Cytokines Gene Expression on Macrophages Exposed to Triatoma Salivary Gland Extracts

Triatoma sanguisuga and Triatoma Indictiva are vectors of Chagas disease. These two vectors goes to the host and bites down to feed on blood, which is necessary for the egg laying process. The disease however is not spread through their bite, but through their feces. When they become full of blood, they defecate and that is where the parasite is. The parasite is then introduced into the skin when the host scratches at the bite and feces enter the skin. An estimated 8 million people worldwide are infected with T Cruzi, and the United States has the 7th highest prevalence of Chagas infections. The Macrophages produces cytokines including TNF (Tumoral Necrosis Factor), IL-10 and IL-18 in responses to danger or infections, the function include tissue inflammation and destruction

Neuronal in vitro impact of Amblyommaamericanumsalivary glands extracts

When a tick feeds off a host, the salivary glands of the tick excrete saliva to assist the tick in feeding (1). The reason saliva assists the tick in consuming its blood meal is due to its immunosuppressive, anti-inflammatory, and anti-coagulant properties (2).Tick salivary glands also play an important role in the transmission of tick-borne pathogens (3). We wanted to investigate the effect of tick salivary gland extracts (SGE) on human neurons. For our experiment, the organism whose salivary gland extract we used was the Amblyomma americanum. We compared the effects of salivary gland extract from ticks collected in the field and ticks reared in a lab colony. Our results showed that the salivary gland extract from the two types of ticks affected the neurons differently, and the salivary gland extract of the field tick was more damaging to the neurons. This indicates that SGE from field ticks, together with infectious agents, could result in a more severe neuronal impairment in a human host than the infectious agent alone

Role Of Processed And Natural Cotton On Aedes Aegypti Egg Hatching

Ae. aegypti is an invasive species and playing a crucial role in disseminating the infectious diseases like dengue and Zika fever. This mosquito, prefers to live in areas close to humans where blood is easily accessible (Powell, et al. 2013). Female Ae. aegypti mosquitoes use the blood meal to obtain the nutrients necessary for reproduction to complete their life cycle. After a female takes the blood meal into her midgut, the blood proteins are enzymatically digested into amino acids, which are then released into the hemolymph nutrients (Pacey & O'Donnell, 2014). While working on mosquitoes in insectary, we observed that certain cotton types have effect on oogenesis as the obtained eggs were not hatching and if hatched it took longer time than usual. This leads us to key hypothesis, that either cotton fibers are blocking certain essential nutrients or there could be some chemicals in processed cotton that are affecting egg development. The current research can be a big step towards the suppression of mosquitoes. Considering the current situation in endemic areas we need to come up with new and effective tools

Human Antibody Response Against Anopheles gambiae Salivary Proteins

Malaria is a life-threatening disease caused by parasites that are transmitted to people through the bites of infected female Anopheles mosquitoes. There are more than 400 different species of Anopheles mosquitoes; however only 30 are major malaria vectors. Anopheles vector species bite between dusk and dawn. During blood feeding, the female mosquito injects saliva into the human skin to facilitate meal intake. The salivary proteins (mSP) stimulate immune responses that may lead to antibody production. It is hypothesized that in endemic settings, after repeated mosquito bites, human hosts develop an immune response against mSP that correlates with the level of exposure

Human Antibody Response Against Aedes aegypti D7 Salivary Proteins

Dengue is one of the most geographically significant mosquito transmitted diseases caused by dengue virus (DENV). In endemic areas of tropics and subtropics, this disease has become the leading cause of morbidity and mortality. In the Americas, DENV is primarily transmitted to humans by Aedes aegypti and Ae. albopictus mosquitoes. During blood feeding, the female mosquito injects saliva into the human skin to facilitate meal intake. The salivary proteins (mSP) stimulate immune responses that may lead to antibody production and modulation of cellular and cytokine function with a strong effect on viral infectivity. Previous studies have showed that the salivary allergen D7 exhibits anti-viral properties for DENV in the human skin. It is hypothesized that in endemic settings, after repeated exposure to mosquito bites, human hosts develop an immune response against mSP that can enhance or block viral infectivity

Arthropod EVs Mediate Dengue Virus Transmission Through Interaction With a Tetraspanin Domain Containing Glycoprotein Tsp29Fb

