Mucosal addressin cell adhesion molecule-1 of rhesus macaques: molecular cloning, expression, and alteration after...

Mucosal addressin cell adhesion molecule-1 (MAdCAM-1), a member of the immunoglobulin superfamily, is essential for gut-specific homing of leukocytes; however, it has not been well characterized in rhesus macaques.

To obtain the complete nucleotide sequence of rhesus macaque MAdCAM-1 cDNA and determine its distribution in gut-associated lymphoid tissues (GALT) and its alteration in duodenal mucosa after simian/human immunodeficiency virus (SHIV) infection.

MAdCAM-1 cDNA was cloned from the colon mucosa of a rhesus macaque by 3'- and 5'-RACE. The distribution and abundance of MAdCAM-1 mRNA in the GALT were examined by nested and real-time RT-PCR. The alterations of MAdCAM-1 mRNA levels in SHIV-infected duodenal mucosa were determined by real-time RT-PCR.

The nucleotide sequence of rhesus macaque MAdCAM-1 cDNA (1,503 bp nucleotides) including the 5'- and 3'-untranslated regions was obtained. The coding region (1,086 bp) showed 87.56% and the Ig-like domain 1, 2 and TM + cytoplasmic domains showed >93% nucleotide sequence identity to that of humans. Like humans, rhesus macaques lacked MAdCAM-1 IgA1-like domain, which could be a common feature for all primates appeared later during vertebrate evolution. Two species of MAdCAM-1 mRNA were detected and high-level transcripts were observed primarily in the GALT. The full-length MAdCAM-1 expressed in vitro could bind to human α4β7. MAdCAM-1 mRNA levels were statistically significantly reduced in SHIV-infected duodenal mucosa.

These data provided a basis for using rhesus macaques in pathological and therapeutic studies on leukocyte homing related diseases such as inflammatory bowel disease and HIV/AIDS.