Transient knockdown of Anopheles stephensi LRIM1 using RNAi increases Plasmodium falciparum sporozoite salivary gland infections

Malaria Journal

David A. O’Brochta¹  Robert Alford²  Robert A. Harrell²  Kasim I. George³  Sumana Chakravarty⁴  Stephen L. Hoffman⁴  Peter F. Billingsley⁴  Abraham G. Eappen⁴  Tao Li⁴  B. Kim Lee Sim⁵ 

[1] Institute for Bioscience and Biotechnology Research and Department of Entomology, University of Maryland, Gudelsky Drive, 20850, Rockville, MD, USA;Foundation for the National Institutes of Health, 11400 Rockville Pike, Suite 600, 20852, North Bethesda, MD, USA;Institute for Bioscience and Biotechnology Research and Department of Entomology, University of Maryland, Gudelsky Drive, 20850, Rockville, MD, USA;Insect Transformation Facility, Institute for Bioscience and Biotechnology Research, University of Maryland, 9600 Gudelsky Drive, 20850, Rockville, MD, USA;Institute for Bioscience and Biotechnology Research and Department of Entomology, University of Maryland, Gudelsky Drive, 20850, Rockville, MD, USA;Qiagen Inc, 19300 Germantown Road, 20874, Germantown, MD, USA;Sanaria Inc, Suite A209, 9800 Medical Center Drive, 20850, Rockville, MD, USA;Sanaria Inc, Suite A209, 9800 Medical Center Drive, 20850, Rockville, MD, USA;Protein Potential, Suite A209, 9800 Medical Center Drive, 20850, Rockville, MD, USA;

关键词: Anopheles stephensi;    Mosquito;    Immune system;    Gene silencing;    Plasmodium falciparum;    Oocyst;    Sporozoite;    PfSPZ vaccine;   

DOI  :  10.1186/s12936-021-03818-8

来源: Springer

【 摘 要 】

BackgroundPlasmodium falciparum (Pf) sporozoites (PfSPZ) can be administered as a highly protective vaccine conferring the highest protection seen to date. Sanaria® PfSPZ vaccines are produced using aseptically reared Anopheles stephensi mosquitoes. The bionomics of sporogonic development of P. falciparum in A. stephensi to fully mature salivary gland PfSPZ is thought to be modulated by several components of the mosquito innate immune system. In order to increase salivary gland PfSPZ infections in A. stephensi and thereby increase vaccine production efficiency, a gene knock down approach was used to investigate the activity of the immune deficiency (IMD) signaling pathway downstream effector leucine-rich repeat immune molecule 1 (LRIM1), an antagonist to Plasmodium development.MethodsExpression of LRIM1 in A. stephensi was reduced following injection of double stranded (ds) RNA into mosquitoes. By combining the Gal4/UAS bipartite system with in vivo expression of short hairpin (sh) RNA coding for LRIM1 reduced expression of LRIM1 was targeted in the midgut, fat body, and salivary glands. RT-qPCR was used to demonstrate fold-changes in gene expression in three transgenic crosses and the effects on P. falciparum infections determined in mosquitoes showing the greatest reduction in LRIM1 expression.ResultsLRIM1 expression could be reduced, but not completely silenced, by expression of LRIM1 dsRNA. Infections of P. falciparum oocysts and PfSPZ were consistently and significantly higher in transgenic mosquitoes than wild type controls, with increases in PfSPZ ranging from 2.5- to tenfold.ConclusionsPlasmodium falciparum infections in A. stephensi can be increased following reduced expression of LRIM1. These data provide the springboard for more precise knockout of LRIM1 for the eventual incorporation of immune-compromised A. stephensi into manufacturing of Sanaria’s PfSPZ products.

【 授权许可】

CC BY