Identification of the gC1qR sites for the HIV-1 viral envelope protein gp41 and the HCV core protein: Implications in viral-specific pathogenesis and therapy.

نویسندگان

  • Lina Pednekar
  • Alisa Valentino
  • Yan Ji
  • Nithin Tumma
  • Christopher Valentino
  • Adarsh Kadoor
  • Kinga K Hosszu
  • Mahalakshmi Ramadass
  • Richard R Kew
  • Uday Kishore
  • Ellinor I B Peerschke
  • Berhane Ghebrehiwet
چکیده

A substantial body of evidence accumulated over the past 20 years supports the concept that gC1qR is a major pathogen-associated pattern recognition receptor (PRR). This conclusion is based on the fact that, a wide range of bacterial and viral ligands are able to exploit gC1qR to either suppress the host's immune response and thus enhance their survival, or to gain access into cells to initiate disease. Of the extensive array of viral ligands that have affinity for gC1qR, the HIV-1 envelope glycoprotein gp41, and the core protein of hepatitis C virus (HCV) are of major interest as they are known to contribute to the high morbidity and mortality caused by these pathogens. While the HCV core protein binds gC1qR and suppresses T cell proliferation resulting in a significantly diminished immune response, the gp41 employs gC1qR to induce the surface expression of the NK cell ligand, NKp44L, on uninfected CD4(+) T cells, thereby rendering them susceptible to autologous destruction by NKp44 receptor expressing NK cells. Because of the potential for the design of peptide-based or antibody-based therapeutic options, the present studies were undertaken to define the gC1qR interaction sites for these pathogen-associated molecular ligands. Employing a solid phase microplate-binding assay, we examined the binding of each viral ligand to wild type gC1qR and 11 gC1qR deletion mutants. The results obtained from these studies have identified two major HCV core protein sites on a domain of gC1qR comprising of residues 144-148 and 196-202. Domain 196-202 in turn, is located in the last half of the larger gC1qR segment encoded by exons IV-VI (residues 159-282), which was proposed previously to contain the site for HCV core protein. The major gC1qR site for gp41 on the other hand, was found to be in a highly conserved region encoded by exon IV and comprises of residues 174-180. Interestingly, gC1qR residues 174-180 also constitute the cell surface-binding site for soluble gC1qR (sgC1qR), which can bind to the cell surface in an autocrine/paracrine manner via surface expressed fibrinogen or other membrane molecules. The identification of the sites for these viral ligands should therefore provide additional targets for the design of peptide-based or antigen-based therapeutic strategies.

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

Expression and Purification of HCV Core and Core-E1E2 Proteins in Different Bacterial Strains

Background: Hepatitis C virus (HCV) is a main public health problem causing chronic liver infection and subsequently liver cirrhosis and lethal hepatocellular carcinoma (HCC). Vaccination based on HCV capsid proteins has attracted a special interest for prevention of viral infections. The core protein is a basic and evolutionary most conserved protein, which regulates the cellular processes rel...

متن کامل

Small molecules that bind the inner core of gp41 and inhibit HIV envelope-mediated fusion.

HIV-1 enters cells by membrane fusion, mediated by the trimeric viral envelope glycoprotein gp160, which is processed by a single proteolytic cleavage into stably associated gp120 and gp41. The gp120/gp41 trimer can be triggered to undergo an irreversible conformational change. Using a protein-based assay designed to mimic the gp41 conformational change, we screened for small molecules that pre...

متن کامل

Cloning and expression of NS3 helicase fragment of hepatitis C virus and the study of its immunoreactivity in HCV infected patients

Objective(s): Hepatitis C is a major cause of liver failure worldwide. Current therapies applied for this disease are not fully effective and produce side effects in most cases. Non-structural protein 3 helicase (NS3) of HCV is one of the key enzymes in viral replication and infection. Therefore, this region is a promising target to design new drugs and therapies against HCV infection. The aim ...

متن کامل

Different protein expression systems can influence the direction of the immune responses against HCV core protein in animal model

Introduction: Hepatitis C virus (HCV) infection is a major public health problem which influences about 170 million people worldwide. Different types of vaccines have been designed using HCV structural proteins to control the viral infection. The core nucleocapsid protein is one of the most conserved proteins and a desirable target for HCV vaccines, especially the protein-based vaccines. In cur...

متن کامل

Assessment of HCV Infection in Suspected Orphans Newborns by Real-Time PCR and HCV-Core Ag-Elisa

Background & Objective: HCV infection may be transmitted from an infected mother to her fetus in a low percentage however, it is the most important route of infancy HCV infection. The chance of HCV transmission in HIV/HCV co-infected mothers is higher than that in HCV mono-infected ones. The aim of this study is to assess HCV infection status in orphan newborns in Shiraz, Iran by quantitative P...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

عنوان ژورنال:
  • Molecular immunology

دوره 74  شماره 

صفحات  -

تاریخ انتشار 2016