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1.
BMC Immunol ; 25(1): 23, 2024 Apr 27.
Article in English | MEDLINE | ID: mdl-38678193

ABSTRACT

BACKGROUND: Flow cytometry-based basophil activation tests (BAT) have been performed with various modifications, differing in the use of distinct identification and activation markers. Established tests use liquid reagents while a new development involves the use of tubes with dried antibody reagents. The aim of this pilot study was to compare these two techniques in patients with insect venom allergy. METHODS: Seventeen patients with an insect venom allergy were included in the study. The established "BAT 1" utilizes conventional antibody solutions of anti-CCR3 for basophil identification and anti-CD63 to assess basophil activation, whereas "BAT 2" uses dried anti-CD45, anti-CD3, anti-CRTH2, anti-203c and anti-CD63 for identification and activation measurement of basophils. Negative and positive controls as well as incubations with honey bee venom and yellow jacket venom at three concentrations were performed. RESULTS: Seven patients had to be excluded due to low basophil counts, high values in negative controls or negative positive controls. For the remaining 10 patients the overall mean (± SD) difference in activated basophils between the two tests was 0.2 (± 12.2) %P. In a Bland-Altman plot, the limit of agreement (LoA) ranged from 24.0 to -23.7. In the qualitative evaluation (value below/above cut-off) Cohen's kappa was 0.77 indicating substantial agreement. BAT 2 took longer to perform than BAT 1 and was more expensive. CONCLUSION: The BAT 2 technique represents an interesting innovation, however, it was found to be less suitable compared to an established BAT for the routine diagnosis of insect venom allergies.


Subject(s)
Basophils , Flow Cytometry , Humans , Basophils/immunology , Female , Male , Adult , Middle Aged , Flow Cytometry/methods , Arthropod Venoms/immunology , Pilot Projects , Animals , Hypersensitivity/immunology , Hypersensitivity/diagnosis , Insect Bites and Stings/immunology , Insect Bites and Stings/diagnosis , Bee Venoms/immunology , Young Adult , Aged , Antibodies/immunology , Adolescent , Basophil Degranulation Test/methods , Venom Hypersensitivity
2.
Vet Med Sci ; 10(3): e1462, 2024 05.
Article in English | MEDLINE | ID: mdl-38659360

ABSTRACT

BACKGROUND: Culicoides is a genus of ubiquitous biting midges (Ceratopogonidae). Female midges have blood-sucking habit. They not only bite and harass humans and animals but also may be an important vector of disease transmission. Therefore, building an animal allergy model caused by Culicoides biting is very beneficial for studying its pathogenesis and exploring the therapeutic methods. MATERIAL AND METHOD: Kunming mice were used in this study to build the model and sensitised by two-step injection of midge extracts. Scratching behaviour and histological examination were used to check the immediate and delayed responses. Immunoglobulin E (IgE) and Immunoglobulin G (IgG) were detected using indirect enzyme-linked immunosorbent assay (ELISA) assay. Splenic cell proliferation and cytokine production were determined using 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyl tetrazolium bromide (MTT) and ELISA assays. The response of cytokine gene expression to midge stimulation was analysed through quantitative real-time polymerase chain reaction (qPCR). RESULTS: Behavioural results revealed a significant increase in scratching frequency among the midge-sensitised animals (p < 0.05). Histological examination showed more inflammatory cytokine infiltration at the injection site of midge-sensitised mice comparing to the ones in the control group. The serum levels of IgE and IgG1 antibodies in the midge-sensitised group were significantly elevated (p < 0.05). After splenocytes were stimulated in vitro with midge extracts, the midge-sensitised group's splenocyte count significantly increased in comparison to the control group. The midge-sensitised group's qPCR data revealed a down-regulation of tumor necrosis factor alpha (TNF-α) expression and an increase in the expression of interleukin (IL)-4, IL-5, IL-10 and IL-13 but not in the control group (p < 0.05). CONCLUSIONS: In this study, an animal model of Culicoides-mouse sensitisation was successfully constructed using a two-step method. The mode of administration of the model was in good agreement with the natural immune pathway, and the immune response induced by the sensitisation of the model was similar to that produced by the bite of a midge.


Subject(s)
Ceratopogonidae , Disease Models, Animal , Hypersensitivity , Animals , Ceratopogonidae/physiology , Mice , Female , Hypersensitivity/veterinary , Hypersensitivity/immunology , Insect Bites and Stings/veterinary , Insect Bites and Stings/immunology
4.
Int Arch Allergy Immunol ; 185(5): 456-459, 2024.
Article in English | MEDLINE | ID: mdl-38412847

ABSTRACT

INTRODUCTION: Changes in the cytokine profile from type 2 to type 1 together with the induction of regulatory cells are expected during hymenoptera venom immunotherapy (VIT). The present study was aimed to investigate the changes in type 1, type 2, and regulatory cytokines induced by a Vespula spp. VIT in patients with anaphylaxis to Vespa velutina. METHODS: Twenty consecutive patients with anaphylaxis due to Vespa velutina were treated with Vespula spp. VIT. Serum cytokines (IL-4, IL-5, IL-10, IL-13, and IFN-É£) were measured at baseline, 6, and 12 months after starting VIT. RESULTS: A significant increase in serum IFN-y was detected after 6 and 12 months of VIT. An increase in serum IL-10 and a decrease in IL-5 were observed after 12 months. IL-4 was undetectable all along the study, and an unexpected increase of IL-13 was present at 12 months of treatment. CONCLUSION: Vespula spp. VIT seems to be able to induce a shift to type 1 cytokine production measured through IFN-y levels and IL-10 production after, at least, 6 and 12 months of VIT, respectively.


