Two cases of subacute thyroiditis after different types of SARS-CoV-2 vaccination

SUMMARY Although the development of subacute thyroiditis (SAT) following viral infections is well-documented, the actual mechanism has not been clearly elucidated. The occurrence of SAT after vaccination has been reported in several case series and possible mechanisms such as molecular mimicry due to the exposure to viral proteins and/or abnormal reactogenicity by adjuvants have been implicated. We describe two cases who developed SAT three days after the messenger RNA vaccine against COVID-19 (Pfizer-BioNTech®) and six days after the inactivated COVID-19 vaccine (CoronaVac®). SAT diagnosis of these patients was delayed for more than two weeks. When the current cases were evaluated together with 1 Pfizer-BioNTech® and 3 CoronaVac® related cases reported previously, the patients were female aged between 30-42, except for the male patient we presented, and the complaints of the patients initiated within the first 2-7 days. While two Pfizer-BioNTech® vaccine-related cases were severely symptomatic and thyrotoxic at presentation, there were cases with mild to moderate clinical manifestations in CoronaVac® vaccine-related group. Physicians should be aware of SAT that may occur within a few days following the COVID-19 vaccination.

Pericarditis and myocarditis after COVID-19 mRNA vaccination in a nationwide setting

INTRODUCTION@#Despite reports suggesting an association between COVID-19 mRNA vaccination and pericarditis and myocarditis, detailed nationwide population-based data are sparsely available. We describe the incidence of pericarditis and myocarditis by age categories and sex after COVID-19 mRNA vaccination from a nationwide mass vaccination programme in Singapore.@*METHODS@#The incidence of adjudicated cases of pericarditis and myocarditis following COVID-19 mRNA vaccination that were reported to the vaccine safety committee between January to July 2021 was compared with the background incidence of myocarditis in Singapore.@*RESULTS@#As of end July 2021, a total of 34 cases were reported (9 pericarditis only, 14 myocarditis only, and 11 concomitant pericarditis and myocarditis) with 7,183,889 doses of COVID-19 mRNA vaccine administered. Of the 9 cases of pericarditis only, all were male except one. The highest incidence of pericarditis was in males aged 12-19 years with an incidence of 1.11 cases per 100,000 doses. Of the 25 cases of myocarditis, 80% (20 cases) were male and the median age was 23 years (range 12-55 years) with 16 cases after the second dose. A higher-than-expected number of cases were seen in males aged 12-19 and 20-29 years, with incidence rates of 3.72 and 0.98 case per 100,000 doses, respectively.@*CONCLUSION@#Data from the national registry in Singapore indicate an increased incidence of pericarditis and myocarditis in younger men after COVID-19 mRNA vaccination.

Establishment of a production process for a novel vaccine candidate against Lawsonia intracellularis

BACKGROUND: Lawsonia intracellularis remains a problem for the swine industry worldwide. Previously, we designed and obtained a vaccine candidate against this pathogen based on the chimeric proteins: OMP1c, OMP2c, and INVASc. These proteins formed inclusion bodies when expressed in E. coli, which induced humoral and cellular immune responses in vaccinated pigs. Also, protection was demonstrated after the challenge. In this study, we established a production process to increase the yields of the three antigens as a vaccine candidate. RESULTS: Batch and fed-batch fermentations were evaluated in different culture conditions using a 2 L bioreactor. A fed-batch culture with a modified Terrific broth medium containing glucose instead of glycerol, and induced with 0.75 mM IPTG at 8 h of culture (11 g/L of biomass) raised the volumetric yield to 627.1 mg/L. Under these culture conditions, plasmid-bearing cells increased by 10% at the induction time. High efficiency in cell disruption was obtained at passage six using a high-pressure homogenizer and a bead mill. The total antigen recovery was 64% (400 mg/L), with a purity degree of 70%. The antigens retained their immunogenicity in pigs, inducing high antibody titers. CONCLUSIONS: Considering that the antigen production process allowed an increment of more than 70-fold, this methodology constitutes a crucial step in the production of this vaccine candidate against L. intracellularis.

