title: Effect of Anti-IL-15 Administration on T Cell and NK Cell Homeostasis in Rhesus Macaques.
abstract: IL-15 has been implicated as a key regulator of T and NK cell homeostasis in multiple systems; however, its specific role in maintaining peripheral T and NK cell populations relative to other γ-chain (γc) cytokines has not been fully defined in primates. In this article, we address this question by determining the effect of IL-15 inhibition with a rhesusized anti-IL-15 mAb on T and NK cell dynamics in rhesus macaques. Strikingly, anti-IL-15 treatment resulted in rapid depletion of NK cells and both CD4(+) and CD8(+) effector memory T cells (TEM) in blood and tissues, with little to no effect on naive or central memory T cells. Importantly, whereas depletion of NK cells was nearly complete and maintained as long as anti-IL-15 treatment was given, TEM depletion was countered by the onset of massive TEM proliferation, which almost completely restored circulating TEM numbers. Tissue TEM, however, remained significantly reduced, and most TEM maintained very high turnover throughout anti-IL-15 treatment. In the presence of IL-15 inhibition, TEM became increasingly more sensitive to IL-7 stimulation in vivo, and transcriptional analysis of TEM in IL-15-inhibited monkeys revealed engagement of the JAK/STAT signaling pathway, suggesting alternative γc cytokine signaling may support TEM homeostasis in the absence of IL-15. Thus, IL-15 plays a major role in peripheral maintenance of NK cells and TEM However, whereas most NK cell populations collapse in the absence of IL-15, TEM can be maintained in the face of IL-15 inhibition by the activity of other homeostatic regulators, most likely IL-7.
authors.affiliation: Vaccine and Gene Therapy Institute, Oregon Health & Science University, Beaverton, OR 97006; Oregon National Primate Research Center, Oregon Health & Science University, Beaverton, OR 97006;
authors.forename: Maren Q
authors.initials: MQ
authors.lastname: DeGottardi
authors.affiliation: Vaccine and Gene Therapy Institute, Oregon Health & Science University, Beaverton, OR 97006; Oregon National Primate Research Center, Oregon Health & Science University, Beaverton, OR 97006;
authors.forename: Afam A
authors.initials: AA
authors.lastname: Okoye
authors.affiliation: Vaccine and Gene Therapy Institute, Oregon Health & Science University, Beaverton, OR 97006; Oregon National Primate Research Center, Oregon Health & Science University, Beaverton, OR 97006;
authors.forename: Mukta
authors.initials: M
authors.lastname: Vaidya
authors.affiliation: Department of Pathology, Case Western Reserve University, Cleveland, OH 44106;
authors.forename: Aarthi
authors.initials: A
authors.lastname: Talla
authors.affiliation: Vaccine and Gene Therapy Institute, Oregon Health & Science University, Beaverton, OR 97006; Oregon National Primate Research Center, Oregon Health & Science University, Beaverton, OR 97006;
authors.forename: Audrie L
authors.identifier: 0000-0002-7994-5458
authors.initials: AL
authors.lastname: Konfe
authors.affiliation: Vaccine and Gene Therapy Institute, Oregon Health & Science University, Beaverton, OR 97006; Oregon National Primate Research Center, Oregon Health & Science University, Beaverton, OR 97006;
authors.forename: Matthew D
authors.initials: MD
authors.lastname: Reyes
authors.affiliation: Vaccine and Gene Therapy Institute, Oregon Health & Science University, Beaverton, OR 97006; Oregon National Primate Research Center, Oregon Health & Science University, Beaverton, OR 97006;
authors.forename: Joseph A
authors.initials: JA
authors.lastname: Clock
authors.affiliation: Vaccine and Gene Therapy Institute, Oregon Health & Science University, Beaverton, OR 97006; Oregon National Primate Research Center, Oregon Health & Science University, Beaverton, OR 97006;
authors.forename: Derick M
authors.initials: DM
authors.lastname: Duell
authors.affiliation: Vaccine and Gene Therapy Institute, Oregon Health & Science University, Beaverton, OR 97006; Oregon National Primate Research Center, Oregon Health & Science University, Beaverton, OR 97006;
authors.forename: Alfred W
authors.initials: AW
authors.lastname: Legasse
authors.affiliation: Department of Pathology, Case Western Reserve University, Cleveland, OH 44106;
authors.forename: Amit
authors.identifier: 0000-0002-6868-888X
authors.initials: A
authors.lastname: Sabnis
authors.affiliation: Division of Biostatistics, Department of Public Health and Preventative Medicine, Oregon Health & Science University, Portland, OR 97239;
authors.forename: Byung S
authors.identifier: 0000-0003-3516-7516
authors.initials: BS
authors.lastname: Park
authors.affiliation: Vaccine and Gene Therapy Institute, Oregon Health & Science University, Beaverton, OR 97006; Oregon National Primate Research Center, Oregon Health & Science University, Beaverton, OR 97006;
authors.forename: Michael K
authors.identifier: 0000-0002-1984-5906
authors.initials: MK
authors.lastname: Axthelm
authors.affiliation: AIDS and Cancer Virus Program, Leidos Biomedical Research, Inc., Frederick National Laboratory, Frederick, MD 21702; and.
authors.forename: Jacob D
authors.initials: JD
authors.lastname: Estes
authors.affiliation: MassBiologics, University of Massachusetts Medical School, Boston, MA 02126.
authors.forename: Keith A
authors.initials: KA
authors.lastname: Reiman
authors.affiliation: Department of Pathology, Case Western Reserve University, Cleveland, OH 44106;
authors.forename: Rafick-Pierre
authors.initials: RP
authors.lastname: Sekaly
authors.affiliation: Vaccine and Gene Therapy Institute, Oregon Health & Science University, Beaverton, OR 97006; Oregon National Primate Research Center, Oregon Health & Science University, Beaverton, OR 97006; pickerl@ohsu.edu.
authors.forename: Louis J
authors.initials: LJ
authors.lastname: Picker
mesh_terms: D000818:Animals; D002469:Cell Separation; D004797:Enzyme-Linked Immunosorbent Assay; D005434:Flow Cytometry; D006706:Homeostasis / Q000276:immunology*; D007150:Immunohistochemistry; D019409:Interleukin-15 / Q000037:antagonists & inhibitors / Q000276:immunology*; D020381:Interleukin-17 / Q000276:immunology; D007694:Killer Cells, Natural / Q000276:immunology*; D016131:Lymphocyte Subsets / Q000276:immunology*; D008253:Macaca mulatta; D020411:Oligonucleotide Array Sequence Analysis; D013601:T-Lymphocytes / Q000276:immunology*
chemical_list: D019409:Interleukin-15; D020381:Interleukin-17