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

Abstract

C-type lectins (CTLs) have received widespread attention in animal immune responses. In the present study, two CTLs (ToCTL1 and ToCTL2) were identified from obscure puffer Takifugu obscurus. 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 ToCTL1 and ToCTL2 transcripts in all examined tissues, with high levels in the intestine and kidney, and their expression levels were remarkably altered upon Vibrio harveyi and Aeromonas hydrophila infection. The recombinant proteins ToCTL1-CRD and ToCTL2-CRD agglutinated the Gram-negative and Gram-positive bacteria in a Ca 2+-dependent manner. rToCTL1-CRD and rToCTL2-CRD exhibited evident binding activities against seven kinds of bacteria and polysaccharides (lipopolysaccharide and peptidoglycan) in a Ca 2+-independent manner. Moreover, rToCTL1-CRD and rToCTL2-CRD could inhibit the growth of four types of bacteria in vitro. These findings collectively demonstrated that ToCTL1 and ToCTL2 could be involved in host defense against bacterial infection in T. obscurus.

An Update of Lectins from Marine Organisms: Characterization, Extraction Methodology, and Potential Biofunctional Applications

“…The levels of expression of two obscure puffer ( Takifugu obscurus) C-type lectins were upregulated in response to infection with A. hydrophila and V. harveyi . The recombinant forms of the lectins showed Ca 2+ -dependent agglutinating activity toward Gram-positive and Gram-negative bacteria, exhibited binding to bacterial peptidoglycan and lipopolysaccharide, and manifested in vitro growth inhibitory activity on four types of bacteria [ 177 ]. Calreticulin with lectin-like and immune activities is a highly conserved protein.…”

Eco-Interactions of Engineered Nanomaterials in the Marine Environment: Towards an Eco-Design Framework

“…Among marine invertebrates, the sea urchin P. lividus and bivalves belonging to genus Mytilus spp., have been proposed as suitable models to study NP-cellular interactions and immunotoxicity [ 136 , 150 , 151 ], as previously adopted to study other legacy marine pollutants as well as other stressors, including seawater acidification, UV-radiation and microplastics [ 152 , 153 , 154 , 155 ]. Several harmful effects of PS NPs have been reported in mussel hemocytes both in vitro and in vivo, and all of these highlighted the nano-immunomodulation features [ 156 , 157 , 158 ]. Studies performed with short-term primary cultures of coelomocytes exposed to functionalized PS NPs showed that the immune response exerted by sea urchin coelomocytes differed according to PS NP surface charge.…”

C-Type Lectins in Veterinary Species: Recent Advancements and Applications

“…The antimicrobial effects of several CTLs were recently shown for both sweet water [ 71 ] and salt water [ 72 ] fish species. In carp, a number of CTLs were identified to be downregulated on macrophages upon stimulation with the ß-glucan curdlan [ 73 ], which is a well-known ligand of Dectin-1 in mammals [ 74 ].…”