RESUMEN
Croquemort, the homologue of human CD36, is a member of class B scavenger receptors, which is involved in bacteria phagocytosis and cytokins release. However, there is still less information about Croquemort in crustaceans. Here, a Croquemort from Pacific white shrimp Litopenaeus vannamei (LvCroquemort) and its truncated form (LvCroquemort-S1) cDNA sequences were identified, characterized and their role in bacteria clearance was investigated. The deduced protein of LvCroquemort is 533 amino acids and contains typical domains of CD36: the N-terminus and C-terminus in cytoplasm, two transmembrane regions and a large extracellular loop-like domain. However, LvCroquemort-S1 losses partial cDNA sequence in its middle and its deduced protein losses the C-terminal transmembrane region and C-terminus in cytoplasm, the latter of which is found participating in cytokins release in human CD36. LvCroquemort transcript is highly expressed in gills, hemocytes, testis and slightly in heart, hepatopancreas and nerve. Besides, its responses to bacteria Vibrio anguillarum and white spot syndrome virus were examined. Knock-down of LvCroquemort by specific dsRNA reduces bacteria clearance. These initial data will help to further understand roles of Croquemort in crustacean innate immunity.
Asunto(s)
Proteínas de Artrópodos/genética , Penaeidae/genética , Virus del Síndrome de la Mancha Blanca 1/fisiología , Secuencia de Aminoácidos , Animales , Proteínas de Artrópodos/química , Proteínas de Artrópodos/metabolismo , Antígenos CD36/química , Antígenos CD36/genética , Antígenos CD36/metabolismo , ADN Complementario/química , ADN Complementario/genética , ADN Complementario/metabolismo , Inmunidad Innata/genética , Especificidad de Órganos , Penaeidae/inmunología , Penaeidae/microbiología , Penaeidae/virología , Filogenia , Interferencia de ARN , ARN Mensajero/genética , ARN Mensajero/metabolismo , Homología de Secuencia de Aminoácido , Vibrio/fisiologíaRESUMEN
In the animal kingdom, innate immunity is the first line of defense against invading pathogens. The dangers of microbial and parasitic attacks are countered by similar mechanisms, involving the prototypes of the cell-mediated immune responses, the phagocytosis and encapsulation. Work on Drosophila has played an important role in promoting an understanding of the basic mechanisms of phylogenetically conserved modules of innate immunity. The aim of this review is to survey the developments in the identification and functional definition of immune cell types and the immunological compartments of Drosophila melanogaster. We focus on the molecular and developmental aspects of the blood cell types and compartments, as well as the dynamics of blood cell development and the immune response. Further advances in the characterization of the innate immune mechanisms in Drosophila will provide basic clues to the understanding of the importance of the evolutionary conserved mechanisms of innate immune defenses in the animal kingdom.