Identification and functional analysis of a Hemolin like protein from Litopenaeus vannamei.

Abstract

Hemolin is a specific immune protein belonging to immunoglobulin superfamily and firstly identified in insects. Growing evidences suggest that Hemolin can be activated by bacterial and viral infections and may play an important role in antimicrobial immunity. In this paper, we firstly identified a Hemolin-like protein from Litopenaeus vannamei (LvHemolin). Sequence analysis showed that LvHemolin shares high similarity with insect Hemolins and is mainly composed of seven immunoglobulin (Ig) domains which form a 'horseshoe' tertiary structure. Tissue distribution analysis demonstrated that LvHemolin mainly expressed in stomach, gill, epithelium and pyloric cecum of L. vannamei. After challenge with pathogens or stimulants, expression of LvHemolin was significantly up-regulated in both gill and stomach. Agglutination analysis demonstrated that recombinant LvHemolin protein purified from Escherichia coli could accelerate the agglutination of Vibrio parahaemolyticus, E. coli, Staphylococcus aureus, and Bacillus subtilis in the presence of Ca(2+). To verify the immune function of LvHemolin in vivo, shrimps were injected with gene-specific dsRNA, followed by challenge with white spot syndrome virus (WSSV) or V. parahaemolyticus. The results revealed that silence of LvHemolin could increase the cumulative mortalities of shrimps challenged by pathogens and increase the WSSV copies in shrimp tissues. These suggested that Hemolin could play an important role in shrimp innate immune defense against bacterial and viral infections.

• Authors: Hongliang Zuo, Haoyang Li, Erman Wei, Ziqi Su, Jieyao Zheng, Chaozheng Li, Yonggui Chen, Shaoping Weng, Jianguo He, Xiaopeng Xu
• Journal: Fish & shellfish immunology (Fish Shellfish Immunol) Vol. 43 Issue 1 Pg. 51-9 (Mar 2015) ISSN: 1095-9947 [Electronic] England
• PMID: 25527138 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
• Copyright: Copyright © 2014 Elsevier Ltd. All rights reserved.

Chemical References

• Arthropod Proteins
• DNA, Complementary
• Immunoglobulins
• Insect Proteins
• RNA, Double-Stranded
• RNA, Messenger
• hemolin

Topics

• Agglutination Tests
• Amino Acid Sequence
• Animals
• Arthropod Proteins (chemistry, genetics, metabolism)
• Cloning, Molecular
• DNA, Complementary (genetics, metabolism)
• Gram-Negative Bacteria (physiology)
• Gram-Positive Bacteria (physiology)
• Immunoglobulins (chemistry, genetics, metabolism)
• Insect Proteins (chemistry, genetics, metabolism)
• Molecular Sequence Data
• Penaeidae (immunology, microbiology, virology)
• Phylogeny
• RNA, Double-Stranded (metabolism)
• RNA, Messenger (genetics, metabolism)
• Real-Time Polymerase Chain Reaction
• Sequence Alignment
• White spot syndrome virus 1 (physiology)