University of Pennsylvania ScholarlyCommons Publicly Accessible Penn Dissertations 2017 Widespread Use Of Cxcr6 For Entry By Natural Host Sivs: Implications For Cell Targeting And Infection Outcome Katherine Wetzel University of Pennsylvania, [email protected] Follow this and additional works at: https://repository.upenn.edu/edissertations Part of the Virology Commons Recommended Citation Wetzel, Katherine, "Widespread Use Of Cxcr6 For Entry By Natural Host Sivs: Implications For Cell Targeting And Infection Outcome" (2017). Publicly Accessible Penn Dissertations. 2793. https://repository.upenn.edu/edissertations/2793 This paper is posted at ScholarlyCommons. https://repository.upenn.edu/edissertations/2793 For more information, please contact [email protected]. Widespread Use Of Cxcr6 For Entry By Natural Host Sivs: Implications For Cell Targeting And Infection Outcome Abstract Natural hosts of simian immunodeficiency virus (SIV) are African primates that have coevolved with species-species SIVs and do not progress to AIDS despite high viral loads. This is in stark contrast to the immunodeficiency observed in infection of “non-natural” hosts of SIV/HIV, Asian macaques and humans. Certain critical CD4+ T cell subsets and anatomic niches that are required for maintaining immune system homeostasis and function are infected less frequently in natural hosts than in non-natural hosts, suggesting that the determinants of virus target cells contribute to the outcome of infection. SIV and HIV target cells are largely defined by the expression of the receptor CD4 and a coreceptor. Our lab recently discovered that the entry coreceptor CCR5 is dispensable for SIV infection of the natural host sooty mangabey (SM), and then identified CXCR6 as an additional coreceptor for this SIV. In this thesis, I defined entry coreceptors of a second natural host virus, SIVagmSab that infects sabaeus African green monkeys and found that CXCR6 was a robust coreceptor for this virus as well. I also investigated coreceptor use by the HIV-1 forerunners: the natural host virus SIVmus that infects mustached monkeys and crossed into chimpanzees; and SIVcpz that infects chimpanzees and causes AIDS-like disease and crossed into humans to found HIV-1. SIVmus infected cells expressing CXCR6 and CCR5, while SIVcpz was restricted to use of CCR5, indicating that loss of CXCR6 use coincided with the emergence of pathogenesis in this lineage. Lastly, I defined expression of CXCR6 on SM lymphocytes, and found little or no CXCR6 expression on CD4+ T cell subsets that are critical in lymphocyte homeostasis, but enrichment on replenishable effector memory CD4+ T cells. CXCR6+ CD4+ T cells were largely distinct from CCR5+ CD4+ T cells, thus forming a previously unappreciated SIV target cell population in SM. These data support a model where use of CXCR6 is a common feature among natural host SIVs that targets the virus towards more expendable cell subsets, and away from critical subsets and anatomic niches that are required to maintain immune system function, thus permitting high viral replication without immunodeficiency. Degree Type Dissertation Degree Name Doctor of Philosophy (PhD) Graduate Group Cell & Molecular Biology First Advisor Ronald G. Collman Keywords Coreceptor, CXCR6, Simian Immunodeficiency Virus, SIV Natural Host, Virus Entry Subject Categories Virology This dissertation is available at ScholarlyCommons: https://repository.upenn.edu/edissertations/2793 WIDESPREAD USE OF CXCR6 FOR ENTRY BY NATURAL HOST SIVS: IMPLICATIONS FOR CELL TARGETING AND INFECTION OUTCOME Katherine S. Wetzel A DISSERTATION in Cell and Molecular Biology Presented to the Faculties of the University of Pennsylvania in Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy 2017 Supervisor of Dissertation ____________________________ Ronald G. Collman, M.D. Professor of Medicine Graduate Group Chairperson ____________________________ Daniel S. Kessler, Ph.D., Associate Professor of Cell and Developmental Biology Dissertation Committee: Frederic D. Bushman, Ph.D., William Maul Measey Professor and Chair of Microbiology Michael R. Betts, Ph.D., Associate Professor of Microbiology James A. Hoxie, M.D., Professor of Medicine Scott E. Hensley, Ph.D., Associate Professor of Microbiology Dedication To my parents, Bruce and Peggy Sheehan, and my husband, Chris Wetzel, who have always supported my pursuit of learning. ii ACKNOWLEDGEMENT Thank you to my thesis mentor, Dr. Ron Collman, for his enthusiastic support and mentorship throughout my time in his lab. I’d also like to thank my thesis committee: Drs. Rick Bushman, Scott Hensley, Jim Hoxie and Mike Betts for their mentorship and experimental advice, as well as Collman lab members past and present: Sarah Elliott, Nick