Subject(s)
Anaphylaxis , Cytokines , Desensitization, Immunologic , Wasp Venoms , Wasps , Humans , Anaphylaxis/immunology , Anaphylaxis/therapy , Anaphylaxis/etiology , Cytokines/metabolism , Cytokines/blood , Male , Female , Adult , Animals , Desensitization, Immunologic/methods , Wasp Venoms/immunology , Wasps/immunology , Middle Aged , Insect Bites and Stings/immunology , Insect Bites and Stings/therapy , Young Adult , Allergens/immunology
5.
Acta Parasitol ; 69(1): 483-504, 2024 Mar.
Article in English | MEDLINE | ID: mdl-38194049

ABSTRACT

BACKGROUND: Skeeter syndrome is a severe local allergic response to mosquito bites that is accompanied by considerable inflammation and, in some cases, a systemic response like fever. People with the syndrome develop serious allergies, ranging from rashes to anaphylaxis or shock. The few available studies on mosquito venom immunotherapy have utilized whole-body preparations and small sample sizes. Still, owing to their little success, vaccination remains a promising alternative as well as a permanent solution for infections like Skeeter's. METHODS: This study, therefore, illustrated the construction of an epitope-based vaccine candidate against Skeeter Syndrome using established immunoinformatic techniques. We selected three species of mosquitoes, Anopheles melas, Anopheles funestus, and Aedes aegypti, to derive salivary antigens usually found in mosquito bites. Our construct was also supplemented with bacterial epitopes known to elicit a strong TH1 response and suppress TH2 stimulation that is predicted to reduce hypersensitivity against the bites. RESULTS: A quality factor of 98.9496, instability index of 38.55, aliphatic index of 79.42, solubility of 0.934747, and GRAVY score of -0.02 indicated the structural (tertiary and secondary) stability, thermostability, solubility, and hydrophilicity of the construct, respectively. The designed Aedes-Anopheles vaccine (AAV) candidate was predicted to be flexible and less prone to deformability with an eigenvalue of 1.5911e-9 and perfected the human immune response against Skeeter (hypersensitivity) and many mosquito-associated diseases as we noted the production of 30,000 Th1 cells per mm3 with little (insignificant production of Th2 cells. The designed vaccine also revealed stable interactions with the pattern recognition receptors of the host. The TLR2/vaccine complex interacted with a free energy of - 1069.2 kcal/mol with 26 interactions, whereas the NLRP3/vaccine complex interacted with a free energy of - 1081.2 kcal/mol with 16 molecular interactions. CONCLUSION: Although being a pure in-silico study, the in-depth analysis performed herein speaks volumes of the potency of the designed vaccine candidate predicting that the proposition can withstand rigorous in-vitro and in-vivo clinical trials and may proceed to become the first preventative immunotherapy against mosquito bite allergy.


Subject(s)
Aedes , Anopheles , Epitopes , Hypersensitivity , Insect Bites and Stings , Animals , Insect Bites and Stings/immunology , Insect Bites and Stings/prevention & control , Anopheles/immunology , Aedes/immunology , Epitopes/immunology , Hypersensitivity/prevention & control , Hypersensitivity/immunology , Vaccines/immunology , Humans
6.
PLoS Pathog ; 18(2): e1010282, 2022 02.
Article in English | MEDLINE | ID: mdl-35108339

ABSTRACT

Immunization with radiation-attenuated sporozoites (RAS) can confer sterilizing protection against malaria, although the mechanisms behind this protection are incompletely understood. We performed a systems biology analysis of samples from the Immunization by Mosquito with Radiation Attenuated Sporozoites (IMRAS) trial, which comprised P. falciparum RAS-immunized (PfRAS), malaria-naive participants whose protection from malaria infection was subsequently assessed by controlled human malaria infection (CHMI). Blood samples collected after initial PfRAS immunization were analyzed to compare immune responses between protected and non-protected volunteers leveraging integrative analysis of whole blood RNA-seq, high parameter flow cytometry, and single cell CITEseq of PBMCs. This analysis revealed differences in early innate immune responses indicating divergent paths associated with protection. In particular, elevated levels of inflammatory responses early after the initial immunization were detrimental for the development of protective adaptive immunity. Specifically, non-classical monocytes and early type I interferon responses induced within 1 day of PfRAS vaccination correlated with impaired immunity. Non-protected individuals also showed an increase in Th2 polarized T cell responses whereas we observed a trend towards increased Th1 and T-bet+ CD8 T cell responses in protected individuals. Temporal differences in genes associated with natural killer cells suggest an important role in immune regulation by these cells. These findings give insight into the immune responses that confer protection against malaria and may guide further malaria vaccine development. Trial registration: ClinicalTrials.gov NCT01994525.


