Parasitemic Rates, IL-4 and IFN-γ Profile on Mice Model Vaccinated by Salivary Glands from Anopheles maculatus for Developing TBV Against Malaria

Abstract

Malaria is a major health problem, especially in tropical countries with mortality of one million deaths each year. Malaria is an infectious disease caused by the parasite Plasmodium and transmitted by Anopheles mosquito. Recent researches have shown that salivary Gland (SG) contains active compounds that play an important role in transmitting the plasmodium into the host's body. Therefore, SG of malaria vector could be used as potential target to inhibit the transmission of pathogens for the development of Transmission Blocking Vaccine (TBV). The objective of this study was to observe the potential of SG from Anopheles maculatus (An. maculatus) in modulating pathogen infection. An. maculatus is 1 out of 13 important malaria vectors in Indonesia. BALB-C Mice was used as model organism to examine its immune response i.e. IFN γ (Interferon- γ) and IL-4 (Interleukin-4) in relation with saliva injection as vaccine model. Furthermore, parasitemic rates of Plasmodium berghei was also observed to investigate the potential role of saliva in relation with the establishment of malaria infection in mouse model. Several methods were used in this research including rearing An. maculatus and microscopy dissection to isolate SG’s mosquitoes, preparation of experimental animals and vaccination, preparation of P. berghei and its mice donor. Levels of IFN γ and IL-4 was analyzed by ELISA (enzyme-linked immunosorbent assay). Murine parasitemia was assessed by using thin-layer blood smears stained with Giemsa. The influence of SG vaccination model in modulating host immune response was able to detect from increasing titer of IFN γ and decreasing titer of IL-4 from vaccinated mice group compared to control groups. This could explain the reducing parasitemic rates in vaccinated mice compared to control group, since mosquito salivary components may be served as a nonspecific potentiator whose effect to induce a Th1-biased environment (represented by IFN γ in this research) that is known to be effective against malaria infection rather than Th2 (represented by IL-4 in this research). Further studies on molecular characterization of component in salivary gland that is responsible for this process in needed to understand salivary role in blocking transmission of pathogen.