New Insights into Cockroach Allergens

Spatial distribution of histamine in bed bug-infested homes

Histamine is a component of the bed bug aggregation pheromone. It was recently identified as an environmental contaminant in homes with active bed bug infestations, posing a potential health risk to humans via skin contact or inhalation. It remains unclear how histamine is distributed in homes and if histamine can become airborne. In the present study, histamine levels in household dust were quantified from multiple locations within bed bug infested and uninfested apartments. Bed bug population levels were quantified using both traps and visual counts. The amount of histamine detected varied significantly with respect to sampling location, with the highest concentration of histamine quantified from bedding material. Infestation severity did not have a significant effect on histamine quantified at any location. Our results indicate that the bedroom should be the primary focus of histamine mitigation efforts, although histamine can be found throughout the home. Histamine quantified from homes without active bed bug infestations suggests that histamine from previous infestations can persist following pest eradication. These findings highlight the importance of histamine as a potential insect allergen and will be important for the development of targeted mitigation strategies of bed bug histamine.

Mechanisms of and Potential Medications for Oxidative Stress in Ovarian Granulosa Cells: A Review

Granulosa cells are essential for follicle initiation and development, and their abnormal function or apoptosis is a crucial factor leading to follicular atresia. A state of oxidative stress occurs when the balance between the production of reactive oxygen species and the regulation of the antioxidant system is disturbed. Oxidative stress is one of the most important causes of the abnormal function and apoptosis of granulosa cells. Oxidative stress in granulosa cells causes female reproductive system diseases, such as polycystic ovary syndrome and premature ovarian failure. In recent years, studies have confirmed that the mechanism of oxidative stress in granulosa cells is closely linked to the PI3K-AKT signaling pathway, MAPK signaling pathway, FOXO axis, Nrf2 pathway, NF-κB signaling pathway, and mitophagy. It has been found that drugs such as sulforaphane, Periplaneta americana peptide, and resveratrol can mitigate the functional damage caused by oxidative stress on granulosa cells. This paper reviews some of the mechanisms involved in oxidative stress in granulosa cells and describes the mechanisms underlying the pharmacological treatment of oxidative stress in granulosa cells.

Cockroach allergy: Understanding complex immune responses to develop novel therapies

Cockroach allergy is associated with the development of asthma. The identification of cockroach allergens, which began in the 1990 s, is an ongoing process that has led to the current listing of 20 official allergen groups in the WHO/IUIS Allergen Nomenclature database. The function and structure of some of these allergens has been determined and define their natural delivery into the environment and their allergenicity. Analysis of antigenic determinants by X-ray crystallography and rational design of site-directed mutagenesis led to the identification of IgE binding sites for the design of molecules with reduced IgE reactivity and T cell modulatory capacity. New developments in recent years include component analyses of B and T cell reactivity and a recent cockroach immunotherapy trial, CRITICAL, that will contribute to understand the immune response to cockroach and to define future directions for cockroach allergy diagnosis and immunotherapy.

Allergic rhinitis co-morbidity on asthma outcomes in city school children

BACKGROUND

School based asthma programs have demonstrated that preventive asthma therapy administered in school reduces asthma morbidity. The burden of co-morbid allergic disease on asthma outcomes in a large school based asthma cohort has been unexplored.

OBJECTIVE

Evaluate the prevalence of allergic rhinitis (AR) in historically minoritized school children with persistent asthma, and determine if AR is an independent risk factor for asthma morbidity.

METHODS

We evaluated the prevalence of AR in children enrolled in 3 NIH funded school based asthma programs in Rochester, NY. We used linear regression and multivariate analyses to compare asthma outcomes for children whose caregivers did and did not report AR.

RESULTS

We used data from 1,029 children with asthma (mean age 7.4, 60.4% Black, 29.5% Hispanic, 72.8% insured with Medicaid). 63% of children reported AR. Children with AR had significantly fewer symptom free days over 2 weeks compared to children without AR (7.2 vs. 8.3, p < 0.001). Children with AR also had more daytime symptoms, (4.7 vs. 3.7, p < 0.001), more rescue medication use (4.5 vs. 3.4, p < 0.01), and more activity limitation due to asthma (3.6 vs. 2.5, p < 0.001). Only 44% of children with AR reported allergy medication use.

CONCLUSIONS

Among a large school-based cohort of minoritized children with asthma, we found that the majority of children have comorbid allergic rhinitis, which was associated with increased asthma morbidity. Inadequate recognition and treatment for allergic rhinitis likely represents substantial preventable morbidity for this group.

Reported Cases and Diagnostics of Occupational Insect Allergy: A Systematic Review

A significant part of adult-onset asthma is caused by occupational exposure to both high- and low-molecular-mass agents. Insects are occasionally described to cause occupational allergy in professions including anglers and fishers, laboratory workers, employees of aquaculture companies, farmers, bakers, sericulture workers and pet shop workers. Occupational insect allergies are often respiratory, causing asthma or rhinoconjunctivitis, but can be cutaneous as well. The European Union recently approved three insect species for human consumption, enabling an industry to develop where more employees could be exposed to insect products. This review overviews knowledge on occupational insect allergy risks and the tools used to diagnose employees. Despite the limited availability of commercial occupational insect allergy diagnostics, 60.9% of 164 included reports used skin prick tests and 63.4% of reports used specific IgE tests. In 21.9% of reports, a more elaborate diagnosis of occupational asthma was made by specific inhalation challenges or peak expiratory flow measurements at the workplace. In some work environments, 57% of employees were sensitized, and no less than 60% of employees reported work-related symptoms. Further development and optimization of specific diagnostics, together with strong primary prevention, may be vital to the health conditions of workers in the developing insect industry.

Ex vivo assays show human gamma-delta T cells specific for common allergens are Th1-polarized in allergic donors

Gamma-delta (γδ) T cells contribute to the pathology of many immune-related diseases; however, no ex vivo assays to study their activities are currently available. Here, we established a methodology to characterize human allergen-reactive γδ T cells in peripheral blood using an activation-induced marker assay targeting upregulated 4-1BB and CD69 expression. Broad and reproducible ex vivo allergen-reactive γδ T cell responses were detected in donors sensitized to mouse, cockroach, house dust mite, and timothy grass, but the response did not differ from that in non-allergic participants. The reactivity to 4 different allergen extracts was readily detected in 54.2%-100% of allergic subjects in a donor- and allergen-specific pattern and was abrogated by T cell receptor (TCR) blocking. Analysis of CD40L upregulation and intracellular cytokine staining revealed a T helper type 1 (Th1)-polarized response against mouse and cockroach extract stimulation. These results support the existence of allergen-reactive γδ T cells and their potential use in rebalancing dysregulated Th2 responses in allergic diseases.

In Silico Comparative Exploration of Allergens of Periplaneta americana, Blattella germanica and Phoenix dactylifera for the Diagnosis of Patients Suffering from IgE-Mediated Allergic Respiratory Diseases

The burden of allergic illnesses is continuously rising, and patient diagnosis is a significant problem because of how intricately hereditary and environmental variables interact. The past three to four decades have seen an outbreak of allergies in high-income countries. According to reports on the illness, asthma affects around 300 million individuals worldwide. Identifying clinically important allergens for the accurate classification of IgE-mediated allergy respiratory disease diagnosis would be beneficial for implementing standardized allergen-associated therapy. Therefore, the current study includes an in silico analysis to identify potential IgE-mediated allergens in date palms and cockroaches. Such an immunoinformatic approach aids the prioritization of allergens with probable involvement in IgE-mediated allergic respiratory diseases. Immunoglobulin E (IgE) was used for molecular dynamic simulations, antigen-antibody docking analyses, epitope identifications, and characterizations. The potential of these allergens (Per a7, Per a 1.0102, and Bla g 1.0101) in IgE-mediated allergic respiratory diseases was explored through the evaluation of physicochemical characteristics, interaction observations, docking, and molecular dynamics simulations for drug and vaccine development.

