Association of serum pertussis antibodies with acute asthma attacks in children.

Objective: The aim of this study was to examine the serum antibody levels against pertussis toxin (PT) in children experiencing an acute asthma attack and to explore the potential association between these levels and asthma. Methods: A prospective investigation was conducted, which involved 107 children with acute asthma attacks and 77 children diagnosed with bronchitis. The serum immunoglobulin G (IgG) antibody levels specific to PT were measured by using an in-house enzyme-linked immunosorbent assay. Based on the serum PT-IgG antibody levels, the children with asthma were categorized into three groups: non-pertussis infected, suspected pertussis infected, and recent pertussis infected. The clinical manifestations and pulmonary function of pediatric patients diagnosed with asthma were assessed and compared across various groups. Results: Of the total asthma group, 25 patients tested positive for PT-IgG, whereas only six patients in the bronchitis group were PT-IgG positive. The prevalence of recent pertussis infection was observed to be higher in the asthma group compared with the bronchitis group. Within the asthma group, those with recent pertussis infection exhibited a higher likelihood of experiencing wheezing and impaired lung function in comparison with the non-pertussis infection group. Conclusion: Pertussis infection is relatively common in children with asthma and correlates with the severity of asthma.

[Sero-epidemiological study and infection rate evaluation of pertussis in Henan Province].

Objective: To analyze the epidemiological distribution characteristics, influencing factors, and infection rates of pertussis in the population of Henan Province. Methods: From 2022 to 2023, a cross-sectional survey was conducted to investigate the permanent population in Henan Province. Enzyme-linked immunosorbent assay (ELISA) was used to detect anti-pertussis toxin IgG (PT-IgG), analyze the antibody positivity rate (≥20 IU/ml) and median concentration (MC), and estimate the pertussis infection rate based on PT IgG ≥40 IU/ml. The rank sum test was used to compare antibody levels among groups, and the χ2 test was used to compare antibody positive rates and infection rates among groups. Results: A total of 4 810 research subjects were included in this study. The overall positive rate of PT-IgG was 12.10% and MC was 3.04 (0.35, 10.36) IU/ml. There were significant differences both in positive rates and antibody levels of PT-IgG among different regions or age groups (region positive rate: χ2=134.06, P<0.001, MC: H=337.74, P<0.001; age group positive rate: χ2=45.27, P<0.001, MC: H=134.49, P<0.001). Both the positive rate of PT-IgG (25.26%) and MC (8.01 IU/ml) were the highest within one year after completing a full course of vaccination. There were significant differences in positive rates and antibody levels among people receiving different types of pertussis vaccines (positive rate: χ2=12.38, P=0.006, MC: H=17.93, P<0.001). The antibody positivity rate (35.71%) and MC (8.88 IU/ml) of the people who received cell-free pertussis inactivated poliomyelitis influenza type b (combined) vaccine throughout the course were higher than those who received other types of vaccines. The natural infection rate of pertussis was evaluated for individuals aged≥3 years who had no history of pertussis vaccine immunization within the year prior to sampling. With a high vaccination rate, the estimated infection rate of pertussis in the population was 5 757.22/100 000. The infection rates in the 3-year-old (1 940.16/100 000) and 4-year-old (1 765.68/100 000) populations were at a low level among the entire population, reaching their peak at the age of 6 (12 656.71/100 000). Subsequently, although the infection rate continued to decline, it remained at a high level and peaked again at the age of 40-49 years (8 740.39/100 000). There was a statistically significant difference in the estimated infection rate of pertussis among different age groups (χ2=53.21, P<0.001). Conclusion: The PT-IgG level of pertussis in the population of Henan Province is generally at a low level. The estimated infection rate of pertussis is much higher than the reported incidence rate. A booster dose of pertussis vaccine is recommended at 6 years old.

Seroepidemiology of pertussis in Huzhou: A population-based, cross-sectional study.

