HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

Published online before print March 16, 2006

This Article Full Text (Reprint (PDF)) All Versions of this Article: jlb.0805456v1 79/6/1242    most recent Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Pilling, D. Articles by Gomer, R. H. Search for Related Content PubMed PubMed Citation Articles by Pilling, D. Articles by Gomer, R. H.

© by The Society for Leukocyte Biology
Journal of Leukocyte Biology, doi:10.1189/jlb.0805456

Received for publication August 16, 2005.
Revised January 5, 2006.
Accepted for publication February 7, 2006.

Article

Aggregated IgG inhibits the differentiation of human fibrocytes

Department of Biochemistry and Cell Biology, Rice University, Houston, Texas

^@ To whom correspondence should be addressed. E-mail: dpilling{at}bioc.rice.edu.

	Abstract

Fibrocytes are fibroblast-like cells, which appear to participate in wound healing and are present in pathological lesions associated with asthma, pulmonary fibrosis, and scleroderma. Fibrocytes differentiate from CD14+ peripheral blood monocytes, and the presence of serum delays this process dramatically. We previously purified the factor in serum, which inhibits fibrocyte differentiation, and identified it as serum amyloid P (SAP). As SAP binds to Fc receptors for immunoglobulin G (IgG; FcRs), FcR activation may be an inhibitory signal for fibrocyte differentiation. FcR are activated by aggregated IgG, and we find aggregated but not monomeric, human IgG inhibits human fibrocyte differentiation. Monoclonal antibodies that bind to FcRI (CD64) or FcRII (CD32) also inhibit fibrocyte differentiation. Aggregated IgG lacking Fc domains or aggregated IgA, IgE, or IgM do not inhibit fibrocyte differentiation. Incubation of monocytes with SAP or aggregated IgG inhibited fibrocyte differentiation. Using inhibitors of protein kinase enzymes, we show that Syk- and Src-related tyrosine kinases participate in the inhibition of fibrocyte differentiation. These observations suggest that fibrocyte differentiation can occur in situations where SAP and aggregated IgG levels are low, such as the resolution phase of inflammation.

Key Words: monocytes • inflammation • cellular differentiation • serum amyloid P • FcR

This article has been cited by other articles:

				H. E. Speich, S. Grgurevich, T. J. Kueter, A. D. Earhart, S. M. Slack, and L. K. Jennings Platelets undergo phosphorylation of Syk at Y525/526 and Y352 in response to pathophysiological shear stress Am J Physiol Cell Physiol, October 1, 2008; 295(4): C1045 - C1054. [Abstract] [Full Text] [PDF]

				D. D. Shao, R. Suresh, V. Vakil, R. H. Gomer, and D. Pilling Pivotal Advance: Th-1 cytokines inhibit, and Th-2 cytokines promote fibrocyte differentiation J. Leukoc. Biol., June 1, 2008; 83(6): 1323 - 1333. [Abstract] [Full Text] [PDF]

				L. P. Golding and J. M. Provenzale Nephrogenic Systemic Fibrosis: Possible Association with a Predisposing Infection Am. J. Roentgenol., April 1, 2008; 190(4): 1069 - 1075. [Abstract] [Full Text] [PDF]

				D. Pilling, D. Roife, M. Wang, S. D. Ronkainen, J. R. Crawford, E. L. Travis, and R. H. Gomer Reduction of Bleomycin-Induced Pulmonary Fibrosis by Serum Amyloid P J. Immunol., September 15, 2007; 179(6): 4035 - 4044. [Abstract] [Full Text] [PDF]

				B. N. Gomperts and R. M. Strieter Fibrocytes in lung disease J. Leukoc. Biol., September 1, 2007; 82(3): 449 - 456. [Abstract] [Full Text] [PDF]

				S. B. Haudek, Y. Xia, P. Huebener, J. M. Lee, S. Carlson, J. R. Crawford, D. Pilling, R. H. Gomer, J. Trial, N. G. Frangogiannis, et al. Bone marrow-derived fibroblast precursors mediate ischemic cardiomyopathy in mice PNAS, November 28, 2006; 103(48): 18284 - 18289. [Abstract] [Full Text] [PDF]