An insight into the sialome of Simulium guianense (DIPTERA:SIMulIIDAE), the main vector of River Blindness Disease in Brazil

Abstract

BackgroundLittle is known about the composition and function of the saliva in black flies such as Simulium guianense, the main vector of river blindness disease in Brazil. The complex salivary potion of hematophagous arthropods counteracts their host's hemostasis, inflammation, and immunity.ResultsTranscriptome analysis revealed ubiquitous salivary protein families--such as the Antigen-5, Yellow, Kunitz domain, and serine proteases--in the S. guianense sialotranscriptome. Insect-specific families were also found. About 63.4% of all secreted products revealed protein families found only in Simulium. Additionally, we found a novel peptide similar to kunitoxin with a structure distantly related to serine protease inhibitors. This study revealed a relative increase of transcripts of the SVEP protein family when compared with Simulium vittatum and S. nigrimanum sialotranscriptomes. We were able to extract coding sequences from 164 proteins associated with blood and sugar feeding, the majority of which were confirmed by proteome analysis.ConclusionsOur results contribute to understanding the role of Simulium saliva in transmission of Onchocerca volvulus and evolution of salivary proteins in black flies. It also consists of a platform for mining novel anti-hemostatic compounds, vaccine candidates against filariasis, and immuno-epidemiologic markers of vector exposure.

Collagen-binding protein, Aegyptin, regulates probing time and blood feeding success in the dengue vector mosquito, Aedes aegypti

“…Aedes aegypti, Anopheles stephensi, and Simulim nigrimanum express salivary collagen-binding proteins that prevent collageninduced platelet aggregation and adhesion by blocking its interaction with the platelet receptors glycoprotein VI and Integrin α 2 β 1 , and von Willebrand factor (vWF) (7)(8)(9)(10). Aegyptin is an A. aegypti salivary protein that binds directly through its C-terminal domain to the vWF binding site in collagen (7,8).…”

Dermatitis de pabellón auricular por picadura de jerjeles: Una entidad clínica diferente no descrita

“…Se ha identificado una toxina llamada apirasa que inhibe la agregación plaquetaria; una proteína antitrombina que potencia la actividad antiagregante plaquetaria de la apirasa; una toxina vasodilatadora que facilita el aflujo de la sangre al sitio de la picadura y que explica el gran enrojecimiento del pabellón auricular al ser picado por estos insectos; se ha pesquisado además, en algunas especies, una toxina salival que afecta la respuesta inmunocelular y la producción de citoquinas y que explicaría la diseminación del nematode en la enfermedad de Robles o ceguera de los ríos tropicales [10][11][12] . En la picadura de las orejas por los jerjeles, la inflamación alcanza su máxima intensidad al quinto día, para después ir remitiendo lentamente al cabo de dos semanas aproximadamente.…”

Simplagrin, a Platelet Aggregation Inhibitor from Simulium nigrimanum Salivary Glands Specifically Binds to the Von Willebrand Factor Receptor in Collagen and Inhibits Carotid Thrombus Formation In Vivo

“…Within this scenario, the blood feeding sialome evolved within each fly species in concert with their vertebrate “hemostome” and “immunome,” the latter battering the salivary proteins by either neutralizing their function or creating inflammatory reactions such as pain or itching that, in concert with host behavioral defenses, could disrupt feeding. This scenario of concerted “birth and death” evolution of multigene families [31] could explain the evolutionary speed of the blood feeding sialome as well as the recruitment or exaptation of new gene families [15]. Perhaps a collagen-binding salivary protein was an evolutionary innovation present in an ancient dipteran ancestor that evolved into the current Aegyptin-like protein family commonly found in sialomes of Culicomorpha, excluding Corethrella appendiculata [32].…”