Molecular characterization and expression analysis of porcine integrins alphavbeta3, alphavbeta6 and alphavbeta8 that are potentially involved in FMDV infection.

In the present study, we report the sequences and characterization of the porcine integrin cDNAs encoding alphav, beta3, beta6 and beta8 subunits and compare them to those of other species. The coding sequences for the porcine alphav, beta3, beta6 and beta8 subunits were found to be 3141, 2289, 2367 and 2304 nucleotides in length, encoding 1046, 762, 788 and 767-amino-acid-residue protein, respectively. The porcine integrin alphav, beta3, beta6 and beta8 subunit shares common structural and functional elements with their counterparts from the other species. Phylogenetic trees showed that the porcine alphav, beta3, beta6 and beta8 were clustered into the Artiodactyla group, together with those of camels, sheep, and cattle, that are susceptible to FMDV infection. Real-time RT-PCR was used to investigate expression of the integrins alphavbeta3, alphavbeta6 and alphavbeta8 in different tissues of pigs in order to determine the role of these receptors in tissue tropism. Expression analysis showed that alphavbeta6 and alphavbeta8 mRNA expression were detected at high levels in tissues known to support replication of FMDV. Tissue distribution pattern of alphavbeta3 mRNA seems to be unrelated to the known tissue tropism of FMDV. This study provided the first data of porcine integrins for the further studies of the FMDV pathogenesis in pigs.