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.
Tatiana I. Novobrantseva, Gerard R. Majeau, Aldo Amatucci, Sophia Kogan, Ian Brenner, Stefano Casola, Mark J. Shlomchik, Victor Koteliansky, Paula S. Hochman, Alexander Ibraghimov
The Editorial Board will only consider comments that are deemed relevant and of interest to readers. The Journal will not post data that have not been subjected to peer review; or a comment that is essentially a reiteration of another comment.