Expression Analysis of Anopheles cracens:Responses to Plasmodium knowlesiInfection
Plasmodium, the causative agent of the endemic disease malaria has been around for centuries. Nevertheless, it remains as one of the world’s most devastating infectious disease. The lack of effective vaccines, occurrence of drug resistance in Plasmodium parasites and insecticide resistance in mosquitoes have jeapordised the successful control of human malaria in many tropical regions. This is further complicated by the recent occurance of a fifth Plasmodium species, Plasmodium knowlesi(Bronner et al. 2009; Singh et al. 2004) that causes malaria in human populations. Thus, understanding the biology of the Plasmodium-mosquito vector interaction is important to identify potential targets for the development of malaria/vector control strategies to disrupt parasite life cycle in the vectors and prevent the mosquito-to-human transmission (Bahia et al. 2011).
Extensive entomological studies in two districts of high human infection in Malaysia revealed that A. cracens (Peninsular Malaysia) and A. latens (Borneo Island) have been incriminated as the vectors of zoonotic P. knowlesi (Vythilingam, 2010). The immune responses of these species towards P. knowlesi have never been investigated. Previous studies using P. falciparum and An. gambiae as model organisms revealed that at the midgut stage of infection, the mosquito activates immune responses to eliminate the majority of malaria parasites (Dong et al., 2006). The mosquito responses against the malaria parasite are diverse, and the defense against the parasite species involved both common and species-specific components. Some major mosquito genes that play significant roles in the defense mechanism include toll genes (Horton et al., 2010),NF-kB Rel2 transcription factor(Dong et al., 2011),HAT/HDAC (Baton et al., 2009), NOS, defensin, and GNBP (Tahar, 2002).
Figure: Dissected mosquito showing its midgut
Thus, in our proposed study, we hypothesize that similar genes exist in An. cracenswhich play critical roles in the immune response against P. knowlesi. We aim to study the expression profile of An. cracens genes and proteins involved in immune response during the infection.
This project aims to study the immune response of Anopheles cracens to Plasmodium knowlesi. The outcome of this study can help other scientist in research pertaining to malaria “transmission-blocking” strategies such as designing genetically selected/modified vectors. The foreseen impact of this research to the society is in reducing the overall disease prevalence.
For more information on the research, Please contact: ASSOCIATE PROF. DR. LAU YEE LING