The Two NF-κB Pathways Regulating Bacterial and WSSV Infection of Shrimp.

Chaozheng Li,Sheng Wang,Jianguo He

doi:10.3389/fimmu.2019.01785

Abstract

The outbreak of diseases ordinarily results from the disruption of the balance and harmony between hosts and pathogens. Devoid of adaptive immunity, shrimp rely largely on the innate immune system to protect themselves from pathogenic infection. Two nuclear factor-κB (NF-κB) pathways, the Toll and immune deficiency (IMD) pathways, are generally regarded as the major regulators of the immune response in shrimp, which have been extensively studied over the years. Bacterial infection can be recognized by Toll and IMD pathways, which activate two NF-κB transcription factors, Dorsal and Relish, respectively, to eventually lead to boosting the expression of various antimicrobial peptides (AMPs). In response to white-spot-syndrome-virus (WSSV) infection, these two pathways appear to be subverted and hijacked to favor viral survival. In this review, the recent progress in elucidating microbial recognition, signal transduction, and effector regulation within both shrimp Toll and IMD pathways will be discussed. We will also highlight and discuss the similarities and differences between shrimps and their Drosophila or mammalian counterparts. Understanding the interplay between pathogens and shrimp NF-κB pathways may provide new opportunities for disease-prevention strategies in the future.

Highlights

Shrimp farming is an important economic activity in China and many Southeast Asian countries, such as the Philippines, Indonesia, Malaysia, Thailand, and Vietnam, and it provides an important contribution to the diversity of income strategies for a large proportion of people living in these countries
The activating transcription factor 4 (ATF4) and X-Box-binding protein 1 (XBP1), components of the unfolded protein response (UPR), are capable of inducing the expression of LvSpz4, which suggests that LvSpz4 could be a regulator to link the Toll-nuclear factor-κB (NF-κB) pathway and the UPR [38]
Since the LvIMD was identified in L. vannamei, an increasing number of components of the canonical immune deficiency (IMD) pathway in shrimp have been identified, including TAK1, TAB1, TAB2, Relish, mitogen-activated protein kinase kinase 3 (MKK3), MKK4, MKK6, MKK7, c-Jun N-terminal kinase (JNK), c-Jun, c-Fos, p38, ATF2, NF-κB repressing factor (NKRF), Akirin, Bap60, and 14-3-3 [12, 17, 73, 105, 109,110,111,112,113,114,115,116,117,118,119,120,121,122,123,124,125,126,127]

Summary

Introduction

Shrimp farming is an important economic activity in China and many Southeast Asian countries, such as the Philippines, Indonesia, Malaysia, Thailand, and Vietnam, and it provides an important contribution to the diversity of income strategies for a large proportion of people living in these countries. The activating transcription factor 4 (ATF4) and X-Box-binding protein 1 (XBP1), components of the unfolded protein response (UPR), are capable of inducing the expression of LvSpz4, which suggests that LvSpz4 could be a regulator to link the Toll-NF-κB pathway and the UPR [38].

Results

Conclusion