Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2001 May;44(5):1114-21.
doi: 10.1002/1529-0131(200105)44:5<1114::AID-ANR192>3.0.CO;2-B.

Fc epsilon receptor type I gamma chain replaces the deficient T cell receptor zeta chain in T cells of patients with systemic lupus erythematosus

E J Enyedy  1 , M P Nambiar, S N Liossis, G Dennis, G M Kammer, G C Tsokos
Affiliations

Fc epsilon receptor type I gamma chain replaces the deficient T cell receptor zeta chain in T cells of patients with systemic lupus erythematosus

E J Enyedy et al. Arthritis Rheum. 2001 May.

Abstract

Objective: T cells from the majority of patients with systemic lupus erythematosus (SLE) express significantly lower levels of T cell receptor zeta chain, a critical signaling molecule. However, TCR/CD3 triggering of SLE T cells shows increased phosphorylation of downstream signaling intermediates and increased [Ca2+]i response, suggesting the presence of alternative signaling mechanisms. We investigated whether Fcepsilon receptor type I gamma chain (FcepsilonRIgamma) could substitute for TCR zeta chain and contribute to T cell signaling in SLE.

Methods: T cells were purified from the peripheral blood of 21 patients with SLE and 5 healthy volunteers. The expression of FcepsilonRIgamma was investigated using immunoblotting, reverse transcriptase-polymerase chain reaction, and flow cytometry methods. Involvement of the FcepsilonRIgamma in T cell signaling was studied by immunoprecipitation and/or immunoblotting after TCR/CD3 stimulation.

Results: Western blotting and densitometric analysis showed that the expression of FcepsilonRIgamma in SLE T cells was 4.3-fold higher than in normal T cells (P < 0.001). Flow cytometric analyses of T lymphocyte subsets revealed that the proportions of FcepsilonRIgamma+,CD3+, FcepsilonRIgamma+,CD4+, and FcepsilonRIgamma+, CD8+ cells were significantly greater in SLE patients than in healthy controls (P < 0.001). Immunoprecipitation of SLE T cell lysates with an anti-FcepsilonRIgamma antibody showed that FcepsilonRIgamma associates with the tyrosine kinase Syk and the CD3epsilon chain, suggesting that FcepsilonRIgamma is functionally involved in TCR signaling.

Conclusion: These results demonstrate that the FcepsilonRIgamma chain is expressed at high levels in a large proportion of SLE T cells. The increased expression of FcepsilonRIgamma chain in SLE T cells may account in part for the aberrant antigen receptor-initiated signaling and contribute to the diverse cellular abnormalities found in this disease.

PubMed Disclaimer

Publication types

MeSH terms