The impact of spike mutated variants of SARS-CoV2 [Alpha, Beta, Gamma, Delta, and Lambda] on the efficacy of subunit recombinant vaccines

ABSTRACT Since the first described human infection with SARS-CoV-2 in December of 2019 many subunit protein vaccines have been proposed for use in humans. Subunit vaccines use one or more antigens suitable for eliciting a robust immune response. However, the major concern is the efficacy of subunit vaccines and elicited antibodies to neutralize the variants of SARS-CoV-2 like B.1.1.7 (Alpha), B.1.351 (Beta) and P1 (Gamma), B.1.617 (Delta) and C.37 (Lambda). The Spike protein (S) is a potential fragment for use as an antigen in vaccine development. This protein plays a crucial role in the first step of the infection process, as it binds to Angiotensin-Converting Enzyme 2 (ACE2) receptor and enters the host cell after binding. Immunization-induced specific antibodies against the receptor binding domain (RBD) may block and effectively prevent virus invasion. The focus of this review is the impact of spike mutated variants of SARS-CoV2 (Alpha, Beta, Gamma, Delta, and Lambda) on the efficacy of subunit recombinant vaccines. To date, a low or no significant impact on vaccine efficacy against Alpha and Delta variants has been reported. Such an impact on vaccine efficacy for Beta, Delta, Gamma, and Lambda variants may be even greater compared to the Alpha variant. Nonetheless, more comprehensive analyses are needed to assess the real impact on vaccine efficacy brought about by SARS-CoV-2 variants.

Adverse reactions and safety profile of the mRNA COVID-19 vaccines among Asian military personnel

INTRODUCTION@#The use of novel mRNA platforms for COVID-19 vaccines raised concern about vaccine safety, especially in Asian populations that made up less than 10% of study populations in the pivotal vaccine trials used for emergency use authorisation. Vaccine safety issues also remain a concern in assessing the clinical risks and benefits of vaccine boosters, particularly in specific age groups or segments of the population. This study describes a vaccination exercise involving Asian military personnel, and the adverse reactions and safety events observed.@*METHODS@#Minor adverse reactions, hospitalisations and adverse events of special interest were monitored as part of the organisation's protocol for safety monitoring of COVID-19 vaccinations. All vaccine recipients were invited to complete an online adverse reaction questionnaire. Medical consults at the military's primary healthcare facilities were monitored for vaccine-related presentations. All hospitalisations involving vaccine recipients were analysed. Adverse reaction rates between doses, vaccines and age groups were compared.@*RESULTS@#A total of 127,081 mRNA vaccine doses were administered to 64,661 individuals up to 24 July 2021. Common minor adverse reactions included fever/chills, body aches and injection site pain. These were more common after dose 2. Younger individuals experienced minor adverse reactions more frequently. Rare cases of anaphylaxis, Bell's palsy and myocarditis/pericarditis were observed. No deaths occurred.@*CONCLUSION@#Minor adverse reactions were less common than reported in other studies, and rates of anaphylaxis, Bell's palsy and myocarditis/pericarditis were comparable. Our study supports the favourable safety profile of mRNA COVID-19 vaccines, which may help guide decisions about booster doses if required.

Clostridium perfringens α and ß recombinant toxoids in equine immunization / Toxóides recombinantes α e ß de Clostridium perfringens na imunização de equinos

Clostridium perfringens is considered one of the main causative agents of superacute enterocolitis, usually fatal in the equine species, due to the action of the ß toxin, and is responsible for causing severe myonecrosis, by the action of the α toxin. The great importance of this agent in the equine economy is due to high mortality and lack of vaccines, which are the main form of prevention, which guarantee the immunization of this animal species. The aim of this study was to evaluate three different concentrations (100, 200 and 400µg) of C. perfringens α and ß recombinant toxoids in equine immunization and to compare with a group vaccinated with a commercial toxoid. The commercial vaccine was not able to stimulate an immune response and the recombinant vaccine was able to induce satisfactory humoral immune response in vaccinated horses, proving to be an alternative prophylactic for C. perfringens infection.(AU)

Clostridium perfringens é considerado um dos principais agentes causadores de enterocolites superagudas, geralmente fatais na espécie equina, devido à ação da toxina ß, além de ser responsável por causar quadros graves de mionecrose, pela ação da toxina α. A grande importância desses agentes na equinocultura, deve-se a elevada mortalidade e a inexistência de vacinas, principal forma de prevenção, que garantam a imunização dessa espécie animal. O objetivo deste trabalho foi avaliar três diferentes concentrações (100, 200 e 400µg) dos toxóides recombinantes α e ß de C. perfringens na imunização de equinos, bem como comparar com um grupo vacinado com um toxóide comercial. A vacina comercial não se mostrou capaz de estimular uma resposta imune e a vacina recombinante foi capaz de induzir resposta imune humoral satisfatória em equinos vacinados, provando ser uma alternativa profilática para infecção por C. Perfringens.(AU)