Francella, Yanjie Yi, Anjana Yadav, Ize Imai, Melanie Duncan, Vince Knecht, John McGinniss, Aurea Simon Soro, Arwa Abbas, Nadeene Riddick, Dino Romero, Ezekiel Bello, Anya Bauer, Farida Shaheen, Vanessa Marsh and Steven Bryan, who have offered technical and moral support throughout my tenure at UPenn. The Shaw/Hahn, Betts, Bushman, Hoxie, Cohen/Eisenberg and Bar labs were sources of valuable advice, expertise and support. I’d especially like to thank Fred Bibollet-Ruche, Ranjit Warrier, Emily Roberts and Kyle Bittinger. I am also grateful to Sabine Baxter in UPenn Cell Center Services for her contribution to the generation of the anti-CXCR6 antibody 20D8. This thesis work would not have been possible without generous sharing of samples from our collaborators: Drs. Guido Silvestri, Mirko Paiardini, Martine Peeters, Michaela Muller-Trutwin, Cristian Apetrei and Ivona Pandrea. I would also like to thank all involved with the Cell and Molecular Biology graduate group, MVP, the Microbiology Department, and the Center for Teaching and Learning. Lastly, I’d like to thank my funding, particularly the training grant in HIV Pathogenesis: 2T32AI007632 iii ABSTRACT WIDESPREAD USE OF CXCR6 FOR ENTRY BY NATURAL HOST SIVS: IMPLICATIONS FOR CELL TARGETING AND INFECTION OUTCOME Katherine S. Wetzel Ronald G. Collman, M.D. Natural hosts of simian immunodeficiency virus (SIV) are African primates that have coevolved with species-species SIVs and do not progress to AIDS despite high viral loads. This is in stark contrast to the immunodeficiency observed in infection of “non-natural” hosts of SIV/HIV, Asian macaques and humans. Certain critical CD4+ T cell subsets and anatomic niches that are required for maintaining immune system homeostasis and function are infected less frequently in natural hosts than in non-natural hosts, suggesting that the determinants of virus target cells contribute to the outcome of infection. SIV and HIV target cells are largely defined by the expression of the receptor CD4 and a coreceptor. Our lab recently discovered that the entry coreceptor CCR5 is dispensable for SIV infection of the natural host sooty mangabey (SM), and then identified CXCR6 as an additional coreceptor for this SIV. In this thesis, I defined entry coreceptors of a second natural host virus, SIVagmSab that infects sabaeus African green monkeys and found that CXCR6 was a robust coreceptor for this virus as well. I also investigated coreceptor use by the HIV-1 forerunners: the natural host virus SIVmus that infects mustached monkeys and crossed into chimpanzees; and SIVcpz that infects chimpanzees and causes AIDS- like disease and crossed into humans to found HIV-1. SIVmus infected cells expressing CXCR6 and CCR5, while SIVcpz was restricted to use of CCR5, indicating that loss of CXCR6 use coincided with the emergence of pathogenesis in this lineage. Lastly, I defined expression of CXCR6 on SM lymphocytes, and found little or no CXCR6 expression on CD4+ T cell subsets that are critical in lymphocyte homeostasis, but enrichment on replenishable effector memory CD4+ T cells. CXCR6+ CD4+ T cells were largely distinct from CCR5+ CD4+ T cells, thus forming a previously unappreciated SIV target cell population in SM. These data support a model where use of CXCR6 is a common feature among natural host SIVs that targets the virus towards more expendable cell subsets, and away from critical subsets and anatomic niches that are required to maintain immune system function, thus permitting high viral replication without immunodeficiency. iv TABLE OF CONTENTS ABSTRACT ........................................................................................................... iv LIST OF TABLES ................................................................................................ vii LIST OF ILLUSTRATIONS ................................................................................. viii CHAPTER 1 .......................................................................................................... 1 Introduction .......................................................................................................... 1 Introduction to HIV-1 and AIDS ..................................................................................... 2 HIV/SIV genome and replication ................................................................................... 3 Pathogenesis of HIV-1 infection and the animal model infection SIVmac ..................... 4 SIV+ African monkeys do not progress to AIDS ............................................................ 6 Natural host SIV origin of HIV-1 and SIVmac ................................................................ 6 Main features that vary between natural and non-natural