The Maternally InheritableWolbachia wAlbB Induces Refractoriness toPlasmodium bergheiinAnopheles stephensi.
The endosymbiontWolbachia wAlbB induces refractoriness toPlasmodium falciparuminAnopheles stephensi, the primary mosquito vector of human malaria in the Middle East and South Asia. However, it remains unknown whether such refractoriness can be extended to other malaria species. In particular, it was reported that under very specific conditions,wAlbB can enhancePlasmodiuminfection in some hosts. Here, we measured the impact ofwAlbB on the rodent malaria parasitePlasmodium bergheiinA. stephensiby comparing the load of oocysts and sporozoites in midguts and salivary glands, respectively, betweenwAlbB-infected and -uninfected mosquitoes. To investigate whetherwAlbB modulated mosquito immune defense against parasites, we compared the expression of the immune genes, which were previously reported to involve in antimalarial response, in both midguts and the remaining carcass tissues of mosquitoes. The stable association ofwAlbB withA. stephensiresulted in reduction of parasites by more than half at the oocyst stage, and up to 91.8% at the sporzoite stage. The anti-plasmodiumimmune genes, includingTEP1,LRIM1, Toll pathway geneRel1and the effectorDefensin 1, were induced bywAlbB in different mosquito body tissues. These findings suggest that immune priming is a potential cause ofwAlbB-mediated antimalarial response inA. stephensi. More importantly, no evidence was found for any enhancement ofPlasmodiuminfection inA. stephensistably infected withwAlbB. We discuss these findings with possible implementations ofWolbachiafor malaria control in disease endemic areas.
Department of Microbiology and Molecular Genetics, Michigan State University East Lansing, MI, USA.
Deepak
D
Joshi
Department of Microbiology and Molecular Genetics, Michigan State University East Lansing, MI, USA.
Xiaoling
X
Pan
Department of Microbiology and Molecular Genetics, Michigan State University East Lansing, MI, USA.
Michael J
MJ
McFadden
Department of Microbiology and Molecular Genetics, Michigan State University East Lansing, MI, USA.
David
D
Bevins
Comparative Medicine and Integrative Biology Program, Michigan State University East Lansing, MI, USA.
Xiao
X
Liang
Department of Microbiology and Molecular Genetics, Michigan State University East Lansing, MI, USA.
Peng
P
Lu
Department of Microbiology and Molecular Genetics, Michigan State UniversityEast Lansing, MI, USA; Department of Entomology, Michigan State UniversityEast Lansing, MI, USA.
Suzanne
S
Thiem
Department of Microbiology and Molecular Genetics, Michigan State UniversityEast Lansing, MI, USA; Sun Yat-sen University-Michigan State University Joint Center of Vector Control for Tropical DiseasesGuangzhou, China.
Zhiyong
Z
Xi
Plasmodium; Wolbachia; innate immunity; malaria; population replacement; vector-borne disease