Subject(s)
Immunity , Inflammation , Malaria Vaccines/immunology , Malaria, Falciparum/immunology , Plasmodium falciparum/immunology , Sporozoites/immunology , Adult , Animals , Anopheles/parasitology , Female , Humans , Immunization/methods , Insect Bites and Stings/immunology , Malaria, Falciparum/parasitology , Male , Mosquito Vectors/parasitology , T-Lymphocytes/immunology , Vaccination/methods , Vaccines, Attenuated/immunology
7.
J Investig Allergol Clin Immunol ; 32(6): 451-459, 2022 Dec 15.
Article in English | MEDLINE | ID: mdl-34213416

ABSTRACT

BACKGROUND AND OBJECTIVES: Although exposure to stings has been identified as the leading risk factor for anaphylaxis due to Hymenoptera venom allergy, professional beekeepers receive hundreds of stings yearly without developing systemic reactions. This study aims to analyze the mechanisms underlying bee venom tolerance in beekeepers. METHODS: A cross-sectional study was conducted. Participants were recruited and classified into 3 groups: allergic patients (APs), who experienced systemic reactions after bee stings, with a positive intradermal test and specific IgE (sIgE) to Apis mellifera venom (AmV); tolerant beekeepers (TBKs), who received ≥50 stings/year; and healthy nonexposed controls (HCs). We measured serum levels of sIgE and specific IgG4 (sIgG4) to AmV, rApi m 1, rApi m 2, rApi m 3, Api m 4, rApi m 5, and rApi m10, as well as AmV-induced basophil degranulation, percentage of T-cell subsets, regulatory T cells (Treg), and IL-10 production. RESULTS: Compared with TBKs, APs had high levels of sIgE to AmV and all its allergic components (P<.001), together with a high basophil activation rate (P<.001). Conversely, compared with APs, TBKs had higher levels of sIgG4 (P<.001) and IL-10 (P<.0001), as well as an enhanced CTLA-4+ Treg population (P=.001), expanded Helios- Treg (P<.003), and reduced type 1 helper T cells (TH1) (P=.008), TH2 (P=.004), and TH17 (P=.007) subsets. CONCLUSIONS: The profile of TBKs, which was strongly marked by Treg activity, differed from that of TBKs. This natural tolerance would be led by the expansion of inducible Helios- Treg cells at the peripheral level. The Helios- Treg population could be a novel candidate biomarker for monitoring tolerance.


Subject(s)
Anaphylaxis , Bee Venoms , Hypersensitivity , Immune Tolerance , Insect Bites and Stings , T-Lymphocytes, Regulatory , Humans , Anaphylaxis/diagnosis , Anaphylaxis/metabolism , Bees , Cross-Sectional Studies , Hypersensitivity/diagnosis , Immunoglobulin E/chemistry , Immunoglobulin G/chemistry , Insect Bites and Stings/complications , Insect Bites and Stings/immunology , Interleukin-10
8.
J. investig. allergol. clin. immunol ; 32(2): 116-123, 2022. ilus, graf, tab
Article in English | IBECS | ID: ibc-203901

ABSTRACT

Background: Component-resolved diagnosis plays a key role in the diagnosis and treatment of honeybee venom allergy (HVA). Our aimwas to study whether any of the allergens not included in the usual diagnostic platforms are relevant in our population.Patients and Methods: The allergenic sensitization profile of Spanish patients who experienced a systemic reaction after a honeybee stingand were diagnosed with HVA was studied by immunoblotting based on raw autochthonous Apis mellifera venom characterized usingSDS-PAGE and mass spectrometry and a commercial assay (ImmunoCAP).Results: Allergens in the International Union of Immunological Societies database were detected in the raw A mellifera venom extract used,except Api m 12. Sera from 51 patients with a median (IQR) age of 46.2 years (35.6-54.6) were analyzed. ImmunoCAP revealed Api m 1and Api m 10 to be major allergens (88.2% and 74.5%, respectively). Moreover, Api m 6 (85.4%) was detected by immunoblotting.Conclusion: Api m 1, Api m 6, and Api m 10 are major A mellifera venom allergens in our population (AU)


