Since increased levels of serum soluble CD23/Fc epsilon RII (sCD23) were evidently demonstrated in patients with autoimmune diseases such as rheumatoid arthritis (RA), the possible mechanisms responsible for the elevation of serum sCD23 were investigated in RA patients. In keeping with increased serum sCD23, high proportion of CD23+ B cells was detected in the patients; this was associated with the enhanced expression of only Fc epsilon RIIa mRNA. Upon incubation at 37 degrees C, peripheral blood mononuclear cells of the patients spontaneously released high levels of sCD23 into the culture supernatant, while the CD23 expression on their B cells was considerably maintained even after the culture. Dot blot analysis further revealed that in contrast to normal subjects, RA patients showed no complete disappearance of Fc epsilon RIIa mRNA after the spontaneous culture. In addition, sCD23 release was significantly reduced in the patients by the addition of cycloheximide. It was also found that cycloheximide exerted the inhibitory influence on the spontaneous culture-mediated expression of CD23 on CD5+ but not CD5- B cells of the patients. However, the disappearance of CD23 from CD5+ as well as CD5- B cells of cord blood samples was unaffected by the agent. These results strongly suggest that CD5+ B cells of RA patients may be specifically activated by some mechanisms responsible for the persistent expression of Fc epsilon RIIa mRNA leading to the accelerated turnover of CD23 and in turn the increased release of sCD23.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1159/000236485 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Spectral shift mechanisms of chlorophylls in liquids and proteins.
Spectrochim Acta A Mol Biomol Spectrosc
February 2013
Institute of Physics, University of Tartu, 142 Riia Street, EE51014 Tartu, Estonia.
Origins of non-excitonic spectral shifts of chlorophylls that can reach -1,000 cm(-1) in pigment-protein complexes are actively debated in literature. We investigate possible shift mechanisms, basing on absorption and fluorescence measurements in large number of liquids. Transition wavelength in solvent-free state was estimated (±2 nm) for chlorophyll a (Chl a, 647 nm), Chl b (624 nm), bacteriochlorophyll a (BChl a, 752 nm), and pheophytines.
View Article and Find Full Text PDFNonlinear polarization of solvatochromic betaine 30.
J Phys Chem A
June 2010
Institute of Physics, University of Tartu, 142 Riia Street, EE51014 Tartu, Estonia.
Evidence is presented that solvatochromism of 2,6-diphenyl-4-(2,4,6-triphenylpyridinio)-phenolate (Reichardt's dye or Betaine 30) results not only from a large reduction of dipole moment and hydrogen bonding, but also from the modulation of mesomeric effect. The polarizability change between the ground and the excited state, estimated from the refractive index (n) dependence of absorption energy E(T)(30), increases from 20 to approximately 150 A(3) on going from apolar to highly polar media. The dependence of E(T)(30) on dielectric permittivity (epsilon) could be linearized using an empirical function of susceptibility difference (epsilon-n(2)), but not in terms of conventional expressions written as phi(epsilon)-phi(n(2)).
View Article and Find Full Text PDFZ39Ig is co-expressed with activated macrophage genes.
Biochim Biophys Acta
April 2002
Incyte Genomics, 3160 Porter Drive, Palo Alto, CA 94304, USA.
Z39Ig is a recently-identified gene with immunoglobulin-like domains whose function is unknown. We examined expression of Z39Ig in 1432 human cDNA libraries, and found it primarily in synovium of patients with rheumatoid arthritis, in placenta, and in lung. We analyzed its co-expression pattern using the Guilt-by-Association (GBA) algorithm, and found that it is most similar in expression to early genes in the classical complement system (C1qA, C1qB, C1qC, C1r, and C1 inhibitor), MHC class II genes (HLA-DR alpha, HLA-DR beta 1, and HLA-DP alpha 1), Fc receptors (Fc gamma RIIa and Fc epsilon R1), lysosomal protein (LAPTm5), tissue transglutaminase, and macrophage receptors (MARCO and CD163/M130).
View Article and Find Full Text PDFFcR-mediated inhibition of cell activation and other forms of coinhibition.
Crit Rev Immunol
March 1999
Department of Microbiology and Immunology, University of Western Ontario, London, Canada.
The tripartite inactivation model proposed that coaggregation of the B cell antigen receptor (BCR) with the Fc receptor (FcR) by antigen and specific IgG antibody complexes explained the Fc-dependent inhibition of immune responses by antibody. This model has since been substantiated by many observations and its impact on studies of immune regulation has been threefold: (1) IgG antibody, via Fc gamma RIIB, mediates inhibition of cell activation in many cell types, demonstrating the general importance of this mechanism in immune regulation; (2) Fc gamma RIIB was the first receptor described that regulates immune responses by coinhibition, that is, regulation as a result of interaction between activating receptors (BCR, TCR, Fc epsilon RI, Fc gamma RIII, Fc gamma RIIA) and inhibitory receptors (Fc gamma RIIB, CTLA4, CD5, CD22, p58/70/140 KIR, gp49B1/gp91, Ly49A/C/E/F/G, NKG2-A/B, APCR, Fas (CD95), TGF beta-R, TNF-R, IFN gamma-R, and others). The list of coinhibitors is expanding, just as the list of costimulators has grown.
View Article and Find Full Text PDFPhosphorylated immunoreceptor signaling motifs (ITAMs) exhibit unique abilities to bind and activate Lyn and Syk tyrosine kinases.
J Immunol
November 1995
Department of Pediatrics, National Jewish Hospital for Immunology and Respiratory Medicine, Denver, CO 80206, USA.
Signal transduction by T and B cell Ag receptors and certain receptors for Ig Fc regions (Fc gamma RI, hFc gamma RIIA, Fc gamma RIII, Fc alpha R, and Fc epsilon RI) involves a conserved sequence motif, termed an immunoreceptor tyrosine-based activation motif (ITAM) and found in multiple receptor chains. Phosphorylation of the two ITAM tyrosines is a critical event in signal transduction. To address the function of this phosphorylation, we assessed the ability of nonphosphorylated and biphosphorylated ((p)2ITAM) ITAM peptides to bind and modify the activity of src and syk family kinases in vivo and in vitro.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!