Emerging cell and molecular targets for treating mucus hypersecretion in asthma.

Mucus provides a protective barrier that is crucial for host defense in the lungs. However, excessive or abnormal mucus can have pathophysiological consequences in many pulmonary diseases, including asthma. Patients with asthma are treated with agents that relax airway smooth muscle and reduce airway inflammation, but responses are often inadequate. In part, this is due to the inability of existing therapeutic agents to directly target mucus. Accordingly, there is a critical need to better understand how mucus hypersecretion and airway plugging are affected by the epithelial cells that synthesize, secrete, and transport mucus components. This review highlights recent advances in the biology of mucin glycoproteins with a specific focus on MUC5AC and MUC5B, the chief macromolecular components of airway mucus. An improved mechanistic understanding of key steps in mucin production and secretion will help reveal novel potential therapeutic strategies.

The disulfide catalyst QSOX1 maintains the colon mucosal barrier by regulating Golgi glycosyltransferases.

Mucus is made of enormous mucin glycoproteins that polymerize by disulfide crosslinking in the Golgi apparatus. QSOX1 is a catalyst of disulfide bond formation localized to the Golgi. Both QSOX1 and mucins are highly expressed in goblet cells of mucosal tissues, leading to the hypothesis that QSOX1 catalyzes disulfide-mediated mucin polymerization. We found that knockout mice lacking QSOX1 had impaired mucus barrier function due to production of defective mucus. However, an investigation on the molecular level revealed normal disulfide-mediated polymerization of mucins and related glycoproteins. Instead, we detected a drastic decrease in sialic acid in the gut mucus glycome of the QSOX1 knockout mice, leading to the discovery that QSOX1 forms regulatory disulfides in Golgi glycosyltransferases. Sialylation defects in the colon are known to cause colitis in humans. Here we show that QSOX1 redox control of sialylation is essential for maintaining mucosal function.

Epithelial immunomodulation by aerosolized Toll-like receptor agonists prevents allergic inflammation in airway mucosa in mice.

Allergic asthma is a chronic inflammatory respiratory disease associated with eosinophilic infiltration, increased mucus production, airway hyperresponsiveness, and airway remodeling. Epidemiologic data reveal that the prevalence of allergic sensitization and associated diseases has increased in the twentieth century. This has been hypothesized to be partly due to reduced contact with microbial organisms (the hygiene hypothesis) in industrialized society. Airway epithelial cells, once considered a static physical barrier between the body and the external world, are now widely recognized as immunologically active cells that can initiate, maintain, and restrain inflammatory responses, such as those that mediate allergic disease. Airway epithelial cells can sense allergens via expression of myriad Toll-like receptors (TLRs) and other pattern-recognition receptors. We sought to determine whether the innate immune response stimulated by a combination of Pam2CSK4 ("Pam2", TLR2/6 ligand) and a class C oligodeoxynucleotide ODN362 ("ODN", TLR9 ligand), when delivered together by aerosol ("Pam2ODN"), can modulate the allergic immune response to allergens. Treatment with Pam2ODN 7 days before sensitization to House Dust Mite (HDM) extract resulted in a strong reduction in eosinophilic and lymphocytic inflammation. This Pam2ODN immunomodulatory effect was also seen using Ovalbumin (OVA) and A. oryzae (Ao) mouse models. The immunomodulatory effect was observed as much as 30 days before sensitization to HDM, but ineffective just 2 days after sensitization, suggesting that Pam2ODN immunomodulation lowers the allergic responsiveness of the lung, and reduces the likelihood of inappropriate sensitization to aeroallergens. Furthermore, Pam2 and ODN cooperated synergistically suggesting that this treatment is superior to any single agonist in the setting of allergen immunotherapy.

Mucins MUC5AC and MUC5B Are Variably Packaged in the Same and in Separate Secretory Granules.