Antecedentes: El diagnóstico molecular puede ser una herramienta valiosa en el diagnóstico y el tratamiento de la alergia al veneno deabeja. Este estudio investiga si alguno de los alérgenos no incluidos en las plataformas diagnósticas habituales son relevantes en nuestrapoblación.Pacientes y métodos: Estudiamos mediante immunoblotting el perfil de sensibilización alergénica en pacientes españoles diagnosticadosde alergia al veneno de abeja. Los resultados se compararon con los obtenidos usando un ensayo comercial (ImmunoCAP). El venenocrudo de Apis mellifera autóctona se obtuvo y caracterizó mediante SDS-PAGE y espectrometría de masas.Resultados: Los alérgenos descritos en la base de datos International Union of Immunological Societies (IUIS) fueron detectados enel extracto crudo de veneno de A. mellifera utilizado. Se analizaron sueros de 51 pacientes con una edad media de 46,2 años (rangointercuartil 35,6–54,6). Api m 1 y Api m 10 fueron detectados como alérgenos mayoritarios (88,2% y 74,5%, respectivamente) usandoImmunoCAP. Además, se encontró Api m 6 (85,4%) mediante immunoblotting.Conclusión: Nuestra población reconoce Api m 1, Api m 6 y Api m 10 como alérgenos mayoritarios del veneno de A. mellifera (AU)


Subject(s)
Humans , Animals , Male , Female , Adult , Middle Aged , Hypersensitivity/diagnosis , Insect Bites and Stings/diagnosis , Bee Venoms , Allergens , Bees , Immunoglobulin E , Insect Bites and Stings/immunology
10.
PLoS One ; 16(11): e0257819, 2021.
Article in English | MEDLINE | ID: mdl-34780496

ABSTRACT

BACKGROUND: Insect bite hypersensitivity (IBH) is an IgE-mediated allergic dermatitis in horses incited by salivary allergens from Culicoides spp. IBH does not occur in Iceland, as the causative agents are absent, however a high prevalence is seen in horses exported to Culicoides-rich environments. AIMS: To study the natural course of sensitization to Culicoides allergens and identify the primary sensitizing allergen(s) in horses exported from Iceland utilizing a comprehensive panel of Culicoides recombinant (r-) allergens. METHOD: IgE microarray profiling to 27 Culicoides r-allergens was conducted on 110 serological samples from horses imported to Switzerland from Iceland that subsequently developed IBH or remained healthy. Furthermore, a longitudinal study of 31 IBH horses determined IgE profiles the summer preceding first clinical signs of IBH (TIBH-1), the summer of first clinical signs (TIBH) and the following summer (TIBH+1). In a group of Icelandic horses residing in Sweden, effects of origin (born in Iceland or Sweden) and duration of IBH (<4 years, 4-7 years, >7 years) on Culicoides-specific IgE was evaluated. Sero-positivity rates and IgE levels were compared. RESULTS: At TIBH, horses were sensitized to a median of 11 r-allergens (range = 0-21), of which nine were major allergens. This was significantly higher than TIBH-1 (3, 0-16), as well as the healthy (1, 0-14) group. There was no significant increase between TIBH and TIBH+1(12, 0-23). IBH-affected horses exported from Iceland had a significantly higher degree of sensitization than those born in Europe, while duration of IBH did not significantly affect degree of sensitization. CONCLUSION: Significant sensitization is only detected in serum the year of first clinical signs of IBH. Horses become sensitized simultaneously to multiple Culicoides r-allergens, indicating that IgE-reactivity is due to co-sensitization rather than cross-reactivity between Culicoides allergens. Nine major first sensitizing r-allergens have been identified, which could be used for preventive allergen immunotherapy.


Subject(s)
Allergens/immunology , Ceratopogonidae/immunology , Dermatitis, Atopic/immunology , Horse Diseases/immunology , Horses/immunology , Insect Bites and Stings/immunology , Animals , Cross Reactions , Dermatitis, Atopic/blood , Horse Diseases/blood , Iceland , Immunoglobulin E/blood , Insect Bites and Stings/blood , Longitudinal Studies , Protein Array Analysis/methods , Seasons , Sweden , Switzerland
12.
PLoS One ; 16(8): e0256168, 2021.
Article in English | MEDLINE | ID: mdl-34388201

ABSTRACT

INTRODUCTION: Platelet-activating factor (PAF) has a direct role as a mediator in the pathogenesis of various disorders with an inflammatory component, including those with allergic aetiology. The peripheral blood concentration of PAF is dynamically regulated by plasma PAF acetylhydrolase (PAF-AH). Previous research suggest that low activity of plasma PAF-AH could be a predictive marker for increased severity of some types of allergic hypersensitivity reactions-especially anaphylaxis. The purpose of the study was to evaluate the association between plasma PAF-AH activity and severity in patients with anaphylactic reactions following a wasp or bee sting. MATERIALS AND METHODS: The study group of 89 patients was divided into two subgroups depending on the increasing severity of the most severe anaphylactic reaction in the past, which was assessed according to the Müller's scale. The first subgroup included participants with a history of hypersensitivity reactions up to grade II. The second subgroup consisted of patients who have experienced at least one grade III or IV reactions in the past. A control group of 20 people was established. Plasma PAF-AH activity was measured using a colorimetric method. RESULTS: It has been observed that plasma activity of platelet-activating factor acetylhydrolase was significantly lower in patients with anaphylaxis history compared to the control group with negative atopic history (on average 21.38 nmol/min/ml for the control group, 9.47 nmol/min/ml for the first subgroup and 10.16 nmol/min/ml for the second subgroup, in both cases p < 0.0001). CONCLUSION: The plasma activity of PAF-AH is a promising parameter that can help to distinguish a group of patients not threatened with development of anaphylaxis and not requiring laborious or expensive prophylactic procedures.


