Objective:To investigate the effects of plasmid containing human IL-18 gene on the humoral immune response of mice immunized by Ag85A DNA vaccines of Mycobacterium tuberculosis H 37R v strain.Methods: Human IL-...Objective:To investigate the effects of plasmid containing human IL-18 gene on the humoral immune response of mice immunized by Ag85A DNA vaccines of Mycobacterium tuberculosis H 37R v strain.Methods: Human IL-18 cDNA was amplified from RNA of peripheral blood mononuclear cells(PBMCs)by RT-PCR and cloned into the pGEM-TEasy vector.After sequencing IL-18 gene was subcloned into the the sites of BamH Ⅰ and EcoR Ⅰ digestion of pcDNA3.1. BALB/c mice were injected intramuscularly with eukaryotic expression plasmid pcIL18,together with MTB pcAg85A DNA vaccines.The same immunization was repeated three times at intervals of two weeks.Mouse sera were collected at two weeks after the each injection.The titers of anti-Ag85A antibody were detected by ELISA. Results:IL-18 cDNA was amplified successfully from RNA of human PBMCs by RT-PCR and the result of sequencing was correct.The IL-18 gene was correctly inserted into the vector pcDNA3.1, which was confirmed with BamHⅠ and EcoRⅠ digestion analysis. The positive plasmid was called pcIL18.After being immunized with DNA vaccines,the titers of antibody obtained from mice being immunized by pcAg85A combining with pcIL18 were superior to mice immunized by pcAg85A independently.Conclusion:Combination of IL-18 gene with MTB pcAg85A DNA vaccine could observably enhance the humoral immune responses to pcAg85A.It remains further investigated whether IL-18 gene plus MTB pcAg85A DNA vaccine could markedly induce the cellular mediated immune response to Ag85A or not.展开更多
Tuberculosis (TB) is the most common cause of death in infectious diseases; it is estimated that approximately 2 million people per year die of TB. The present available TB vaccine is a live attenuated strain, Mycoba...Tuberculosis (TB) is the most common cause of death in infectious diseases; it is estimated that approximately 2 million people per year die of TB. The present available TB vaccine is a live attenuated strain, Mycobacterium bovis Bacillus Calmette Guérin (BCG). However, it has been shown that BCG has variable protective efficacy, ranging from 0 to 85% in different clinical experiments. 1 Therefore, a new TB vaccine is urgently needed. Many trials have been done to develop the second-generation TB vaccines in recent years; candidates include avirulent, auxotrophic, subunit, DNA, and recombinant vaccines. 2 The outcomes of these vaccines disappointed investigators. Encouragingly, recombinant BCG, which overexpressed the mycobacterial antigen Ag85B, produced an excellent protective response, 3,4 suggesting that a vaccine based on recombinant BCG technique was a potential approach against TB.展开更多
文摘Objective:To investigate the effects of plasmid containing human IL-18 gene on the humoral immune response of mice immunized by Ag85A DNA vaccines of Mycobacterium tuberculosis H 37R v strain.Methods: Human IL-18 cDNA was amplified from RNA of peripheral blood mononuclear cells(PBMCs)by RT-PCR and cloned into the pGEM-TEasy vector.After sequencing IL-18 gene was subcloned into the the sites of BamH Ⅰ and EcoR Ⅰ digestion of pcDNA3.1. BALB/c mice were injected intramuscularly with eukaryotic expression plasmid pcIL18,together with MTB pcAg85A DNA vaccines.The same immunization was repeated three times at intervals of two weeks.Mouse sera were collected at two weeks after the each injection.The titers of anti-Ag85A antibody were detected by ELISA. Results:IL-18 cDNA was amplified successfully from RNA of human PBMCs by RT-PCR and the result of sequencing was correct.The IL-18 gene was correctly inserted into the vector pcDNA3.1, which was confirmed with BamHⅠ and EcoRⅠ digestion analysis. The positive plasmid was called pcIL18.After being immunized with DNA vaccines,the titers of antibody obtained from mice being immunized by pcAg85A combining with pcIL18 were superior to mice immunized by pcAg85A independently.Conclusion:Combination of IL-18 gene with MTB pcAg85A DNA vaccine could observably enhance the humoral immune responses to pcAg85A.It remains further investigated whether IL-18 gene plus MTB pcAg85A DNA vaccine could markedly induce the cellular mediated immune response to Ag85A or not.
文摘Tuberculosis (TB) is the most common cause of death in infectious diseases; it is estimated that approximately 2 million people per year die of TB. The present available TB vaccine is a live attenuated strain, Mycobacterium bovis Bacillus Calmette Guérin (BCG). However, it has been shown that BCG has variable protective efficacy, ranging from 0 to 85% in different clinical experiments. 1 Therefore, a new TB vaccine is urgently needed. Many trials have been done to develop the second-generation TB vaccines in recent years; candidates include avirulent, auxotrophic, subunit, DNA, and recombinant vaccines. 2 The outcomes of these vaccines disappointed investigators. Encouragingly, recombinant BCG, which overexpressed the mycobacterial antigen Ag85B, produced an excellent protective response, 3,4 suggesting that a vaccine based on recombinant BCG technique was a potential approach against TB.
