| Summary: | Malaria is a major cause of disease and death in tropical countries. With the spread of
insecticide-resistant mosquito vector and increase in the prevalence of resistant parasite to
anti-malarial drugs, there is an urgent need to develop an effective vaccine to control malaria infection. By utilizing Mycobacterium bovis BCG as a delivery system, a
recombinant BCG vaccine expressing the 19 kDa MSP-1C of P. falciparum was
constructed previously by assembly PCR. This vaccine candidate has been known to be
capable of stimulating humoral immune response in mice and induce activation of mouse
macrophage cell line in vitro. However, the effect of the rBCG vaccine on macrophage
apoptosis, an important mechanism for parasite clearance has not been determined. Thus,
the objective of this study was to determine the apoptosis activity of human macrophage
cell line THP-1 infected with the rBCG clone. The apoptosis of untreated macrophage,
macrophage infected with BCG and macrophage stimulated with LPS were used as
controls. Expression of caspase 9 was also determined in order to identify the pathway
involved in the apoptosis activity. The results demonstrated that macrophage apoptosis
would be detected in all macrophage culture conditions. However, the apoptosis activity
macrophages and LPS-stimulated macrophages. In addition, ELISA analysis also showed
that caspase 9 activity was increased in rBCG infected macrophages compare to those of
BCG and LPS stimulated macrophages. In conclusion, these data demonstrated that the
presence of MSP-1C in rBCG increased macrophage apoptotic activity and the expression
of caspase 9 in the infected macrophages. Thus, the rBCG candidate vaccine is potential to
be used to control malaria infection in the future
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