Subject(s)
1-Alkyl-2-acetylglycerophosphocholine Esterase/blood , Anaphylaxis/diagnosis , Insect Bites and Stings/diagnosis , Platelet Activating Factor/metabolism , Adult , Aged , Anaphylaxis/blood , Anaphylaxis/immunology , Anaphylaxis/physiopathology , Animals , Bees , Biomarkers/blood , Body Mass Index , Case-Control Studies , Female , Humans , Immunoglobulin E/blood , Insect Bites and Stings/blood , Insect Bites and Stings/immunology , Insect Bites and Stings/physiopathology , Male , Middle Aged , ROC Curve , Severity of Illness Index , Wasps
13.
Vet Immunol Immunopathol ; 238: 110289, 2021 Aug.
Article in English | MEDLINE | ID: mdl-34214910

ABSTRACT

Insect bite hypersensitivity (IBH) is an allergic dermatitis of horses, an IgE-mediated reaction to Culicoides midges. Causative Culicoides spp. are not indigenous in Iceland resulting in high prevalence of IBH in horses born in Iceland and exported as compared to Icelandic horses born in a Culicoides rich environment. The aims were (i) to compare IgE levels in sera of IBH-affected horses born in Iceland (n = 47) with horses of the Icelandic breed (n = 23) and of other breeds (n = 27) born in Culicoides infested area; (ii) to investigate if barley could be a useful production system of allergens for IBH immunoassays. IgE binding in sera was tested by ELISA on two recombinant Culicoides allergens, rCul n 3 and rCul n 4, each produced in E. coli, insect cells and barley. Significantly more IgE was detected against all allergens in sera from IBH-affected compared to healthy horses. Icelandic-born Icelandic horses stand out with higher IgE levels against the allergens and higher area under the curve (AUC) on rCul n 4 as compared to the European-born horses. The barley and E.coli produced allergens had very similar performance in distinguishing between IBH-affected and healthy horses.


Subject(s)
Allergens/immunology , Ceratopogonidae/immunology , Dermatitis, Atopic/veterinary , Horse Diseases/immunology , Immunoglobulin E/blood , Insect Bites and Stings/immunology , Animals , Dermatitis, Atopic/immunology , Horses , Humans , Insect Proteins/immunology
14.
PLoS Negl Trop Dis ; 15(6): e0009512, 2021 06.
Article in English | MEDLINE | ID: mdl-34157020

ABSTRACT

BACKGROUND: Simulium damnosum sensu lato (s.l.) blackflies transmit Onchocerca volvulus, a filarial nematode that causes human onchocerciasis. Human landing catches (HLCs) is currently the sole method used to estimate blackfly biting rates but is labour-intensive and questionable on ethical grounds. A potential alternative is to measure host antibodies to vector saliva deposited during bloodfeeding. In this study, immunoassays to quantify human antibody responses to S. damnosum s.l. saliva were developed, and the salivary proteome of S. damnosum s.l. was investigated. METHODOLOGY/PRINCIPAL FINDINGS: Blood samples from people living in onchocerciasis-endemic areas in Ghana were collected during the wet season; samples from people living in Accra, a blackfly-free area, were considered negative controls and compared to samples from blackfly-free locations in Sudan. Blackflies were collected by HLCs and dissected to extract their salivary glands. An ELISA measuring anti-S. damnosum s.l. salivary IgG and IgM was optimized and used to quantify the humoral immune response of 958 individuals. Both immunoassays differentiated negative controls from endemic participants. Salivary proteins were separated by gel-electrophoresis, and antigenic proteins visualized by immunoblot. Liquid chromatography mass spectrometry (LC-MS/MS) was performed to characterize the proteome of S. damnosum s.l. salivary glands. Several antigenic proteins were recognized, with the major ones located around 15 and 40 kDa. LC-MS/MS identified the presence of antigen 5-related protein, apyrase/nucleotidase, and hyaluronidase. CONCLUSIONS/SIGNIFICANCE: This study validated for the first time human immunoassays that quantify humoral immune responses as potential markers of exposure to blackfly bites. These assays have the potential to facilitate understanding patterns of exposure as well as evaluating the impact of vector control on biting rates. Future studies need to investigate seasonal fluctuations of these antibody responses, potential cross-reactions with other bloodsucking arthropods, and thoroughly identify the most immunogenic proteins.