Avances en el desarrollo de una vacuna efectiva contra Cryptosporidium parvum: una revisión de la literatura / Advances in the development of an effective vaccine against Cryptosporidium parvum: An review of the literature / Avanços no desenvolvimento de uma vacina eficaz contra Cryptosporidium parvum: uma revisão da literatura

Introducción. Cryptosporidium parvum es un parásito zoonótico altamente prevalente, asociado a enfermedad diarreica en población inmunocomprometida, niños y terneros menores de 30 días. Esta infección puede ocasionar deshidratación, alteración del estado de conciencia, retraso en el desarrollo global y, en algunos casos, la muerte del paciente. A pesar de la alta prevalencia de C. parvum, no existen medicamentos completamente efectivos ni una vacuna aprobada para prevenir dicha enfermedad. Objetivo. Realizar una revisión de la literatura sobre candidatos vacunales contra C. parvum. Método. Revisión documental mediante la búsqueda de la literatura de los últimos 20 años, disponible en las bases de datos PubMed central, WEB OF SCIENCE, Embase, REDALYC y LILACS. Resultados. Las vacunas atenuadas, recombinantes, basadas en ADN, expresadas en vectores bacterianos y sintéticas han mostrado resultados prometedores en la inducción de inmunogenicidad contra los antígenos de C. parvum, siendo el antígeno de superficie de 15 kilodaltons de Cryptosporidium parvum (cp15), el antígeno inductor de una mejor respuesta inmune celular y humoral en el modelo murino estudiado. Conclusión. Se espera que la incorporación de nuevas técnicas para la selección de antígenos promisorios y la ejecución de una gran cantidad de ensayos in vivo, favorezcan el desarrollo de una vacuna totalmente efectiva contra C. parvum. Aunque el camino para lograr este objetivo será largo y difícil, se convierte en la mejor alternativa para controlar una de las enfermedades de interés en salud pública, con mayor impacto en la población inmunocomprometida.

Introduction. Cryptosporidium parvum is a highly prevalent zoonotic parasite, associated with diarrheal disease in immunocompromised population, children and calves under 30 days. This infection is associa- ted to dehydration, delayed global development and, in some cases, the death of the patient. Despite the high prevalence of C. parvum, there are no fully effective medications and an approved vaccine to prevent such disease. Objective. To conduct a thorough review of the literature on vaccine candidates against C. parvum. Method Documentary review by searching the literature of the last 20 years, available in the central PubMed, WEB OF SCIENCE, Embase, REDALYC and LILACS databases. Results. Attenuated, recombinant, DNA-based, expressed in bacterial vectors and synthetic vaccines have shown promising results in inducing immunogenicity against C. parvum, being the Cryptospori- dium parvum 15 kiloDalton surface antigen (cp15), the antigen inducer of a better cellular and humoral immune response in the murine model studied. Conclusion. It is expected that the incorporation of new techniques for the selection of promising antigens and the execution of a large number of in vivo assays will favor the development of a fully effective vaccine against C. parvum. Although the way to achieve this goal will be long and difficult, it will become the best alternative to control one of the diseases with the greatest impact on the immu- nocompromised population.

Introdução. O Cryptosporidium parvum é um parasita zoonótico de alta prevalência associado à doença diarreica em populações imunocomprometidas, crianças e bezerros com menos de 30 dias. Essa infecção pode causar desidratação, alteração do estado de consciência, atraso no desenvolvi- mento global e, em alguns casos, a morte do paciente. Apesar da alta prevalência de C. parvum, não existem medicamentos totalmente eficazes e uma vacina aprovada para prevenir a doença. Objetivo. Realizar uma revisão literária dos candidatos à vacina contra C. parvum. Método. Revisão documental, mediante pesquisa da literatura dos últimos 20 anos, disponível nas bases de dados PubMed central, WEB OF SCIENCE, Embase, REDALYC e LILACS. Resultados. Vacinas atenuadas, recombinantes e baseadas em DNA, expressas em vetores bacteria- nos e sintéticos, mostraram resultados promissores na indução de imunogenicidade contra antígenos de C. parvum, sendo o antígeno de superfície de 15 kilodaltons de Cryptosporidium parvum (cp15) o antígeno indutor de uma melhor resposta imune celular e humoral no modelo murino estudado. Conclusão. Se espera que a incorporação de novas técnicas para a seleção de antígenos promissores e a execução de um grande número de ensaios in vivo favoreçam o desenvolvimento de uma vacina totalmente eficaz contra C. parvum. Embora o caminho para alcançar este objetivo seja longo e difícil, torna-se a melhor alternativa para controlar uma das doenças de interesse na saúde pública com maior impacto na população imunocomprometida.

