Immune Responses of Some Insects to Some Bacterial Antigens

Abstract

Pseudomonas aeruginosa (Schroeter) Migula antigen remained in the blood of larvae of the wax moth, Galleria mellonella (L.), during the resistant period of the insect. Bacterial antigen present in the immune blood produces agglutinating titers in rabbits about 10 times as great a s those produced by a n approximately equal volume of standard P. aeruginosa vaccine. Attempts to demonstrate the mechanism that enhances the antigen showed that the active portion was contained in the serum, that the action occurred within several hours in vivo and only reached the same level after 3 days in vitro mixture, and that the action was probably not caused by lysis of the bacterial cells and the consequent liberation of more antigen in the blood. Electrophoretic studies on the blood mixture indicated that the altered or enhanced antigen may be bound to a blood fraction, the exact nature of which was not determined. The larvae were actively or passively immunized against lethal doses of P. aert~gginosa within 20 to 24 hours. Concentration of vaccine had little effect upon the degree of immunity conferred upon the larvae. T h e immunity lasted about three days and was more specific than nonspecific. The larvae were not actively protected against P. aeruginosa by introductioil of albuminous foreign material into the body cavity. True antibodies were not detectable in the immune blood though the bactericidal action of immune blood was a t least twice as great a s that of normal blood. Preliminary investigations on immune responses of other lepidopterous insects to P. aeruginosa antigen and of the wax moth to antigens of some other Gram-negative bacteria indicated similar results. lManuscript received October 17, 1958. Contribution No. 3864,

Prior infection of Manduca sexta with non-pathogenic Escherichia coli elicits immunity to pathogenic Photorhabdus luminescens: Roles of immune-related proteins shown by RNA interference

“…But it has been recognised for many years that 'immunisation' with killed bacteria (e.g. with Pseudomonas aeruginosa -Stephens, 1959-Stephens, , 1962 or prior infection with living bacteria (e.g. with Enterobacter cloacae- Boman et al, 1972Boman et al, , 1974 can induce in insects a temporary state of markedly enhanced resistance to subsequent infection, either to the same bacterium or a different one.…”

Biologie larvaire et mécanisme de transmission de la Filaire Dipetalonema viteae

“…L'existence de réac tions humorales chez les Insectes n'a jamais été prouvée pour les parasites métazoaires ; mais Briggs (1958) et Stephens (1959) semblent avoir démontré son existence vis-à-vis des bactéries. L'observation de destruction de filaires dans l'haemocoele, sans faire intervenir de mécanisme cellulaire, ne peut à elle seule prouver la mise en jeu, dans ce cas, de mécanismes humoraux ; on peut penser en effet, comme l'écrit Salt (1963) que la destruction du parasite n'est qu'un effet retardé de substances nocives qui seraient présentes uniquement dans le tube digestif.…”

Reactions of Tenebrio molitor and Galleria mellonella to MS2 bacteriophage and Pseudomonas aeruginosa

“…aeruginosa seemed to be relatively heat stabile as compared with the cultures used by other workers (28,30,46), Three sets of 15 larvae each of W strain, and three sets of 15 larvae each of the N strain of Galleria were treated with 4 jul/larva of bacterin.…”

“…Stephens (46) showed that Pseudomonas aeruginosa bacterins would protect Galleria mellonella larvae from challenge with viable cells, that the antigen (immunogen) remained in the hemolymph throughout the re fractory period (unlike the situation in vertebrates where the antigen needs to be processed), and that the antigen was somehow altered during immunity in the insect so that it has an increased antigenicity for rabbits.…”

“…Since Stephens (46,47) had reported that immunization was accompanied by a loss of the ability of the hemolymph to melanize I decided to see if rnelanization times could be used as an index of immunity. This should be possible if the inverse relationship described by Stephens (46,47) and by Taylor (49) is a result of immunization.…”