Role of F4/80Mac-1 adherent non-parenchymal liver cells in concanavalin A-induced hepatic injury in mice.

Aim: Non-parenchymal liver cells (NPLC) play an important role in the regulation of immune responses and the inflammatory process. In this study, we hypothesized that F4/80(+)Mac-1(high+) cells were involved in the regulative feedback-modulated regulation of inflammatory responses during concanavalin A (Con A)-induced hepatitis.

Methods: Hepatitis was induced in BALB/c mice by the intravenous injection of Con A.

Unresponsiveness of intrahepatic lymphocytes to bacterial superantigen: rapid development of suppressive Mac-1(high) cells in the mouse liver.

We previously found that a small dose (2 microg per mouse) of staphylococcal enterotoxin B (SEB) induced early emerging unresponsiveness in intrahepatic-lymphocyte populations (IHLs). The purpose of this study was to reveal the inducing role of accessory cells involved in IHLs in this phenomenon. IHLs prepared at 3 to 24 hours after SEB injection failed to proliferate in response not only to SEB but also to SEA, representing ligand-nonspecific unresponsiveness, whereas spleen cells (SPCs) and mesenteric lymph-node cells showed transient proliferation.

Cultured murine parenchymal liver cells induce differentiation of bone marrow cells to macrophage-like cells which present antigen to Th1 clones but inhibit their proliferation by nitric oxide and prostaglandins.

Suppressor cells were developed from nylon wool nonadherent CD4(-)8(-)TCRbeta(-) bone marrow cells cocultured with parenchymal liver cells for 2.5 days. The major suppressor cell population consisted of nylon wool/plastic dish-adherent, phagocytic Mac-1(+) CD3(-)4(-)8(-) cells (Ad cells), with 34% of the Ad cells being F4/80(+).

Antigen-driven clonal accumulation of peritoneal gammadelta T cells in vivo.

How the clonality of gammadelta T cells changes in response to exogenous antigens is uncertain. Here we analyzed kinetics of Vgamma1.1 and Vgamma2 T cell clonality after intraperitoneal injection of purified protein derivatives (PPD) by the heterogeneity of the third complementarity determining region (CDR3) length in Vgamma1.

Quantitative analysis of cytokine gene expression in the liver.

The relative levels of cytokine gene expression in the liver were analysed, focusing on IL-2, IL-4, IL-5, IL-6 and IFN-gamma compared to those in the spleen and Peyer's patch by using the reverse transcriptase polymerase chain reaction (RT-PCR). The levels of expression of cytokines in the liver mononuclear cells (MNC). especially that of IL-6, were significantly higher than in other organs when mice were reared under specific pathogen-free (SPF) or conventional conditions.