Generation and evaluation of a recombinant myxomavirus expressing the VP60 protein of rabbit haemorrhagic disease virus / 生物工程学报

Rabbit haemorrhagic disease virus (RHDV) and myxoma virus (MYXV), are two pathogens that have harmful effect on rabbit breeding and population decline of European rabbits in their native range, causing rabbit haemorrhagic disease (rabbit fever) and myxomatosis, respectively. The capsid protein VP60 of the RHDV represents the major antigenic protein. To develop a recombinant bivalent vaccine candidate that can simultaneously prevent these two diseases, we used the nonessential gene TK (thymidine kinase) of MYXV as the insertion site to construct a recombinant shuttle vector p7.5-VP60-GFP expressing the RHDV major capsid protein (VP60) and the selectable marker GFP. Then the shuttle vector p7.5-VP60-GFP was transfected into rabbit kidney cell line RK13 which was previously infected with MYXV. After homologous recombination, the recombinant virus expressing GFP was screened under a fluorescence microscope and named as rMV-VP60-GFP. Finally, the specific gene-knock in and expression verification of the vp60 and gfp genes of the recombinant virus was confirmed by PCR and Western blotting. The results showed that these two genes were readily knocked into the MYXV genome and also successfully expressed, indicating that the recombinant MYXV expressing the vp60 of RHDV was generated. Protection against MYXV challenge showed that the recombinant virus induced detectable antibodies against MYXV which would shed light on development of the effective vaccine.

Co-expression, purification and bioassay of three avian viral antigens / 生物工程学报

To achieve uniform soluble expression of multiple proteins in the same Escherichia coli strain, and simplify the process steps of antigen production in genetic engineering subunit multivalent vaccine, we co-expressed three avian virus proteins including the fowl adenovirus serotype 4 (FAdV-4) Fiber-2 protein, infectious bursal disease virus (IBDV) VP2 protein and egg-drop syndrome virus (EDSV) Fiber protein in E. coli BL21(DE3) cells after optimization of gene codon, promoter, and tandem expression order. The purified proteins were analyzed by Western blotting and agar gel precipitation (AGP). The content of the three proteins were well-proportioned after co-expression and the purity of the purified proteins were more than 80%. Western blotting analysis and AGP experiment results show that all the three co-expression proteins had immunoreactivity and antigenicity. It is the first time to achieve the three different avian virus antigens co-expression and co-purification, which simplified the process of antigen production and laid a foundation for the development of genetic engineering subunit multivalent vaccine.

Construction and characterization of a recombinant vaccine encoding the nucleocapsid protein gene of avian infectious bronchitis virus / Construção e caracterização de uma vacina recombinante codificando o gene da proteina do nucleocapsideo do virus da bronquite infecciosa das galinhas

A vacinação é a forma mais utilizada para prevenir a bronquite infecciosa causada pelo vírus da bronquite infecciosa das galinhas (IBV). Contudo, as vacinas convencionais são incapazes de diferenciar aves infectadas de vacinadas. No presente trabalho foi construído, caracterizado, e avaliado como candidato vacinal, um adenovírus recombinante expressando o gene N do IBV. O gene N foi clonado em um adenovírus humano tipo 5 defectivo e transfectado para as células HEK-293A para gerar rAd5_N. Após o vetor ser obtido como esperado e a confirmação da expressão da proteína N em HEK-293ª, foi realizada inoculação pela via oculo-nasal na dose de 10 7 TCID 50 /0,1mL para imunização de galinhas livres de patógenos específicos (SPF). A resposta imunológica do Ad5_N e a proteção contra o desafio ao IBV foram avaliadas e comparadas com uma vacina viva comercial. Não foram detectados anticorpos anti-IBV em aves vacinadas com o Ad5_N. A vacina comercial induziu anticorpos detectáveis a partir do 7º dia pós-vacinal. Em aves vacinadas com o Ad5_N não houve aumento na expressão de IFNγ. Neste estudo, o rAd5_N obtido não conferiu proteção contra desafio com IBV-M41. Os resultados indicam a necessidade de avaliar adenovírus recombinantes expressando outros genes do IBV.(AU)

