Transcriptome-wide identification, functional characterization, and expression analysis of two novel invertebrate-type Toll-like receptors from disk abalone (Haliotis discus discus).
Fish Shellfish Immunol
; 84: 802-815, 2019 Jan.
Article
in En
| MEDLINE
| ID: mdl-30368026
ABSTRACT
Toll-like receptors (TLRs) are well-known pattern recognition receptors that play key immunological roles in a diverse range of organisms. In this study, two novel invertebrate TLRs from disk abalone (designated as AbTLR-A and AbTLR-B) were identified and functionally characterized for the first time. AbTLR-A and AbTLR-B comprised the typical TLR domain architecture containing an extracellular leucine-rich repeat domain, transmembrane domain, and Toll/interleukin-1 receptor domain. Expressional analysis revealed that both TLRs were constitutively expressed at all the early embryonic stages of disk abalone analyzed, with the highest level of AbTLR-A found at the 16-cell stage and AbTLR-B at the trochophore stage. According to tissue distribution analysis, prominent mRNA expression of AbTLR-A and AbTLR-B was detected in the hemocytes and gills, respectively. AbTLR-A and AbTLR-B mRNAs were significantly up-regulated in response to Gram-negative Vibrio parahemolyticus, Gram-positive Listeria monocytogenes, and viral hemorrhagic septicemia virus injections in abalone hemocytes and gills. Overexpression of AbTLR-A and AbTLR-B in HEK293T cells directly activated nuclear factor-κB (NF-κB) and activator protein-1 (AP-1) responsive reporters. Neither TLRs showed a high response to pathogen-associated molecular patterns in vitro. Co-expression of AbTLR-A and AbTLR-B with AbMyD88-2 and AbMyD88-X activated NF-κB-responsive reporters in a synergetic manner. These findings demonstrate the involvement of AbTLR-A and AbTLR-B in abalone innate immunity.
Key words
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Gene Expression Regulation
/
Gastropoda
/
Toll-Like Receptors
/
Immunity, Innate
Type of study:
Diagnostic_studies
/
Prognostic_studies
Limits:
Animals
/
Humans
Language:
En
Journal:
Fish Shellfish Immunol
Journal subject:
BIOLOGIA
/
MEDICINA VETERINARIA
Year:
2019
Type:
Article