AUTHOR=Huang Ying , Shi Yan , Hu Sufei , Wu Ting , Zhao Zhe 

TITLE=Characterization and Functional Analysis of Two Transmembrane C-Type Lectins in Obscure Puffer (Takifugu obscurus)

JOURNAL=Frontiers in Immunology

VOLUME=11

YEAR=2020

URL=https://www.frontiersin.org/journals/immunology/articles/10.3389/fimmu.2020.00436

DOI=10.3389/fimmu.2020.00436

ISSN=1664-3224

ABSTRACT=<p>C-type lectins (CTLs) have received widespread attention in animal immune responses. In the present study, two CTLs (<italic>ToCTL1</italic> and <italic>ToCTL2</italic>) were identified from obscure puffer <italic>Takifugu obscurus</italic>. The open reading frames of ToCTL1 and ToCTL2 were 687 and 1,380 bp, respectively. The predicted ToCTL1 and ToCTL2 proteins contained a single transmembrane region and one typical carbohydrate recognition domain (CRD). Quantitative real-time polymerase chain reaction detected <italic>ToCTL1</italic> and <italic>ToCTL2</italic> transcripts in all examined tissues, with high levels in the intestine and kidney, and their expression levels were remarkably altered upon <italic>Vibrio harveyi</italic> and <italic>Aeromonas hydrophila</italic> infection. The recombinant proteins ToCTL1-CRD and ToCTL2-CRD agglutinated the Gram-negative and Gram-positive bacteria in a Ca<sup>2+</sup>-dependent manner. rToCTL1-CRD and rToCTL2-CRD exhibited evident binding activities against seven kinds of bacteria and polysaccharides (lipopolysaccharide and peptidoglycan) in a Ca<sup>2+</sup>-independent manner. Moreover, rToCTL1-CRD and rToCTL2-CRD could inhibit the growth of four types of bacteria <italic>in vitro</italic>. These findings collectively demonstrated that ToCTL1 and ToCTL2 could be involved in host defense against bacterial infection in <italic>T. obscurus</italic>.</p>