Anti-mosquito Antibodies Research Articles

Reproductive and developmental performance of the yellow fever mosquito, Aedes aegypti, fed on the Syrian hamster, Mesocricetus auratus, immunized with a mosquito midgut lectin

ABSTRACT Eco-friendly alternatives to unsafe conventional pesticides against disease vectors are currently needed. Host vaccination using an insect gut antigen is a feasible approach. Thus, the present study aimed to examine the effect of ingestion of antibodies from hamsters, raised via immunization of hamsters with a partially purified midgut lectin of Aedes aegypti, in a blood meal of this disease vector on the different biological parameters (mortality percentage, number of eggs/female (fecundity), longevity, egg incubation period, larval duration and larval weight). The biological parameters of the parental (P), first (F1) and second (F2) filial generations of Ae. aegypti adult females fed for 48 h on immunized hamsters were compared with those of the controls at each generation separately, and among the different generations. Mortality percentage, egg incubation period and larval duration were significantly higher than those of the controls at each generation tested. In contrast, fecundity, longevity and larval weight were significantly lower than those of the controls at each generation tested. The greatest change in all the biological parameters tested was observed in the F2 generation. The results obtained provide preliminary evidence for the potential of anti-mosquito antibodies to disrupt the development of mosquito vectors. Future studies using monoclonal antibodies as well as cytotoxicity will be evaluated.

Detection of mosquito saliva–specific IgE and IgG 4 antibodies by immunoblotting

IgE and IgG subclass antibodies against Aedes communis mosquito saliva were studied by immunoblotting in 12 adults with immediate and/or delayed skin reactions to mosquito bites. Four antigenic proteins, with molecular weights of 22, 30, 36, and 64 kd, were found in the mosquito saliva. Almost all subjects (11 of 12) had anti-mosquito saliva–specific IgE antibodies directed against the 36 kd protein. The IgG antibody response appeared to be restricted mostly to IgG 4 (11 of 12) and IgG 1 (8 of 11) subclasses against the same 36 kd antigen. Ten of the 12 subjects had both IgE and IgG 4 antibodies to the 36 kd protein. No anti-mosquito antibodies were found in pooled sera of five infants never exposed to mosquito bites. These results show that most persons with immediate skin reactivity to A. communis mosquito bites have both IgE and IgG 4 antibodies that recognize the 36 kd antigen present in the mosquito saliva, suggesting that anti-saliva antibodies may play a role in the pathogenesis of mosquito bite reactions. (J A LLERGY C LIN I MMUNOL 1994;93:551-5.)

Host immunity to mosquitoes: effect of antimosquito antibodies on Anopheles tessellatus and Culex quinquefasciatus (Diptera: Culicidae).

Rabbit antibodies to antigens derived from the tissues of sugar-fed Anopheles tessellatus Theobald were fed to An. tessellatus and Culex quinquefasciatus Say in blood meals. These antibodies tended to reduce the number of eggs produced by An. tessellatus, but had no effect on the fecundity of Cx. quinquefasciatus. Ingestion of the rabbit antibodies did not detectably affect the mortality of An. tessellatus but increased the mortality of Cx. quinquefasciatus. The results provide preliminary evidence for the potential of antimosquito antibodies to disrupt the physiology of mosquito vectors and indicate the need for further studies with high-titer, monospecific antibodies against the relevant target antigens.

Immunology and treatment of mosquito bites

Cutaneous reactions to mosquito bites are usually pruritic weals and delayed papules. Arthus-type local and systemic symptoms can also occur but anaphylactic reactions are very rare. Both clinical and experimental evidence suggest that the various bite reactions result from sensitization to the mosquito saliva injected into the skin during feeding. Recent immunoblot studies have shown both IgG- and IgE-class anti-mosquito antibodies, but their species-specificity and clinical importance is at present unknown. In addition to an Arthus-type mechanism, both cutaneous late-phase reactivity and cell-mediated immunity may be involved in the pathophysiology of delayed mosquito-bite lesions. Cutaneous sensitization to mosquito bites can be divided into five different stages ranging from the stages of immediate wealing and delayed bite papules, to the stage of non-reactivity. No desensitization treatment is generally available for mosquito allergy but it has recently been shown that cetirizine, a potent non-sedating antihistamine, is effective against the wealing and pruritus caused by mosquito bites.

Effect of anti‐mosquito antibodies on the infectivity of the rodent malaria parasite Plasmodium berghei to Anopheles farauti

The effect of mouse anti-mosquito antibodies, present in the bloodmeal, on the infectivity of Plasmodium berghei Vincke to Anopheles farauti Laveran was investigated. Significantly fewer oocysts developed in mosquitoes feeding on mice immunized with sugar-fed mosquito midgut antigens than in mosquitoes feeding on control mice. Mosquitoes feeding on mice immunized with the midgut antigens derived from sugar-fed mosquitoes also showed reduced mortality and had lower infection rates than those fed on unimmunized mice. Blood-fed midgut antigen was less effective in producing these effects than sugar-fed midgut antigen.

Immunization of Rabbits with Mosquito Bites: Immunoblot Analysis of IgG Antimosquito Antibodies in Rabbit and Man

Rabbits immunized with 50-60 Aedes communis mosquito bites developed IgG antibodies recognizing a 21.5-kD mosquito antigen detected by the immunoblot technique. This protein seems to be a major immunogen in the saliva of A. communis mosquitoes. Studies on 60 human sera revealed that IgG antibodies recognizing the 21.5-kD antigen occurred in about 50% of young children and adults but were not found in the sera of 20 unexposed infants. The present immunoblot method allows further characterization of antigens and antibodies specific to mosquito saliva and contributes to understanding their role in mosquito bite reactions.

Anti-mosquito antibodies and their effects on feeding, fecundity and mortality of Aedes aegypti.

Anti-mosquito antibodies, produced in mice inoculated with mosquito homogenates or exposed to mosquito bites, reacted with a variety of mosquito antigens including muscle, gut, fat body and nervous tissue; those in anti-mosquito bite sera reacted solely with salivary glands. Mosquitoes fed on restrained immunized mice showed a significant increase in mortality correlated to both the titre and specificity of the anti-mosquito antibodies ingested. No changes in their fecundity or feeding success were noted. Mosquitoes exposed to unrestrained immunized mice or mosquito-bitten mice, however, showed a significant reduction in feeding success, possibly reflecting enhanced host grooming.

Anti-mosquito antibodies decrease the reproductive capacity of Aedes aegypti.

Aedes aegypti (L.) fed on rabbits immunized with mosquito antigens showed a reduction in fecundity in the first oviposition and decreased viability of the progeny. Feeding behaviour of mosquitoes was not affected and no significant mortality was observed due to the presence of anti-mosquito antibodies in the bloodmeal. Antibodies were detected in the oocytes of mosquitoes 48 h after the bloodmeal. The role of specific antibodies in influencing fecundity is discussed.

Demonstration of antibodies to mosquito antigens in man by immunodiffusion and ELISA.

Cutaneous reactions to mosquito bites are believed to be immunologically mediated, but knowledge of the underlying mechanisms is very limited. In the present work, comprising 598 subjects, we show that precipitating and ELISA-reactive IgG-class antibodies occur frequently in the adult population. The operating antigen(s) were found in whole-body extracts of Aedes mosquitoes and also in a continuous mosquito cell line culture. The appearance of antimosquito antibodies seems to be correlated with the exposure to mosquito bites; however, massive exposure at an early age may result in a suppressed response.