In Silico Prediction of Cross-Reactive Epitopes of Tropomyosin from Shrimp and Other Arthropods Involved in Allergy

Tropomyosin in shellfish is considered a major cross-reactive allergen in house dust mites and cockroaches; however, the specific epitopes have not been elucidated. Therefore, this study aimed to identify the consensus antigenic determinant among shrimp, house dust mites, and cockroaches using in silico methods. The protein sequences of tropomyosin, including Der f 10, Mac r 1, Pen a 1, Pen m 1, Per a 7, and Bla g 7, were retrieved from the UniProt database. The 3D structures were derived from the AlphaFold or modeled using the Robetta. The determination of linear epitopes was performed by AlgPRED and BepiPRED for B cell epitope, and NetMHCIIpan and NetMHCII for T cell epitope, while Ellipro was used to evaluate conformational epitopes. Fourteen peptides were discovered as the consensus linear B cell epitopes, while seventeen peptides were identified as linear T cell epitopes specific to high-frequency HLA-DR and HLA-DQ alleles. The conformational determination of B cell epitopes provided nine peptides, in which residues 209, 212, 255–256, and 258–259 were found in both linear B cell and linear T cell epitope analysis. This data could be utilized for further in vitro study and may contribute to immunotherapy for allergic diseases associated with tropomyosin.

Transcriptome Responses to Defined Insecticide Selection Pressures in the German Cockroach (Blattella germanica L.)

Cockroaches are important global urban pests from aesthetic and health perspectives. Insecticides represent the most cost-effective way to control cockroaches and limit their impacts on human health. However, cockroaches readily develop insecticide resistance, which can quickly limit efficacy of even the newest and most effective insecticide products. The goal of this research was to understand whole-body physiological responses in German cockroaches, at the metatranscriptome level, to defined insecticide selection pressures. We used the insecticide indoxacarb as the selecting insecticide, which is an important bait active ingredient for cockroach control. Six generations of selection with indoxacarb bait produced a strain with substantial (>20×) resistance relative to inbred control lines originating from the same parental stock. Metatranscriptome sequencing revealed 1,123 significantly differentially expressed (DE) genes in ≥two of three statistical models (81 upregulated and 1,042 downregulated; FDR P < 0.001; log2FC of ±1). Upregulated DE genes represented many detoxification enzyme families including cytochrome-P450 oxidative enzymes, hydrolases and glutathione-S-transferases. Interestingly, the majority of downregulated DE genes were from microbial and viral origins, indicating that selection for resistance is also associated with elimination of commensal, pathogenic and/or parasitic microbes. These microbial impacts could result from: (i) direct effects of indoxacarb, (ii) indirect effects of antimicrobial preservatives included in the selecting bait matrix, or (iii) selection for general stress response mechanisms that confer both xenobiotic resistance and immunity. These results provide novel physiological insights into insecticide resistance evolution and mechanisms, as well as novel insights into parallel fitness benefits associated with selection for insecticide resistance.

Structural racism and its pathways to asthma and atopic dermatitis

Black, Latinx, and Indigenous people in the United States experience a disproportionate burden of asthma and atopic dermatitis. The study of these disease disparities has focused on proximal socioenvironmental exposures and on the biomechanistic (including genetic) differences between racial and ethnic groups. Although biomedical research in allergy and immunology stands to benefit from the inclusion of diverse study populations, the narrow focus on biologic mechanisms disregards the complexity of interactions across biologic and structural factors, including the effects of structural racism. Structural racism is the totality of ways in which society fosters discrimination by creating and reinforcing inequitable systems through intentional policies and practices sanctioned by government and institutions. It is embedded across multiple levels, including the economic, educational, health care, and judicial systems, which are manifested in inequity in the physical and social environment. In this review, we present a conceptual framework and pull from the literature to demonstrate how structural racism is a root cause of atopic disease disparities by way of residential segregation, socioeconomic position, and mass incarceration, which may lead to aberrations in the innate and adaptive immune response and the augmentation of physiologic stress responses, contributing to a disproportionate disease burden for racial and ethnic populations.

Effectiveness of Ethyl Formate as a Fumigant of Blattella germanica and Periplaneta americana (Blattodea: Ectobiidae, Blattidae) in Cross-Border Trade Transportation

Simple Summary

Fumigation is one effective cockroach control method. Ethyl formate (EF) has recently been employed as a grain fumigant and has been evaluated as relatively safer than other fumigants. In this experiment, the effects of an ethyl formate fumigant on two species of cockroaches were investigated. Cockroach nymphs and adults had 100% mortality, but the effect on egg hatching inhibition was weak. Therefore, ethyl formate could be used as a fumigant if the control period and its usage should be adjusted considering the developmental stage of the cockroach.

Abstract

Cockroaches cause problems as pests not only locally in residential areas but also internationally, as they can disperse across borders in transport vessels. We investigated the effects of the ethyl formate (EF) fumigant on all developmental stages of Blattella germanica and Periplaneta americana. For B. germanica eggs, the hatching inhibition rate increased directly proportionately with the increasing treatment concentration of EF, but the 100% control was not observed. P. americana eggs did not show any fumigation effect, even after exposure to 60 mg/L of fumigant in a 12 L desiccator. Adults and nymphs of the two species showed various fumigation effects dependent on the concentration in the 12 L desiccator. When EF was applied at the lethal concentration for 99% mortality (LCT₉₉) values of 35 mg/L for 4 h (78.5 mg·h/L) and 60 mg/L for 2 h (70.8 mg·h/L), respectively, adults and nymphs of both species had 100% mortality in a 0.65 m³ fumigation chamber with a 20% loading ratio. However, no significant difference from the control was observed in the egg stage of either species of cockroach. The results of this experiment indicate that EF can be used as a fumigant for cross-border transport vessels if the control period occurs during the cockroach developmental stage and continuous refumigation is performed.

Identification of B cell epitopes of Per a 5 allergen using bioinformatic approach

BACKGROUND

Immune epitopes of allergens are pivotal for development of novel diagnostic and therapeutic modalities. Present study aims to identify antigenic determinants of Per a 5, a clinically relevant cross reactive cockroach allergen.

METHODS

The three dimensional structure of Per a 5 was modelled using Modeller 9v11 software. A combination of sequence and structure based computational tools were employed for predicting B cell epitopes. Epitopes were synthesized and immunoreactivity was assessed by ELISA using cockroach hypersensitive patient's sera. Cross-reactivity potential of predicted epitopes was assessed with SDAP and ConSurf and validated by IgE ELISA with fungal and mite hypersensitive patient's sera.

