Liver Immunobiology

Abstract

The liver has a number of important functions in innate and adaptive immunity. Contributions to the innate (nonspecific) immune system include production of acute phase proteins, nonspecific phagocytosis of particles, nonspecific pinocytosis of molecules, and nonspecific cell killing. Hepatic involvement in innate immunity contributes to the systemic response to local inflammation, clearance of particles and soluble molecules from the circulation, and killing of invading cells such as neoplastic cells. Liver involvement in the adaptive (specific) immune system includes deletion of activated T cells, induction of tolerance to ingested and self-antigens, extrathymic proliferation of T cells, and deletion of many of the signaling and effector molecules. Hepatic involvement in adaptive immunity allows clearance of activated T cells and signaling molecules following inflammatory reactions, and promotes immunologic tolerance toward potentially antigenic proteins that are absorbed from the intestinal tract. The liver is a major site of extrathymic T cell development, which assumes increasing significance with aging in mammals. Perturbations in hepatic structure or function can result in significant ramifications in both the innate and adaptive immune systems.

Duality of liver and kidney lesions after systemic infection of immunosuppressed and immunocompetent mice withAspergillus fumigatus

“…4 In the liver, nonspecific phagocytosis is mediated primarily by Kupffer cells. 17 In agreement, in the immunocompetent condition conidia were detected in the cytoplasm of some Kupffer cells. As these conidia remained in a resting state even at late stages of infection (day 6 post-infection and beyond), it can be assumed that Kupffer cells efficiently phagocytose conidia and inhibit their germination.…”

Receptor-mediated endocytosis of immune complexes in rat liver sinusoidal endothelial cells is mediated by FcγRIIb2

“…Consistent with this notion is the suggestion that LSECs resemble resting dendritic cells more than endothelial cells of other organs. 62 …”

Immune Functioning in Non lymphoid Organs: The Liver

“…Functions of the liver in normal immunobiology were previously reviewed (Parker and Picut 2005). The present treatise addresses alteration in liver immune functions that are related to age and other life events.…”