ASTMH 2016, Cyrille Ndo: “Investigating Anopheles funestus susceptibility and immune response to Plasmodium falciparum infection”

In collaboration with ASTMH, Image Audiovisuals, and session presenters, MESA brings you this webcast from the 65th ASTMH annual meeting in Atlanta, November 2016.

Title: “Investigating Anopheles funestus susceptibility and immune response to Plasmodium falciparum infection”

Speaker: Cyrille Ndo, OCEAC, Yaoundé, Cameroon

Session information: Scientific Session 130: “Mosquitoes: Biochemistry and Molecular Biology”

Wednesday, 16 November, 10:15am – 12:00pm, Marriott – Room A706 / A707

Abstract:

Anopheles funestus is a major vector of malaria in Africa. However, because it is difficult to colonize, research on this mosquito species has lagged behind other vectors, particularly the understanding of its susceptibility and interactions with the Plasmodium parasite. In order to fill this important knowledge gap, experimental infections were conducted from March to June 2015. 3-5 day old An. funestus F1 mosquitoes derived from wild-caught females from Cameroon were fed with infected blood taken from gametocyte carriers using an artificial glass-parafilm feeding system. Feeding rate was recorded, and fed mosquitoes were dissected at day 7 for oocysts count. Comparative and parallel experiments were performed with the known Plasmodium-susceptible, An. coluzzii Ngousso laboratory strain. Microarrays analysis was performed to assess the molecular basis of An. funestus immune response to P. falciparum invasion.The results revealed that An. funestus displays a similar level of susceptibility to Plasmodium infection compared to An. coluzzii. The prevalence of infection in fed An. funestus mosquitoes was 38.52% (range: 6.25-100%) and the median oocyst number was 12.5 (range: 1-139). In parallel, the prevalence in An. coluzzii was 39.92% (range: 6.85-97.5%), while the median oocyst number was 32.1 (range: 1-351). Genome-wide microarray-based transcription analysis showed that An. funestus innate immune system is activated during midgut invasion. A total of 222 genes were found to be differentially expressed between infected and non-infected mosquitoes including several known immune response genes such as C-type Lectine, APL1 family genes, LRIM1, Serine protease, Serine collagenase and niemann-pick type c. However, genes such as TEP1 were not over-expressed in contrast to An. gambiae suggesting possible differences between both species. The high susceptibility of An. funestus to P. falciparum and its widespread distribution across Africa highlight the need to also tackle this vector for significant malaria vector control program.