Rhoptry antigens as Toxoplasma gondii vaccine target

Toxoplasmosis is a cosmopolitan zoonotic infection, caused by a unicellular protozoan parasite known as Toxoplasma gondii that belongs to the phylum Apicomplexa. It is estimated that over one-third of the world's population has been exposed and are latently infected with the parasite. In humans, toxoplasmosis is predominantly asymptomatic in immunocompetent persons, while among immunocompromised individuals may be cause severe and progressive complications with poor prognosis. Moreover, seronegative pregnant mothers are other risk groups for acquiring the infection. The life cycle of T. gondii is very complex, indicating the presence of a plurality of antigenic epitopes. Despite of great advances, recognize and construct novel vaccines for prevent and control of toxoplasmosis in both humans and animals is still remains a great challenge for researchers to select potential protein sequences as the ideal antigens. Notably, in several past years, constant efforts of researchers have made considerable advances to elucidate the different aspects of the cell and molecular biology of T. gondii mainly on microneme antigens, dense granule antigens, surface antigens, and rhoptry proteins (ROP). These attempts thereby provided great impetus to the present focus on vaccine development, according to the defined subcellular components of the parasite. Although, currently there is no commercial vaccine for use in humans. Among the main identified T. gondii antigens, ROPs appear as a putative vaccine candidate that are vital for invasion procedure as well as survival within host cells. Overall, it is estimated that they occupy about 1%–30% of the total parasite cell volume. In this review, we have summarized the recent progress of ROP-based vaccine development through various strategies from DNA vaccines, epitope or multi epitope-based vaccines, recombinant protein vaccines to vaccines based on live-attenuated vectors and prime-boost strategies in different mouse models.

Construção, caracterização biológica e imunológica de vírus recombinante de vírus vacinal da febre amarela 17d, que expressam o fator de infectividade viral (vif) do vírus da imunodeficiência símia sivmac239 / Construction, biological and immunological characterization of 17d yellow fever vaccine virus recombinant virus, which express the viral infectivity factor (vif) of the simian immunodeficiency virus sivmac239

O desenvolvimento de uma vacina segura e eficiente contra o HIV é considerada uma ótima medida/estratégia para controlar a epidemia mundial do HIV. Este projeto visou construir e avaliar a imunogenicidade dos vírus da febre amarela recombinante da vacina 17D que expressam antígenos do fator de infectividade viral (Vif) do vírus da imunodeficiência símia SIVmac239. O vírus da vacina da febre amarela 17D tem sido usado como vetor de protótipos de vacinas por ser um imunógeno robusto e seguro. Nosso objetivo foi avaliar vírus recombinantes da febre amarela 17D que carreiam fragmentos de genes Vif (HIV/SIV), e que foram construídos com a tecnologia do clone infeccioso e a inserção do gene de Vif na região intergênica E/NS1 do genoma do vírus vacinal da febre amarela 17D. Verificamos anteriormente que o vírus recombinante FA/Vif 1-110 original era geneticamente instável, perdendo completamente o fragmento Vif 1-110 até à quinta passagem em série em células Vero. Nós alcançamos a estabilidade genética quando deletamos a região N-terminal de Vif, que provavelmente estava interferindo na replicação do vírus da FA 17D. Chamamos de FA/Vif 42-110, o vírus que sofreu a deleção do N-terminal, e que é geneticamente estável. Mas também construímos o FA/Vif 1-110 variante, que possui o mesmo fragmento do FA/Vif 1-110 original, porém é mais estável devido as mudanças realizadas na plataforma de expressão da proteína heteróloga. Incluímos nas primeiras investigações de imunogenicidade, o FA/Vif 102-214 construído anteriormente. Nós hipotetizamos que a estabilidade genética viral poderia aumentar a imunogenicidade viral

Assim, realizamos duas imunizações em camundongos C57BL/6 com os vírus FA/Vif para a avaliação da imunogenicidade em relação à formação de células T de memória contra o vírus da FA e Vif, e indução de anticorpos neutralizantes contra o vírus da FA, gerados pelas imunizações. O vírus FA/Vif 1-110 variante e o FA/Vif 42-110 se apresentaram como bons indutores de resposta celular, porém o FA/Vif 42-110 apresentou a menor média de título de anticorpos neutralizantes. O vírus FA/Vif 102-214 apresentou bons resultados de resposta imune celular e humoral, apesar de não ter sido avaliado dentro da resposta imune celular específica. O vírus FA/Vif 1-110 variante conseguiu uma boa indução da resposta celular e humoral, e o vírus FA/Vif 1-110 original parece promissor segundo os nossos dados de resposta celular de memória efetora, apesar de ter apresentado uma média baixa de títulos de anticorpos neutralizantes. De maneira geral, os vírus FA/Vif induzem diferentes braços de resposta imune, sendo uns mais indutores de resposta celular que humoral e vice-versa. Com os vírus FA/Vif apresentando essas características em relação a resposta imune, não conseguimos relacionar a estabilidade genética com imunogenicidade, mas uma estratégia promissora para abranger os dois tipos de resposta, seria o uso de formulações virais, utilizando dois ou mais vírus FA/Vif no regime vacinal. (AU)