Rationale: MUC5AC (mucin 5AC, oligomeric gel-forming) and MUC5B (mucin 5B, oligomeric gel-forming) are the predominant secreted polymeric mucins in mammalian airways. They contribute differently to the pathogenesis of various muco-obstructive and interstitial lung diseases, and their genes are separately regulated, but whether they are packaged together or in separate secretory granules is not known. Objectives: To determine the packaging of MUC5AC and MUC5B within individual secretory granules in mouse and human airways under varying conditions of inflammation and along the proximal-distal axis. Methods: Lung tissue was obtained from mice stimulated to upregulate mucin production by the cytokines IL-1ß and IL-13 or by porcine pancreatic elastase. Human lung tissue was obtained from donated normal lungs, biopsy samples of transplanted lungs, and explanted lungs from subjects with chronic obstructive pulmonary disease. MUC5AC and MUC5B were labeled with antibodies from different animal species or, in mice only, by transgenic chimeric mucin-fluorescent proteins and imaged using widefield deconvolution or Airyscan fluorescence microscopy. Measurements and Main Results: In both mouse and human airways, most secretory granules contained both mucins interdigitating within the granules. Smaller numbers of granules contained MUC5B alone, and even fewer contained MUC5AC alone. Conclusions: MUC5AC and MUC5B are variably stored both in the same and in separate secretory granules of both mice and humans. The high fraction of granules containing both mucins under a variety of conditions makes it unlikely that their secretion can be differentially controlled as a therapeutic strategy. This work also advances knowledge of the packaging of mucins within secretory granules to understand mechanisms of epithelial stress in the pathogenesis of chronic lung diseases.

Mucus.

Mucus is a slimy hydrogel that lines the mucosal surfaces in our body, including the intestines, stomach, eyes, lungs and urogenital tract. This glycoprotein-rich network is truly the jack of all trades. As a barrier, it lubricates surfaces, protects our cells from physical stress, and selectively allows the passage of nutrients while clearing out pathogens and debris. As a home to our microbiota, it supports a level of microbial diversity that is unattainable with most culture methods. As a reservoir of complex carbohydrate structures called glycans, it plays critical roles in controlling cell adhesion and signaling, and it alters the behavior and spatial distribution of microbes. On top of all this, mucus regulates the passage of sperm during fertilization, heals wounds, helps us smell, and prevents the stomach from digesting itself, to name just a few of its functions. Given these impressive features, it is no wonder that mucus crosses boundaries of species and kingdoms - mucus gels are made by organisms ranging from the simplest metazoans to corals, snails, fish, and frogs. It is also no surprise that mucus is exploited in everyday applications, including foods, cosmetics, and other products relevant to medicine and industry.

Disulfide disruption reverses mucus dysfunction in allergic airway disease.

Airway mucus is essential for lung defense, but excessive mucus in asthma obstructs airflow, leading to severe and potentially fatal outcomes. Current asthma treatments have minimal effects on mucus, and the lack of therapeutic options stems from a poor understanding of mucus function and dysfunction at a molecular level and in vivo. Biophysical properties of mucus are controlled by mucin glycoproteins that polymerize covalently via disulfide bonds. Once secreted, mucin glycopolymers can aggregate, form plugs, and block airflow. Here we show that reducing mucin disulfide bonds disrupts mucus in human asthmatics and reverses pathological effects of mucus hypersecretion in a mouse allergic asthma model. In mice, inhaled mucolytic treatment loosens mucus mesh, enhances mucociliary clearance, and abolishes airway hyperreactivity (AHR) to the bronchoprovocative agent methacholine. AHR reversal is directly related to reduced mucus plugging. These findings establish grounds for developing treatments to inhibit effects of mucus hypersecretion in asthma.

The Midgut Microbiota of Colombian Aedes aegypti Populations with Different Levels of Resistance to the Insecticide Lambda-cyhalothrin.

