title: Manipulation of EAT-2 expression promotes induction of multiple beneficial regulatory and effector functions of the human innate immune system as a novel immunomodulatory strategy.
abstract: The signaling lymphocytic activation molecule (SLAM) receptor-associated adaptor Ewing's sarcoma-associated transcript-2 (EAT-2) is primarily expressed in innate immune cells including dendritic cells (DCs), macrophages and NK cells. A recent human HIV vaccine study confirmed that EAT-2 expression was associated with the enhanced immunogenicity induced by the MRKAd5/HIV vaccine. We previously harnessed the capability of EAT-2 to modulate signaling mediated by SLAM receptors and demonstrated that by incorporating EAT-2 expression into vaccines, one could enhance innate and adaptive immune responses in mice, even in the face of pre-existing immunity to the vaccine vectors. Herein, we investigated the innate immune responses of human cells exposed to EAT-2-over-expressing vaccines. Our results demonstrate that EAT-2 over-expression can significantly alter the kinetics of critical pro-inflammatory cytokine and chemokine responses elaborated by human PBMCs. In addition, enhanced DC maturation and increased monocyte phagocytosis were observed in EAT-2-transduced human cells. We also found that EAT-2 over-expression improved antigen presentation by human cells. Moreover, EAT-2 over-expression increased the anti-tumor activity of human NK cells against K562 tumor cell targets. Many of these responses were extinguished with use of an EAT-2 variant carrying a mutant SH2 domain (R31Q), suggesting a critical role for the interaction between EAT-2 and SLAM receptors in mediating these responses. In conclusion, these results provide evidence that EAT-2 interacts with key components of multiple arms of the human innate immune system, and that this role highlights the potential for targeting EAT-2 functions so as to improve a number of human immunotherapeutic approaches, including vaccine development.
authors.affiliation: Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, MI 48824, USA.
authors.forename: Yasser A
authors.initials: YA
authors.lastname: Aldhamen
authors.forename: Sergey S
authors.initials: SS
authors.lastname: Seregin
authors.forename: Charles F
authors.initials: CF
authors.lastname: Aylsworth
authors.forename: Sarah
authors.initials: S
authors.lastname: Godbehere
authors.forename: Andrea
authors.initials: A
authors.lastname: Amalfitano
mesh_terms: D017951:Antigen Presentation / Q000235:genetics / Q000276:immunology; D002478:Cells, Cultured; D018920:Coculture Techniques; D016207:Cytokines / Q000276:immunology / Q000378:metabolism; D003602:Cytotoxicity, Immunologic / Q000276:immunology; D003713:Dendritic Cells / Q000276:immunology / Q000378:metabolism; D005434:Flow Cytometry; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism; D057809:HEK293 Cells; D006367:HeLa Cells; D006801:Humans; D007107:Immune System / Q000166:cytology / Q000276:immunology* / Q000378:metabolism; D007113:Immunity, Innate / Q000235:genetics / Q000276:immunology*; D056747:Immunomodulation / Q000235:genetics / Q000276:immunology*; D018836:Inflammation Mediators / Q000276:immunology / Q000378:metabolism; D020014:K562 Cells; D007694:Killer Cells, Natural / Q000276:immunology / Q000378:metabolism; D007963:Leukocytes, Mononuclear / Q000276:immunology / Q000378:metabolism; D008856:Microscopy, Fluorescence; D009000:Monocytes / Q000276:immunology / Q000378:metabolism; D009154:Mutation; D055629:Natural Cytotoxicity Triggering Receptor 2 / Q000276:immunology / Q000378:metabolism; D010587:Phagocytosis / Q000276:immunology; D014157:Transcription Factors / Q000235:genetics / Q000276:immunology* / Q000378:metabolism; D018909:src Homology Domains / Q000235:genetics / Q000276:immunology
chemical_list: D016207:Cytokines; D018836:Inflammation Mediators; C112837:NCR2 protein, human; D055629:Natural Cytotoxicity Triggering Receptor 2; C103572:SH2D1B protein, human; D014157:Transcription Factors; D049452:Green Fluorescent Proteins
keywords: EAT-2 adaptor; NK cells; SLAM receptors; chemokines; cytokines; dendritic cells; immune modulation; innate immunity; monocytes