Introduction of Vaccinomics to Develop Personalized Vaccines in Light of Changes in the Usage of Hantaan Virus Vaccine (Hantavax®) in Korea / 예방의학회지

The Ministry of Food and Drug Safety of Korea made an official announcement in March 2018 that the total number of inoculations of Hantaan virus vaccine (Hantavax®) would change from 3 to 4. Some aspects of this decision remain controversial. Based on the characteristics of Hantaan virus (HTNV) and its role in the pathogenesis of hemorrhagic fever with renal syndrome, it might be difficult to develop an effective and safe HTNV vaccine through the isolate-inactivate-inject paradigm. With the development of high-throughput ‘omics’ technologies in the 21st century, vaccinomics has been introduced. While the goal of vaccinomics is to develop equations to describe and predict the immune response, it could also serve as a tool for developing new vaccine candidates and individualized approaches to vaccinology. Thus, the possibility of applying the innovative field of vaccinomics to develop a more effective and safer HTNV vaccine should be considered.

Histopathological Evaluation of the Efficacy for Plant-produced E2 Protein Vaccine against Classical Swine Fever Virus (CSFV) in Piglets

Classical swine fever (CSF), previously known as hog cholera, remains one of the most important swine-related contagious diseases worldwide. In order to eradicate classical swine fever virus (CSFV), it is commonly used in LOM-850 strain as a live attenuated CSF vaccine. However, there are symptoms of vaccination, such as the depression of feed intake, and difficulty of differentiation between infected and vaccinated hosts is impossible based on the antibodies induced. Nicotiana benthamiana were considered as an alternative to the production of recombinant vaccines on account of higher yields and levels of soluble protein than other models and crops in protein recombinant products. This study was conducted to evaluate histopathological validation of the plant-produced E2 fusion protein (ppE2) in piglets. The piglets were challenged by an injection of YC11WB strain in 7 days, 11 days and 14 days after one shot of the vaccination. The histopathological examination indicated that ppE2 can protect against lethal CSFV challenge at least 11 days of vaccination in piglets. These data suggest that the ppE2 can be an effective vaccine against CSFV in piglets.

Plant factory: new resource for the productivity and diversity of human and veterinary vaccines

Vaccination is one of the most successful strategies to prevent diseases caused by pathogens. Although various expression systems including Escherichia coli, yeast, insect, and mammalian cells are currently used for producing many of vaccines, these conventional platforms have the limitation of post-translational modification, high cost, and expensive scalability. In this respect, the plant-based expression system has been considered as an attractive platform to produce recombinant vaccines due to fast, cost-effective and scalable production as well as safety. This review discusses the development of plant-derived vaccines and the current stage of plant-based expression system.

Avaliação da imunogenicidade de diferentes formas alélicas da proteí­na recombinante PvAMA-1expressa em Pichia pastoris: impacto da diversidade antigênica / Evaluation of the immunogenicity of different allelic forms of PvAMA-1 protein expressed in Pichia pastoris: impact of antigenic diversity

A malária é um problema de saúde pública no Brasil e no mundo. Em 2016, o número de casos estimado pela Organização Mundial de Saúde foi de 216 milhões. Plasmodium falciparum é a espécie mais prevalente e responsável pelo maior número de mortes no mundo, sobretudo no continente africano. Por outro lado, o Plasmodium vivax é conhecido por sua ampla distribuição geográfica, sendo a espécie que predomina nas Américas, incluindo o Brasil. Nos últimos 20 anos, nosso grupo tem gerado e caracterizado diversas proteínas recombinantes baseadas em antígenos imunodominantes de P. vivax que podem servir como base para o desenvolvimento de uma vacina contra malária. Entre os antígenos de merozoítas, uma das principais proteínas em estudo pelo nosso grupo é o Antígeno 1 de Membrana Apical de P. vivax (PvAMA-1), caracterizado previamente como altamente imunogênico em infecções naturais e em camundongos imunizados, na presença de diferentes adjuvantes. O objetivo do presente estudo foi investigar o efeito da diversidade antigênica dessa proteína no reconhecimento por anticorpos específicos e na indução de imunidade contra o parasita. Para isso, foram geradas seis novas proteínas representando diferentes alelos descritos na natureza: PvAMA-1-Belem, PvAMA-1-Sal-I, PvAMA-1-Chesson-I, PvAMA-1-SK0814-apical, PvAMA-1-Indonesia-XIX e PvAMA-1-PNG_62_MU. As proteínas recombinantes foram expressas em leveduras Pichia pastoris e purificadas em duas etapas cromatográficas. Em seguida, as imunizações em camundongos C57BL/6 foram realizadas com as proteínas administradas de forma isolada, ou em combinação, na presença do adjuvante agonista de TLR3 (Poly I:C). Por ELISA, observamos que todas as formulações foram capazes de induzir anticorpos IgG contra as proteínas homólogas e heterólogas, o que sugere que a diversidade antigênica entre as formas alélicas não compromete o reconhecimento. Os dados gerados no presente trabalho sugerem que uma formulação contendo mistura de diferentes alelos representando a proteína AMA-1 pode ser explorada para o desenvolvimento de uma vacina de ampla cobertura contra o P. vivax

