05). Thus, the major but not exclusive source of TNF-α was monocytes, and production of TNF-α was relatively greater in PBC. We have shown that direct contact of LMCs and TNF-α were necessary for production of CX3CL1 by BECs. In addition, it is known that TLR4 ligands
stimulate LMCs to produce TNF-α. Accordingly, ICG-001 clinical trial we sought to ascertain which cell population among LMCs is critical for CX3CL1 production by BECs. Our procedures included measurement of production of CX3CL1 by poly(I:C) pretreated BECs, with LPS pretreated mononuclear cells of either T cells, monocytes, NKT cells, NK cells, or mDCs (Fig. 6). Even though NK cells and mDCs did produce small amounts of TNF-α with LPS, production of CX3CL1 was rarely detectable when
poly(I:C)-pretreated BECs were cocultured with LPS-pretreated T cells, NKT cells, or NK cells, or mDCs; Fig. 6A shows representative data for one PBC liver. On the Ensartinib cost other hand, CX3CL1 production was prolific when poly(I:C)-pretreated BECs were cultured with LPS-pretreated monocytes. Such production was not observed in the absence of LPS-pretreated monocytes, and the production was markedly inhibited after addition of anti–TNF-α (Fig. 6B), indicating that LPS-pretreated monocytes provided the necessary direct contact, and TNF-α, for subsequent CX3CL1 production by BECs. Comparison of PBC and disease control livers showed that poly(I:C)-pretreated BECs from PBC livers produced relatively large amounts of CX3CL1 when cultured with LPS-pretreated monocytes (2.1 ± 0.5 ng/mL versus 1.3 ± 0.4 ng/mL Teicoplanin [P < 0.01]) (Fig. 6C). Of note, in these experiments, only small amounts of CX3CL1 were produced from the
two primary sclerosing cholangitis livers. Finally, we investigated the presence of monocytes around bile ducts in the liver by way of immunohistochemical analysis. Comparing livers of patients with PBC and those with hepatitis C (disease controls), CD68+ monocytes/macrophages were enriched in PBC, predominantly in the portal area (Fig. 7A), as were CD154+-activated T cells around biliary ductules (Fig. 7B); this is indicative of greater invasion of CD68 and CD154+ cells into portal areas of liver in patients with PBC compared with hepatitis C patients. Actual cell counts are shown in Table 1. To facilitate understanding of the data herein, we have developed a schema to reflect the chain of events among the liver subpopulations studied (Fig. 8). We also note that the hypothesis that aberrant homing of T cell subsets are involved in the pathogenesis of PBC is based on earlier data in primary sclerosing cholangitis.23 Samples from the study herein were primarily derived from end-stage disease, thus raising the issue of whether pathogenetic mechanisms that induce disease are overwhelmed by secondary immunological processes, including the contributions of fibrosis and extensive cholestasis. However, by reason of tissue access, this was a necessity.