Journal of Clinical and Cellular Immunology
Open Access
ISSN: 2155-9899
ISSN: 2155-9899
Lang Bao
Sichuan University, China
Scientific Tracks Abstracts: J Clin Cell Immunol
Introduction: Tuberculosis (TB) is a serious infectious disease caused by M. tuberculosis. BCG had been
considered to be the only available and effective vaccine in prevention of TB. However, the protective efficacy
of BCG on TB was still controversial in different populations and age. Thus, improved TB vaccines are
urgently needed to develop as an alternative to BCG which was able to activate immune response and protect
against severe forms of TB effectively.
Method: Two BCG strains (Pasteur and Shanghai) were used parental strain and specific antigens of M.
tuberculosis Ag85A, CFP10, ESAT-6 and immune regulation cytokines GM-CSF, IL-12p70 were integrated
into BCGs respectively. BALB/c female mice were immunized subcutaneously with single-gene rBCGs and
multiple-gene rBCGs. The specific antibody levels of lgG, lgG1 and lgG2a in immunized mice were detected
by ELISA assay. Detection of proliferation of splenic lymphocytes and splenocytes subsets by flow cytometry
were conducted. Nine rBCG strains were chosen for protective efficacy test. After eight weeks of immunization
with rBCGs, mice were challenged intravenously by M. tuberculosis H37Rv. Histopathological examination
and bacterial load was performed on the lung, spleen tissues of immune mice.
Results: Both single-gene rBCGs and multiple-gene rBCGs could induce strong humoral and Th1 cellular
immune reaction. Significantly higher levels of Th1 cytokines IFN-γ was revealed in both multiple and singlegene
rBCGs, while Th2 cytokines IL-4 was not detected in all rBCGs. After 18 weeks, the survival rate was
100% in rBCG- Pasteur: A, rBCG- Pasteur: AE and 80% in rBCG-SHanghai: IE, rBCG-Pasteur: GC only 60%
in rBCG- Pasteur: GCE.
Conclusion:rBCG had excellent immunogenicity and immune protective efficacy. It could regulate the level
of TNF- alpha by p38 MAPK and NF-kB signaling pathway and induce the apoptosis of macrophages. BCGPasteur
is more suitable for parental BCG than the BCG-SHanghai. These findings can provide ideas and
experimental basis for the development of anti-tuberculosis recombinant vaccines.
Lang Bao is currently working as a Professor in Microbiology and Immunology. He has completed his PhD from West China University of Medical Sciences in 1999 and then moved to WHO Collaborative Research Centre of Infectious Disease, Royal Tropical Institute, Netherlands for his Post-doctoral training. He has published around 100 research papers.