PURPOSE: The resurgence of pertussis has occurred around the world. However, the epidemiological profiles of pertussis cannot be well understood by current diseases surveillance. This study was designed to understand the seroepidemiological characteristics of pertussis infection in the general population of Huzhou City, evaluate the prevalence infection of pertussis in the population, and offer insights to inform adjustments in pertussis prevention and control strategies. METHODS: From September to October 2023, a cross-sectional serosurvey was conducted in Huzhou City, involving 1015 permanent residents. Serum samples were collected from the study subjects, and pertussis toxin IgG antibodies (Anti-PT-IgG) were quantitatively measured using enzyme-linked immunosorbent assay (ELISA). The analysis included the geometric mean concentration (GMC) of Anti-PT-IgG, rates of GMC≥40IU/mL, ≥100IU/mL, and <5IU/mL. Stratified comparisons were made based on age, vaccination history, and human categories. RESULTS: Among the 1015 surveyed individuals, the geometric mean concentration (GMC) of Anti-PT-IgG was 10.52 (95% CI: 9.96-11.11) IU/mL, with a recent infection rate of 1.58%, a serum positivity rate of 11.43%, and a proportion with <5IU/mL of 40.49%. Among 357 children with clear vaccination history, susceptibility decreased with an increasing number of vaccine doses (Z = -6.793, P < 0.001). The concentration of Anti-PT-IgG exhibited a significant post-vaccination decline over time (Z = -5.143, P < 0.001). In women of childbearing age, the GMC of Anti-PT-IgG was 7.71 (95% CI: 6.90-8.62) IU/mL, with no significant difference in susceptibility among different age groups (χ2 = 0.545, P = 0.909). The annual pertussis infection rate in individuals aged ≥3 years was 9321 (95%CI: 3336-16039) per 100,000, with peak infection rates in the 20-29, 40-49, and 5-9 age groups at 34363 (95%CI: 6327-66918) per 100,000, 22307.72 (95%CI: 1380-47442) per 100,000, and 18020(95%CI: 1093-37266) per 100,000, respectively. CONCLUSIONS: In 2023, the actual pertussis infection rate in the population of Huzhou City was relatively high. Vaccine-induced antibodies exhibit a rapid decay, and the estimated serum infection rate increases rapidly from post-school age, peaking in the 20-29 age group. It is recommended to enhance pertussis monitoring in adolescents and adults and refine vaccine immunization strategies.

Seroprevalence of IgG antibodies against pertussis toxin in the Chinese population: A systematic review and meta-analysis.

Pertussis is a vaccine-preventable infectious disease; however, data on pertussis antibody levels in a nationwide population are still limited in China. We aimed to pool the seropositivity rates of IgG antibodies against pertussis toxin (PT-IgG) across the country. We systematically searched PubMed, Web of Science, Embase, and the China National Knowledge Infrastructure Database for studies published between January 1, 2010, and June 30, 2023. Studies reporting the seroprevalence of PT-IgG among a healthy Chinese population were included. Pooled estimates were obtained using random-effects meta-analyzes. The meta-analysis included 39 studies (47,778 participants) reporting anti-PT IgG seropositivity rates. The pooled rate for all ages was 7.06% (95% CI, 5.50%-9.07%). Subgroup analyzes showed rates ranging from 6.36% to 12.50% across different age groups. This meta-analysis indicated a low anti-PT IgG seropositivity rate in the Chinese population, particularly among school-aged children and young adults. This finding underscores the urgent need to refine immunization strategies.

Transplacental transfer of maternal antibodies following immunization with recombinant pertussis vaccines during pregnancy: Real-world evidence.

AIM/OBJECTIVE: This study investigates placental antibody transfer following recombinant pertussis vaccination in pregnancy in a real-world setting. METHODS: This postmarketing observational study recruited pregnant women vaccinated with monovalent recombinant acellular pertussis (aP) vaccine (aPgen; n = 199) or combined to tetanus-diphtheria (TdaPgen; n = 200), or Td-vaccine only (n = 54). Pregnancy, delivery, and neonatal outcomes were assessed. Cord blood was collected postdelivery and pertussis toxin (PT)-IgG, filamentous hemagglutinin (FHA)-IgG, and PT-neutralizing antibodies (PT-Nab) were assessed. RESULTS: No adverse pregnancy, delivery, or neonatal outcomes attributed to aPgen, TdaPgen, or Td vaccination were reported. High anti-PT antibody levels were detected in cord samples from women vaccinated with aPgen (geometric mean concentration [GMC] PT-IgG 206.1 IU/ml, 95% confidence intervals [CI]: 164.3-258.6; geometric mean titer [GMT] PT-Nab 105.3 IU/ml, 95% CI: 81.7-135.8) or TdaPgen (GMC PT-IgG 153.1 IU/ml, 95% CI: 129.1-181.5; GMT PT-Nab 81.5 IU/ml, 95% CI: 66.4-100.0). In the Td-only group, anti-PT antibodies were low (GMC PT-IgG 6.5 IU/ml, 95% CI: 4.9-8.8; GMT PT-Nab 3.8 IU/ml, 95% CI: 2.8-5.1). The same was found for FHA-IgG. Recombinant pertussis vaccination at <27 or 27-36 weeks gestation induced similar cord pertussis antibody levels. CONCLUSION: This first real-world study confirms that recombinant pertussis vaccination in the second or third trimester of pregnancy results in high levels of passive immunity in infants. Thai Clinical Trial Registry: TCTR20200528006.