Insecticide resistance in Aedes aegypti populations is a problem that hinders vector control and dengue prevention programs. In this study, we determined the susceptibility of Ae. aegypti populations from six Colombian regions to the pyrethroid lambda-cyhalothrin and evaluated the presence of the V1016I mutation in the sodium channel gene, which has been broadly involved in the resistance to this insecticide. The diversity of the gut microbiota of these mosquito populations was also analyzed. Only mosquitoes from Bello were susceptible to lambda-cyhalothrin and presented a lower allelic frequency of the V1016I mutation. Remarkably, there was not an important change in allelic frequencies among populations with different resistance ratios, indicating that other factors or mechanisms contributed to the resistant phenotype. Treatment of mosquitoes with antibiotics led us to hypothesize that the intestinal microbiota could contribute to the resistance to lambda-cyhalothrin. Beta diversity analysis showed significant differences in the species of bacteria present between susceptible and resistant populations. We identified 14 OTUs of bacteria that were unique in resistant mosquitoes. We propose that kdr mutations are important in the development of resistance to lambda-cyhalothrin at low insecticide concentrations but insect symbionts could play an essential role in the metabolization of pyrethroid insecticides at higher concentrations, contributing to the resistant phenotype in Ae. aegypti.

Immune Modulation to Improve Survival of Viral Pneumonia in Mice.

Viral pneumonias remain global health threats, as exemplified in the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic, requiring novel treatment strategies both early and late in the disease process. We have reported that mice treated before or soon after infection with a combination of inhaled Toll-like receptor (TLR) 2/6 and 9 agonists (Pam2-ODN) are broadly protected against microbial pathogens including respiratory viruses, but the mechanisms remain incompletely understood. The objective of this study was to validate strategies for immune modulation in a preclinical model of viral pneumonia and determine their mechanisms. Mice were challenged with the Sendai paramyxovirus in the presence or absence of Pam2-ODN treatment. Virus burden and host immune responses were assessed to elucidate Pam2-ODN mechanisms of action and to identify additional opportunities for therapeutic intervention. Enhanced survival of Sendai virus pneumonia with Pam2-ODN treatment was associated with reductions in lung virus burden and with virus inactivation before internalization. We noted that mortality in sham-treated mice corresponded with CD8+ T-cell lung inflammation on days 11-12 after virus challenge, after the viral burden had declined. Pam2-ODN blocked this injurious inflammation by minimizing virus burden. As an alternative intervention, depleting CD8+ T cells 8 days after viral challenge also decreased mortality. Stimulation of local innate immunity within the lungs by TLR agonists early in disease or suppression of adaptive immunity by systemic CD8+ T-cell depletion late in disease improves outcomes of viral pneumonia in mice. These data reveal opportunities for targeted immunomodulation to protect susceptible human subjects.

Pregnancy in teenagers with heart disease / Embarazo en pacientes adolescentes con cardiopatía

Abstract The prevalence of pregnancy in adolescent women is high in Mexico and represents a public health problem. The pregnant teenager with heart disease has a high probability of complications during pregnancy and the delivery, which carries a risk of death of both the mother and the product. In many cases the pregnancy should have been avoided, planned or interrupted, however the majority at this age is vulnerable and although certain cases must be interrupted by their high risk of maternal-fetal death, prevention and legal aspects should be considered. In some cases the woman wants a pregnancy although her health condition does not allow it, but there are options of adoption or recourse to a surrogate belly. In response to this growing social problem, the National Cardiology Institute Ignacio Chávez and National Institute of Perinatology, with the coordination of Ministry of Health in Mexico, started a pregnancy prevention module within a clinic of follow-up of cardiopathy and pregnancy. This review raises the global problem in our country that occupies the first place in pregnancies in adolescents, with more than 400,000 pregnancies a year and the form of immediate response in a multidisciplinary way.

Resumen La prevalencia de embarazo en mujeres adolescentes es muy alta en México, y representa un problema de salud pública. La adolescente embarazada con cardiopatía tiene altas posibilidades de complicaciones durante el embarazo y su resolución, lo que pone en riesgo la vida tanto de la madre como del producto. En muchos casos el embarazo debió ser evitado, planeado o interrumpido, sin embargo la mayoría a esta edad es vulnerable y si bien ciertos casos deben ser interrumpidos por su alto riesgo de muerte materno-fetal, es fundamental considerar la prevención y los aspectos legales. En algunos casos la mujer desea un embarazo aunque su condición de salud no se lo permite, pero existen opciones de adopción o recurrir a un vientre subrogado. Atendiendo este problema social cada vez más creciente, el Instituto Nacional de Cardiología Ignacio Chávez, en coordinación con la Comisión Coordinadora de la Secretaría de Salud y el Instituto Nacional de Perinatología, echaron a andar un módulo de prevención de embarazo dentro de una clínica de seguimiento de cardiopatía y embarazo. Esta revisión plantea el problema global en nuestro país, que ocupa el primer lugar en embarazos en adolescentes, con más de 400 mil embarazos al año y la forma de dar respuesta inmediata de manera multidisciplinaria.

