Insect immunity

The humoral antibacterial response of Drosophila

“…Drosophila also produces larger-sized antibacterial polypeptides, according to the data of earlier studies [7,18], and we speculate that the total number of inducible antibacterial molecules is well in excess of a dozen. It is at present unclear why Drosophila would need such a large number of different antibacterial peptides for its protection.…”

“…Studies by Boman and associates [6] demonstrated that in Drosophila, like in other insect species, a primary infection can induce a protection against a secndary infection which otherwise would be lethal. However, as Boman later put it, 'the biochemistry behind this phenomenon could not be worked out at that time' [7]. In spite of the obvious interest of Drosophila as a model system, Boman and associates turned to the large pupae of the Cecropia moth for the first successful isolation of induced antibacterial molecules (cecropins [8] and attacins [9]), while other groups worked on large-sized fly species, like Sarcophaga peregrina (isolation of the cecropin-like sarcotoxins I [lo], the attacin-related sarcotoxins II [l I] and sapecin, a homologue of insect defensin [I 21) or Phormiu terranovae (isolation of diptericins [13] and insect defensins [14]) (for reviews on these peptides, see e.g.…”

“…In the mid-eighties, two independent studies confirmed that Drosophila, like other insects, responds to the inoculation of bacteria within a few hours by the de novo synthesis of several peptidic or polypeptidic molecules, some of which were presumed to be homologous of cecropins and attacins [7,18]. However, still at that time, the structures of the molecules remained elusive, as a consequence of the low amounts which could be extracted from these small-sized insects.…”

A Novel Protease in the Pupal Yellow Body of Sarcophaga peregrina (Flesh Fly)

“…As sarcotoxin IA is a small peptide consisting of 39 amino acid residues, we first coated reverse-phase column packing material (C 18 ) with sarcotoxin IA according to the method of Flyg et al (11), then immunized albino rabbits with the sarcotoxin IA-coated particles. The resulting antiserum was affinity-purified with sarcotoxin IA.…”

Effects of Cecropin Peptides on Aquatic Animal Pathogens and Shrimp Hemocytes.

“…Antimicrobial pep tides thus provide an important defense mechanism in animals and the first line of host defense during the time required for mobilization of specific immunity in verte brates. Cecropins, the highly basic and amphipathic small peptides, have been induced and isolated from insects (Hultmark et al, 1980;Hoffmann et al,1981;Flyg et al, 1987;Matsumoto et al, 1986;Dickinson et al, 1988) and porcine (Lee et al, 1989). They have broad-spec trum bactericidal activity.…”