The seroepidemiology of immunoglobulin G antibodies against pertussis toxin and filamentous hemagglutinin in the east of China during the COVID-19 pandemic.

This study employed sero-epidemiological methods to estimate the incidence of pertussis within a healthy population located in eastern China. The aim was to gain deeper insights into the epidemiological characteristics and burden of pertussis within the country. Blood samples were collected from healthy individuals in Jiangsu Province between June 2019 and December 2022. The levels of IgG antibodies against pertussis toxin (anti-PT) and filamentous hemagglutinin (anti-FHA) in the serum were quantitatively measured using enzyme-linked immunosorbent assay (ELISA). Additionally, pertussis case data reported in Jiangsu Province were collected from the China Information System for Disease Control and Prevention and compared with the results of this study. In 2022, the reported incidence of pertussis stood at 1.0 per 100,000 individuals, marking the highest rate observed in the past two decades. Among 1,909 patients examined, the geometric mean concentration (GMC) of anti-PT IgG antibody was 20.2 (18.5-21.9) IU/ml, while that of anti-FHA IgG antibody was 27.0 (25.4-28.7) IU/ml. The IgG-PT and IgG-FHA seropositivity rate (>20.0 IU/ml) was highest in the 1 ~ 2 y old group and decreased rapidly to the lowest in the 3 ~ 4 y old group and then increased gradually with age. The estimated rate of pertussis infection based on seroprevalence was approximately 25,625-fold higher than the reported notification rate in the ≥15 year age group. Our findings highlight decreased immunity post-vaccination, stressing the importance of additional booster shots for adolescents and adults to maintain immunity and reduce severe illness. Additionally, they offer vital guidance for policymakers to enhance immunization strategies.

Seroprevalence of tetanus and pertussis antibodies among health care workers in Wuhu, China.

This study aimed to elucidate the seroprevalence of antibodies to tetanus and pertussis among Chinese health care workers. Blood specimens from health care workers were collected during the 2021 annual medical examination at the First People's Hospital of Wuhu. Commercial ELISA kits were employed to quantify serum IgG antibodies against tetanus toxin (anti-TT IgG) and both IgG and IgA antibodies against pertussis toxin (anti-PT IgG, anti-PT IgA). A concentration of anti-TT IgG exceeding 0.1 IU/ml was deemed seroprotective against tetanus, while concentrations of anti-PT IgG ≥ 50 IU/ml or anti-PT IgA ≥ 15 IU/ml were indicative of a prior pertussis infection. The overall seroprotective rate for anti-TT IgG stood at 10.43% (92/882), with the highest seroprotective rate (13.91%) in the 20-29 age group, followed by the 30-39 age group (10.57%), 40-49 age group (5.80%), and 50-59 age group (5.63%). Eighteen (2.04%) of the studied subjects were positive to anti-PT IgG, and the positive rate in 20-39 age group and 40-59 age group was 1.19% (8/673) and 4.78% (10/209), respectively. Thirty (3.40%) subjects displayed anti-PT IgG levels ≥100 IU/ml and/or anti-PT IgA ≥ 15 IU/ml, suggesting a recent pertussis infection within the preceding year. Over half (503/882, 57.03%) had undetectable anti-PT IgG antibodies. The majority of health care workers in China appear susceptible to tetanus and pertussis, and a significant subset has experienced pertussis infection. The implementation of booster vaccinations against these diseases for Chinese health care workers is recommended.