Subject(s)
Insect Bites and Stings/epidemiology , Insect Vectors/physiology , Saliva , Simuliidae/physiology , Adolescent , Adult , Aged , Animals , Child , Child, Preschool , Enzyme-Linked Immunosorbent Assay , Female , Ghana , Humans , Immunoglobulin G/blood , Immunoglobulin M/blood , Insect Bites and Stings/immunology , Male , Middle Aged , Onchocerciasis , Sudan
15.
Future Microbiol ; 16: 657-670, 2021 06.
Article in English | MEDLINE | ID: mdl-34100305

ABSTRACT

Drawing of host blood is a natural phenomenon during the bite of blood-probing insect vectors. Along with the blood meal, the vectors introduce salivary components and a trail of microbiota. In the case of infected vectors, the related pathogen accompanies the aforementioned biological components. In addition to Anopheles gambiae or Anopheles stephensi, the bites of other nonmalarial vectors cannot be ignored in malaria-endemic regions. Similarly, the bite incidence of Phlebotomus papatasi cannot be ignored in visceral leishmaniasis-endemic regions. Even the chances of getting bitten by uninfected vectors are higher than the infected vectors. We have discussed the probability or possibility of uninfected, infected, and/or nonvector's saliva and gut microbiota as a therapeutic option leading to the initial deterrent to pathogen establishment.


Subject(s)
Gastrointestinal Microbiome/immunology , Insect Vectors , Saliva/immunology , Animals , Culicidae/immunology , Humans , Immunomodulation , Insect Bites and Stings/immunology , Insect Bites and Stings/prevention & control , Insect Vectors/immunology , Psychodidae/immunology , Vector Borne Diseases/immunology , Vector Borne Diseases/prevention & control
16.
PLoS Negl Trop Dis ; 15(5): e0009440, 2021 05.
Article in English | MEDLINE | ID: mdl-34043621

ABSTRACT

BACKGROUND: Aedes mosquitoes are vectors for several major arboviruses of public health concern including dengue viruses. The relationships between Aedes infestation and disease transmission are complex wherein the epidemiological dynamics can be difficult to discern because of a lack of robust and sensitive indicators for predicting transmission risk. This study investigates the use of anti-Aedes saliva antibodies as a serological biomarker for Aedes mosquito bites to assess small scale variations in adult Aedes density and dengue virus (DENV) transmission risk in northeastern Thailand. Individual characteristics, behaviors/occupation and socio-demographics, climatic and epidemiological risk factors associated with human-mosquito exposure are also addressed. METHODS: The study was conducted within a randomized clustered control trial in Roi Et and Khon Kaen provinces over a consecutive 19 months period. Thirty-six (36) clusters were selected, each of ten houses. Serological and entomological surveys were conducted in all houses every four months and monthly in three sentinel households per cluster between September 2017 and April 2019 for blood spot collections and recording concurrent immature and adult Aedes indices. Additionally, the human exposure to Aedes mosquito bites (i.e., Mosquito Exposure Index or MEI) was estimated by ELISA measuring levels of human antibody response to the specific Nterm-34 kDa salivary antigen. The relationships between the MEI, vector infestation indices (adult and immature stages) and vector DENV infection were evaluated using a two-level (house and individual levels) mixed model analysis with one-month lag autoregressive correlation. RESULTS: There was a strong positive relationship between the MEI and adult Aedes (indoor and outdoor) density. Individuals from households with a medium mosquito density (mean difference: 0.091, p<0.001) and households with a high mosquito density (mean difference: 0.131, p<0.001) had higher MEI's compared to individuals from households without Aedes. On a similar trend, individuals from households with a low, medium or high indoor Aedes densities (mean difference: 0.021, p<0.007, 0.053, p<0.0001 and 0.037, p<0.0001 for low, medium and high levels of infestation, respectively) had higher MEI than individuals from houses without indoor Aedes. The MEI was driven by individual characteristics, such as gender, age and occupation/behaviors, and varied according to climatic, seasonal factors and vector control intervention (p<0.05). Nevertheless, the study did not demonstrate a clear correlation between MEI and the presence of DENV-infected Aedes. CONCLUSION: This study represents an important step toward the validation of the specific IgG response to the Aedes salivary peptide Nterm-34kDa as a proxy measure for Aedes infestation levels and human-mosquito exposure risk in a dengue endemic setting. The use of the IgG response to the Nterm-34 kDa peptide as a viable diagnostic tool for estimating dengue transmission requires further investigations and validation in other geographical and transmission settings.


