Fat body and hemocyte contribution to the antimicrobial peptide synthesis in Calliphora vicina R.-D. (Diptera: Calliphoridae) larvae

Abstract

Antimicrobial peptides accumulated in the hemolymph in response to infection are a key element of insect innate immunity. The involvement of the fat body and hemocytes in the antimicrobial peptide synthesis is widely acknowledged, although release of the peptides present in the hemolymph from the immune cells was not directly verified so far. Here, we studied the presence of antimicrobial peptides in the culture medium of fat body cells and hemocytes isolated from the blue blowfly Calliphora vicina using complex of liquid chromatography, mass spectrometry, and antimicrobial activity assays. Both fat body and hemocytes are shown to synthesize and release to culture medium defensin, cecropin, diptericins, and proline-rich peptides. The spectra of peptide antibiotics released by the fat body and hemocytes partially overlap. Thus, the results suggest that insect fat body and blood cells are capable of releasing mature antimicrobial peptides to the hemolymph. It is notable that the data obtained demonstrate dramatic difference in the functioning of insect antimicrobial peptides and their mammalian counterparts localized into blood cells' phagosomes where they exert their antibacterial activity.

Anti-tumor effects of antimicrobial peptides, targets of the innate immune system, against hematopoietic tumors inDrosophila mxcmutants

“…Surprisingly, we observed that circulating hemocytes containing AMPs were associated with the LG tumors. However, previous studies have reported that Drosophila AMPs stored in the cytoplasmic granules of circulating hemocytes were discharged against infecting microbes (Destoumieux et al, 2000; Yakovlev et al, 2017). Moreover, AMP-containing hemocytes are reportedly recruited to neoplastic tumors in Drosophila (Cordero et al, 2010; Parisi et al, 2014; Pastor-Pareja et al, 2008).…”

“…Moreover, AMP-containing hemocytes are reportedly recruited to neoplastic tumors in Drosophila (Cordero et al, 2010; Parisi et al, 2014; Pastor-Pareja et al, 2008). Subsequently, the hemocytes release the stored AMPs against the tumor cells by regulated exocytosis (Destoumieux et al, 2000; Yakovlev et al, 2017). In this study, we showed that Drosomycin and Defensin have an anti-tumor activity against hematopoietic tumors with the help of circulating hemocytes in the hemolymph.…”

Anti-tumour effects of antimicrobial peptides, components of the innate immune system, against haematopoietic tumours in Drosophila mxc mutants

“…Subsequently, the haemocytes were recruited into the LG tumours. Previous studies have reported that Drosophila AMPs stored in the cytoplasmic granules of circulating haemocytes were discharged against infectious microbes (Destoumieux et al, 2000; Yakovlev et al, 2017). Moreover, AMP-containing haemocytes are reportedly recruited to neoplastic tumours in Drosophila (Cordero et al, 2010; Parisi et al, 2014; Pastor-Pareja et al, 2008).…”

Sarconesin: Sarconesiopsis magellanica Blowfly Larval Excretions and Secretions With Antibacterial Properties

“…They have been shown to be mainly effective against Gram-positive bacteria, such as MRSA and its strains ( Andersen et al, 2010 ; Cerovsky and Bem, 2014 ). Amongst the most recent studies on antimicrobial peptides isolated from flies from the Calliphoridae family different to those obtained from larval ES, it is worth mentioning a study by Yakovlev et al (2017) ( Yakovlev et al, 2017 ), who studied the presence of AMPs in the culture medium from both fat bodies and haemocytes derived of Calliphora vicina larvae. They demonstrated that both cell types synthesized and released an AMPs complex to the culture medium, corresponding to defensins, cecropins, diptericins, and proline-rich peptides.…”