title: Characterization of Human CD8 T Cell Responses in Dengue Virus-Infected Patients from India.
abstract: Epidemiological studies suggest that India has the largest number of dengue virus infection cases worldwide. However, there is minimal information about the immunological responses in these patients. CD8 T cells are important in dengue, because they have been implicated in both protection and immunopathology. Here, we provide a detailed analysis of HLA-DR+CD38+and HLA-DR-CD38+effector CD8 T cell subsets in dengue patients from India and Thailand. Both CD8 T cell subsets expanded and expressed markers indicative of antigen-driven proliferation, tissue homing, and cytotoxic effector functions, with the HLA-DR+CD38+subset being the most striking in these effector qualities. The breadth of the dengue-specific CD8 T cell response was diverse, with NS3-specific cells being the most dominant. Interestingly, only a small fraction of these activated effector CD8 T cells produced gamma interferon (IFN-γ) when stimulated with dengue virus peptide pools. Transcriptomics revealed downregulation of key molecules involved in T cell receptor (TCR) signaling. Consistent with this, the majority of these CD8 T cells remained IFN-γ unresponsive even after TCR-dependent polyclonal stimulation (anti-CD3 plus anti-CD28) but produced IFN-γ by TCR-independent polyclonal stimulation (phorbol 12-myristate 13-acetate [PMA] plus ionomycin). Thus, the vast majority of these proliferating, highly differentiated effector CD8 T cells probably acquire TCR refractoriness at the time the patient is experiencing febrile illness that leads to IFN-γ unresponsiveness. Our studies open novel avenues for understanding the mechanisms that fine-tune the balance between CD8 T cell-mediated protective versus pathological effects in dengue.
  
  
  OBJECTIVE
  Dengue is becoming a global public health concern. Although CD8 T cells have been implicated both in protection and in the cytokine-mediated immunopathology of dengue, how the balance is maintained between these opposing functions remains unknown. We comprehensively characterized CD8 T cell subsets in dengue patients from India and Thailand and show that these cells expand massively and express phenotypes indicative of overwhelming antigenic stimulus and tissue homing/cytotoxic-effector functions but that a vast majority of them fail to produce IFN-γ in vitro Interestingly, the cells were fully capable of producing the cytokine when stimulated in a T cell receptor (TCR)-independent manner but failed to do so in TCR-dependent stimulation. These results, together with transcriptomics, revealed that the vast majority of these CD8 T cells from dengue patients become cytokine unresponsive due to TCR signaling insufficiencies. These observations open novel avenues for understanding the mechanisms that fine-tune the balance between CD8-mediated protective versus pathological effects.
authors.affiliation: ICGEB-Emory Vaccine Center, International Center for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi, India.
authors.forename: Anmol
authors.initials: A
authors.lastname: Chandele
authors.affiliation: Emory Vaccine Center, Emory University School of Medicine, Atlanta, Georgia, USA.|Department of Microbiology, Faculty of Medicine, Siriraj Hospital, Mahidol University, Bangkok, Thailand.|Department of Microbiology and Immunology, Emory University School of Medicine, Atlanta, Georgia, USA.
authors.forename: Jaturong
authors.initials: J
authors.lastname: Sewatanon
authors.affiliation: Department of Pediatrics, Division of Infectious Disease, and Emory Vaccine Center, Emory University School of Medicine, Atlanta, Georgia, USA.
authors.forename: Sivaram
authors.initials: S
authors.lastname: Gunisetty
authors.affiliation: Pediatric Pulmonary Division, Department of Pediatrics, All India Institute of Medical Sciences, Ansari Nagar, New Delhi, India.
authors.forename: Mohit
authors.initials: M
authors.lastname: Singla
authors.affiliation: Department of Research and Development, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand.
authors.forename: Nattawat
authors.initials: N
authors.lastname: Onlamoon
authors.affiliation: Emory Vaccine Center, Emory University School of Medicine, Atlanta, Georgia, USA.
authors.forename: Rama S
authors.initials: RS
authors.lastname: Akondy
authors.affiliation: Department of Microbiology and Immunology, Emory University School of Medicine, Atlanta, Georgia, USA.|Department of Urology, Emory University School of Medicine, Atlanta, Georgia, USA.
authors.forename: Haydn Thomas
authors.initials: HT
authors.lastname: Kissick
authors.affiliation: ICGEB-Emory Vaccine Center, International Center for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi, India.
authors.forename: Kaustuv
authors.initials: K
authors.lastname: Nayak
authors.affiliation: ICGEB-Emory Vaccine Center, International Center for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi, India.
authors.forename: Elluri Seetharami
authors.initials: ES
authors.lastname: Reddy
authors.affiliation: Immunology Group, International Center for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi, India.
authors.forename: Haroon
authors.initials: H
authors.lastname: Kalam
authors.affiliation: Immunology Group, International Center for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi, India.
authors.forename: Dhiraj
authors.initials: D
authors.lastname: Kumar
authors.affiliation: Pediatric Pulmonary Division, Department of Pediatrics, All India Institute of Medical Sciences, Ansari Nagar, New Delhi, India.
