A novel lectin with a fibrinogen‐like domain and its potential involvement in the innate immune response of Armigeres subalbatus against bacteria

Abstract

Mosquitoes have an efficient cellular innate immune response that includes phagocytosis of microbial pathogens and encapsulation of metozoan parasites. In this study, we describe a novel lectin in the mosquito, Armigeres subalbatus (aslectin or AL-1). The 1.27 kb cDNA clone for the AL-1 gene (AL-1) encodes a 279 deduced amino acid sequence that contains a C-terminal fibrinogen-like domain. AL-1 is transcribed in all life stages. AL-1 mainly exists in the haemolymph of adult female mosquitoes, and is upregulated following both Escherichia coli and Micrococcus luteus challenge. AL-1 specifically recognizes N-acetyl-d-glucosamine and is able to bind both E. coli and M. luteus. These results suggest that AL-1 might function as a pattern recognition receptor in the immune response in Ar. subalbatus.

A Galectin of Unique Domain Organization from Hemocytes of the Eastern Oyster (Crassostrea virginica) Is a Receptor for the Protistan Parasite Perkinsus marinus

“…In other invertebrate species, wettability, hydrophobicity, or charge of the particle, have been proposed as surface properties that determine nonspecific recognition leading to phagocytosis or encapsulation (62). However, a variety of pattern recognition receptors including peptidoglycan recognition proteins (63)(64)(65), ␤ integrins (39), and lectins (66,67) have been shown to mediate specific recognition leading to phagocytosis, Oysters have a very diversified lectin repertoire, which includes C-and F-type lectins, ficolins, and galectins, some of which are present on the hemocyte surface (37,38), but their potential roles as phagocytosis receptors have not been explored. The present study shows that the four-CRD galectin CvGal is present on the cell surface of attached and spread hemocytes, most likely along other specific and nonspecific receptors.…”

Expression profiling and binding properties of fibrinogen-related proteins (FREPs), plasma proteins from the schistosome snail host Biomphalaria glabrata

“…17 In mosquitoes of the genera Anopheles and Armigeres, FBG-like proteins have been implicated in immune responses to microbes or malaria parasites because their transcript levels are up-regulated after infection. [19][20][21][22][23] Sialic-acid-binding lectins which contain FBG domains have been identified from the slug Limax flavus and found to be down-regulated after parasitism. 25 With respect to human ficolins, which are the best-studied FBG-bearing proteins in terms of structure and function, three types of ficolins (L-, H-, and M-ficolin) have lectin activity and can activate the lectin complement pathway.…”

The Primary Role of Fibrinogen-Related Proteins in Invertebrates Is Defense, Not Coagulation

“…An overview of the known roles that FBNs play in Anopheles summarizes the current knowledge of their functional properties [32] . Identification of another FBG-domain-containing molecule (AL-1) in the mosquito Armigeres subalbatus demonstrated that the AL-1 molecule was located primarily in the hemolymph of an adult mosquito and that it was capable of recognizing N-acetyl-D -glucosamine, and thereby bind to both Gram-positive and Gram-negative bacteria [22] . Many of the FReDs identified in Drosophila spp.…”