RESULTS

Per a 5 structure exhibited good quality factor in ERRAT and high stereochemical stability. In silico analysis revealed six B cell epitopes (BC-P1 to P6). BC-P3 demonstrated significant IgE binding followed by BC-P2 and BC-P1 with cockroach hypersensitive patient's sera. Per a 5 epitopes demonstrate considerable similarity with broad spectrum of allergens from fungal, mites, helminths, fruits and nuts. Analysis of PD values indicate BC-P4 to be well conserved among dust mite and helminth GSTs (8.89, 10.63 and 10.69 with D. pteronyssinus, W. bancrofti and F. hepatica respectively). ConSurf analysis of Per a 5 revealed specific enrichment of evolutionarily similar amino acid residues in BC-P2 (with fungal and mite GSTs) and BC-P4 (with mite and helminth GSTs). Further, IgE binding analysis of epitopes demonstrate BC-P2, BC-P3 and BC-P5 as high IgE binders in fungal hypersensitive sera while BC-P1, BC-P2, BC-P4 and BC-P5 demonstrated significant IgE binding with mite hypersensitive sera.

CONCLUSIONS

Among the predicted epitopes, BC-P3 demonstrates maximal IgE binding ability. Computational analysis suggests strong evolutionary conservation and cross reactive potential of BC-P4 with allergens in dust mite and helminths. ELISA highlights predictive potential of analysing evolutionarily conserved residues for uncovering potentially cross reactive antigenic determinants.

GENERAL SIGNIFICANCE

Immune epitopes of Per a 5 were identified for aiding molecular diagnosis and potential cross reactivity.

Heterogeneity of magnitude, allergen immunodominance, and cytokine polarization of cockroach allergen-specific T cell responses in allergic sensitized children

BACKGROUND

Characterization of allergic responses to cockroach (CR), a common aeroallergen associated with asthma, has focused mainly on IgE reactivity, but little is known about T cell responses, particularly in children. We conducted a functional evaluation of CR allergen-specific T cell reactivity in a cohort of CR allergic children with asthma.

METHODS

Peripheral blood mononuclear cells (PBMCs) were obtained from 71 children, with mild-to-moderate asthma who were enrolled in a CR immunotherapy (IT) clinical trial, prior to treatment initiation. PBMC were stimulated with peptide pools derived from 11 CR allergens, and CD4+ T cell responses assessed by intracellular cytokine staining.

RESULTS

Highly heterogeneous responses in T cell reactivity were observed among participants, both in terms of the magnitude of cytokine response and allergen immunodominance. Reactivity against Bla g 9 and Bla g 5 was most frequent. The phenotype of the T cell response was dominated by IL-4 production and a Th2 polarized profile in 54.9% of participants, but IFNγ production and Th1 polarization was observed in 25.3% of the participants. The numbers of regulatory CD4+ T cells were also highly variable and the magnitude of effector responses and Th2 polarization were positively correlated with serum IgE levels specific to a clinical CR extract.

CONCLUSIONS

Our results demonstrate that in children with mild-to-moderate asthma, CR-specific T cell responses display a wide range of magnitude, allergen dominance, and polarization. These results will enable examination of whether any of the variables measured are affected by IT and/or are predictive of clinical outcomes.

Respiratory diseases in patients with bed bugs

INTRODUCTION

Some arthropods such as cockroaches can exacerbate asthma, but it is unknown is this is true of bed bugs.

OBJECTIVES

The objective of this work is to determine if bronchospastic diseases like asthma and chronic obstructive pulmonary disease (COPD) would be higher for ED patients who have bed bug infestation compared with patients who do not have bed bug infestation.

METHODS

A case-control study was performed with 332 adult emergency department (ED) patients with bed bug infestation and 4952 without infestation. Univariable and multivariable regression analysis was performed.

RESULTS AND CONCLUSION

Patients with bed bug infestation were not more likely to have a past history of or an ED diagnosis of asthma or chronic obstructive pulmonary disease (COPD). However, bed bug infested patients were significantly more likely to undergo chest radiography, be admitted to the hospital, and receive albuterol in the ED (P < 0.05). Infested patients receiving albuterol in the ED were more likely to be admitted to the hospital compared with uninfested patients receiving albuterol (P < 0.001). Patients with an ED or inpatient diagnosis of asthma or COPD and bed bugs (compared with those without bed bugs) had significantly more ED visits during the study (P < 0.03). Bed bug infestations may be associated with respiratory pathology, which requires further investigation.

Concordance of skin test reactivity between indoor inhalant allergens among children with allergic respiratory disease

Background

In vitro studies have demonstrated cross-reactivity among indoor allergen proteins in children with allergic respiratory diseases. However, there are only few studies evaluating in vivo response. A skin prick test (SPT) with commercial indoor solutions is widely used in clinical practice. We aimed to evaluate SPT agreement in children with allergic respiratory disease between pairs of common indoor allergens.

Methods

We reviewed SPT results of children 2 to 18 years old, diagnosed with respiratory allergic disease. Results from house dust mite (Dermatophagoides farinae, Dermatophagoides pteronyssinus), cockroach (Periplaneta americana, Blatella germanica), cat and dog were collected. Sensitization was defined as ≥ 3 mm in wheal diameter. Kappa coefficient (κ) was used to analyze sensitization concordance for each allergen pair.

Results

The charts of 300 children, 187 (62.33%) males, were reviewed. Mean age was 7.43 ± 3.29 years with 183 (61%), 140 (46.67%), 45 (15%), 30 (10%) sensitizations to house dust mite (HDM), cockroach, cat and dog, respectively. Sensitization concordance between HDM and cockroach was moderate: κ = 0.53 (95% CI: 0.42–0.64). Moderate agreement occurred between dog and cat: κ = 0.41 (95%CI: 0.30–0.52). HDM-sensitized children showed poor concordance with both cat κ = 0.17 (95%CI: 0.09–0.24) and dog κ = 0.09 (95%CI: 0.03–0.14). There was also poor concordance between cockroach-sensitized children to cat κ = 0.19 (95%CI; 0.11–0.28) and dog κ = 0.11 (95%CI; 0.04–0.18).

Conclusion

We demonstrated moderate agreement of SPT response between HDM and cockroach as well as dog and cat. This may be due to cross-reactivity. Component-resolved diagnosis should be considered in children with co-sensitization of these allergen pairs.

Allergens and their associated small molecule ligands-their dual role in sensitization

Many allergens feature hydrophobic cavities that allow the binding of primarily hydrophobic small‐molecule ligands. Ligand‐binding specificities can be strict or promiscuous. Serum albumins from mammals and birds can assume multiple conformations that facilitate the binding of a broad spectrum of compounds. Pollen and plant food allergens of the family 10 of pathogenesis‐related proteins bind a variety of small molecules such as glycosylated flavonoid derivatives, flavonoids, cytokinins, and steroids in vitro. However, their natural ligand binding was reported to be highly specific. Insect and mammalian lipocalins transport odorants, pheromones, catecholamines, and fatty acids with a similar level of specificity, while the food allergen β‐lactoglobulin from cow's milk is notably more promiscuous. Non‐specific lipid transfer proteins from pollen and plant foods bind a wide variety of lipids, from phospholipids to fatty acids, as well as sterols and prostaglandin B2, aided by the high plasticity and flexibility displayed by their lipid‐binding cavities. Ligands increase the stability of allergens to thermal and/or proteolytic degradation. They can also act as immunomodulatory agents that favor a Th2 polarization. In summary, ligand‐binding allergens expose the immune system to a variety of biologically active compounds whose impact on the sensitization process has not been well studied thus far.

Knowledge, attitudes, and practices concerning cockroach exposure among caregivers of children with asthma

Background

Cockroach allergen is one of the most important asthma triggers for children. There is an extensive body of research on interventions to reduce exposure. However, adherence to these interventions is low. Insight into the knowledge, attitudes, and practices (KAP) associated with cockroach remediation is needed. We assessed KAP using the Health Beliefs Model (HBM) as a framework for predicting behavior. This study aimed to assess the socio-demographic and psycho-social characteristics associated with cockroach KAP and to quantify the relationship between KAP and number of cockroaches in the home.

