Viral Evasion of Natural Killer Cell Activation
نویسندگان
چکیده
Natural killer (NK) cells play a key role in antiviral innate defenses because of their abilities to kill infected cells and secrete regulatory cytokines. Additionally, NK cells exhibit adaptive memory-like antigen-specific responses, which represent a novel antiviral NK cell defense mechanism. Viruses have evolved various strategies to evade the recognition and destruction by NK cells through the downregulation of the NK cell activating receptors. Here, we review the recent findings on viral evasion of NK cells via the impairment of NK cell-activating receptors and ligands, which provide new insights on the relationship between NK cells and viral actions during persistent viral infections.
منابع مشابه
How the Virus Outsmarts the Host: Function and Structure of Cytomegalovirus MHC-I-Like Molecules in the Evasion of Natural Killer Cell Surveillance
Natural killer (NK) cells provide an initial host immune response to infection by many viral pathogens. Consequently, the viruses have evolved mechanisms to attenuate the host response, leading to improved viral fitness. One mechanism employed by members of the β-herpesvirus family, which includes the cytomegaloviruses, is to modulate the expression of cell surface ligands recognized by NK cell...
متن کاملNatural Killer Cell Cytotoxicity Against SKOV3 after HLA-G Downregulation by shRNA
Background: HLA-G is a nonclassical HLA class I molecule which, when elevated in tumor cells, is one of the main factors involved in tumor evasion of immune responses including NK and T cells. Objective: To evaluate the effect of HLA-G downregulation on NK cell cytotoxicity in tumor cell lines. Methods: The expression level of HLA-G was measured by real-time PCR and flowcytometry after transfec...
متن کاملHuman Herpesviridae Methods of Natural Killer Cell Evasion
Human herpesviruses cause diseases of considerable morbidity and mortality, ranging from encephalitis to hematologic malignancies. As evidence emerges about the role of innate immunity and natural killer (NK) cells in the control of herpesvirus infection, evidence of viral methods of innate immune evasion grows as well. These methods include interference with the ligands on infected cell surfac...
متن کاملNKp46 and DNAM-1 NK-cell receptors drive the response to human cytomegalovirus-infected myeloid dendritic cells overcoming viral immune evasion strategies.
Information on natural killer (NK)-cell receptor-ligand interactions involved in the response to human cytomegalovirus (HCMV) is limited and essentially based on the study of infected fibroblasts. Experimental conditions were set up to characterize the NK response to HCMV-infected myeloid dendritic cells (DCs). Monocyte-derived DCs (moDCs) infected by the TB40/E HCMV strain down-regulated the e...
متن کاملDown-regulation of NKG2D and NKp80 ligands by Kaposi's sarcoma-associated herpesvirus K5 protects against NK cell cytotoxicity.
Natural killer (NK) cells are important early mediators of host immunity to viral infections. The NK activatory receptors NKG2D and NKp80, both C-type lectin-like homodimeric receptors, stimulate NK cell cytotoxicity toward target cells. Like other herpesviruses, Kaposi's sarcoma-associated herpesvirus (KSHV) down-regulates MHC class I molecules to avoid detection by cytotoxic T lymphocytes but...
متن کامل