Mosquitoes immunization

In the United States in recent years several diseases with animal hosts are now infecting humans. The Arena virus has as its host certain desert rodents. Rodent droppings when dry and airborne as dust particles infect humans, often with lethal consequences. The West Nile virus appeared in the United States in 1999. Birds carry this virus, and mosquitoes are the vector to humans. In 1999 the virus was localized in the New York City area. By 2000 it has spread across New York State and into New Jersey and Massachusetts. The West Nile virus is especially lethal when it infects children, the elderly, or those with a compromised immune system. 

Blandin S, Levashina EA. Mosquito immune responses against malaria parasites. Curr Opin Immunol 2004 16 16-20. 

The malaria parasite Plasmodium has a complex life cycle with several forms and spends much of its life hiding within red blood cells.1 It may also suppress the immune system. The unicellular sporozoites, which are injected into the bloodstream by mosquitos, are protected by an external coat protein that is unusual in containing many short repeated sequences. For example, that of P. falciparum, which causes the most deadly form of malaria, contains the sequence Asn-Ala-Asn-Pro repeated 37 times.q These coat proteins undergo unusually rapid evolution, which makes the preparation of vaccines difficult.1... 

A partially purified Bacillus thurlnglensis var. israelensls (Bti) 6-endotoxin was used to Immunize rabbits. The antisera obtained have an improved specificity towards the mosquito larvacidal activity of the toxin, as opposed to antiserum raised when the whole crystal was used as immunogen. Using a two step/indirect ELISA (enzyme linked immunosorbent assay) procedure developed in our laboratory, fourteen experimental formulations were tested, and the results were compared with bioassays. An average of 69.1 international units 20% c.v. was found to associate with each ug of toxin detected by the ELISA. Our data indicate that when toxin specific antisera are available, Immunoassays can be used to predict the biological activity of Bti samples with reasonable accuracy. 

Turell, M.J., Knudson, G.B. (1987). Mechanical transmission of Bacillus anthracis by stable flies (Stomoxys calcitrans) and mosquitoes (Aedes aegypti and Aedes taeniorhynchus). Infect. Immun. 55 1859-61. 

Contraction of malaria, today known to be a protozoan infection caused by the bite of the Anopheles mosquito, does not accord immediate and/or universal immunity. Whereas those in geographical regions frequently exposed to malarial infection often exhibit no or attenuated symptoms, those less exposed can become severely and repeatedly ill. Even today the molecular mechanisms underlying natural immunity to malaria are not clearly understood. For details, see the Oxford Research on Childhood Disease Malaria at and WHO/TDR [World Health Organization/Tropical Disease Research] Database at (reviewed Feb. 6, 2001). Repeated attacks may even cause chronic malaria characterized by severe anemia, emaciation, enlargement of the spleen, weakness, edema of the ankles, and... 

Yellow fever is another mosquito-borne disease, which causes jaundice in the victim. The mosquito that carries the yellow fever virus to humans during its blood meal is Aedes aegypti. Jaundice causes a person to ajpear yellow in color, hence the name. While there is no exact treatmerrt for yellow fever, most people recover and have an immunity to the disease for the rest of their lives. Im-murrizafion against the disease is available through cci-nation, but the most effective method used to preverrt yel-... 

The virus was not, however, isolated until 1928, and a vaccine was first developed by the South African Max Theiler in 1939. Early attempts to eradicate the mosquito by physical means, and later through the use of insecticides like DDT, were only partially successful, and the disease is still endemic in much of West Africa and in South America, but not, surpisingly, in Asia. It has been suggested that this may be due to the fact that it closely resembles the virus that causes dengue fever, which is endemic in all of Asia. They are both arboviruses, which stands for arthropod-borne viruses, are both transmitted via the bite of a mosquito and cause a haemorrhagic illness. Survivors of dengue fever would be expected to have partial immunity (at least) to yellow fever. 

Differentiation of the ookinete involves three key processes (1) a change in the surface from a fertilization-receptive macrogamete into an invasive cell capable of resisting immune attack by the mosquito and interaction with the mosquito mid-gut, (2) fabrication of a cortex and apical complex that contain the molecular motor and secretory apparatus to escape the bloodmeal and invade the mid-gut wall and (3) meiosis... 

In immunologically stressed mosquitoes some or all of the ookinetes reaching the basal lamina may be subjected to melanization via the phenol oxidase cascade (Lehane et al., 2004b). Development underneath the basal lamina is thought to shield the developing oocyst from the mosquito immune system because the basal lamina is self however when unprotected the immune system can attack the developing oocyst. Indeed, melanized oocysts were first reported in non-natural mosquito vectors by Ross as black spores (Ross, 1923). 

Jin, Y., Kebaier, C., and Vanderberg, J. (2007). Direct microscopic quantification of dynamics of Plasmodium berghei sporozoite transmission from mosquitoes to mice. Infect. Immun. 75, 5532-5539. 

Eggleston, P., Lu, W, Zhao, Y. Genomic organization and immune regulation of the defensin gene from the mosquito. Anopheles gambiae. Insect Mol. Biol. 2000, 9, 481-490... 

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