Subject(s)
Aedes/physiology , Aedes/virology , Insect Bites and Stings/epidemiology , Aedes/growth & development , Animals , Biomarkers/blood , Dengue/epidemiology , Dengue/transmission , Dengue Virus/isolation & purification , Enzyme-Linked Immunosorbent Assay , Female , Humans , Immunoglobulin G/analysis , Insect Bites and Stings/immunology , Male , Mosquito Vectors/virology , Saliva/immunology , Thailand/epidemiology
17.
Front Immunol ; 12: 653151, 2021.
Article in English | MEDLINE | ID: mdl-33841437

ABSTRACT

We evaluated the safety, optimal dose, and preliminary effectiveness of a new-approach Africanized honeybee (Apis mellifera) Antivenom (AAV) in a phase I/II, multicenter, non-randomized, single-arm clinical trial involving 20 participants with multiple stings. Participants received 2 to 10 vials of AAV depending on the number of stings they suffered, or a predefined adjuvant, symptomatic, and complementary treatment. The primary safety endpoint was the occurrence of early adverse reactions within the first 24 h of treatment. Preliminary efficacy based on clinical evolution, including laboratory findings, was assessed at baseline and at various time points over the four following weeks. ELISA assays and mass spectrometry were used to estimate venom pharmacokinetics before, during, and after treatment. Twenty adult participants, i.e., 13 (65%) men and 7 (35%) women, with a median age of 44 years and a mean body surface area of 1.92 m2 (median = 1.93 m2) were recruited. The number of stings ranged from 7 to > 2,000, with a median of 52.5. Symptoms of envenoming were classified as mild, moderate, or severe in 80% (16), 15% (3), and 5% (1) of patients, respectively; patients with mild, moderate, or severe envenoming received 2, 6, and 10 vials of AAV as per the protocol. None of the patients had late reactions (serum sickness) within 30 d of treatment. There was no discontinuation of the protocol due to adverse events, and there were no serious adverse events. One patient had a moderate adverse event, transient itchy skin, and erythroderma. All participants completed the intravenous antivenom infusion within 2 h, and there was no loss to follow-up after discharge. ELISA assays showed venom (melittin and PLA2) concentrations varying between 0.25 and 1.479 ng/mL prior to treatment. Venom levels decreased in all patients during the hospitalization period. Surprisingly, in nine cases (45%), despite clinical recovery and the absence of symptoms, venom levels increased again during outpatient care 10 d after discharge. Mass spectrometry showed melittin in eight participants, 30 d after treatment. Considering the promising safety results for this investigational product in the treatment of massive Africanized honeybee attack, and its efficacy, reflected in the clinical improvements and corresponding immediate decrease in blood venom levels, the AAV has shown to be safe for human use. Clinical Trial Registration: UTN: U1111-1160-7011, identifier [RBR-3fthf8].


Subject(s)
Antivenins/administration & dosage , Bee Venoms/antagonists & inhibitors , Bees/immunology , Insect Bites and Stings/therapy , Adult , Aged , Animals , Antivenins/adverse effects , Bee Venoms/blood , Brazil , Female , Humans , Insect Bites and Stings/blood , Insect Bites and Stings/diagnosis , Insect Bites and Stings/immunology , Male , Middle Aged , Severity of Illness Index , Treatment Outcome , Young Adult
18.
Parasit Vectors ; 14(1): 209, 2021 Apr 20.
Article in English | MEDLINE | ID: mdl-33879250

ABSTRACT

BACKGROUND: Anopheles arabiensis is an opportunistic malaria vector that rests and feeds outdoors, circumventing current indoor vector control methods. Furthermore, this vector will readily feed on both animals and humans. Targeting this vector while feeding on animals can provide an additional intervention for the current vector control activities. Previous results have displayed the efficacy of using Subolesin/Akirin ortholog vaccines for the control of multiple ectoparasite infestations. This made Akirin a potential antigen for vaccine development against An. arabiensis. METHODS: The efficacy of three antigens, namely recombinant Akirin from An. arabiensis, recombinant Akirin from Aedes albopictus, and recombinant Q38 (Akirin/Subolesin chimera) were evaluated as novel interventions for An. arabiensis vector control. Immunisation trials were conducted based on the concept that mosquitoes feeding on vaccinated balb/c mice would ingest antibodies specific to the target antigen. The antibodies would interact with the target antigen in the arthropod vector, subsequently disrupting its function. RESULTS: All three antigens successfully reduced An. arabiensis survival and reproductive capacities, with a vaccine efficacy of 68-73%. CONCLUSIONS: These results were the first to show that hosts vaccinated with recombinant Akirin vaccines could develop a protective response against this outdoor malaria transmission vector, thus providing a step towards the development of a novel intervention for An. arabiensis vector control.


