Antiviral and antitumor peptides from insects

Abstract

Insects can rapidly clear microbial infections by producing a variety of immune-induced molecules including antibacterial and͞or antifungal peptides͞polypeptides. In this report, we present the isolation, structural characterization, and biological properties of two variants of a group of bioactive, slightly cationic peptides, referred to as alloferons. Two peptides were isolated from the blood of an experimentally infected insect, the blow fly Calliphora vicina (Diptera), with the following amino acid sequences: HGVSGHGQH-GVHG (alloferon 1) and GVSGHGQHGVHG (alloferon 2). Although these peptides have no clear homologies with known immune response modifiers, protein database searches established some structural similarities with proteins containing amino acid stretches similar to alloferon. In vitro experiments reveal that the synthetic version of alloferon has stimulatory activities on natural killer lymphocytes, whereas in vivo trials indicate induction of IFN production in mice after treatments with synthetic alloferon. Additional in vivo experiments in mice indicate that alloferon has antiviral and antitumoral capabilities. Taken together, these results suggest that this peptide, which has immunomodulatory properties, may have therapeutic capacities. The fact that insects may produce cytokine-like materials modulating basic mechanisms for human immunity suggests a source of anti-infection and antitumoral biopharmaceuticals.insect innate immunity ͉ cytokine-like ͉ immunomodulatory peptide

Morphological characterization of Anticarsia gemmatalis M nucleopolyhedrovirus infection in haemocytes from its natural larval host, the velvet bean caterpillar Anticarsia gemmatalis (Hübner) (Lepidoptera: Noctuidae)

“…The cytokine-like factor alloferon, described for the diperan Calliphora vicina, was shown to stimulate NK lymphocytes activity in vitro and to induce IFN production in mice, having antiviral and antitumoural capabilities ( Chernysh et al, 2002). This report, together with our finding of a putative early death of baculovirus-infected haemocytes, suggest the possibility of a cytotoxic response against virus-infected cells in insects, in some way similar to the one triggered by T lymphocytes in mammals.…”

Activity of the De Novo Engineered Antimicrobial Peptide WLBU2 against Pseudomonas aeruginosa in Human Serum and Whole Blood: Implications for Systemic Applications

“…Numerous studies of CAP interactions with variably charged liposomes suggest that antimicrobial peptides selectively bind bacterial over eukaryotic cell membranes because of the negatively charged lipids found on the outer leaflets of the former (10,20). The mechanisms of the antitumor and antiviral properties of CAPs are thought to be related to the presence of negatively charged phosphatidylserine on the surfaces of tumor cells (15,60) and sialic acid and heparan sulfate associated with viruses (2,15,18,38). CAP antifungal (7,16) and immunomodulatory (1,5,24,40,52) properties have also been reported.…”

Identification of a Soluble NADPH Oxidoreductase (BmNOX) with Antiviral Activites in the Gut Juice ofBombyx mori

“…Insects can rapidly clear microbial infections by producing a variety of immune-induced molecules including antibacterial and/or antifungal peptides/polypeptides 7) collectively known as antimicrobial peptides (AMPs). In Drosophila, seven groups of inducible AMPs have been identified.…”