Malaria is a public health problem in Brazil and throughout the world. In 2016, the World Health Organization estimated there were 216 million cases of malaria. Plasmodium falciparum is the most prevalent species and is responsible for the largest number of deaths, especially in the African continent. However, Plasmodium vivax is known for its wide geographic distribution, being the species that prevails in the Americas, including Brazil. In the last 20 years, our group has generated and characterized several recombinant proteins based on immunodominant antigens of P. vivax that can serve as a basis for the development of a malaria vaccine. Among the merozoite antigens, one of the main proteins studied by our group is P. vivax apical membrane antigen-1 (PvAMA-1), previously characterized as highly immunogenic in natural infections and immunized mice, in the presence of different adjuvants. The objective of this study was to investigate the effect of antigenic diversity of this protein in the recognition of specific antibodies and the induction of immunity against the parasite. For this, six new proteins were generated representing different alleles described in nature: PvAMA-1-Belem, PvAMA-1-Sal-i, PvAMA-1-Chesson-i, PvAMA-1-SK0814-apical, PvAMA-1-Indonesia-XIX, and PvAMA-1-PNG_62_MU. Recombinant proteins were expressed in Pichia pastoris yeast and purified by two chromatographic stages. Then, C57BL/6 mice were immunized with these proteins administered in isolation or in combination, in the presence of the TLR3 agonist adjuvant, Poly I:C. Using an enzyme-linked immunosorbent assay, we observed that all formulations induced IgG antibodies against homologous and heterologous proteins. This indicates that antigenic diversity between allele forms does not compromise recognition. This finding suggests that a formulation containing a mixture of different alleles representing the PvAMA-1 protein can be exploited for developing of a wide coverage vaccine against P. vivax

Marek's disease vaccine activates chicken macrophages

To provide insights into the role of innate immune responses in vaccine-mediated protection, we investigated the effect of Marek's disease (MD) vaccine, CVI988/Rispens, on the expression patterns of selected genes associated with activation of macrophages in MD-resistant and MD-susceptible chicken lines. Upregulation of interferon γ, interleukin (IL)-1β, IL-8, and IL-12 at different days post-inoculation (dpi) revealed activation of macrophages in both chicken lines. A strong immune response was induced in cecal tonsils of the susceptible line at 5 dpi. The highest transcriptional activities were observed in spleen tissues of the resistant line at 3 dpi. No increase in the population of CD3³ T cells was observed in duodenum of vaccinated birds at 5 dpi indicating a lack of involvement of the adaptive immune system in the transcriptional profiling of the tested genes. There was, however, an increase in the number of macrophages in the duodenum of vaccinated birds. The CVI988/Rispens antigen was detected in the duodenum and cecal tonsils of the susceptible line at 5 dpi but not in the resistant line. This study sheds light on the role of macrophages in vaccine-mediated protection against MD and on the possible development of new recombinant vaccines with enhanced innate immune system activation properties.

Prevención de la infección por Streptococcus del grupo B en gestantes / Prevention of Group B Streptococcal Infection in Pregnant Women / Prevenção da infecção pelo Streptococcus do grupo B as mulheres grávidas: Revisão do tema

