Characterization of Anopheles gambiae D7 salivary proteins as markers of human–mosquito bite contact

Parasites & Vectors

Ramadhan Mwakubambanya¹  James Njunge²  Robert Mwakesi²  Faith Marura²  Martha Muturi²  Rodney Ogwang²  Brenda Oseno³  Irene Nkumama⁴  James Tuju⁵  Martin K. Rono⁵  Faith Osier⁶  Kennedy Mwai⁷ 

[1] Egerton University, P.O. Box 536-20115, Nakuru, Kenya;KEMRI-Wellcome Trust Research Programme CGMRC, P.O. Box 230-80108, Kilifi, Kenya;KEMRI-Wellcome Trust Research Programme CGMRC, P.O. Box 230-80108, Kilifi, Kenya;Egerton University, P.O. Box 536-20115, Nakuru, Kenya;KEMRI-Wellcome Trust Research Programme CGMRC, P.O. Box 230-80108, Kilifi, Kenya;Heidelberg University Hospital, Neuenheimer Feld, 672 69120, Heidelberg, Germany;KEMRI-Wellcome Trust Research Programme CGMRC, P.O. Box 230-80108, Kilifi, Kenya;Pwani University, P.O. Box 195-80108, Kilifi, Kenya;KEMRI-Wellcome Trust Research Programme CGMRC, P.O. Box 230-80108, Kilifi, Kenya;Pwani University, P.O. Box 195-80108, Kilifi, Kenya;Heidelberg University Hospital, Neuenheimer Feld, 672 69120, Heidelberg, Germany;KEMRI-Wellcome Trust Research Programme CGMRC, P.O. Box 230-80108, Kilifi, Kenya;School of Public Health, University of the Witwatersrand, 1 Jan Smuts Avenue, Braamfontein 2000, Johannesburg, South Africa;

关键词: Biomarker of exposure;    Anopheles gambiae;    Plasmodium falciparum;    Infectious bites;    Malaria;   

DOI  :  10.1186/s13071-021-05130-5

来源: Springer

【 摘 要 】

BackgroundMalaria is transmitted when infected Anopheles mosquitoes take a blood meal. During this process, the mosquitoes inject a cocktail of bioactive proteins that elicit antibody responses in humans and could be used as biomarkers of exposure to mosquito bites. This study evaluated the utility of IgG responses to members of the Anopheles gambiae D7 protein family as serological markers of human–vector contact.MethodsThe D7L2, D7r1, D7r2, D7r3, D7r4 and SG6 salivary proteins from An. gambiae were expressed as recombinant antigens in Escherichia coli. Antibody responses to the salivary proteins were compared in Europeans with no prior exposure to malaria and lifelong residents of Junju in Kenya and Kitgum in Uganda where the intensity of malaria transmission is moderate and high, respectively. In addition, to evaluate the feasibility of using anti-D7 IgG responses as a tool to evaluate the impact of vector control interventions, we compared responses between individuals using insecticide-treated bednets to those who did not in Junju, Kenya where bednet data were available.ResultsWe show that both the long and short forms of the D7 salivary gland antigens elicit a strong antibody response in humans. IgG responses against the D7 antigens reflected the transmission intensities of the three study areas, with the highest to lowest responses observed in Kitgum (northern Uganda), Junju (Kenya) and malaria-naïve Europeans, respectively. Specifically, the long form D7L2 induced an IgG antibody response that increased with age and that was lower in individuals who slept under a bednet, indicating its potential as a serological tool for estimating human–vector contact and monitoring the effectiveness of vector control interventions.ConclusionsThis study reveals that D7L2 salivary antigen has great potential as a biomarker of exposure to mosquito bites and as a tool for assessing the efficacy of vector control strategies such as bednet use.Graphical abstract

【 授权许可】

CC BY