authors.forename: Anil
authors.initials: A
authors.lastname: Verma
authors.affiliation: ICGEB-Emory Vaccine Center, International Center for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi, India.
authors.forename: HareKrushna
authors.initials: H
authors.lastname: Panda
authors.affiliation: Department of Research and Development, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand.
authors.forename: Siyu
authors.initials: S
authors.lastname: Wang
authors.affiliation: Department of Pediatrics, Faculty of Medicine, Siriraj Hospital, Mahidol University, Bangkok, Thailand.
authors.forename: Nasikarn
authors.initials: N
authors.lastname: Angkasekwinai
authors.affiliation: Department of Research and Development, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand.
authors.forename: Kovit
authors.initials: K
authors.lastname: Pattanapanyasat
authors.affiliation: Department of Pediatrics, Faculty of Medicine, Siriraj Hospital, Mahidol University, Bangkok, Thailand.
authors.forename: Kulkanya
authors.initials: K
authors.lastname: Chokephaibulkit
authors.affiliation: Translational Health Science and Technology Institute, Faridabad, Haryana, India.
authors.forename: Guruprasad R
authors.identifier: http://orcid.org/0000-0001-5333-9743
authors.initials: GR
authors.lastname: Medigeshi
authors.affiliation: Pediatric Pulmonary Division, Department of Pediatrics, All India Institute of Medical Sciences, Ansari Nagar, New Delhi, India.
authors.forename: Rakesh
authors.initials: R
authors.lastname: Lodha
authors.affiliation: Pediatric Pulmonary Division, Department of Pediatrics, All India Institute of Medical Sciences, Ansari Nagar, New Delhi, India.
authors.forename: Sushil
authors.initials: S
authors.lastname: Kabra
authors.affiliation: Emory Vaccine Center, Emory University School of Medicine, Atlanta, Georgia, USA.|Department of Microbiology and Immunology, Emory University School of Medicine, Atlanta, Georgia, USA.
authors.forename: Rafi
authors.initials: R
authors.lastname: Ahmed
authors.affiliation: ICGEB-Emory Vaccine Center, International Center for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi, India Murali.kaja@emory.edu.|Emory Vaccine Center, Emory University School of Medicine, Atlanta, Georgia, USA.|Department of Pediatrics, Division of Infectious Disease, and Emory Vaccine Center, Emory University School of Medicine, Atlanta, Georgia, USA.
authors.forename: Kaja
authors.initials: K
authors.lastname: Murali-Krishna
mesh_terms: D051997:ADP-ribosyl Cyclase 1 / Q000235:genetics / Q000276:immunology; D000293:Adolescent; D000906:Antibodies / Q000494:pharmacology; D018106:CD28 Antigens / Q000037:antagonists & inhibitors / Q000235:genetics / Q000276:immunology; D017252:CD3 Complex / Q000235:genetics / Q000276:immunology; D018414:CD8-Positive T-Lymphocytes / Q000187:drug effects / Q000276:immunology* / Q000821:virology; D049109:Cell Proliferation / Q000187:drug effects; D002648:Child; D002675:Child, Preschool; D003602:Cytotoxicity, Immunologic; D003716:Dengue Virus / Q000187:drug effects* / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D005260:Female; D005786:Gene Expression Regulation; D006684:HLA-DR Antigens / Q000235:genetics / Q000276:immunology; D006801:Humans; D007111:Immunity, Cellular; D007194:India; D007223:Infant; D007371:Interferon-gamma / Q000235:genetics / Q000276:immunology; D015759:Ionomycin / Q000494:pharmacology; D008297:Male; D008562:Membrane Glycoproteins / Q000235:genetics / Q000276:immunology; D061251:Primary Cell Culture; D020365:RNA Helicases / Q000235:genetics / Q000276:immunology; D011948:Receptors, Antigen, T-Cell / Q000235:genetics / Q000276:immunology; D012697:Serine Endopeptidases / Q000235:genetics / Q000276:immunology; D015398:Signal Transduction; D016176:T-Lymphocyte Subsets / Q000187:drug effects / Q000276:immunology* / Q000821:virology; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D059467:Transcriptome / Q000276:immunology*; D017361:Viral Nonstructural Proteins / Q000235:genetics / Q000276:immunology; D043583:Nucleoside-Triphosphatase; D053487:DEAD-box RNA Helicases; D000085242:Viral Proteases
chemical_list: D051997:ADP-ribosyl Cyclase 1; D000906:Antibodies; D018106:CD28 Antigens; D017252:CD3 Complex; D006684:HLA-DR Antigens; D007371:Interferon-gamma; D015759:Ionomycin; D008562:Membrane Glycoproteins; D020365:RNA Helicases; D011948:Receptors, Antigen, T-Cell; D012697:Serine Endopeptidases; D013755:Tetradecanoylphorbol Acetate; D017361:Viral Nonstructural Proteins; C060028:NS3 protein, flavivirus; D043583:Nucleoside-Triphosphatase; D053487:DEAD-box RNA Helicases; D000085242:Viral Proteases; C498154:CD38 protein, human