The Salivary Gland Transcriptome of the Eastern Tree Hole Mosquito,Ochlerotatus triseriatus

Abstract

Saliva of blood-sucking arthropods contains a complex mixture of peptides that affect their host's hemostasis, inflammation, and immunity. These activities can also modify the site of pathogen delivery and increase disease transmission. Saliva also induces hosts to mount an antisaliva immune response that can lead to skin allergies or even anaphylaxis. Accordingly, knowledge of the salivary repertoire, or sialome, of a mosquito is useful to provide a knowledge platform to mine for novel pharmacological activities, to develop novel vaccine targets for vector-borne diseases, and to develop epidemiological markers of vector exposure and candidate desensitization vaccines. The mosquito Ochlerotatus triseriatus is a vector of La Crosse virus and produces allergy in humans. In this work, a total of 1,575 clones randomly selected from an adult female O. triseriatus salivary gland cDNA library was sequenced and used to assemble a database that yielded 731 clusters of related sequences, 560 of which were singletons. Primer extension experiments were performed in selected clones to further extend sequence coverage, allowing for the identification of 159 protein sequences, 66 of which code for putative secreted proteins. Supplemental spreadsheets containing these data are available at http://exon.niaid.nih.gov/transcriptome/Ochlerotatus_triseriatus/S1/Ot-S1.xls and http://exon.niaid.nih.gov/transcriptome/Ochlerotatus_triseriatus/S2/Ot-S2.xls.

Members of the Salivary Gland Surface Protein (SGS) Family Are Major Immunogenic Components of Mosquito Saliva

“…Based on our proteomic analyses (Figs. 3B and 6) as well as transcriptomic analyses by others (16,38), SGSs are the only anopheline or culicine saliva proteins whose mass approximates the value predicted for this ϳ387-kDa protein. In support of our hypothesis that Sgs4 and Sgs5 are immunomodulatory, it has recently been shown that bacterial RHS/YD-repeat proteins (distant relatives of SGS) play a role during the deactivation of human macrophages by the bacterial pathogen Burkholderia pseudomallei (39).…”

A Deep Insight into the Sialotranscriptome of the Gulf Coast Tick, Amblyomma maculatum

“…Proteins containing single or multiple Kunitz domains were described and functionally characterized in ticks, such as Ixolaris, a double-Kunitz protein, and Pentalaris, containing five domains [57], [58], [59], [60], [61], both acting as blood-clotting inhibitors of the extrinsic pathway. The Kunitz fold can also perform functions beyond protease inhibition, such as ion channel inhibition [62], [63], [64], [65]; in R. appendiculatus , a modified Kunitz domain peptide [66] was shown to activate maxiK channels in an in vitro system, suggesting a vasodilator function.…”

Delayed-Type Hypersensitivity to Sand Fly Saliva in Humans from a Leishmaniasis-Endemic Area of Mali Is TH1-Mediated and Persists to Midlife

“…The difference in the hypersensitivity responses of humans to mosquitoes and sand flies is not surprising. Salivary components from sand flies and mosquitoes are considerably different sharing only a small number of molecules with significantly divergent sequences (Anderson, Oliveira et al 2006; Calvo, Sanchez-Vargas et al 2010). In fact, several sand fly salivary proteins are unique to these insects (Anderson, Oliveira et al 2006), potentially accounting for the distinct hypersensitivity responses observed here.…”