Methods

To identify factors associated with cockroach KAP a cross-sectional study was conducted using a structured questionnaire administered to caregivers of children with asthma in New Orleans, Louisiana. Positive scores in each metric of the KAP signified better cockroach knowledge, increased concern about cockroaches’ impact on health (attitudes), and participation in recommended cockroach remediation practices (practices). To evaluate cockroach KAP scores as a predictor of cockroach exposure in the home, a cohort study was conducted among a sub-sample of participants.

Results

Fifty-six caregivers participated in the study. Participants had positive scores on all subscales of KAP with knowledge having a lower score compared to attitudes and practices. Cockroach knowledge was inversely correlated with age at asthma diagnosis (ρ = − 0.36, p = 0.01). Caregivers identifying as black/African American had higher cockroach knowledge scores compared to other races (Median: 6.0 v 3.0; p = 0.05). Caregivers other than mothers had higher cockroach attitude scores (Median 6.5 v 4.0; p = 0.003) and total KAP scores (Median 18.0 v 14.0; p = 0.05). Twenty-six participants completed the cohort study. Cockroach exposure was not significantly associated with higher cockroach knowledge, cockroach practice, or total KAP score. For attitude scores, participants in the highest quartile had significantly lower exposure (β: -1.96, 95% CI: − 3.50 - 0.42) compared to those in the lowest quartile (p = 0.01).

Conclusions

Different socio-demographic and psycho-social factors were associated with the components of cockroach KAP. Greater concern about cockroaches (attitude) was significantly associated with reduced cockroach exposure. This highlights the importance of identifying the key elements of caregiver KAP to improve cockroach remediation among caregivers of children with asthma.

Component-Resolved Diagnosis of American Cockroach (Periplaneta americana) Allergy in Patients From Different Geographical Areas

Background: Manifestation of respiratory allergy to American cockroach (Periplaneta americana) is prominent in the subtropical and tropical areas. However, co-existing perennial indoor inhalant allergies frequently compromise clinical diagnosis of cockroach allergy, and the analysis of sensitization pattern is limited by the lack of Periplaneta allergens widely available for component-resolved diagnostics (CRD).

Objective: To evaluate a collection of previously described recombinant Periplaneta allergens for CRD in cockroach allergy.

Methods: A panel of nine recombinant Periplaneta allergens (Per a 1–5, 7–10) was generated, purified, and subjected to physicochemical characterization by applying circular dichroism (CD) spectroscopy, dynamic light scattering (DLS), amino acid (AA) analysis, and mass spectrometry (MS). Patients (n = 117) from India, Korea, Venezuela, and Iran, reporting perennial respiratory indoor allergies with IgE sensitization to cockroach (P. americana and/or Blattella germanica), were included. The sensitization profile was monitored by the experimental ImmunoCAP testing.

Results: ImmunoCAP testing confirmed IgE sensitization to Periplaneta and/or Blattella extract in 98 of 117 patients (r = 0.95). Five out of 117 patients were sensitized to only one of the two cockroach species. Within the whole study group, the prevalence of sensitization to individual allergens varied from 4% (Per a 2) to 50% (Per a 9), with the highest IgE values to Per a 9. Patients from four countries displayed different sensitization profiles at which Per a 3 and Per a 9 were identified as major allergens in India and Korea. Periplaneta-derived lipocalin and myosin light chain were characterized as new minor allergens, designated as Per a 4 and Per a 8. Periplaneta extract showed higher diagnostic sensitivity than all individual components combined, suggesting the existence of allergens yet to be discovered.

Conclusion: Utilization of a panel of purified Periplaneta allergens revealed highly heterogeneous sensitization patterns and allowed the classification of lipocalin and myosin light chain from Periplaneta as new minor allergens.

The merits of entomophagy in the post COVID-19 world

BACKGROUND

In 2020, human society underwent several drastic changes due to the coronavirus disease 2019 (COVID-19) pandemic, which generated an unprecedented global impact. Since the onset of the COVID-19 pandemic, various pressing concerns underlying food security, such as transport, production, and maintenance of the supply chain, have been raised.

SCOPE AND APPROACH

The present study aimed to describe and review the merits of entomophagy in the post COVID-19 world, especially with regard to the low risk for zoonotic disease spread, high production rate, and future prospects for inducing entomophagy to enhance the diversity in the food system in comparison to conventional livestock.

KEY FINDINGS AND CONCLUSIONS

The advantages of entomophagy in the post COVID-19 world have been elucidated herein, with particular emphasis on the minimal risk of zoonotic disease transmission and production efficiency, in addition to the future goal of establishment of entomophagy to expand redundancy and diversity in the food system as against the utility of conventional livestock. In the current scenario, as well as in the post COVID-19 situation, boosting entomophagy may play a pivotal role in global food security, as the aspects already touched upon have amply demonstrated.

Cockroach exposure and perceived stress interact to predict clinical outcomes in childhood asthma

Background

Nonpharmacologic interventions for asthma management rely on identification and mitigation of important asthma triggers. Cockroach exposure is strongly associated with asthma morbidity. It is also associated with stress, another risk factor for asthma. Despite high prevalence of both in vulnerable populations, the impact of joint exposure has not been examined.

Methods

Participants included 173 children with asthma in New Orleans, Louisiana. Cockroach exposure was based on visual inspection using standard protocols. Caregiver stress was measured using Cohen’s 4-item Perceived Stress Scale. Outcomes included unscheduled clinic or emergency department (ED) visits, hospitalization, and pulmonary function. Multivariable logistic regression was performed to assess independent effects of the exposure on the outcome and effect modification was examined in stratified analysis based on stress. Path analysis to explore the mediation effect by stress was performed using a probit link with parameters based on Bayes’ method with non-informative priors.

Results

Adjusting for stress and other covariates, cockroach exposure was associated with unscheduled clinic/ED visits (aOR = 6.2; 95% CI 1.8, 21.7). Positive associations were also found for hospitalization and FEV₁ < 80%. High stress modified the relationship with unscheduled clinic/ED visits (high aOR = 7.7 95% CI 1.0, 60.2, versus normal aOR = 4.1 95% CI 0.8, 21.9). Path models identified direct and indirect effects (p = 0.05) indicating that a majority of the total effect on unscheduled clinic/ED visits is attributed directly to cockroach exposure.

Conclusion

The strong association between cockroach exposure and asthma morbidity is not due to uncontrolled confounding by stress. The combination of cockroach exposure and high stress, common in urban homes, are modifiable factors associated with poor asthma outcomes.

Resistance development characteristics of reared German cockroach (Blattodea: Blattellidae) to chlorpyrifos

Understanding the process of resistance development of German cockroach, Blattella germanica (L.), in detail is necessary to potentially delay the development of insecticides resistance by rotation or discontinuation of insecticides at the right time. In this study, we investigated the resistance development of the reared German cockroach to chlorpyrifos (CPF) for 23 generations from susceptible cockroaches. CPF 50% lethal dose (LD₅₀) and resistance ratio of each generation cockroaches were determined. The CPF LD₅₀ to each generation cockroaches was used as the insecticide selection pressure of this generation by topical application. The resistance development curve was depicted according to the CPF LD₅₀ to all 23 generations of cockroaches. As a result, a highly resistant German cockroach cohort to CPF, which the resistance ratio was 21.63, was obtained after 23 generations’ selection. During the selection, the cockroaches developed low resistance from F1 to F5, moderate resistance from F6 to F12, and high resistance from F13 to F23. There was a rapid resistance increase every 5–7 generations. The resistance growing showed relatively slow from F1 to F11. The fastest growing phase of the resistance was from F12 to F20, in which accounted for more than 80% of the total resistance increase in 23 generations. The development of resistance to CPF tended to slow down from F21 to F23. These findings may provide a basis for the rational use of insecticides, delaying the development of resistance by rotation or discontinuation.