Inducible epithelial resistance against acute Sendai virus infection prevents chronic asthma-like lung disease in mice.

BACKGROUND AND PURPOSE: Respiratory viral infections play central roles in the initiation, exacerbation and progression of asthma in humans. An acute paramyxoviral infection in mice can cause a chronic lung disease that resembles human asthma. We sought to determine whether reduction of Sendai virus lung burden in mice by stimulating innate immunity with aerosolized Toll-like receptor (TLR) agonists could attenuate the severity of chronic asthma-like lung disease. EXPERIMENTAL APPROACH: Mice were treated by aerosol with 1-µM oligodeoxynucleotide (ODN) M362, an agonist of the TLR9 homodimer, and 4-µM Pam2CSK4 (Pam2), an agonist of the TLR2/6 heterodimer, within a few days before or after Sendai virus challenge. KEY RESULTS: Treatment with ODN/Pam2 caused ~75% reduction in lung Sendai virus burden 5 days after challenge. The reduction in acute lung virus burden was associated with marked reductions 49 days after viral challenge in eosinophilic and lymphocytic lung inflammation, airway mucous metaplasia, lumenal mucus occlusion and hyperresponsiveness to methacholine. Mechanistically, ODN/Pam2 treatment attenuated the chronic asthma phenotype by suppressing IL-33 production by type 2 pneumocytes, both by reducing the severity of acute infection and by down-regulating Type 2 (allergic) inflammation. CONCLUSION AND IMPLICATIONS: These data suggest that treatment of susceptible human hosts with aerosolized ODN and Pam2 at the time of a respiratory viral infection might attenuate the severity of the acute infection and reduce initiation, exacerbation and progression of asthma.

Pregnancy in teenagers with heart disease.

The prevalence of pregnancy in adolescent women is high in Mexico and represents a public health problem. The pregnant teenager with heart disease has a high probability of complications during pregnancy and the delivery, which carries a risk of death of both the mother and the product. In many cases the pregnancy should have been avoided, planned or interrupted, however the majority at this age is vulnerable and although certain cases must be interrupted by their high risk of maternal-fetal death, prevention and legal aspects should be considered. In some cases the woman wants a pregnancy although her health condition does not allow it, but there are options of adoption or recourse to a surrogate belly. In response to this growing social problem, the National Cardiology Institute Ignacio Chávez and National Institute of Perinatology, with the coordination of Ministry of Health in Mexico, started a pregnancy prevention module within a clinic of follow-up of cardiopathy and pregnancy. This review raises the global problem in our country that occupies the first place in pregnancies in adolescents, with more than 400,000 pregnancies a year and the form of immediate response in a multidisciplinary way.

La prevalencia de embarazo en mujeres adolescentes es muy alta en México, y representa un problema de salud pública. La adolescente embarazada con cardiopatía tiene altas posibilidades de complicaciones durante el embarazo y su resolución, lo que pone en riesgo la vida tanto de la madre como del producto. En muchos casos el embarazo debió ser evitado, planeado o interrumpido, sin embargo la mayoría a esta edad es vulnerable y si bien ciertos casos deben ser interrumpidos por su alto riesgo de muerte materno-fetal, es fundamental considerar la prevención y los aspectos legales. En algunos casos la mujer desea un embarazo aunque su condición de salud no se lo permite, pero existen opciones de adopción o recurrir a un vientre subrogado. Atendiendo este problema social cada vez más creciente, el Instituto Nacional de Cardiología Ignacio Chávez, en coordinación con la Comisión Coordinadora de la Secretaría de Salud y el Instituto Nacional de Perinatología, echaron a andar un módulo de prevención de embarazo dentro de una clínica de seguimiento de cardiopatía y embarazo. Esta revisión plantea el problema global en nuestro país, que ocupa el primer lugar en embarazos en adolescentes, con más de 400 mil embarazos al año y la forma de dar respuesta inmediata de manera multidisciplinaria.

