Reconstitution of deficient T cell receptor zeta chain restores T cell signaling and augments T cell receptor/CD3-induced interleukin-2 production in patients with systemic lupus erythematosus.
OBJECTIVE
T cells from a majority of patients with systemic lupus erythematosus (SLE) display antigen receptor-mediated signaling aberrations associated with defective T cell receptor (TCR) zeta chain, a subunit of the TCR/CD3 complex. This study was undertaken to explore the possibility that forced expression of TCR zeta chain may reverse the known signaling abnormalities and defective interleukin-2 (IL-2) production in SLE T cells.


METHODS
Freshly isolated SLE T cells were transfected with TCR zeta chain construct in a eukaryotic expression vector at high efficiency, by a recently developed nucleoporation technique. Restoration of TCR/CD3-mediated signaling was studied in the zeta chain-transfected cells.


RESULTS
In SLE T cells transfected with TCR zeta chain, surface expression of TCR chain was increased and the TCR/CD3-induced increased free intracytoplasmic calcium concentration response was normalized, as was hyperphosphorylation of cellular substrates. Simultaneously, the previously noted increased expression of the Fc receptor gamma chain was diminished in SLE T cells transfected with the zeta chain expression vector, and the surface membrane clusters of cell signaling molecules were redistributed to a more continuous pattern. TCR zeta chain replacement also augmented the expression of diminished TCR/CD3-mediated IL-2 production in SLE T cells, associated with increased expression of the p65 subunit of nuclear factor kappaB in the nuclear fractions of these T cells.


CONCLUSIONS
These results suggest that reconstitution of deficient TCR zeta chain can reverse the TCR/CD3-mediated signaling abnormalities as well as the defective IL-2 production in T cells of patients with SLE.
Nambiar
Madhusoodana P
MP
Walter Reed Army Institute of Research, Silver Spring, Maryland 20910, USA.
Fisher
Carolyn U
CU
Warke
Vishal G
VG
Krishnan
Sandeep
S
Mitchell
Jeanne P
JP
Delaney
Nancy
N
Tsokos
George C
GC
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D017252:CD3 Complex / Q000378:metabolism*; D002118:Calcium / Q000378:metabolism; D003600:Cytosol / Q000378:metabolism; D015536:Down-Regulation / Q000276:immunology; D005260:Female; D015870:Gene Expression / Q000276:immunology; D006801:Humans; D007376:Interleukin-2 / Q000096:biosynthesis*; D008180:Lupus Erythematosus, Systemic / Q000276:immunology* / Q000378:metabolism; D008297:Male; D008565:Membrane Proteins / Q000235:genetics / Q000276:immunology* / Q000378:metabolism; D008875:Middle Aged; D010766:Phosphorylation; D011948:Receptors, Antigen, T-Cell / Q000235:genetics / Q000276:immunology* / Q000378:metabolism; D017452:Receptors, IgG / Q000235:genetics / Q000378:metabolism; D015398:Signal Transduction / Q000276:immunology; D013601:T-Lymphocytes / Q000276:immunology* / Q000378:metabolism; D014162:Transfection; D014443:Tyrosine / Q000378:metabolism
D017252:CD3 Complex; D007376:Interleukin-2; D008565:Membrane Proteins; D011948:Receptors, Antigen, T-Cell; D017452:Receptors, IgG; C054979:antigen T cell receptor, zeta chain; D014443:Tyrosine; D002118:Calcium