Dengue virus (DENV) is a mosquito-borne flavivirus that causes dengue fever in humans, worldwide. Using in vitro cell lines derived from Aedes albopictus and Aedes aegypti, the primary vectors of DENV, we report that DENV2/DENV3-infected cells secrete extracellular vesicles (EVs), including exosomes, containing infectious viral RNA and proteins. A full-length DENV2 genome, detected in arthropod EVs, was infectious to naïve mosquito and mammalian cells, including human-skin keratinocytes and blood endothelial cells. Cryo-electron microscopy showed mosquito EVs with a size range from 30 to 250 nm. Treatments with RNase A, Triton X-100, and 4G2 antibody-bead binding assays showed that infectious DENV2-RNA and proteins are contained inside EVs. Viral plaque formation and dilution assays also showed securely contained infectious viral RNA and proteins in EVs are transmitted to human cells. Up-regulated HSP70 upon DENV2 infection showed no role in viral replication and transmission through EVs. In addition, qRT-PCR and immunoblotting results revealed that DENV2 up-regulates expression of a mosquito tetraspanin-domain–containing glycoprotein, designated as Tsp29Fb, in A. aegypti mosquitoes, cells, and EVs. RNAi-mediated silencing and antibody blocking of Tsp29Fb resulted in reduced DENV2 loads in both mosquito cells and EVs. Immunoprecipitation showed Tsp29Fb to directly interact with DENV2 E-protein. Furthermore, treatment with GW4869 (exosome-release inhibitor) affected viral burden, direct interaction of Tsp29Fb with E-protein and EV-mediated transmission of viral RNA and proteins to naïve human cells. In summary, we report a very important finding on EV-mediated transmission of DENV2 from arthropod to mammalian cells through interactions with an arthropod EVs-enriched marker Tsp29Fb

Serosurvey of human antibodies recognizing Aedes aegypti D7 salivary proteins in Colombia

Citation: Londono-Renteria, B. L., Shakeri, H., Rozo-Lopez, P., Conway, M. J., Duggan, N., Jaberi-Douraki, M., & Colpitts, T. M. (2018). Serosurvey of Human Antibodies Recognizing Aedes aegypti D7 Salivary Proteins in Colombia. Frontiers in Public Health, 6. https://doi.org/10.3389/fpubh.2018.00111Background: Dengue is one of the most geographically significant mosquito-borne viral diseases transmitted by Aedes mosquitoes. During blood feeding, the mosquito deposits salivary proteins that induce antibody responses. These can be related to the intensity of exposure to bites. Some mosquito salivary proteins, such as D7 proteins, are known as potent allergens. The antibody response to D7 proteins can be used as a marker to evaluate the risk of exposure and disease transmission, and provide critical information for understanding the dynamics of vector-host interactions. Methods: The study was conducted at the Los Patios Hospital, Cucuta, Norte de Santander, Colombia. A total of 63 participants were enrolled in the study. Participants were categorized into three disease status groups, age groups, and socioeconomic strata. The level of IgG antibodies against D7 Aedes proteins was determined by ELISA. We used a statistical approach to determine if there is an association between antibody levels and factors such as age, living conditions, and dengue virus infection. Results: We found that IgG antibodies against D7 proteins were higher in non-DENV infected individuals in comparison to DENV-infected participants. Also, age factor showed a significant positive correlation with IgG antibodies against D7 proteins, and the living conditions (socioeconomic stratification), in people ages 20 years or older, are a statistically significant factor in the variability of IgG antibodies against D7 proteins. Conclusions: This pilot study represents the first approximation to elucidate any correlation between the antibody response against mosquito D7 salivary proteins and its correlation with age, living conditions and dengue virus infection in a dengue endemic area

Prevalence of Plasmodium falciparum Infection in Rainy Season, Artibonite Valley, Haiti, 2006

We conducted a population-based survey to estimate the prevalence of Plasmodium falciparum infection among persons older than 1 month in the Artibonite Valley of Haiti during the high malaria transmission season in 2006. Results from PCR for 714 persons showed a prevalence of 3.1% for P. falciparum infection

Chloroquine-Resistant Haplotype Plasmodium falciparum Parasites, Haiti

Chloroquine resistance is now present in this country

Dengue Virus Infection of Aedes aegypti Requires a Putative Cysteine Rich Venom Protein

Citation: Londono-Renteria, B., Troupin, A., Conway, M. J., Vesely, D., Ledizet, M., Roundy, C. M., . . . Colpitts, T. M. (2015). Dengue Virus Infection of Aedes aegypti Requires a Putative Cysteine Rich Venom Protein. Plos Pathogens, 11(10), 23. doi:10.1371/journal.ppat.1005202Dengue virus (DENV) is a mosquito-borne flavivirus that causes serious human disease and mortality worldwide. There is no specific antiviral therapy or vaccine for DENV infection. Alterations in gene expression during DENV infection of the mosquito and the impact of these changes on virus infection are important events to investigate in hopes of creating new treatments and vaccines. We previously identified 203 genes that were >= 5-fold differentially upregulated during flavivirus infection of the mosquito. Here, we examined the impact of silencing 100 of the most highly upregulated gene targets on DENV infection in its mosquito vector. We identified 20 genes that reduced DENV infection by at least 60% when silenced. We focused on one gene, a putative cysteine rich venom protein (SeqID AAEL000379; CRVP379), whose silencing significantly reduced DENV infection in Aedes aegypti cells. Here, we examine the requirement for CRVP379 during DENV infection of the mosquito and investigate the mechanisms surrounding this phenomenon. We also show that blocking CRVP379 protein with either RNAi or specific antisera inhibits DENV infection in Aedes aegypti. This work identifies a novel mosquito gene target for controlling DENV infection in mosquitoes that may also be used to develop broad preventative and therapeutic measures for multiple flaviviruses