Further observations on the induction of immunity by hemolymph transfer in Galleria mellonella.

Humoral immune responses of Galleria mellonella larvae were provoked by transfer of hemolymph lysate supernatant preparations (HLS) from untreated donor larvae to recipient larvae. Eighteen hours after transfer the antibacterial activity in cell-free hemolymph of recipient larvae was as high as after injection of high dosages of living Enterobacter cloacae beta 12 bacteria. Filtration of HLS (FHLS; 0.2 microns filter) prior to injection enhanced its induction capacity. Injection of FHLS concentrates (> 30 < 100 kDa) provoked the same immune responses as injection of FHLS itself. Heat treatment did not destroy the induction capacity of FHLS. Hemolymph samples of larvae immunized by hemolymph transfer or by injection of bacteria showed the same characteristic protein pattern in SDS-PAGE. At least six new or enhanced bands were detected in hemolymph of immunized larvae. These bands were missing or very weak in hemolymph from untreated or saline injected larvae.