Comparison of Bordetella pertussis Antibody Levels in Pregnant Women and Umbilical Cord Blood: A Multicenter Study.

BACKGROUND: In countries where pertussis vaccination is not administered during pregnancy, the determination of pertussis antibody levels in pregnant women is very important in terms of knowing the current seroepidemiology and potential strategies for immunizations. METHODS: We included 396 pregnant women who were admitted to 4 different obstetrics and gynecology clinics. Anti-Bordetella pertussis toxin (PT) IgG and anti-Bordetella pertussis filamentous hemagglutinin IgG levels in maternal and cord blood pairs were determined by the ELISA method. RESULTS: Venous blood serum anti-PT level was below 5 IU/mL in 58.8%, 5-40 IU/mL in 34.8%, 40-100 IU/mL in 5.1% and >100 IU/mL in 1.3% of pregnant women. Cord blood serum anti-PT level was below 5 IU/mL in 47.7%, 5-40 IU/mL in 44.5%, 40-100 IU/mL in 6.8% and >100 IU/mL in 1% of pregnant women. In our study, the anti-PT level was found below 40 IU/mL in 93.6% of pregnant women and 92.2% of cord blood. Our study found the anti-filamentous hemagglutinin level below 40 IU/mL in 81% of pregnant women and 66.2% of cord blood. CONCLUSIONS: Although it is known that pertussis causes serious morbidity and mortality in young infants all over the world and that the most effective and reliable way to prevent it is vaccination of pregnant women, it is a remarkable contradiction that pertussis vaccination rates and therefore seropositivity rates in pregnant women are very low.

The Chaperonin TRiC/CCT Inhibitor HSF1A Protects Cells from Intoxication with Pertussis Toxin.

Pertussis toxin (PT) is a bacterial AB5-toxin produced by Bordetella pertussis and a major molecular determinant of pertussis, also known as whooping cough, a highly contagious respiratory disease. In this study, we investigate the protective effects of the chaperonin TRiC/CCT inhibitor, HSF1A, against PT-induced cell intoxication. TRiC/CCT is a chaperonin complex that facilitates the correct folding of proteins, preventing misfolding and aggregation, and maintaining cellular protein homeostasis. Previous research has demonstrated the significance of TRiC/CCT in the functionality of the Clostridioides difficile TcdB AB-toxin. Our findings reveal that HSF1A effectively reduces the levels of ADP-ribosylated Gαi, the specific substrate of PT, in PT-treated cells, without interfering with enzyme activity in vitro or the cellular binding of PT. Additionally, our study uncovers a novel interaction between PTS1 and the chaperonin complex subunit CCT5, which correlates with reduced PTS1 signaling in cells upon HSF1A treatment. Importantly, HSF1A mitigates the adverse effects of PT on cAMP signaling in cellular systems. These results provide valuable insights into the mechanisms of PT uptake and suggest a promising starting point for the development of innovative therapeutic strategies to counteract pertussis toxin-mediated pathogenicity.

Signaling Specificity and Kinetics of the Human Metabotropic Glutamate Receptors.

Metabotropic glutamate receptors (mGluRs) are obligate dimer G protein coupled receptors that can all function as homodimers. Here, each mGluR homodimer was examined for its G protein coupling profile using a bioluminescence resonance energy transfer-based assay that detects the interaction between a split YFP-tagged Gß 1γ2 and a Nanoluciferase tagged free Gßγ sensor, MAS-GRK3-ct- nanoluciferase with 14 specific Gα proteins heterologously expressed, representing each family. Canonically, the group II and III mGluRs (2 and 3 and 4, 6, 7, and 8, respectively) are thought to couple to Gi/o exclusively. In addition, the group I mGluRs (1 and 5) are known to couple to the Gq/11 family and generally thought to also couple to the pertussis toxin-sensitive Gi/o family some reports have suggested Gs coupling is possible as cAMP elevations have been noted. In this study, coupling was observed with all eight mGluRs through the Gi/o proteins and only mGluR1 and mGluR5 through Gq/11, and, perhaps surprisingly, not G14 None activated any Gs protein. Interestingly, coupling was seen with the group I and II but not the group III mGluRs to G16 Slow but significant coupling to Gz was also seen with the group II receptors. SIGNIFICANCE STATEMENT: Metabotropic glutamate receptor (mGluR)-G protein coupling has not been thoroughly examined, and some controversy remains about whether some mGluRs can activate Gαs family members. Here we examine the ability of each mGluR to activate representative members of every Gα protein family. While all mGluRs can activate Gαi/o proteins, only the group I mGluRs couple to Gαq/11, and no members of the family can activate Gαs family members, including the group I receptors alone or with positive allosteric modulators.

