Naturally infected- macaques develop strong humoral immune responses against RV1 and RV2 ORF59 homologs. 6Xhis-ORF59 fusion proteins from MneRV2 (lanes 1,4 and 7), RRV (lanes 2,5 and 8) and RFHVMn (lanes 3,6 and 9) were electrophoresed and transferred to membranes. The blots were first probed with 1:1,000 dilution of macaque plasma from either dBL2 (adult, non-SIVinfected rhesus macaque; lanes 1-3), J00079 (adult SIV-infected pig-tailed macaque; lanes 4-6) and K99344 (adult SIV-infected pit-tailed macaque; lanes 7-9) with a secondary Dylight 700 anti-human IgG antibody (green, Row A). The blots were washed and the levels of recombinant protein were quantitated using an anti-6XHis mouse monoclonal antibody and a secondary Dylight 800 anti-mouse IgG antibody (red, Row B). The overlay of red and green staining (yellow) is shown in Row C.