A novel C-type lectin with triple carbohydrate recognition domains has critical roles for the hard tick Haemaphysalis longicornis against Gram-negative bacteria. (April 2016)

• Record Type: Journal Article
• Authors: Maeda, Hiroki; Miyata, Takeshi; Kusakisako, Kodai; Galay, Remil Linggatong; Talactac, Melbourne Rio; Umemiya-Shirafuji, Rika; Mochizuki, Masami; Fujisaki, Kozo; Tanaka, Tetsuya
• Is Part Of: Developmental and comparative immunology. Volume 57(2016)
• Page Start: 38
• Page End: 47
• Publication Date: 2016-04
• Subjects: Tick -- C-type lectin -- Innate immunity -- Recombinant -- Gram-negative bacteria; Immunology -- Periodicals; Developmental immunology -- Periodicals; 616.079
• DOI: 10.1016/j.dci.2015.12.015
• Languages: English
• ISSNs: 0145-305X

Abstract

Abstract: C-type lectins (CLecs) play an important role in innate immunity against invaders. In this study, a novel CLec was identified from Haemaphysalis longicornis ticks (HlCLec). HlCLec contains a signal peptide and a transmembrane region. Interestingly, HlCLec possesses three dissimilar carbohydrate recognition domains (CRDs). Each CRD contains the mutated motif of Ca 2+ -binding site 2. HlCLec mRNA was up-regulated during blood feeding, and had highest expression in the midgut and ovary. HlCLec localization was also confirmed by immunofluorescent antibody test (IFAT). HlCLec was found on the cell membrane and basal lamina of midgut and ovary. In addition, the recombinant HlCLec and individual CRDs demonstrated direct binding activity to Escherichia coli and Staphylococcus aureus ; however, no growth inhibition activity was observed. Furthermore, E. coli injection after silencing of HlCLec caused drastic reduction in survival rate of ticks. These results strongly suggest the key role of HlCLec in tick innate immunity against Gram-negative bacteria. Graphical abstract: Highlights: HlCLec with triple CRDs was identified from Haemaphysalis longicornis . HlCLec mRNA is upregulated during blood feeding and highest in the midgut and ovary. Each CRD showed binding ability to both Escherichia coli and S. aureus . Each CRD had no growth inhibitory effeect to both E. coli and S. aureus . E. coli injection after HlCLec silencing caused significant decrease in tick survival.