Subject(s)
Anopheles/immunology , Insect Bites and Stings/immunology , Insect Proteins/immunology , Transcription Factors/immunology , Vaccines/immunology , Animals , Anopheles/genetics , Anopheles/physiology , Female , Humans , Insect Bites and Stings/blood , Insect Bites and Stings/parasitology , Insect Proteins/administration & dosage , Insect Proteins/genetics , Male , Mice , Mice, Inbred BALB C , Mosquito Control , Reproduction , Transcription Factors/administration & dosage , Transcription Factors/genetics , Vaccines/administration & dosage , Vaccines/genetics , Vaccines, Synthetic/administration & dosage , Vaccines, Synthetic/genetics , Vaccines, Synthetic/immunology
19.
Medicine (Baltimore) ; 100(4): e24492, 2021 Jan 29.
Article in English | MEDLINE | ID: mdl-33530269

ABSTRACT

INTRODUCTION: Multiple wasp stings is an emergency result from systemic reactions to the toxin with a wide range of manifestations, and we presented 2 patients with distinct clinical and transcriptomic findings. PATIENT CONCERNS: Two patients without systemic disease presented with nearly 90 painful papules after attacked by a swarm of wasps (Vespa basalis). DIAGNOSIS: Patient 1 was a 44-year-old healthy male whose clinical manifestations mainly comprised hemolysis, hepatic injury, rhabdomyolysis, and acute kidney injury. Patient 2 was a 49-year-old healthy female who presented with severe acute respiratory distress syndrome (ARDS) in addition to certain clinical manifestations that were also found in patient 1. We used ribo- nucleic acid sequencing (RNA-Seq) to characterize the inflammatory responses of 2 patients with distinct clinical manifestations after multiple wasp stings. INTERVENTIONS: Both 2 patients received 5 sessions of plasmapheresis, and patient-1 further received mechanical ventilation for 8 days as well as 8 sessions of hemodialysis until day 17. OUTCOMES: Both patients recovered uneventfully after the aforementioned management. We used RNA-Seq to demonstrate a largely regulated neutrophil-predominated immune response in patient 1. In patient 2, we found a profound neutrophilc response on week 1 and a robust neutrophilic as well as pro-inflammatory responses on week 2. Furthermore, we found increased expression of signals that were associated with renal system process on week 2. CONCLUSION: In conclusion, we report 2 patients who manifested with shared and distinct presentations after an attack by the same swarm of wasps. Both patients had hemolysis, rhabdomyolysis, hepatic injury and acute kidney injury, and 1 patient had ARDS. The whole transcriptomic analyses were consistent with the distinct clinical manifestation, and these results suggest the potential of RNA-Sequencing to disentangle complex inflammatory responses in patients with multiple wasp stings. Plasmapheresis and corticosteroid were administered to both patients and case 2 also underwent 8 sessions of hemodialysis.


Subject(s)
Insect Bites and Stings/complications , Wasp Venoms/adverse effects , Acute Kidney Injury/etiology , Adrenal Cortex Hormones/therapeutic use , Adult , Animals , Female , Humans , Insect Bites and Stings/immunology , Insect Bites and Stings/therapy , Male , Middle Aged , Plasmapheresis , Respiratory Distress Syndrome/etiology , Rhabdomyolysis/etiology , Treatment Outcome , Wasp Venoms/immunology , Wasps
20.
PLoS One ; 16(2): e0245788, 2021.
Article in English | MEDLINE | ID: mdl-33556084

ABSTRACT

Acetaminophen (N-acetyl-p-aminophenol, APAP) overdose is the most common cause of drug-induced liver injury (DILI). Although the primary hepatic damage is induced by APAP-derived toxic intermediates resulting from cytochrome P450 metabolism, immune components also play an important role in DILI pathophysiology. Aedes aegypti saliva is a source of bioactive molecules with in vitro anti-inflammatory and immunomodulatory activities. However, evidences on the therapeutic use of Ae. aegypti salivary preparations in animal models of relevant clinical conditions are still scarce. Thus, the present study was designed to evaluate the protective role of Ae. aegypti saliva in a murine model of APAP-induced DILI. C57BL/6 mice were exposed to Ae. aegypti bites 2 hours after APAP overdose. Biochemical and immunological parameters were evaluated in blood and liver samples at different time points after APAP administration. Exposure to Ae. aegypti saliva attenuated liver damage, as demonstrated by reduced hepatic necrosis and serum levels of alanine aminotransferase in APAP-overdosed mice. The levels of hepatic CYP2E1, the major enzyme responsible for the bioactivation of APAP, were not changed in Ae. aegypti exposed animals, suggesting no effects in the generation of hepatotoxic metabolites. On the other hand, mice treated with Ae. aegypti saliva following APAP overdose presented lower serum concentration of TNF-α, IL-6, IL-1ß and IL-10, as well as reduced frequency of inflammatory cell populations in the liver, such as NKT cells, macrophages and dendritic cells. These findings show that Ae. aegypti saliva has bioactive molecules with therapeutic properties and may represent a prospective source of new compounds in the management of DILI-associated inflammatory disorders and, perhaps, many other inflammatory/autoimmune diseases.


Subject(s)
Acetaminophen/adverse effects , Aedes/physiology , Chemical and Drug Induced Liver Injury/blood , Immunologic Factors/metabolism , Insect Bites and Stings/immunology , Saliva/metabolism , Alanine Transaminase/blood , Animals , Chemical and Drug Induced Liver Injury/immunology , Cytochrome P-450 CYP2E1/metabolism , Cytokines/blood , Disease Models, Animal , Liver/metabolism , Male , Mice , Mice, Inbred C57BL
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