Department of Medical Parasitology, School of Basic Medical Sciences, Wenzhou Medical University, Wenzhou, 325035, Zhejiang, China.
Parasit Vectors. 2024 Sep 4;17(1):375. doi: 10.1186/s13071-024-06453-9.
C-type lectins (CTLs) are a large family of proteins with sugar-binding activity. CTLs contain an evolutionarily conserved C-type lectin domain (CTLD) that binds microbial carbohydrates in a calcium-dependent manner, thereby playing a key role in both microbial pathogenesis and innate immune responses. Aedes albopictus is an important vector for transmitting dengue virus (DENV) worldwide. Currently, the molecular characteristics and functions of CTLs in Ae. albopictus are largely unknown.
Transcripts encoding CTL proteins in the Ae. albopictus genome assembly were analyzed via sequence blast. Phylogenetic analysis and molecular characterization were performed to identify the functional domains of the CTLs. Quantitative analysis was performed to determine the gene expression features of CTLs during mosquito development and in different tissues of female adults after blood feeding. In addition, the functional role of CTLs in response to DENV infection was investigated in Ae. albopictus mosquito cells.
We identified 39 transcripts encoding CTL proteins in the Ae. albopictus transcriptome. Aedes albopictus CTLs are classified into three groups based on the number of CTLDs and the domain architecture. These included 29 CTL-Ss (single-CTLDs), 1 immulectins (dual-CTLD) and 9 CTL-Xs (CTLDs with other domains). Phylogenetic analysis and structural modeling indicated that CTLs in Ae. albopictus are highly conserved with the homologous CTLs in Aedes aegypti. The expression profile assay revealed differential expression patterns of CTLs in both developmental stages and in adult female tissues. Knockdown and overexpression of three CTLs (CTL-S12, S17 and S19) confirmed that they can promote dengue virus infection in Ae. albopictus cells.
The CTL genes in Ae. albopictus mosquito and other mosquito species are evolutionarily conserved and exhibit different developmental and tissue expression features. The functional assay indicated that three CTLs in Ae. albopictus mosquitoes are involved in promoting dengue virus infection. Our study revealed that CTLs play important roles in both the physiological processes and viral infection in mosquito vectors.
C 型凝集素（CTLs）是一类具有糖结合活性的蛋白质家族。CTLs 包含一个进化上保守的 C 型凝集素结构域（CTLD），该结构域以钙离子依赖的方式结合微生物碳水化合物，从而在微生物发病机制和先天免疫反应中发挥关键作用。白纹伊蚊是全球传播登革热病毒（DENV）的重要媒介。目前，白纹伊蚊 CTLs 的分子特征和功能在很大程度上尚不清楚。
通过序列比对分析白纹伊蚊基因组组装中编码 CTL 蛋白的转录本。进行系统发育分析和分子特征分析，以鉴定 CTLs 的功能域。定量分析了 CTLs 在蚊子发育过程中和雌性成蚊吸血后不同组织中的基因表达特征。此外，还研究了 CTLs 在白纹伊蚊蚊细胞中对 DENV 感染的功能作用。
我们从白纹伊蚊转录组中鉴定出 39 个编码 CTL 蛋白的转录本。根据 CTLD 数量和结构域结构，白纹伊蚊 CTLs 分为三组，包括 29 个 CTL-Ss（单 CTLD）、1 个免疫凝集素（双 CTLD）和 9 个 CTL-Xs（具有其他结构域的 CTLD）。系统发育分析和结构建模表明，白纹伊蚊 CTLs 与埃及伊蚊同源 CTLs 高度保守。表达谱分析显示 CTLs 在发育阶段和成年雌性组织中的表达模式存在差异。敲低和过表达 3 个 CTLs（CTL-S12、S17 和 S19）证实它们可以促进白纹伊蚊细胞中的登革热病毒感染。
白纹伊蚊和其他蚊种的 CTL 基因在进化上是保守的，表现出不同的发育和组织表达特征。功能分析表明，白纹伊蚊中的 3 个 CTLs 参与促进登革热病毒感染。我们的研究表明，CTLs 在蚊媒的生理过程和病毒感染中都发挥重要作用。
