In this work the mechanisms of transduction triggered in Mytilus galloprovincialis hemocytes by bacterial challenge were investigated in an in vitro model of infection of hemocyte monolayers with Escherichia coli. Western blot analyses of hemocyte extracts with phospho-specific anti-MAPK (Mitogen Activated Protein Kinase) antibodies indicate that E. coli induced a time dependent activation of different classes of MAPKs, mainly of the stress-activated p38 MAPK. P38 activation was confirmed by the use of the selective kinase inhibitor SB203580. Moreover, hemocyte pretreatment with SB203580 significantly reduced bacterial killing, whereas PD98059, an inhibitor of extracellularly regulated kinase (ERK) activation, was ineffective. Interestingly, the PI3-kinase (phosphatidylinositol-3-OH-kinase) inhibitor, Wortmannin, reduced both p38 activation and bacterial killing, indicating a critical role also for this lipid kinase in the hemocyte immune response.
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http://dx.doi.org/10.1016/s0145-305x(01)00078-7 | DOI Listing |
Comp Biochem Physiol C Toxicol Pharmacol
January 2025
Key Laboratory of South China Sea Fishery Resources Exploitation & Utilization, Ministry of Agriculture and Rural Affairs, South China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou, Guangdong 510300, China. Electronic address:
The small abalone (Haliotis diversicolor) is an economic shellfish cultured in the south coast of China. In recent years, the frequent occurrence of the disease has led to significant mortality in abalone farms. Deleted in malignant brain tumors 1 (DMBT1), a member of the scavenger receptor cysteine-rich (SRCR) protein family, plays an important role in host defense.
View Article and Find Full Text PDFInt J Biol Macromol
January 2025
Key Laboratory of Breeding Biotechnology and Sustainable Aquaculture, Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, China; University of Chinese Academy of Sciences, Beijing, 100049, China.
NLR inflammasomes recognize pathogen-associated molecular patterns (PAMPs), triggering Caspase-1 activation and leading to gasdermin D (GSDMD)-mediated pyroptosis, a crucial immune response in mammals. The functional GSDME-mediated pyroptosis has been reported in invertebrates, yet the existence of an NLR-Caspase-GSDME axis mediating pyroptosis signaling cascades remains unclear. In this study, we reported an NLRC4 homolog named ChNLRC4, a pattern recognition receptor from the oyster Crassostrea hongkongensis that is able to bind to LPS and Lys-type PGN through its LRR domain.
View Article and Find Full Text PDFFront Cell Infect Microbiol
December 2024
Department of Pathobiological Sciences, School of Veterinary Medicine, Louisiana State University, Baton Rouge, LA, United States.
Ixodid ticks serve as hosts and transmission vectors for several obligate intracellular bacteria, including members of the spotted fever group (SFG) of . Although ticks generate an immune response to bacterial insults, many of the signaling molecules associated with the response and how they may contribute to vector competence for are undefined. In this study, we isolated a full-length transcript from , which encoded a Relish-type NF-κB.
View Article and Find Full Text PDFFish Shellfish Immunol
February 2025
Univ Brest, CNRS, IRD, Ifremer, UMR 6539, LEMAR, Plouzané, France. Electronic address:
The vibriosis of the European abalone, Haliotis tuberculata, is characterized by the rapidity of the infection by the pathogen Vibrio harveyi ORM4, leading to death of animals only after two days. The lethality of the pathogen is linked to the production of the type III secretion system (T3SS) and to genes regulated by quorum sensing (QS). The aim of this study was to investigate the colonization of the European abalone by both virulent and avirulent V.
View Article and Find Full Text PDFFish Shellfish Immunol
February 2025
School of Aquatic and Life Sciences, Shanghai Ocean University, Shanghai, China. Electronic address:
Mucosa-associated lymphoid tissue lymphoma translocation protein 1 (MALT1), a scaffold protein, plays a pivotal role in the NF-κB pathway downstream of T-cell receptors (TCRs) and B-cell receptors (BCRs). As a key signaling hub, MALT1 integrates various pathways, making it essential for both innate and adaptive immunity. However, its role in the antibacterial immune responses of crustaceans remains unclear.
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