Evaluation of an alternative indirect-ELISA test using in vitro-propagated Trypanosoma brucei brucei whole cell lysate as antigen for the detection of anti-Trypanosoma evansi IgG in Colombian livestock.

Surra is a zoonotic disease caused by Trypanosoma evansi, affecting the health and production of the livestock significantly. There are several methods to diagnose this disease, which have different principles, sensitivity, and specificity. Among them, the serological techniques using T. evansi as antigen are powerful tools for its epidemiological surveillance. However, they are poorly used due to inefficient in vitro propagation of T. evansi, which requires the use of laboratory animals for antigen production. In the present study, whole cell lysate of T. brucei brucei propagated in vitro was used as an antigen for the detection of anti-T. evansi immunoglobulin G in cattle through an indirect-ELISA. Based on a total of 45 samples from non-infected and 45 samples from T. evansi infected cattle, the sensitivity and specificity were estimated as 100% and 97.7%, respectively. After the validation, serological and molecular surveys were carried out in 710 cattle samples from two endemic Colombian regions (Antioquia and Arauca departments) for T. evansi where molecular prevalences of ˜7.0% were detected through the year and sporadic outbreaks of T. vivax infections have been associated to low prevalence of this species (<1%). A total of 424 (59.7%) samples were positive by indirect-ELISA T. b. brucei, while PCR test for T. evansi and T. vivax, showed 49 (6.9%) and no positive samples, respectively. Interestingly, categories of animals aged>1 year, Bos taurus breed, and those raised under intensive farming system exhibited a higher seroprevalence to T. evansi (P < 0.05). The results displayed a new alternative for antibody detection anti-T. evansi in livestock, using parasites propagated in vitro as antigen, which presents the advantage of higher standardization potential, and avoid the use of live animal for antigen production. A larger availability of this ELISA will generate useful information for a better understanding of the epidemiologic aspects, as well as for the management and control of these diseases in Colombia. However, the ability of the test to detect and/or cross react with T. vivax infections remains to be investigated.

Different Munc18 proteins mediate baseline and stimulated airway mucin secretion.

Airway mucin secretion is necessary for ciliary clearance of inhaled particles and pathogens but can be detrimental in pathologies such as asthma and cystic fibrosis. Exocytosis in mammals requires a Munc18 scaffolding protein, and airway secretory cells express all 3 Munc18 isoforms. Using conditional airway epithelial cell-deletant mice, we found that Munc18a has the major role in baseline mucin secretion, Munc18b has the major role in stimulated mucin secretion, and Munc18c does not function in mucin secretion. In an allergic asthma model, Munc18b deletion reduced airway mucus occlusion and airflow resistance. In a cystic fibrosis model, Munc18b deletion reduced airway mucus occlusion and emphysema. Munc18b deficiency in the airway epithelium did not result in any abnormalities of lung structure, particle clearance, inflammation, or bacterial infection. Our results show that regulated secretion in a polarized epithelial cell may involve more than one exocytic machine at the apical plasma membrane and that the protective roles of mucin secretion can be preserved while therapeutically targeting its pathologic roles.

Inflammation-induced upregulation of P2X4 expression augments mucin secretion in airway epithelia.