Comprehensive analysis of allergen-specific IgE in COPD: mite-specific IgE specifically related to the diagnosis of asthma-COPD overlap

Background

Although the relationship between allergic sensitization and increased respiratory symptoms of chronic obstructive pulmonary disease (COPD) has been suggested, which allergen has a significant effect on COPD pathology is unclear. This study aimed to identify the specific IgE related to clinical features of COPD and the diagnosis of asthma-COPD overlap (ACO).

Methods

We recruited 76 patients with COPD and analyzed 39 IgE using panel IgE test (View Allergy 39^®). ACO was diagnosed according to the Japanese Respiratory Society Guidelines.

Results

As for perennial aeroallergens, the positivity for moth (31.5%), Candida (23.7%), Dermatophagoides pteronyssinus (22.4%) and house dust (22.4%), and concerning pollen, Japanese cedar (35.5%) and Japanese cypress (22.2%) exceeded 20%. Only the positivity of IgE for Dermatophagoides pteronyssinus and house dust was significantly higher in ACO compared with that in non-ACO COPD. Moreover, it contributed to the diagnosis of ACO in an IgE class-dependent manner. Patients with cockroach IgE exhibited higher residual volume, whereas those with Japanese cedar IgE exhibited better diffusion capacity than negative patients. The contribution for ACO diagnosis by the receiver operating characteristic curve analysis was comparable among total IgE (cutoff value: 158 IU/mL), blood eosinophil count (234/μL), and fraction of exhaled nitric oxide (31.0 ppb).

Conclusions

The prominent role of mite-specific IgE in the diagnosis and pathology of ACO and the potentially detrimental effect of cockroach sensitization on air trapping in COPD were suggested. The finding highlights the future development of a treatment targeting IgE as a treatable trait in COPD.

Insect Allergens on the Dining Table

Edible insects are important sources of nutrition, particularly in Africa, Asia, and Latin America. Recently, edible insects have gained considerable interest as a possible solution to global exhaustion of the food supply with population growth. However, little attention has been given to the adverse reactions caused by insect consumption. Here, we provide an overview of the food allergens in edible insects and offer insights for further studies. Most of the edible insect allergens identified to date are highly cross-reactive invertebrate pan-allergens such as tropomyosin and arginine kinase. Allergic reactions to these allergens may be cross-reactions resulting from sensitization to shellfish and/or house dust mites. No unique insect allergen specifically eliciting a food allergy has been described. Many of the edible insect allergens described thus far have counterpart allergens in cockroaches, which are an important cause of respiratory allergies, but it is questionable whether inhalant allergens can cause food allergies. Greater effort is needed to characterize the allergens that are unique to edible insects so that safe edible insects can be developed. The changes in insect proteins upon food processing or cooking should also be examined to enhance our understanding of edible insect food allergies.

Protozoan Cysts in Faecal Pellets of German Cockroaches (Blattella germanica), with Particular Emphasis on Lophomonas blattarum

Purpose

The aim of this study was to investigate protozoan cysts and oocyts in the faecal pellets of the German cockroach (Blattella germanica), with emphasis on the prevalence of Lophomonas blattarum.

Methods

Thirty adult Blattella germanica (12 males; 18 females) were trapped near Madrid, Spain. Expelled faecal pellets were collected in the laboratory over 5 days in two plastic containers. Protozoan cysts from one container were weighted and those in the other used for morphologically identification.

Results

Protozoan cysts/oocysts per gram of faecal pellet were: Nyctotherus sp. (0.0019/g), Entamoeba (0.0007/g), Balantidium coli (0.0001/g), Lophomonas blattarum (0.00038/g). Observation of 189 protozoan cysts/oocysts indicated the following prevalence: Nyctotherus sp. 65 (34.4%); Gregarina spp. 34 (18%); Entamoeba sp. 24 (12.7%); Cryptosporidium sp. 17 (9%); Coccidia 16 (8.4%); Lophomonas blattarum 13 (6.8%); Balantidium coli 4 (2.1%); and unclassified 16 (8.4%).

Conclusion

Lophomonas blattarum has previously been demonstrated in the gut of cockroaches, but this is the first assessment of the prevalence in Blattella germanica in faecal pellets. The presence of protozoa in faecal pellets provides some evidence for one step in a hypothesised route of respiratory infection whereby protozoa from household insects enter the respiratory tract.

Ovarian morphological features and proteome reveal fecundity fitness disadvantages in β-cypermethrin-resistant strains of Blattella germanica (L.) (Blattodea: Blattellidae)

To evaluate whether the development of β-cypermethrin resistance in Blattella germanica (L.) (Blattaria: Blattellidae) affects the fecundity fitness of this insect and to determine the underlying mechanism, we compared fecundity differences between β-cypermethrin-resistant (R) and sensitive (S) strains of B. germanica, observed the physiological structural changes of ovaries from an visual perspective, and analyzed differences in the ovarian proteome using proteomic methods. The results showed that, compared with the S strain of B. germanica, the R strain of B. germanica had a significantly higher ootheca shedding rate, a significantly lower number of hatched and surviving nymphs, a significantly higher female proportion in the population and defective ovarian development. Ovarian proteomic analysis showed a total of 64 differentially expressed proteins in the R strain, including 18 upregulated proteins and 46 downregulated proteins. Twenty-four significantly differentially expressed proteins were further studied, and 14 were successfully identified, which were mainly classified into the following categories: immunity-related proteins, development-related proteins, structural proteins, energy metabolism-related proteins and proteins with unknown functions. The differential expression of these proteins reflects the overall changes in cell structure and metabolism associated with β-cypermethrin resistance and explains the possible molecular mechanism of fecundity fitness disadvantages. In summary, β-cypermethrin resistance can cause fecundity fitness disadvantages in B. germanica. The metabolic deviations needed to overcome the adverse effects of insecticides may result in an energy exchange that affects energy allocation and, ultimately, the basic needs of the insect. The fitness cost due to insecticide resistance is critical to the delay of the evolution of resistance.

Optimising the use of proteins from rich meat co-products and non-meat alternatives: Nutritional, technological and allergenicity challenges

An exponential growth in the global demand for high quality proteins over the next 20 years is expected, mainly due to global population growth and the increasing awareness toward protein rich foods for more nutritive diets. Coupled with this, is the pressing need for more sustainable approaches within a bio-economy mindset. Although meat production is expected to increase to address this rising demand, a better use of the currently available resources provided by the food, and specially, the meat industry is required. In this regard, despite the high-quality proteins and other nutrients found in meat co-products; they are currently underused and their valorisation needs to be revisited. Also, emerging protein sources need to be investigated to alleviate the environmental pressure coming from the meat industry. In this review, the main focus was attributed to (i) the current and forthcoming challenges for the use of meat co-products as meat replacers to produce a new range of meat derived products (with high nutritional value, improved technological properties and better consumer acceptance); (ii) their performance regarding to the non-animal origin proteins currently used as meat protein replacers; and (iii) the allergenicity of the proteins that might fall into the category of novel protein sources.

