliation: Laboratory Animal Science Program, Leidos Biomedical Research, Inc., Frederick National Laboratory for Cancer Research, Frederick, Maryland, USA.
authors.forename: Matthew W
authors.initials: MW
authors.lastname: Breed
authors.affiliation: Laboratory Animal Science Program, Leidos Biomedical Research, Inc., Frederick National Laboratory for Cancer Research, Frederick, Maryland, USA.
authors.forename: Joshua A
authors.initials: JA
authors.lastname: Kramer
authors.affiliation: AIDS and Cancer Virus Program, Leidos Biomedical Research, Inc., Frederick National Laboratory for Cancer Research, Frederick, Maryland, USA.
authors.forename: James A
authors.initials: JA
authors.lastname: Thomas
authors.affiliation: AIDS and Cancer Virus Program, Leidos Biomedical Research, Inc., Frederick National Laboratory for Cancer Research, Frederick, Maryland, USA.
authors.forename: Jacob D
authors.initials: JD
authors.lastname: Estes
authors.affiliation: AIDS and Cancer Virus Program, Leidos Biomedical Research, Inc., Frederick National Laboratory for Cancer Research, Frederick, Maryland, USA.
authors.forename: Jeffrey D
authors.initials: JD
authors.lastname: Lifson
authors.affiliation: AIDS and Cancer Virus Program, Leidos Biomedical Research, Inc., Frederick National Laboratory for Cancer Research, Frederick, Maryland, USA ottde@mail.nih.gov.
authors.forename: David E
authors.initials: DE
authors.lastname: Ott
mesh_terms: D000818:Animals; D001402:B-Lymphocytes / Q000502:physiology* / Q000821:virology; D018414:CD8-Positive T-Lymphocytes / Q000378:metabolism* / Q000821:virology; D060846:Cell Engineering; D002633:Chemotaxis; D018858:Germinal Center / Q000166:cytology / Q000276:immunology* / Q000821:virology; D015658:HIV Infections / Q000276:immunology*; D015497:HIV-1 / Q000502:physiology; D006801:Humans; D008253:Macaca mulatta; D054380:Receptors, CXCR5 / Q000235:genetics* / Q000276:immunology / Q000378:metabolism*; D016201:Receptors, Lymphocyte Homing / Q000276:immunology; D006377:T-Lymphocytes, Helper-Inducer / Q000502:physiology; D014766:Viremia; D014779:Virus Replication / Q000276:immunology
chemical_list: C095085:CXCR5 protein, human; D054380:Receptors, CXCR5; D016201:Receptors, Lymphocyte Homing
keywords: B-cell follicles; CD8 T cells; CXCR5; T-cell homing