Mucus clearance provides an essential innate defense mechanism to keep the airways and lungs free of particles and pathogens. Baseline and stimulated mucin secretion from secretory airway epithelial cells need to be tightly regulated to prevent mucus hypersecretion and mucus plugging of the airways. It is well established that extracellular ATP is a potent stimulus for regulated mucus secretion. Previous studies revealed that ATP acts via metabotropic P2Y2 purinoreceptors on goblet cells. Extracellular ATP, however, is also a potent agonist for ionotropic P2X purinoreceptors. Expression of several P2X isoforms has been reported in airways, but cell type-specific expression and the function thereof remained elusive. With this study, we now provide evidence that P2X4 is the predominant P2X isoform expressed in secretory airway epithelial cells. After IL-13 treatment of either human primary tracheal epithelial cells or mice, P2X4 expression is upregulated in vitro and in vivo under conditions of chronic inflammation, mucous metaplasia, and hyperplasia. Upregulation of P2X4 is strongest in MUC5AC-positive goblet cells. Moreover, activation of P2X4 by extracellular ATP augments intracellular Ca2+ signals and mucin secretion, whereas Ca2+ signals and mucin secretion are dampened by inhibition of P2X4 receptors. These data provide new insights into the purinergic regulation of mucin secretion and add to the emerging picture that P2X receptors modulate exocytosis of large secretory organelles and secretion of macromolecular vesicle cargo.

Airway Mucin Secretion.

Exocytosis of secreted mucins is the final step in their intracellular processing, resulting in their release into the airway lumen to interact with water and ions to form mucus. Mucins are secreted at a low baseline rate and a high stimulated rate, and both rates are regulated by second messengers acting on components of the exocytic machinery. The principal physiologic function of the low baseline rate is to support steady-state mucociliary clearance of inhaled particles and pathogens that enter the airways during normal breathing. Even in the setting of mucin hyperproduction, baseline secretion generally does not induce mucus occlusion. The principal physiologic function of the high stimulated rate of secretion from both submucosal glands and surface goblet cells in proximal airways appears to be to sweep away larger particles, whereas in distal airways it appears to act in concert with mucin hyperproduction to induce mucus occlusion to trap migrating helminths. Pathophysiologically, stimulated mucin secretion in the setting of mucin hyperproduction from allergic or other types of airway inflammation in the absence of helminth infection causes airflow obstruction and infection. Molecular components of the mucin exocytic machinery are increasingly being identified, and surprisingly, many components are not shared between baseline and stimulated machines. The physiologic significance of the presence of two distinct molecular machines is not yet known, such as whether these interact selectively with secretory granules of different sizes or contents. A full understanding of the mechanism and regulation of airway mucin secretion will provide further insight into pathophysiologic processes and may identify therapeutic strategies to alleviate obstructive airway diseases.

Molecular surveillance and phylogenetic traits of Babesia bigemina and Babesia bovis in cattle (Bos taurus) and water buffaloes (Bubalus bubalis) from Colombia.

BACKGROUND: Babesia bigemina and B. bovis are two economically important hemoparasites affecting both cattle and buffaloes involved in dairy and beef production. In Colombia, although some parasitological and serological studies suggest an endemicity of these pathogens in areas under 1000 m, little is known about its molecular prevalence in different host. The objective of this study was to estimate the prevalence and molecular traits of these parasites in cattle and buffaloes from two Colombian regions. METHODS: Between 2014 and 2016, a three-point longitudinal survey was designed in farms from Caribbean and Orinoquia regions to evaluate the molecular prevalence of B. bigemina and B. bovis using a nested PCR (n-PCR) targeting hypothetical protein (hyp) and rhoptry-associated protein (RAP-1) genes, respectively. A total of 1432 cattle, 152 buffalo and 1439 Rhipicephalus microplus samples were analyzed. Moreover, phylogenetic relationship of isolates was analyzed using the 18S rRNA gene. RESULTS: A molecular prevalence of 31.6% (24.2% for B. bigemina and 14.4% for B. bovis), 23.6% (6.5% for B. bigemina and 17.7% for B. bovis) and 4.3% (3.5% for B. bigemina and 1.0% for B. bovis) was observed in cattle, buffaloes and Rhipicephalus microplus, respectively. Higher values of infection were observed during the wet season and late wet season; nevertheless, other variables such as age, production type, sex, breed and babesiosis control were also significantly associated with infection. Prevalence analysis showed that B. bovis infection was higher in cattle that coexist with buffaloes, when compared to those which did not. For each species, phylogenetic analyses revealed a high genetic diversity of isolates without clusters related to the isolation source. CONCLUSIONS: To our knowledge, this is the first longitudinal survey that evaluates through molecular methods, the infection of B. bigemina and B. bovis in two important livestock regions from Colombia. This study reveals that the prevalence of infection by Babesia spp., in cattle and buffaloes are modulated by seasonal variations, host factors and vector traits. Our results provide new insights on the epidemiological aspects of infection of Babesia spp., in cattle and buffaloes, which must be taken into consideration when babesiosis control programs are implemented in the study area.