Cloning, Expression, and Immunological Characterization of Formosan Subterranean Termite (Blattodea: Rhinotermitidae) Arginine Kinase

Several parts of the world regularly consume termites. Arthropod arginine kinase proteins often cross-react with human immunoblobulin E (IgE) antibodies and they are considered pan-allergens. The Formosan subterranean termite Coptotermes formosanus (C. formosanus (Shiraki) [Isoptera: Rhinotermitidae]), along with cockroaches, belong to the order Blattodea and they are common household pests in tropical and subtropical parts of the world. An sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) band migrating at approximately 37 kDa in C. formosanus termite extracts cross-reacted with IgE from five cockroach allergic patient samples by immunoblot. Liquid chromatography-mass spectrometry analysis of gel slices from the corresponding region of a gel indicated several peptides from the excised region were identical to the American cockroach arginine kinase allergen, Per a 9. The sequence of the full-length C. formosanus arginine kinase gene indicates the protein it encodes is 96% identical to American cockroach Per a 9, 94% identical to German cockroach Bla g 9, and 82-84% identical to shrimp arginine kinase proteins Pen m 2, Lit v 2, and Cra c 2. Full-length C. formosanus arginine kinase was fused to a glutathione S-transferase tag and recombinantly expressed and purified from Escherichia coli by affinity chromatography. The recombinant protein was recognized by IgE from 11 of 12 cockroach or shrimp allergic samples, but did not cross-react with dust mite allergic or peanut/tree nut allergic samples. The results of this study indicate the C. formosanus arginine kinase cross-reacts with cockroach and shrimp allergic IgE, and if consumed would likely act as an allergen.

The Indoor Environment and Childhood Asthma

PURPOSE OF REVIEW

Sensitization and exposure to triggers in the indoor environment, including aeroallergens, indoor air pollution, and environmental tobacco smoke, have a significant role in asthma development and morbidity. This review discusses indoor environmental exposures and their effect on children with asthma as well as environmental interventions and their role in improving asthma morbidity.

RECENT FINDINGS

Recent research has emphasized the role of aeroallergen sensitization and exposure in asthma morbidity and the importance of the school indoor environment. There is an established association between indoor exposures and asthma development and morbidity. Recent evidence has highlighted the importance of the indoor environment in childhood asthma, particularly the role of the school indoor environment. While home environmental interventions have had mixed results, interventions in the school environment have the potential to significantly impact the health of children, and ongoing research is needed to determine their effectiveness.

Asthma and Allergies in the School Environment

The school is a complex microenvironment of indoor allergens, pollutants, and other exposures. The school represents an occupational model for children and exposures in this environment have a significant health effect. Current research establishes an association between school exposure and asthma morbidity in children. This review will focus on common school environmental exposures (cockroach, rodents, cat, dog, classroom pets, dust mite, fungus, and pollution) and their impact on children with allergies and asthma. Understanding and evaluation of school-based environments is needed to help guide school-based interventions. School-based interventions have the potential for substantial benefit to the individual, school, community, and public health. However, there is a paucity data on school-based environmental interventions and health outcomes. The studies performed to date are small and cross-sectional with no control for home exposures. Randomized controlled school-based environmental intervention trials are needed to assess health outcomes and the cost-effectiveness of these interventions. The School Inner-City Asthma Intervention Study (SICAS 2), a NIH/NIAID randomized controlled clinical trial using environmental interventions modeled from successful home-based interventions, is currently underway with health outcome results pending. If efficacious, these interventions could potentially help further guide school-based interventions potentially with policy implications. In the meanwhile, the allergist/immunologist can continue to play a vital role in improving the quality of life in children with allergies and asthma at school through the use of the ADA policy and Section 504 of the Rehabilitation Act as well as encouraging adoption of toolkits to build successful school-based asthma programs and asthma-friendly schools.

Antigenic cross-reactivity between Schistosoma mansoni and allergenic invertebrates putatively due to shared glycanic epitopes

Previous studies have shown that rabbit IgG antibodies against Schistosoma mansoni egg antigens (SmSEA) cross-react with allergens in natural rubber latex, peanuts and grass and tree pollens. Here we describe antigenic molecules that cross-react with rabbit anti-S. mansoni IgG antibodies in extracts of the house dust mite (HDM) Dermatophagoides farinae, the Australian cockroach (ACR) Periplaneta australasiae and in the venom of the honey bee Apis mellifera (HBV). Tandem mass spectrometry identified the cross-reactive allergens as Der f 15 in HDM, two homologues of the Periplaneta americana cockroach allergen Cr-PI/Per a 3 in ACR and two isoforms of the allergen Api m 1 (phospholipase A2: PLA2) in HBV. Cross-reactive rabbit anti-SmSEA IgG antibodies eluted from the three invertebrate allergens reacted with S. mansoni egg antigens and variably with schistosome cercarial and worm antigens. Treatment of the electroblotted allergens with sodium metaperiodate abrogated most of the cross-reactivity of the rabbit anti-SmSEA antibodies, suggesting it was due to cross-reactive carbohydrate determinants (CCDs). Furthermore, analyses of the allergens’ amino acid sequences indicated that they had potential for both N- and O-linked glycosylation. A potential role for the CCDs shared by the schistosome and invertebrates in inducing an allergy-protective effect, as proposed by the hygiene hypothesis, is discussed.

Prevalence of Parasitic Contamination of Cockroaches Collected from Fresh Markets in Chachoengsao Province, Thailand

Cockroaches are the greatest potential mechanical vector of various pathogenic microorganisms. This study aimed to determine the prevalence and species type of human pathogenic parasite infestations on the external body surface of the cockroaches. A total of 450 cockroaches collected from three fresh markets were identified in three species belonging to Periplaneta americana, Periplaneta brunnea and Periplaneta australasiae. Helminth and protozoan species were identified by using a direct wet smear technique and modified acid-fast staining technique. The overall prevalence rate of parasitic infestation on the external body surface of cockroaches was 46.4% (209/450). The number of cockroaches infested with protozoa was 44.7% (99/209) and helminths was 44.0% (92/209), while 8.6% (18/209) were infested by both protozoan and helminth parasites. A total of 272 parasite specimens belonging to 16 species were found: ten species of protozoan were identified as Cryptosporidium spp. (15.4%), Entamoeba histolytica/E. dispar (8.5%), Cyclospora spp. (7.0%), Blastocystis hominis (6.6%), Cystoisospora belli (6.6%), Endolimax nana (4.0%), Entamoeba coli (2.2%), Chilomastix mesnili (1.5%), Balantidium coli (1.1%) and Iodamoeba butschlii (1.1%); six species of helminths included Toxocara spp. (8.5%), Trichuris trichiura (6.3%), Ascaris lumbricoides (5.9%), Taenia spp. (5.1%), Strongyloides stercoralis (4.4%), and hookworm (2.2%). Unidentified species of the helminths were isolated, namely nematode larva (9.9%) and helminth eggs (3.7%). Our results show that the cockroaches collected from fresh markets are potential mechanical vectors of several protozoan and helminth species.

Parasite Infections, Allergy and Asthma: A Role for Tropomyosin in Promoting Type 2 Immune Responses

INTRODUCTION

The relationship of parasite infections and promotion or protection from allergy and asthma is controversial. Currently, over 1.5 billion people are infected with parasites worldwide, and Ascaris lumbricoides is the most frequent soil-transmitted helminth.