Adenosine A1 receptor-mediated inhibition of in vitro prolactin secretion from the rat anterior pituitary

In previous studies, we demonstrated biphasic purinergic effects on prolactin (PRL) secretion stimulated by an adenosine A2 agonist. In the present study, we investigated the role of the activation of adenosine A1 receptors by (R)-N6-(2-phenylisopropyl)adenosine (R-PIA) at the pituitary level in in vitro PRL secretion. Hemipituitaries (one per cuvette in five replicates) from adult male rats were incubated. Administration of R-PIA (0.001, 0.01, 0.1, 1, and 10 æM) induced a reduction of PRL secretion into the medium in a U-shaped dose-response curve. The maximal reduction was obtained with 0.1 æM R-PIA (mean ± SEM, 36.01 ± 5.53 ng/mg tissue weight (t.w.)) treatment compared to control (264.56 ± 15.46 ng/mg t.w.). R-PIA inhibition (0.01 æM = 141.97 ± 15.79 vs control = 244.77 ± 13.79 ng/mg t.w.) of PRL release was blocked by 1 æM cyclopentyltheophylline, a specific A1 receptor antagonist (1 æM = 212.360 ± 26.560 ng/mg t.w.), whereas cyclopentyltheophylline alone (0.01, 0.1, 1 æM) had no effect. R-PIA (0.001, 0.01, 0.1, 1 æM) produced inhibition of PRL secretion stimulated by both phospholipase C (0.5 IU/mL; 977.44 ± 76.17 ng/mg t.w.) and dibutyryl cAMP (1 mM; 415.93 ± 37.66 ng/mg t.w.) with nadir established at the dose of 0.1 æM (225.55 ± 71.42 and 201.9 ± 19.08 ng/mg t.w., respectively). Similarly, R-PIA (0.01 æM) decreased (242.00 ± 24.00 ng/mg t.w.) the PRL secretion stimulated by cholera toxin (0.5 mg/mL; 1050.00 ± 70.00 ng/mg t.w.). In contrast, R-PIA had no effect (468.00 ± 34.00 ng/mg t.w.) on PRL secretion stimulation by pertussis toxin (0.5 mg/mL; 430.00 ± 26.00 ng/mg t.w.). These results suggest that inhibition of PRL secretion after A1 receptor activation by R-PIA is mediated by a Gi protein-dependent mechanism.

Sitios de acción inhibitoria de la prolactina sobre la síntesis de estradiol inducida por la hormona folículo estimulante en las células de la granulosa / Sites of prolactin inhibition on gonadotropin-induced estrogen production in cultured rat granulosa cells

En este estudio se investigaron los sitios probables de la acción inhibitoria de prolactina (Prl) sobre la esteroidogénesis ovárica inducida por la hormona folículo estimulante (FSH). Para esta finalidad se estudió la capacidad de cultivos primarios de células de la granulosa de la rata de sintetizar estradiol y AMPc bajo la estimulación con FSH o de activadores de la vía dependiente de AMPc en presencia de Prl humana. La participación de otros sistemas de transducción de señal como los dependientes de PKC y proteínas Gi en los mecanismos de acción inhibitoria de la Prl fue también investigada utilizando inhibidores de estos sistemas como la calfostina C y la toxina pertusis. Los resultados demostraron la habilidad de la Prl de alterar la esteroidogénesis previa y posterior a la generación de AMPc, muy probablemente por mecanismos que involucran la activación de la subunidad catalítica de la adenilato ciclasa, así como a través de interactuar con sistemas de transducción de señal dependientes de PKC y proteínas sensibles a la toxina pertusis. Nuestros resultados sugieren un mecanismo de interacción entre receptores acoplados a proteínas G con aquéllos acoplados a cinasas de tirosinas mediado muy probablemente por vías de señalización dependientes de proteínas Gi.

