Differential expression of toll-like receptor 9 by various immune compartments of buffalo

Abstract

Toll-like receptor 9 (TLR9) has been characterized as a receptor that recognizes unmethylated CpG (2'-deoxyribocytidine-phosphate-guanosine) motifs present in viral and bacterial DNA. Evidence from both in vitro and in vivo studies confirm that CpG-ODN can activate the immune system in variety of domestic species including cattle, sheep, pigs, horses, dogs, cats and chicken (Brown et al. 1998, Kamstrup et al. 2001, Zhang et al. 2001, Mena et al. 2003, Nichani et al. 2007). The flanking sequences in synthetic CpG oligodeoxynucleotide (ODN) and the cellular pattern of TLR9 expression can influence species-specific responses to CpG-ODN (Griebel et al. 2004). The cellular pattern of TLR9 expression and recruitment of specific cell populations may be important factors contributing to interspecies differences in innate and adaptive immune responses following CpG-ODN stimulation (Griebel et al. 2005). Proper targeting of CpG ODN for the induction of innate immune defenses requires an understanding of immune compartments which express high abundance of TLR9. Buffalo is economically important animal in Asia, some European and South American countries. It is mainstay of dairy husbandry and contributes significantly to the milk and meat production in India. It is pertinent to devise effective strategies for prevention and control of buffalo diseases. There is a little information on the differential expression of TLR9 in buffaloes (Bubalus bubalis). Therefore, the present study was carried out to perform quantitative analysis of TLR9, in different immune compartments of buffalo calves.