Ascaris Larval Infection and Lung Invasion Directly Induce Severe Allergic Airway Disease in Mice.

Ascaris lumbricoides (roundworm) is the most common helminth infection globally and a cause of lifelong morbidity that may include allergic airway disease, an asthma phenotype. We hypothesize that Ascaris larval migration through the lungs leads to persistent airway hyperresponsiveness (AHR) and type 2 inflammatory lung pathology despite resolution of infection that resembles allergic airway disease. Mice were infected with Ascaris by oral gavage. Lung AHR was measured by plethysmography and histopathology with hematoxylin and eosin (H&E) and periodic acid-Schiff (PAS) stains, and cytokine concentrations were measured by using Luminex Magpix. Ascaris-infected mice were compared to controls or mice with allergic airway disease induced by ovalbumin (OVA) sensitization and challenge (OVA/OVA). Ascaris-infected mice developed profound AHR starting at day 8 postinfection (p.i.), peaking at day 12 p.i. and persisting through day 21 p.i., despite resolution of infection, which was significantly increased compared to controls and OVA/OVA mice. Ascaris-infected mice had a robust type 2 cytokine response in both the bronchoalveolar lavage (BAL) fluid and lung tissue, similar to that of the OVA/OVA mice, including interleukin-4 (IL-4) (P < 0.01 and P < 0.01, respectively), IL-5 (P < 0.001 and P < 0.001), and IL-13 (P < 0.001 and P < 0.01), compared to controls. By histopathology, Ascaris-infected mice demonstrated early airway remodeling similar to, but more profound than, that in OVA/OVA mice. We found that Ascaris larval migration causes significant pulmonary damage, including AHR and type 2 inflammatory lung pathology that resembles an extreme form of allergic airway disease. Our findings indicate that ascariasis may be an important cause of allergic airway disease in regions of endemicity.

Genetic, host and environmental factors associated with a high prevalence of Anaplasma marginale.

Anaplasma marginale is the most prevalent vector-borne pathogen in the livestock industry in Colombia, causing economic losses of approximately USD 4.2 million per year. The present study reports the seasonal transmission patterns, genetic diversity and phylogeographic traits of A. marginale strains in cattle and buffaloes from Colombian livestock areas. A three-point longitudinal survey was designed to evaluate the above characteristics of farms in the Caribbean and Orinoquía regions. The A. marginale prevalence was evaluated in 1432 cattle blood samples, 152 buffalo blood samples and the hemolymph of 439 ticks using semi-nested PCR (sn-PCR) targeting the msp5 gene. The molecular prevalence in cattle and buffaloes was 54.8% and 13.1%, respectively, with higher values during the wet and late wet seasons. Factors such as age and production system were significantly associated with the infection. Rhipicephalus microplus was the only carrier of A. marginale DNA, with an infection rate of 17.2%. On the other hand, the tandem repeat and microsatellite analyses of the msp1α gene showed high genetic diversity and new tandem repeats that suggested strain adaptation to different transmission modes. Phylogeographic analysis using the msp4 gene showed a relationship between Colombian isolates and Mexican, Brazilian, Venezuelan, European and Asian isolates, as well as two worldwide haplogroups that were associated with the geographical origin of each isolate. In conclusion, this study shows that A. marginale occurs under enzootic stability in both hosts, with a high prevalence of infection during wet months and in animals dedicated to beef production. The genetic variability analyses suggest that a high strain diversity is associated with multiple selective pressures in the study area, while phylogeographic traits suggest a high genetic similarity between Mexican and South American strains.