We studied the sites of prolactin inhibition upon FSH induced ovarian steroidogenesis and the ability of prolactin (Prl) to inhibit the synthesis of estradiol and cAMP accumulation under the stimulation of FSH or cAMP dependent activators. The participation of other signal pathways such as PKC and Gi proteins on the inhibitory actions of Prl was also investigated using calfostine C andpertusis toxin as inhibitors. Results showed a dose dependent prolactin decrease in FSH-induced estradiol and cAMP production prior and after the generation of the cyclic nucleotide by a mechanism involving the catalytic subunit of adenyl cyclase and/or through activation of PKC or by the interaction with pertusin toxin sensitive G proteins. Our results suggest a mechanism by which G protein coupled receptors are linked with those coupled with tyrosine kinase through the involvement of a Gi protein mediated mechanism.

Contribuição ao estudo do mecanismo da citotoxidade in vitro induzida pela toxina pertussis e suas implicações no controle de qualidade da vacina tríplice-DTP / Contribution to the study of the mechanism of the induced cytotoxicity in vitro for pertussis toxin and its implications in the quality control of the diphtheria-tetanus-pertussis vaccine

Face ao objetivo fundamental deste trabalho de estabelecer e padronizar teste capaz de detectar e avaliar quantitativamente a presença de resíduos não-inativados de toxina pertussis (TP) em vacina pertussis (VP) e/ou tríplice (DTP), selecionamos a cultura de células CHO, pois, além de se enquadrar perfeitamente na regra dos 3 Rs, principalmente em termos de possível substituição do teste in vivo, é amplamente usada como linhagem celular modelo para o estudo dos efeitos celulares da TP comparativamente com os causados pela toxina colérica (TC), de características químicas e biológicas muito semelhantes à TP. Assim, as alterações morfológicas de aglomeração celular (efeito clustering) ou de alongamento celular induzidos, respectivamente, pela TP e TC, foram quantificadas e os seus mecanismos de ação estudados, confirmando-se o da TC e propondo-se o da TP, concluindo-se, ao contrário do até agora supostamente admitido, que são epifenômenos mediados por segundos mensageiros diferentes, pois confirmamos o papel do AMPc no alongamento e sugerimos o envolvimento do GMPc no clustering, demonstrando, outrossim, a participação fundamental do Oligômero B, fração molecular da TP, neste fenômeno morfológico, além de apresentarmos evidências sugestivas da participação de proteínas intracelulares diretamente conectadas com o citoesqueleto, tais como, a actina, tubulina e integrinas, na formação do clustering. Finalmente, a correlação entre os níveis de resíduos de TP - não inativada nas vacinas VP e DTP, encontradas in vivo através do Teste de Sensibilização à Histamina e in vitro em células CHO, definitivamente demonstrou a validade deste último teste, não só como complementar aos testes in vivo, mas também como possível substituto destes últimos no Controle de Qualidade das vacinas DTP. Ressalte-se que nas concentrações de TP capazes de induzir o clustering, não mostraram efeitos citotóxicos, avaliados através da análise do crescimento celular, da eficiência de clonagem, do índice mitótico e do ensaio cometa.

Efecto de la toxina pertussis sobre la actividad guanilil ciclasa dependiente de Mg²+ en el músculo liso traqueal de bovino / Effect of the pertussis toxins on the guanylate cyclase dependent activity of Mg² + in the tracheal musde smooth of bovine

Las membranas plasmáticas de músculo liso traqueal de bovino presentan una actividad de guanililciclasa dependiente de Mg²+, determinada utilizando radioinmunoensayo para GMPc, sobre la cual se estudió el efecto de la toxina pertussis. Se observó un comportamiento bimodal dependiente de la concentración de Mg²+: efecto estimulatorio hasta una concentración de Mg²+ 2mM y efecto inhibitorio a concentraciones mayores del ión. El agonista carbamilcolina también mostró un efecto dual sobre esta actividad enzimática: estimulatorio hasta 10-9 M e inhibitorio a concentraciones mayores. La toxina pertussis produce un efecto bloqueador de la guanililciclasa dependiente de Mg²+ y eso permite concluir que dicha actividad es modulada por proteína Go/Gi en forma similar a lo descrito previamente para la actividad guanililciclasa dependiente de Mn²+ en la misma fracción de membranas, pero en el caso de la actividad dependiente de Mg²+, aparentemente se requiere del componente inhibitorio de la proteína G para ejercer su función

