ABSTRACT
Although gap junctions were Ÿrst described in the immune system in the 1970s (Dos Reis and De Oliveira-Castro, 1978; Gaziri et al., 1975; Oliveira-Castro et al., 1973), our knowledge of how connexins might participate in immune function remains incomplete. Of all the connexin family members, connexin 43 (Cx43) is the most widely expressed isoform in the mammalian body, including the immune system. Cx43 has been reported to be expressed in lymphocytes (Oviedo-Orta et al., 2000), neutrophils (Diaz et al., 1995; Zahler et al., 2003), natural killer cells (Oviedo-Orta et al., 2000), dendritic cells (Matsue et al., 2006; Neijssen et al., 2005), monocytes/ macrophages (Anand et al., 2008; Bermudez-Fajardo et al., 2007; Chadjichristos et al., 2010; Eugenin et al., 2003; Jara et al., 1995; Neijssen et al., 2005; Polacek et al., 1993), and mast cells (Vliagoftis et al., 1999). Expression of connexins among immune cells is not limited to mice, as studies have identiŸed family members in rats, hamsters, canines, horses, and humans, suggesting that expression of connexins in the immune system is an evolutionarily conserved phenomenon. Based on this widespread expression among numerous immune cell types, and across a spectrum of mammalian species, it is hypothesized that Cx43 serves some purpose in immune function.