Introducción: La infección neonatal por Streptococcus del Grupo B en mujeres gestantes es un problema creciente a nivel mundial y tiene múltiples consecuencias para el recién nacido, su prevención impacta directamente la morbi-mortalidad neonatal. Objetivo: Brindar al lector información relevante sobre la importancia clínica, nuevos métodos de tamizaje y formas de prevención de la infección por Streptococcus del Grupo B en gestantes, que será de utilidad para evitar complicaciones del binomio materno-fetal. Metodología: En esta revisión de la literatura, se estudiaron 53 artículos, abordando evidencia tanto en el ámbito local e internacional, utilizando las bases de datos PubMed, ScienceDirect y Google Scholar, dentro los criterios de búsqueda se tuvo en cuenta el año de publicación, incluyendo artículos que fueron publicados a partir del año 2011. Resultados: La comunidad internacional ha desarrollado guías y planes de prevención; en la actualidad, para una profilaxis y prevención adecuada se proponen diversos métodos, partiendo del tamizaje para las maternas, uso de antibióticos durante el embarazo y parto, además del desarrollo de vacunas maternas para prevenir infecciones. Conclusiones: La colonización por Streptococcus del Grupo B en gestantes y el riesgo que conlleva para el recién nacido y su madre, exige una constante actualización en técnicas de tamizaje, prevención y manejo. Numerosos avances en estos campos vienen llevándose a cabo en los últimos años y su fortalecimiento y desarrollo será clave para impactar positivamente la morbi-mortalidad materno-fetal. [Martínez-Sánchez LM, Restrepo-Arango M, Sánchez-Díaz E, Marín-Cárdenas JS,Gallego-González D,Vélez-Peláez MC. Prevención de la infección por Streptococcus del grupo B en gestantes. MedUNAB 2017; 20(2): 182-189].

Introduction: The neonatal infection by Group B Streptococcus in pregnant women is a growing problem worldwide and has multiple consequences for the newborn, so its prevention directly impacts neonatal morbimortality. Objective: To provide the reader with relevant information about the clinical importance, new screening methods and ways to prevent Group B Streptococcus infection in pregnant women which will be useful to avoid complications in the pairing of maternal-fetal. Methodology: In this review of literature, 53 articles were studied addressing local and international evidence by using PubMed, ScienceDirect and Google Scholar databases; within the search criteria the year of publication was taken into account to do so, thus articles published from 2011 were included. Results: The international community has developed guidelines and prevention plans for this infection. Currently, for an adequate prophylaxis and prevention, various methods are proposed such as the screening for expectant mothers, the use of antibiotics during pregnancy and childbirth, and the development of maternal immunization to prevent infections as well. Conclusions: The colonization by Group B Streptococcus in pregnant women and the risk that this entails to the newborn and his/her mother requires constant updating in techniques for screening, prevention and management of it. Numerous advances in these fields of study have been carried out in recent years, and this strengthening and its development will be the key to impact, in a positive way, the maternal-fetal morbimortality. [Martínez-Sánchez LM, Restrepo-Arango M, Sánchez-Díaz E, Marín-Cárdenas JS,Gallego-González D, Vélez-Peláez MC. Prevention of Group B Streptococcal Infection in Pregnant Women. MedUNAB 2017; 20(2): 182-189].

Introdução: A infecção neonatal pelo Streptococcus do Grupo B em mulheres grávidas é um problema crescente no mundo inteiro e tem múltiplas conseqüências para o recém-nascido. Sua prevenção afeta diretamente a morbidade e mortalidade neonatal. Objetivo: Oferecer ao leitor a informação relevante sobre a importância clínica, os novos métodos de seleção e as formas de prevenir a infecção por Streptococcus do Grupo B em mulheres grávidas, o que será muito útil para evitar as complicações tanto para a mãe quanto para o feto. Metodologia: Nesta revisão da literatura, foram estudados 53 artigos, ressaltando as evidências tanto no nível local como internacional y se utilizaram os bancos de dados em PubMed, ScienceDirect e Google Scholar. Um dos critérios da pesquisa foi verificar o ano da publicação e incluir somente os artigos publicados a partir de 2011. Resultados: Atualmente, a comunidade internacional desenvolveu diretrizes e planos de prevenção para a profilaxia e a prevenção adequada, propondo diversos métodos como: Atriagem materna, o uso de antibióticos durante a gravidez e o parto, além do desenvolvimento das vacinas maternas para preveniras infecções. Conclusões: A colonização por Streptococcus do Grupo B em mulheres grávidas e o risco que isso implica para o recém-nascido e sua mãe, requer uma atualização constante nas técnicas da triagem, da precaução e do tratamento. São numerosos os avanços realizados, nesta área, nos últimos anos. O seu fortalecimento e desenvolvimento são fundamentais para interferir positivamente na doença e na mortalidade materno-fetal. [Martínez-Sánchez LM, Restrepo-Arango M, Sánchez-Díaz E, Marín-Cárdenas JS, Gallego-González D, Vélez-Peláez MC. Prevenção da infecção pelo Streptococcus do grupo B nas mulheres grávidas: Revisão do tema. MedUNAB 2017; 20(2): 182-189].