Efecto de péptidos natriuréticos sobre la actividad de la guanililciclasa asociada a las membranas plasmáticas de vías aéreas de bovino / Natriurectic peptide effect over the guanylyl cyclase activity asociated to the plasma membranas of the airway of the bovine

En las membranas plasmáticas de la fracción P2, obtenida del fraccionamiento subcelular de las vías aéreas de bovino, está presente una guanililciclasa (GC) sensible a agentes muscarínicos y a inhibición por NaCl, este último efecto está mediado a través de una proteína G sensible a toxina pertussis. Al evaluar el efecto del ANP y CNP sobre esta GC, se encontró que los péptidos estimulan la actividad basal de la enzima y revierten el efecto inhibitorio del NaCl; indicando estos resultados la presencia de GC-A y GC-B en el sistema, y la existencia de una proteína G inhibitoria interviniendo en la regulación de estas enzimas. El mastoparán estimula el efecto del ANP y CNP sobre estas GCs, sugiriendo que en la regulación de estas enzimas interviene una proteína G activadora, a través de la cual media su efecto al mastoparán

G-protein-dependent antagonists binding in M3 mAchR from tracheal smooth muscle

Los subtipos M3 y M2 del mAchR fueron localizados en fracciones de membranas plasmáticas de músculos liso traqueal de bovino (MLTB). Los mAchRs nativos de MLTB fueron estudiados usando enlazamientos de [3H]QNB. La hetereogeneidad del receptor fue expresada para agonista y antagonista muscarínicos siendo los estados de alta afinidad sensibles a GTPyS. Mostramos que los efectos de GTPgS parecen ser mediados por proteínas Gi/o sensibles a PTX. Se detectó la hetereogeneidad del mAchR hacia 4-DAMP (M3) y pirenzepina (M1). Sin embargo, los antagonistas subtipo M2 como methoctramina y AF-DX 116 no mostraron tales respuestas en la presencia o ausencia de GTPyS. A través de la alquilación con 4-DAMP del subtipo M3 del mAchR, prevaleció el subtipo M2 el cual exhibió un enlazamiento dependiente de GTPyS parecido a un agonista mientras el enlazamiento de los antagonistas fue insensibles al GTPgS. Por lo anterior, la heterogeneidad a antagonistas del receptor descrita aquí es debida al subtipo M3 del mAchR, el cual muestra dos estados de afinidad siendo uno regulado por proteínas Gi/o

Histopathological analysis of rat mesentery as a method for evaluating neutrophil migration: differential effects of dexamethasone and pertussis toxin

