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: Yasser A Aldhamen, Sergey S Seregin, Charles F Aylsworth, Sarah Godbehere, Andrea Amalfitano
• Journal: International immunology (Int Immunol) Vol. 26 Issue 5 Pg. 291-303 (May 2014) ISSN: 1460-2377 [Electronic] England
• PMID: 24374770 (Publication Type: Journal Article, Research Support, N.I.H., Extramural, Research Support, Non-U.S. Gov't)

Chemical References

• Cytokines
• Inflammation Mediators
• NCR2 protein, human
• Natural Cytotoxicity Triggering Receptor 2
• SH2D1B protein, human
• Transcription Factors
• Green Fluorescent Proteins

Topics

• Antigen Presentation (genetics, immunology)
• Cells, Cultured
• Coculture Techniques
• Cytokines (immunology, metabolism)
• Cytotoxicity, Immunologic (immunology)
• Dendritic Cells (immunology, metabolism)
• Flow Cytometry
• Green Fluorescent Proteins (genetics, metabolism)
• HEK293 Cells
• HeLa Cells
• Humans
• Immune System (cytology, immunology, metabolism)
• Immunity, Innate (genetics, immunology)
• Immunomodulation (genetics, immunology)
• Inflammation Mediators (immunology, metabolism)
• K562 Cells
• Killer Cells, Natural (immunology, metabolism)
• Leukocytes, Mononuclear (immunology, metabolism)
• Microscopy, Fluorescence
• Monocytes (immunology, metabolism)
• Mutation
• Natural Cytotoxicity Triggering Receptor 2 (immunology, metabolism)
• Phagocytosis (immunology)
• Transcription Factors (genetics, immunology, metabolism)
• src Homology Domains (genetics, immunology)