It is well known that Toll-like receptors (TLRs) play a central role for innate immunity in both in vertebrates and many invertebrates, by recognizing conserved pathogen-associated molecular patterns in order to trigger the innate immune response. Here, we evaluate the expression of TLR4, receptor of GRAM- bacterial lipopolysaccharides LPS, and of TLR2, receptor of GRAM+ lipoteichoic acid LTA after injection in the leech body wall of these two exogenous molecules known to induce a strong inflammatory response. Our results indicate that immune cells migrating toward the body wall of treated animals are macrophages (HmAIF-1+) and granulocytes (CD11b+) and express both TLR4 and TLR2. Moreover, the expression profile of TLR4 and TLR2 has been also evaluated by Western blot analysis highlighting the presence of immunoreactive products at about 130 and 110 kDa (for TLR4) and at about 100 kDa (for TLR2). We hypothesize that, according to literature, the presence of different molecular masses of TLR4 probably depends on its glycosylation state. Functional studies both in vivo and in vitro carried out by using CyP, a cyanobacterium selective TLR4 antagonist, were performed to inhibit the secretion of the pro-inflammatory cytokines, such as tumor necrosis factor alpha. Strikingly, stimulating with CyP and LPS or LTA, we found that only TLR4 pathway was blocked, while the immune response caused by LTA treatment is not affected. Our results, which are consistent with literature on vertebrates, indicate that TLR4 functions as LPS receptor while the recognition of gram-positive bacterial products involves TLR2. Further research will better clarify TLR4 and TLR2 expression and signalling in the medicinal leech.

TLRs EXPRESSION IN THE MEDICINAL LEECH

A GRIMALDI;R GIRARDELLO;N BARANZINI;M DE EGUILEOR
2018-01-01

Abstract

It is well known that Toll-like receptors (TLRs) play a central role for innate immunity in both in vertebrates and many invertebrates, by recognizing conserved pathogen-associated molecular patterns in order to trigger the innate immune response. Here, we evaluate the expression of TLR4, receptor of GRAM- bacterial lipopolysaccharides LPS, and of TLR2, receptor of GRAM+ lipoteichoic acid LTA after injection in the leech body wall of these two exogenous molecules known to induce a strong inflammatory response. Our results indicate that immune cells migrating toward the body wall of treated animals are macrophages (HmAIF-1+) and granulocytes (CD11b+) and express both TLR4 and TLR2. Moreover, the expression profile of TLR4 and TLR2 has been also evaluated by Western blot analysis highlighting the presence of immunoreactive products at about 130 and 110 kDa (for TLR4) and at about 100 kDa (for TLR2). We hypothesize that, according to literature, the presence of different molecular masses of TLR4 probably depends on its glycosylation state. Functional studies both in vivo and in vitro carried out by using CyP, a cyanobacterium selective TLR4 antagonist, were performed to inhibit the secretion of the pro-inflammatory cytokines, such as tumor necrosis factor alpha. Strikingly, stimulating with CyP and LPS or LTA, we found that only TLR4 pathway was blocked, while the immune response caused by LTA treatment is not affected. Our results, which are consistent with literature on vertebrates, indicate that TLR4 functions as LPS receptor while the recognition of gram-positive bacterial products involves TLR2. Further research will better clarify TLR4 and TLR2 expression and signalling in the medicinal leech.
2018
79° CONGRESSO UNIONE ZOOLOGICA ITALIANA
Lecce
25-28 settembre
File in questo prodotto:
Non ci sono file associati a questo prodotto.

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11383/2075451
 Attenzione

Attenzione! I dati visualizzati non sono stati sottoposti a validazione da parte dell'ateneo

Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus ND
  • ???jsp.display-item.citation.isi??? ND
social impact