Objective: To investigate the effect of nuclear factor-kappaB (NF-kappaB) decoy oligodeoxynucleotide (ODN) on proliferation, apoptosis and cytokine synthesis of T lymphocytes from asthmatic patients.
Methods: T lymphocytes were divided into four groups, a normal control group (A group), an asthma control group (B group), a NF-kappaB cis decoy ODN group (B(1) group) and a scrambled ODN group (B(2) group). B(1) and B(2) groups were transfected by cationic lipofectamine to the latter two groups respectively. The proliferation of T lymphocytes was measured by MTT and the apoptosis of them was measured by flow cytometry. The expression levels of interleukin 5 (IL-5) mRNA and protein were detected with cell hybridization in situ and enzyme-linked immunosorbent assay (ELISA). The expression levels of inducible nitric oxide synthase (iNOS) were measured by reverse transcription-polymerase chain reaction (RT-PCR) and Western blot.
Results: The difference of proliferation rate between B(1) group (0.220 +/- 0.020) and B group (0.340 +/- 0.030) was significant (P < 0.05). The difference of apoptosis rate between B(1) group (10.8 +/- 1.3) and B group (8.1 +/- 1.2) was also significant (P < 0.05). The expression levels of IL-5 mRNA and protein in B(1) group (21 +/- 4, 24 +/- 4) were significantly different from those in B group (33 +/- 4, 54 +/- 10, P < 0.05). The differences of iNOS mRNA and protein levels between B(1) group (0.33 +/- 0.05, 782 +/- 117) and B group (0.75 +/- 0.13, 1185 +/- 230) were significant (P < 0.05). However, these indices in B(2) group showed no difference to those in B group (P > 0.05).
Conclusions: NF-kappaB decoy ODN can reduce the abnormally increased proliferation of T lymphocytes in asthma and increase the abnormally decreased apoptosis of these cells, while decrease the abnormally increased levels of cytokine and enzyme in asthmatic T lymphocytes. These may be the mechanisms underlying its potential therapeutic effects in asthma.