The polymeric immunoglobulin receptor is present on hepatocytes in human liver

Abstract

A monoclonal antibody raised against human colostrum secretory component produced even staining of hepatocyte plasma membranes, as well as bile duct lining cells, in all sections examined from eight normal and three abnormal human livers. Human bile samples incubated with free secretory component degraded it to varying extents, probably proteolytically; true levels of free secretory component will therefore often be higher than those reported. It seems likely that human liver resembles that of other mammals in transferring polymeric IgA through hepatocytes to the bile by means of the polymeric IgA receptor.

Different temperature sensitivity of endosomes involved in transport to lysosomes and transcytosis in rat hepatocytes: Analysis by free-flow electrophoresis

“…Endosomes were labeled in the isolatedperfused rat liver using pulse-chase conditions based on the transport kinetics of ASOR and pIgA, as determined above and in previous investigations [9,20,35,[43][44][45].…”

Immunoglobulin Transport and Immunoglobulin Receptors

“…Chewing has been shown to stimulate secretion of SIgA by human parotid glands (Proctor and Carpenter, 2001), and studies with experimental animals have demonstrated the importance of sympathetic nerve stimulation in this process (Carpenter et al, 1998;Proctor et al, 2000). In the human hepatobiliary system, pIgR has generally been reported to be expressed only by the gallbladder and portal bile duct epithelia (Nagura et al, 1981;Brandtzaeg, 1985;Tomana et al, 1988), although some investigators have reported low but detectable staining of human hepatocytes with one of several monoclonal antibodies to SC (Hsu and Hsu, 1980;Foss-Bowman et al, 1983;Perez et al, 1989). By contrast, rodents, rabbits, and some other species exhibit abundant expression of pIgR by hepatocytes, thus allowing transport of pIgA from blood to bile (see subsequent section, Hepatobiliary Transport of IgA).…”

Phylogeny and Comparative Physiology of Mucosal Immunoglobulins

“…In most rodents and rabbits, pIgR is expressed on hepatocytes and efficiently transports pIgA, but not IgM. In humans and other species in which pIgR binds both pIgA and IgM, hepatobiliary clearance of IgM is prevented by low levels of pIgR expression by hepatocytes (Nagura et al, 1981;Delacroix et al, 1983;Daniels and Schmucker, 1987;Perez et al, 1989;Krajci et al, 1991). In species in which pIgR is not expressed on hepatocytes, pIgA synthesized by resident plasmacytes in the lamina propria of the gall bladder can be transported across gall bladder Orlans et al (1983).…”