OBJECTIVES

To evaluate the biological activity of recombinant A. lumbricoides tropomyosin and investigate IgE cross-reactive responses to tropomyosins by means of microarray methodology for the detection of sensitization to allergen components.

METHODS

Forty patients 12-75 years of age (25 males) with asthma and/or rhinitis and 10 nonallergic control subjects participated in this study. All patients presented positive skin tests to cockroach extracts and underwent skin prick testing (SPT) with recombinant (r) tropomyosins rPer a 7 from Periplaneta americana and rAsc l 3 from A. lumbricoides, at 10 μg/mL. IgE to cockroach and parasite tropomyosins were measured by chimeric ELISA and ImmunoCAP-ISAC, and total IgE was quantitated by ImmunoCAP. Agreement of results was assessed by κ statistics.

RESULTS

Recombinant A. lumbricoides showed biological activity, inducing positive skin tests in 50% patients with asthma and/or rhinitis. IgE to cockroach and parasite tropomyosins were detected in 55-62% of patients. There was good-to-excellent agreement of results of SPT and IgE measurements by ELISA and ImmunoCAP-ISAC, with κ indices of 0.66-0.95. No skin test reactivity or IgE antibodies to tropomyosins were found in nonallergic individuals.

CONCLUSIONS

Our results suggest that IgE responses to tropomyosin from A. lumbricoides may enhance reactivity to homologous allergens upon exposure by inhalation or ingestion, promoting allergic reactions and asthma, or increasing the severity of these clinical conditions.

Antipyretic, anti-inflammatory and analgesic activities of Periplaneta americana extract and underlying mechanisms

Periplaneta americana is a common traditional Chinese medicinal material which has been used to treat arthritis, fever, aches, pains, and inflammation of the extremities for several hundred years. However, little scientific data exists in literature to support its use. The purpose of this study was to evaluate the antipyretic, anti-inflammatory and analgesic activities of Periplaneta americana extract (PAE) and explore its underlying mechanism. The antipyretic, anti-inflammatory and analgesic activities were evaluated by LPS-induced fever, carrageenan-induced paw edema, abdominal writhing, hot plate and formalin tests, respectively. The mechanism of action was explored by antioxidant activity analysis, inflammatory cytokines expression and febrile mediator measurement, and pathway activation analysis. The results from UHPLC-HRMS indicated that the extract was found to contain dopamine, coumarin, dipeptide, vitamin, organic acid, amino acid and its metabolites, and other organic compounds. PAE showed in a dose-dependent manner antioxidant activity and reduced the protein production and mRNA expression of NO, IL-1β, IL-6, and TNF-α in RAW 264.7 cells in vitro. Moreover, PAE significantly and dose-dependently inhibited the writhing responses and licking time in formalin tests, increased response latency in the hot plate test, reduced carrageenan-induced paw edema and inflammation in mice, decreased LPS-induced rT increase in rats. Furthermore, PAE treatment markedly inhibited the increase in the levels of NO, IL-6, IL-1β, TNF-α, PGE₂ and cAMP in plasma of fevered rat, greatly suppressed the activation of inflammatory response pathway and the change of MDA and GSH concentration, MPO and SOD activity as well as FRAP capacity in paw induced by carrageenan injection. In conclusion, the findings suggested that PAE produced potential antinociceptive, anti-inflammatory and antipyretic effects by reducing production of endogenous inflammatory mediators and blocking the MAPK/NF-κB signaling pathway which support the claim for its traditional use in the treatment of various diseases.

Update in Pediatric Asthma: Selected Issues

Asthma is a complex condition that affects 14% of the world's children and the approach to management includes both pharmacologic as well as non-pharmacologic strategies including attention to complex socioeconomic status phenomena. After an historical consideration of asthma, allergic and immunologic aspects of asthma in children and adolescents are presented. Concepts of socioeconomic aspects of asthma are considered along with environmental features and complications of asthma disparities. Also reviewed are links of asthma with mental health disorders, sleep disturbances and other comorbidities. A stepwise approach to asthma management is discussed that includes pharmacologic and non-pharmacologic strategies in the pediatric population. The role of immunotherapy and use of various immunomodulators are considered as well.

Rapid evolutionary responses to insecticide resistance management interventions by the German cockroach (Blattella germanica L.)

The German cockroach (Blattella germanica L.) is a worldwide pest that lives exclusively in human environments. B. germanica threatens human health by producing asthma-triggering allergens, vectoring pathogenic/antibiotic-resistant microbes, and by contributing to unhealthy indoor environments. While insecticides are essential for reducing cockroach populations and improving health outcomes, insecticide resistance has been a consistent barrier to cockroach control since the 1950s. We conducted seminal field studies to compare three insecticide resistance intervention strategies for cockroaches and evaluated resistance evolution across multiple generations. Using pre-treatment resistance assessment to drive decisions, we found that single active ingredient (AI) treatments can successfully eliminate cockroaches if starting resistance levels are low. We further established that rotation treatments intuitively reduce selection pressure, and are effective when insecticides with no/low resistance are used. We also found that mixture products containing thiamethoxam + λ-cyhalothrin AIs were universally ineffective and highly repellent; and finally, evolution of cross-resistance among AIs is a significant, previously unrealized challenge.

Natural occurrence in Argentina of a new fungal pathogen of cockroaches, Metarhizium argentinense sp. nov

The aim of this study was to search for entomopathogenic fungi that infect wild cockroaches in forest ecosystems in two protected natural areas of Argentina. Two isolates of Metarhizium argentinense were obtained and identified from wild cockroaches (Blaberidae: Epilamprinae) through the use of morphological characteristics and molecular phylogenetic analyses. This novel species was found in Argentina and is a member of the Metarhizium flavoviride species complex. Phylogenetic analyses, based on sequence similarity analysis using internal transcribed spacer (ITS) and a set of four protein-coding marker sequences (EF1A, RPB1, RPB2 and BTUB), supported the status of this fungus as a new species. In addition, we tested the biological activity of the new species through assays against Blattella germanica nymphs and found that the two evaluated isolates were pathogenic. However, isolate CEP424 was more virulent and caused a confirmed mortality of 76 % with a median lethal time of 7.2 d. This study reports the southernmost worldwide location of a Metarhizium species that infects cockroaches and will help expand the knowledge of the biodiversity of pathogenic fungi of Argentine cockroaches.

T cell epitopes of Per a 10 modulate local-systemic immune responses and airway inflammation by augmenting Th1 and T regulatory cell functions in murine model

Peptide immunotherapy (PIT) represents a safe and efficacious therapeutic modality for allergic diseases. Present study evaluates immunotherapeutic potential of T cell peptides of major cockroach allergen, Per a 10 in murine model of airway allergy. Treatment with peptides T-P8 and T-P10 demonstrated maximal resolution of pathophysiological features such as reduced recruitment of inflammatory cells to airways, lowered specific IgE, induction of IgG2a antibodies in serum, immune deviation towards Th1 cytokine milieu, suppression of Th2 cytokines in BALF and splenocyte culture supernatant and resolution of lung inflammation. A significant increase in CD4⁺Foxp3⁺ cells in spleen indicate towards induction of T regulatory cell mediated peripheral tolerance characterized by shift in cytokine milieu from Th2 to T regulatory cytokines. PIT modulates regulation of immune responses at both local and systemic levels, contributes towards holistic improvement in allergic features in mice and thus demonstrate potential for safe, specific and efficacious treatment for cockroach allergy.

