PT  - JOURNAL ARTICLE
AU  - Emmanuelle C. Zoccola
AU  - Stuart Kellie
AU  - Andrew C. Barnes
TI  - Leucocyte integrins but not caspases or NLR inflammasome are associated with lipopolysaccharide recognition and response in barramundi (<em>Lates calcarifer</em>)
AID  - 10.1101/307017
DP  - 2018 Jan 01
TA  - bioRxiv
PG  - 307017
4099  - http://biorxiv.org/content/early/2018/04/25/307017.short
4100  - http://biorxiv.org/content/early/2018/04/25/307017.full
AB  - The inflammatory response of fish to LPS is subdued, attributed to absence of TLR4, a key pro-inflammatory receptor for LPS in mammals. Nevertheless, LPS is processed in fish in a T-independent manner and is a protective antigen in fish vaccines, yet pathways for processing LPS in fish remain to be elucidated. Here, we report that caspases and NOD-like receptor inflammasomes typically responsible for LPS recognition and processing in mammals lack critical domains or are absent in barramundi (Lates calcarifer). However, leucocyte integrins MAC-1 and LFA-1 induce pro-inflammatory cytokine expression poststimulation with LPS. Moreover, MAC-1 and LFA-1 were detected on the surface of neutrophil- and lymphocyte-like cells respectively in the barramundi spleen by immunocytochemistry, and leucocytes displaying MAC-1 or LFA-1 bound to Factor X and ESM-1 respectively. Our results implicate MAC-1 and LFA-1 in immune processing of LPS in barramundi and potentially in antigen processing in fish.