Editorial

Molecular Insight into Integrin Alpha Beta 6 Receptor of Cattle and their Relationship with FMD Infectivity

Rani Singh, Umesh Singh, Raja TV, Gyanendra Sengar, Sheetal Sharma and Rajib Deb^*

Corresponding author: Rajib Deb, Molecular Genetics Laboratory Central Institute for Research on Cattle, Meerut, Uttar Pradesh, India; E-mail: drrajibdeb@gmail.com

Copyright © 2014 Rajib Deb et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Journal of Cell Science & Molecular Biology | Volume: 1, Issue: 2

Submission: 25/06/2014; Accepted: 27/06/2014; Published: 01/07/2014

Foot and mouth disease (FMD) of cattle, which causes severe economic losses, is caused by the virus under the family of Picornaviridae. There are total seven serotypes viz. A, O, C, Asia-1and South African Territories 1 (SAT1), SAT2, and SAT3 of FMDV was identified, among them serotype O are most prevalentin India. The virus exhibits a strong tropism for the epithelial cells, during natural infection of FMD the viral entry into the host as well as the replication machinery take place in the pharynx as well as soft palate. During viral infection inside the host system the observable lesions developed on feet and mouth (7-8).

The three-dimensional structure of FMDV has revealed a prominent surface feature formed by the loop between the G and H strands of VP1, one of the structural protein of FMDV identified. The virus enters the host cell by receptor-mediated endocytosisprocess after the initial attachment of the virus to the host cellsurface receptors. Once the virus enter the endosome, uncoating of the viral genome takes place due to acidic environment, which is then translocated crossways the endosomal membrane into the cytoplasm [1,2].

Integrins are one of the important biologically active proteins responsible for FMD virus host interaction. Functional integrins consist of two non covalently bound trans membrane glycoprotein subunits viz. alpha (a) and beta ( b). Each subunit is composed of a large extracellular domain of a and b residues (120-180 and 90-110 kDa, respectively), a single transmembrane domain and a small, C-terminal cytoplasmic domain. In mammals, the integrin family consists of around 24 different heterodimers, each of which has a distinct tissue distribution. FMDV has been shownto use four kinds of integrins viz. avb1, avb3, avb6 and avb8 as receptors to initiate infection. Virus attachment to the integrin receptors is mediated by anarginine-glycine-aspartic acid (RGD) tripeptide located onVP1 loop of FMDV. The integrin receptors of FMDV have been investigated extensively in cell culture whichshown that avb6 but not avb3 are expressed constitutively on the epithelial cell surfaces at the site of viral replication to allow initiation of infection. Expression of avb6 is restricted to the epithelial cells at the variety of sites including the epithelia of the uterus, bladder, respiratory tract and salivary glands.

Presently our team investigated that, genetic variation at 5’UTR region of integrin beta 6 receptor are associated with FMD susceptibility in cattle [3-8].

The understanding of the mechanism of infection and replication of this virus is important to the control of this worldwide threat. An important question that has yet to be addressed concerns the role of viral receptors in the pathogenesisof FMD.