Attenuated liver fibrosis in the absence of B cells
Tatiana I. Novobrantseva, … , Paula S. Hochman, Alexander Ibraghimov
Tatiana I. Novobrantseva, … , Paula S. Hochman, Alexander Ibraghimov
Published November 1, 2005
Citation Information: J Clin Invest. 2005;115(11):3072-3082. https://doi.org/10.1172/JCI24798.
View: Text | PDF
Research Article Immunology

Attenuated liver fibrosis in the absence of B cells

Abstract

Analysis of mononuclear cells in the adult mouse liver revealed that B cells represent as much as half of the intrahepatic lymphocyte population. Intrahepatic B cells (IHB cells) are phenotypically similar to splenic B2 cells but express lower levels of CD23 and CD21 and higher levels of CD5. IHB cells proliferate as well as splenic B cells in response to anti-IgM and LPS stimulation in vitro. VDJ gene rearrangements in IHB cells contain insertions of N,P region nucleotides characteristic of B cells maturing in the adult bone marrow rather than in the fetal liver. To evaluate whether B cells can have an impact on liver pathology, we compared CCl4-induced fibrosis development in B cell–deficient and wild-type mice. CCl4 caused similar acute liver injury in mutant and wild-type mice. However, following 6 weeks of CCl4 treatment, histochemical analyses showed markedly reduced collagen deposition in B cell–deficient as compared with wild-type mice. By analyzing mice that have normal numbers of B cells but lack either T cells or immunoglobulin in the serum, we established that B cells have an impact on fibrosis in an antibody- and T cell–independent manner.

Authors

Tatiana I. Novobrantseva, Gerard R. Majeau, Aldo Amatucci, Sophia Kogan, Ian Brenner, Stefano Casola, Mark J. Shlomchik, Victor Koteliansky, Paula S. Hochman, Alexander Ibraghimov

×

Figure 4

Options: View larger image (or click on image) Download as PowerPoint
Collagen production by T6-HSC can be stimulated by B cell–derived solubl...
Collagen production by T6-HSC can be stimulated by B cell–derived soluble factors. T6-HSC cells were seeded at 25% confluence in a 96-well plate in RPMI, 5% FBS, penicillin, streptomycin. After 24 hours, an equal volume of B cell–conditioned medium was added with [3H]-thymidine (to measure proliferation) or with [3H]-proline (to measure de novo collagen synthesis). After 18 hours, the amount of incorporated 3H was quantified. Collagen synthesis per cell is expressed in arbitrary units; we took the ratio of radioactive counts of [3H]-proline/radioactive counts of [3H]-thymidine, considering this ratio equal to 1 in the absence of TGF-β. Each treatment was performed in triplicate. A representative experiment out of 3 is shown. (A) Human TGF-β that is recognized by rat TGF-β receptor was added at different concentration to the culture of T6-HSC cells. [3H]-thymidine incorporation is shown in red. Collagen synthesis as assessed by the rate of [3H]-proline incorporation is shown in blue. T6-HSC proliferation (B) and collagen synthesis relative to cell number as assessed by the ratio of [3H]-proline/[3H]-thymidine incorporation (C) is measured in medium alone (M), with LPS, and with supernatant of B cells cultured with LPS (S). B cells were cultured for 3.5 days prior to harvesting supernatant. Red and blue bars show a mean from triplicate values; error bars show standard deviation.