Characteristics of inert beads provoking humoral immune responses in Galleria mellonella larvae

Abstract

Injection of ion exchange beads or sterile latex beads into the haemocoel of wax moth ( Galleria mellonella) larvae provokes an humoral immune response measurable as antibacterial activity in cell-free haemolymph. The influence of provocator surface properties on the intensity of response was investigated. Comparing the antibacterial activities provoked by injection of anion and cation exchangers it can be concluded, that anion exchangers are better provocators than cation exchangers. The influence of physicochemical parameters was confirmed by the fact, that injection of latex beads pretreated with sulphuric acid lead to enhanced antibacterial activities in larvae as compared to the activities provoked by injection of untreated beads. In order to prove if it is possible to enhance the provocation capacity of beads by binding molecules to their surfaces, the following substances were covalently coupled onto the beads prior to injection: fibronectin, peptides with a cell adhesive signal of fibronectin (GLY-ARG-GLY-ASP-SER-PRO-LYS, GLY-ARG-GLY-ASP-SER, ARG-GLY-ASP-SER), poly-lysine, adjuvant peptide, lysozyme, bovine serum albumin, bovine plasma, cell-free haemolymph and haemolymph lysate supernatant (haemolymph preparations from G. mellonella) Coupling of adjuvant peptide, fibronectin or haemolymph preparations enhanced the provocation capacity of beads very clearly. Likewise, but to a lower extent, an enhancement was noticed for nearly all the other substances tested in comparison to results obtained by injection of unloaded beads. The results will be discussed in relation to the known facts about the influence of provocator characteristics onto the onset of a cellular reaction by arthropod and vertebrate cells.