Transgenic Expression of Human C-Type Lectin Protein CLEC18A Reduces Dengue Virus Type 2 Infectivity in Aedes aegypti

Abstract

The C-type lectins, one family of lectins featuring carbohydrate binding domains which participate in a variety of bioprocesses in both humans and mosquitoes, including immune response, are known to target DENV. A human C-type lectin protein CLEC18A in particular shows extensive glycan binding abilities and correlates with type-I interferon expression, making CLEC18A a potential player in innate immune responses to DENV infection; this potential may provide additional regulatory point in improving mosquito immunity. Here, we established for the first time a transgenic Aedes aegypti line that expresses human CLEC18A. This expression enhanced the Toll immune pathway responses to DENV infection. Furthermore, viral genome and virus titers were reduced by 70% in the midgut of transgenic mosquitoes. We found significant changes in the composition of the midgut microbiome in CLEC18A expressing mosquitoes, which may result from the Toll pathway enhancement and contribute to DENV inhibition. Transgenic mosquito lines offer a compelling option for studying DENV pathogenesis, and our analyses indicate that modifying the mosquito immune system via expression of a human immune gene can significantly reduce DENV infection.

Human rs75776403 polymorphism links differential phenotypic and clinical outcomes to a CLEC18A p.T151M-driven multiomics

“…Second, consistent with speculation that CLEC18A may extract sterols from assembled membranes of pathogens ( e.g. , dengue virus type 2 [ 36 ]) during the intracellular viral replication stage in the ER [ 1 ], we observed negative enrichment of immune activation pathways by rs75776403 p.T151M. Third, genes with the CAP/SCP/TAPS domain were proposed to be a Ca 2+ -specific serine protease [ 37 , 38 ], which is critical for antigen processing and to elicit pathogen-specific immune activation of T cells [ 39 , 40 ].…”

Transgenic refractory Aedes aegypti lines are resistant to multiple serotypes of dengue virus

“…2 ). In a cell, several miRNAs existed as a cluster was not hard to see, each cluster was under controlled by a promoter, however, the expression levels of these miRNAs are different 31 , 40 – 42 , even though they are all produced from the same transcript and driven by one promoter. There are some possible reasons to make this variation of expression, the architecture of miRNAs, including the dimensional structure of the hairpin, the spacing sequence and the length of spacing are all crucial importance for the knockdown efficiency.…”

“…Double-stranded DNA fragments of eight DENV miRNAs were composed using paired oligonucleotides (Supplementary Table 3 ) through annealing and extension, followed by another PCR amplification with a primer set: miR6.1_5′ EcoRI/BglII and miR6.1_3′ XhoI/BamHI, to produce miRNA units that contained restriction enzyme cutting sites. These eight miRNA units were assembled to become a tandem miRNA coding DNA fragment using BglII and BamHI sites and then subcloned into the EcoRI/XhoI sites of pMOS1_ AePUb -CLEC18A-2xHA_3xP3-eGFP 40 to create pMOS1_nanos-DENV-8miR_3xP3-EGFP constructs. To finish the construction, promoter sequences of AeCPA and AePUB were amplified from the genomic DNA of Ae.…”

Role of Lectin in the Response of Aedes aegypti Against Bt Toxin

“…Modification of the mosquito's immune system through expression of the human CTL CLEC18A gene can drastically reduce dengue virus infection. Transgenic mosquitoes showed significant differences in the midgut microbiota (165). Mosquito galectin, mosGCTL-1, interacts with the West Nile virus (WNV) and promotes mosquito infection (166) while mosGCTL-7 interacts with the Japanese encephalitis virus (JEV) in Ae.…”