Concordance of skin prick test and serum-specific IgE to locally produced component-resolved diagnostics for cockroach allergy

BACKGROUND

Diagnosis of Periplaneta americana (American cockroach, ACR) allergy is commonly performed based on clinical history and skin prick test (SPT) or specific serum IgE (sIgE) measurement. The concordance of the findings with the SPT and sIgE results has never been investigated.

OBJECTIVE

To compare the results of SPT with commercial ACR-extract (C-ACE) and sIgE measurement, using commercial kit and in-house enzyme-linked immunosorbent assay (ELISA) to the locally produced ACR extract (L-ACE) and native Per a 1, Per a 5, Per a 7, and Per a 9.

METHODS

Sera from 66 individuals clinically diagnosed with chronic allergic rhinitis were included; 46 were positive SPT to C-ACE, and 20 were negative. Specific serum IgE levels were established by using a commercial test kit (ImmunoCap) and an in-house IgE-ELISA RESULTS: The percentage the C-ACE SPT-positive cases that were positive by the ImmunoCap-sIgE was 32.6%, indicating low concordance of the 2 assays. With the in-house ELISA, Per a 9 gave the highest sensitivity (98.00%), positive predictive value (PPV; 95.74%), and negative predictive value (NPV; 94.74%) of the sIgE quantification. The correlation coefficients (R) of the L-ACE-SPT and sIgE to L-ACE, Per a 1, Per a 5, Per a 7, and Per a 9 and ImmunoCap sIgE were 0.133, 0.278, 0.419, 0.280, and 0.432, and 0.256, respectively.

CONCLUSION

Skin prick test and sIgE measurement using commercial reagents have low concordance. Data of this study showed that sIgE to the native Per a 9 should be considered as an adjunct to the clinical history in diagnosis of ACR sensitization/allergy, particularly when the SPT and the nasal challenge, which is the gold standard method, cannot be performed.

Bedroom Allergen Exposure Beyond House Dust Mites

PURPOSE OF REVIEW

The review provides insight into recent findings on bedroom allergen exposures, primarily focusing on pet, pest, and fungal exposures.

RECENT FINDINGS

Large-scale studies and improved exposure assessment technologies, including measurement of airborne allergens and of multiple allergens simultaneously, have extended our understanding of indoor allergen exposures and their impact on allergic disease. Practical, streamlined methods for exposure reduction have shown promise in some settings, and potential protective effects of early-life exposures have been further elucidated through the investigation of specific bacterial taxa. Advances in molecular allergology have yielded novel data on sensitization profiles and cross-reactivity. The role of indoor allergen exposures in allergic disease is complex and remains incompletely understood. Advancing our knowledge of various co-exposures, including the environmental and host microbiome, that interact with allergens in early life will be crucial for the development of efficacious interventions to reduce the substantial economic and social burden of allergic diseases including asthma.

FABP4 regulates eosinophil recruitment and activation in allergic airway inflammation

Fatty acid binding protein 4 (FABP4), a member of a family of lipid-binding proteins, is known to play a role in inflammation by virtue of its ability to regulate intracellular events such as lipid fluxes and signaling. Studies have indicated a proinflammatory role for FABP4 in allergic asthma although its expression and function in eosinophils, the predominant inflammatory cells recruited to allergic airways, were not investigated. We examined expression of FABP4 in murine eosinophils and its role in regulating cell recruitment in vitro as well as in cockroach antigen (CRA)-induced allergic airway inflammation. CRA exposure led to airway recruitment of FABP4-expressing inflammatory cells, specifically eosinophils, in wild-type (WT) mice. FABP4 expression in eosinophils was induced by TNF-α as well as IL-4 and IL-13. FABP4-deficient eosinophils exhibited markedly decreased cell spreading/formation of leading edges on vascular cell adhesion molecule-1 and significantly decreased adhesion to intercellular adhesion molecule-1 associated with reduced β2-integrin expression relative to WT cells. Furthermore, FABP4-deficient eosinophils exhibited decreased migration, F-actin polymerization, calcium flux, and ERK(1/2) phosphorylation in response to eotaxin-1. In vivo, CRA-challenged FABP4-deficient mice exhibited attenuated eosinophilia and significantly reduced airway inflammation (improved airway reactivity, lower IL-5, IL-13, TNF-α, and cysteinyl leukotriene C4 levels, decreased airway structural changes) compared with WT mice. In conclusion, expression of FABP4 in eosinophils is induced during conditions of inflammation and plays a proinflammatory role in the development of allergic asthma by promoting eosinophil adhesion and migration and contributing to the development of various aspects of airway inflammation.

Insect (food) allergy and allergens

Insects represent an alternative for meat and fish in satisfying the increasing demand for sustainable sources of nutrition. Approximately two billion people globally consume insects. They are particularly popular in Asia, Latin America, and Africa. Most research on insect allergy has focussed on occupational or inhalation allergy. Research on insect food safety, including allergenicity, is therefore of great importance. The objective of this review is to provide an overview of cases reporting allergy following insect ingestion, studies on food allergy to insects, proteins involved in insect allergy including cross-reactive proteins, and the possibility to alter the allergenic potential of insects by food processing and digestion. Food allergy to insects has been described for silkworm, mealworm, caterpillars, Bruchus lentis, sago worm, locust, grasshopper, cicada, bee, Clanis bilineata, and the food additive carmine, which is derived from female Dactylopius coccus insects. For cockroaches, which are also edible insects, only studies on inhalation allergy have been described. Various insect allergens have been identified including tropomyosin and arginine kinase, which are both pan-allergens known for their cross-reactivity with homologous proteins in crustaceans and house dust mite. Cross-reactivity and/or co-sensitization of insect tropomyosin and arginine kinase has been demonstrated in house dust mite and seafood (e.g. prawn, shrimp) allergic patients. In addition, many other (allergenic) species (various non-edible insects, arachnids, mites, seafoods, mammals, nematoda, trematoda, plants, and fungi) have been identified with sequence alignment analysis to show potential cross-reactivity with allergens of edible insects. It was also shown that thermal processing and digestion did not eliminate insect protein allergenicity. Although purified natural allergens are scarce and yields are low, recombinant allergens from cockroach, silkworm, and Indian mealmoth are readily available, giving opportunities for future research on diagnostic allergy tests and vaccine candidates.

RNA interference and functional characterization of a tergal gland alpha amylase in the German cockroach, Blattella germanica L

German cockroach males possess tergal glands that secrete a combination of oligosaccharides, lipids and proteins. Four major proteins occur in the secretion, with one being the 63 kDa alpha-amylase Blattella germanica Tergal Gland protein-1 (BGTG-1). Denaturing and starch gel electrophoresis coupled with peptide sequencing verified amylase activity for the BGTG-1 protein. BGTG-1 gene expression profiles were determined by using quantitative real-time PCR to compare messenger RNA abundance among isolated tissues of males, females and gravid females. Differences in BGTG-1 gene expression occurred among male tissues, with tergal gland tissue showing the highest expression. Tissues of nongravid and gravid females had significantly lower expression in comparison with male tergal glands (gravid females lowest). RNA interference (RNAi) was used to silence BGTG-1 gene expression by injecting BGTG-1 homologous double-stranded RNA (dsRNA) into male cockroaches. Groups injected with BGTG-1 dsRNA showed ∼90% lower BGTG-1 gene and protein expression compared to controls, which correlated with lower amylase activity in colorimetric assays. However, behavioural assays comparing precopulatory behaviour and mating success between RNAi and control males did not reveal differences. These results connect amylase gene expression and activity in tergal gland tissue but suggest other factors, such as other tergal gland components, may contribute more strongly to mating success.