The role of As60A, a TGF-beta homolog, in Anopheles stephensi innate immunity and defense against Plasmodium infection.
We have examined the constitutive and induced expression of As60A in Anopheles stephensi females. As60A is expressed throughout the body of A. stephensi, including the midgut, fat body and developing eggs. We discovered that As60A is induced in the midgut and carcass of A. stephensi in response to Plasmodium infection. Induction of As60A correlates with periods of parasite motility and reproduction. Further, induction is dependent on the intensity of parasite infection: low numbers of parasites do not induce As60A expression. Thus, we conclude that As60A is a component of the A. stephensi immune response to Plasmodium infection. The involvement of a member of the transforming growth factor beta (TGF-beta) super family in the mosquito immune response is analogous to the involvement of TGF-beta1 in the mammalian immune response to Plasmodium. The modulation of As60A and A. stephensi nitric oxide synthase (AsNOS) expression in response to Plasmodium indicates that homologs of effector (NOS) and regulator (TGF-beta1) gene super families may defend evolutionarily diverse hosts against a shared pathogen.
Crampton
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Department of Biochemistry, Virginia Tech, Blacksburg, VA 24061, USA. andreac@vt.edu
Luckhart
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D000818:Animals; D000852:Anopheles / Q000235:genetics / Q000276:immunology* / Q000469:parasitology*; D019143:Evolution, Molecular; D005260:Female; D005786:Gene Expression Regulation; D006790:Host-Parasite Interactions; D007113:Immunity, Innate / Q000276:immunology*; D019476:Insect Proteins / Q000032:analysis / Q000235:genetics / Q000276:immunology*; D010961:Plasmodium / Q000276:immunology*; D012333:RNA, Messenger / Q000032:analysis / Q000235:genetics; D017385:Sequence Homology; D016212:Transforming Growth Factor beta / Q000032:analysis / Q000235:genetics / Q000276:immunology*
C424084:As60A protein, Anopheles stephensi; D019476:Insect Proteins; D012333:RNA, Messenger; D016212:Transforming Growth Factor beta