It is clear that TLR signaling plays a critical role in the activation of the host innate immune response, including cytokine and chemokine secretion and up-regulation of co-stimulatory molecules in APCs (Kawai and Akira, 2006) . Recent studies have shown that these activations indirectly affect the development of adaptive immunity (Iwasaki and Medzhitov, 2010) . In addition, it has been demonstrated that functional TLRs are expressed on various T and B cell subsets (Bekeredjian-Ding and Jego, 2009; Booth et al., 2011; Kulkarni et al., 2011) . For example, functional expression of TLRs has been extensively investigated on γδ-T cells (Wesch et al., 2011) that have been shown to be important in controlling Brucella infection (Bertotto et al., 1993; Ottones et al., 2000) . Interaction of TLRs with their respective microbial ligands provides a third signal for B cell activation, which is essential for optimal antigen-specific antibody production and class switch recombination (Bekeredjian-Ding and Jego, 2009; Booth et al., 2011) .