Selective blockade of NF-kappaB by novel mutated IkappaBalpha suppresses CD3/CD28-induced activation of memory CD4+ T cells in asthma.
BACKGROUND
Nuclear factor kappaB (NF-kappaB) overactivation plays a crucial role in T-helper 2 (Th2)-biased allergic airway inflammation by increased activation and decreased apoptosis of CD4(+) T cells. We have shown that targeted NF-kappaB suppression in dendritic cells by adenoviral gene transfer of a novel mutated inhibitor of NF-kappaB (IkappaBalpha) (AdIkappaBalphaM) contributes to T-cell tolerance, but the immunosuppressive action of AdIkappaBalphaM on memory (CD45RO(+)) CD4(+) T cells remains enigmatic.


METHODS
CD45RO(+) T cells from Dermatophagoides farinaei-sensitized asthmatic patients, untransfected or transfected with AdIkappaBalphaM or AdLacZ (beta-galactosidase) for 24 h, were stimulated with anti-CD3 (1.0 microg/ml) plus anti-CD28 (0.5 microg/ml) monoclonal antibody for an additional 24 h. IkappaBalphaM transgene expression and NF-kappaB activation were detected by polymerase chain reaction (PCR), reverse transcription-PCR (RT-PCR), Western blot analysis, and electrophoretic mobility shift assay. Phenotype and apoptosis were measured by flow cytometry, annexin V binding, and terminal deoxyribonucleotidyl transferase-mediated dUTP nick end labeling analyses. Cytokine production and cell proliferation were determined using enzyme-linked immunosorbent assay and [(3)H] thymidine incorporation.


RESULTS
A unique 801-bp IkappaBalphaM cDNA and a dose-dependent increase in IkappaBalphaM transgene expression were observed in AdIkappaBalphaM-transfected CD45RO(+) T cells. Significantly, AdIkappaBalphaM inhibited CD3/CD28-mediated NF-kappaB activation in CD45RO(+) T cells, leading to evident apoptosis, reduction of eotaxin, RANTES, Th1 [interferon (IFN)-gamma and interleukin (IL)-2], and Th2 (IL-4, IL-5, and IL-13 despite a slight decrease in IL-10) cytokines and secondary proliferative response. AdIkappaBalphaM also upregulated cytotoxic T lymphocyte-associated antigen 4 (CTLA-4) and downregulated CD69 besides no change in CD28.


CONCLUSIONS
IkappaBalphaM might be beneficial to augment memory CD4(+) T-cell tolerance through modulating B7-CD28/CTLA-4 co-stimulatory pathways and NF-kappaB-dependent cytokine profiles in allergic inflammatory diseases including asthma.
Zhou
L-F
LF
Department of Respiratory Medicine, The First Affiliated Hospital, Nanjing Medical University, Nanjing, China.
Zhang
M-S
MS
Hu
A-H
AH
Zhu
Z
Z
Yin
K-S
KS
D000256:Adenoviridae / Q000235:genetics; D001249:Asthma / Q000276:immunology*; D018106:CD28 Antigens / Q000276:immunology; D017252:CD3 Complex / Q000276:immunology; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology*; D016207:Cytokines / Q000378:metabolism; D006801:Humans; D006969:Hypersensitivity, Immediate / Q000276:immunology; D020672:I-kappa B Proteins / Q000235:genetics* / Q000378:metabolism / Q000494:pharmacology; D007156:Immunologic Memory; D017493:Leukocyte Common Antigens / Q000378:metabolism; D008213:Lymphocyte Activation / Q000187:drug effects / Q000276:immunology*; D009154:Mutation; D000072000:NF-KappaB Inhibitor alpha; D016328:NF-kappa B / Q000037:antagonists & inhibitors*; D014162:Transfection
D018106:CD28 Antigens; D017252:CD3 Complex; D016207:Cytokines; D020672:I-kappa B Proteins; D016328:NF-kappa B; C000606204:NFKBIA protein, human; D000072000:NF-KappaB Inhibitor alpha; D017493:Leukocyte Common Antigens