In the present study, histopathological analysis of rat mesentery was used to quantify the effect of two anti-inflammatory agents, dexamethasone (Dex) and pertussis toxin (Ptx), on leukocyte migration. The intravenous injection of Dex (1 mg/kg) and Ptx (1,200 ng) 1 h prior to the intraperitoneal injection of the inflammatory stimuli lipopolysaccharide (LPS) or formyl-methionyl-leucyl-phenylalanine (fMLP) significantly reduced the neutrophil diapedesis (LPS: Ptx = 0.86 ñ 0.19 and Dex = 0.35 ñ 0.13 vs saline (S) = 2.85 ñ 0.59; fMLP: Ptx = 0.43 ñ 0.09 and Dex 0.01 ñ 0.01 vs S = 1.08 ñ 0.15 neutrophil diapedesis/field) and infiltration (LPS: Ptx = 6.29 ñ 1.4 and Dex = 3.06 ñ 0.76 vs S = 15.94 ñ 3.97; fMLP: Ptx = 3.85 ñ 0.56 and Dex = 0.40 ñ 0.16 vs S = 7.15 ñ 1.17 neutrophils/field) induced by the two agonists in the rat mesentery. The inhibitory effect of Dex and Ptx was clearly visible in the fields nearest the venule (up to 200 µm), demonstrating that these anti-inflammatory agents act preferentially in the transmigration of neutrophils from the vascular lumen into the interstitial space, but not in cell movement in response to a haptotactic gradient. The mesentery of rats pretreated with Dex showed a decreased number of neutrophils within the venules (LPS: Dex = 1.50 ñ 0.38 vs S = 4.20 ñ 1.01; fMLP: Dex = 0.25 ñ 0.11 vs S = 2.20 ñ 0.34 neutrophils in the lumen/field), suggesting that this inhibitor may be acting at a step that precedes neutrophil arrival in the inflamed tissue. In contrast to that observed with Dex treatment, the number of neutrophils found in mesenteric venules was significantly elevated in animals pretreated with Ptx (LPS: Ptx = 9.85 ñ 2.25 vs S = 4.20 ñ 1.01; fMLP: Ptx = 4.66 ñ 1.24 vs S = 2.20 ñ 0.34 neutrophils in the lumen/field). This discrepancy shows that Ptx and Dex act via different mechanisms and suggests that Ptx prevents locomotion of neutrophils from the vascular lumen to the interstitial space. In conclusion, the method described here is useful for quantifying the inflammatory and anti-inflammatory effect of different substances. The advantage of this histopathological approach is that it provides additional information about the steps involved in leucocyte migration.

Tos ferina (Coqueluche) / Whooping cougth

La tos ferina es una enfermedad respiratoria infecto contagiosa endémica y epidérmica, causada por la Bordetella pertussis, que se presenta con mayor frecuencia en menores de 5 años. La primera descripción de tos ferina fue realizada por Guillermo de Baillou en París en 1578 durante una epidemia de la enfermedad. En 1670 Sydenham le da el nombre de tos ferina (tos intensa) a esta infección. En China se la conoce como "la tos de los 100 dias". Aunque se dispone de una vacuna efectiva, la moratlidad en lactantes y niños pequeños de países en vías de desarrollo continúa siendo elevada, debido a la falta de inmunización o vacunación incompleta. El objetivo de esta revisión es recordar y actualizar conceptos acerca de este padecimiento.

Pertussis toxin from Bordetella pertussis blocks neutrophil migration and neutrophil-dependent edema in response to inflammation

Pertussis toxin (Ptx) is a hexameric protein with classical AB architecture produced by Bordetella pertussis. The aim of this study was to investigate the effect og Ptx on migration of polymorphonuclear leukocytes to site of inflamation and on cell- dependent edema. Ptx was purified from the supernatant of the culture medium of B. pertussis using hydroxylapatite chromatography and fetuin affinity chromatography. Ptx induced a maximal clusterin of Chinese hamster ovary cells at concentration as low as 0.1 ng/ ml. Intravenous inection of Ptx (400 ng) significantly blocked the neutrophil migration induced by 200 ng of lipopolysaccharide (LPS from E. coli O111:B4; 2.27 ñ 0.13 vs 0.61 ñ 0.16 per 10**6 neutrophils/ml; P < 0.001; N = 5) and by 200 ng of formylmethionyl-leucyl-phenylalanine(fMLP; 2.53 ñ 0.45 vs 0.75 ñ 0.14 per 10**6 neutrophils/ml; P < 0.01; N=6) into the peritoneal cavities of male Wistar rats (eighing 150-180). In addition, Ptx (400ng) pretreatment also blocked the edema induced by intraplantar injection of 100 µg carrageenin ( increase in volume: 0.667 ñ 0.087 vs 0.313 ñ 0.058 ml; P < 0.01; N = 5) but not the edema induced by 100 µg dextran ( increase in volume: 0.537 ñ 0.06 vs 0.385 ñ 0.076 ml; P > 0.05; N = 5). These data demonstrate that Ptx blocked neutrophil migration induced by a direct f MLP stimulus of a site of inflammation. In addition, this toxin blocks the indirect stimulus of LPS on neutrophil migration. Furthermore, Ptx also inhibits the neutrophil-dependent edema induced by carrageenin, but not the edema induced by dextran that is in part dependent on basophil cells. These results warrant further studies on the mechanisms of Ptx inhibition of neutrophil-dependent edema and cell migration