ABSTRACT
Humoral response to SARS-CoV-2 has been studied, predominantly the classical IgG and its subclasses. Although IgE antibodies are typically specific to allergens or parasites, a few reports describe their production in response to SARS-CoV-2 and other viruses. Here, we investigated IgE specific to receptor binding domain (RBD) of SARS-CoV-2 in a Brazilian cohort following natural infection and vaccination. Samples from 59 volunteers were assessed after infection (COVID-19), primary immunization with vectored (ChAdOx1) or inactivated (CoronaVac) vaccines, and booster immunization with mRNA (BNT162b2) vaccine. Natural COVID-19 induced IgE, but vaccination increased its levels. Subjects vaccinated with two doses of ChAdOx1 exhibited a more robust response than those immunized with two doses of CoronaVac; however, after boosting with BNT162b2, all groups presented similar IgE levels. IgE showed intermediate-to-high avidity, especially after the booster vaccine. We also found IgG4 antibodies, mainly after the booster, and they moderately correlated with IgE. ELISA results were confirmed by control assays, using IgG depletion by protein G and lack of reactivity with heterologous antigen. In our cohort, no clinical data could be associated with the IgE response. We advocate for further research on IgE and its role in viral immunity, extending beyond allergies and parasitic infections.
Subject(s)
Antibodies, Viral , COVID-19 Vaccines , COVID-19 , Immunoglobulin E , Immunoglobulin G , SARS-CoV-2 , Spike Glycoprotein, Coronavirus , Humans , Immunoglobulin E/immunology , SARS-CoV-2/immunology , COVID-19/immunology , COVID-19/prevention & control , COVID-19/virology , COVID-19 Vaccines/immunology , Antibodies, Viral/immunology , Male , Female , Adult , Immunoglobulin G/immunology , Immunoglobulin G/blood , Spike Glycoprotein, Coronavirus/immunology , Middle Aged , Brazil , BNT162 Vaccine/immunology , Vaccination , Immunization, Secondary , Young AdultABSTRACT
COVID-19, caused by SARS-CoV-2, and meningococcal disease, caused by Neisseria meningitidis, are relevant infectious diseases, preventable through vaccination. Outer membrane vesicles (OMVs), released from Gram-negative bacteria, such as N. meningitidis, present adjuvant characteristics and may confer protection against meningococcal disease. Here, we evaluated in mice the humoral and cellular immune response to different doses of receptor binding domain (RBD) of SARS-CoV-2 adjuvanted by N. meningitidis C:2a:P1.5 OMVs and aluminum hydroxide, as a combined preparation for these pathogens. The immunization induced IgG antibodies of high avidity for RBD and OMVs, besides IgG that recognized the Omicron BA.2 variant of SARS-CoV-2 with intermediary avidity. Cellular immunity showed IFN-γ and IL-4 secretion in response to RBD and OMV stimuli, demonstrating immunologic memory and a mixed Th1/Th2 response. Offspring presented transferred IgG of similar levels and avidity as their mothers. Humoral immunity did not point to the superiority of any RBD dose, but the group immunized with a lower antigenic dose (0.5 µg) had the better cellular response. Overall, OMVs enhanced RBD immunogenicity and conferred an immune response directed to N. meningitidis too.
Subject(s)
Antibodies, Viral , COVID-19 , Immunoglobulin G , Neisseria meningitidis , SARS-CoV-2 , Animals , Mice , Immunoglobulin G/blood , Neisseria meningitidis/immunology , Female , Antibodies, Viral/blood , Antibodies, Viral/immunology , COVID-19/prevention & control , COVID-19/immunology , SARS-CoV-2/immunology , Adjuvants, Immunologic/administration & dosage , COVID-19 Vaccines/immunology , COVID-19 Vaccines/administration & dosage , Immunity, Cellular , Immunity, Humoral , Mice, Inbred BALB C , Meningococcal Infections/prevention & control , Meningococcal Infections/immunology , Spike Glycoprotein, Coronavirus/immunology , Adjuvants, Vaccine/administration & dosage , Aluminum Hydroxide/administration & dosage , Aluminum Hydroxide/immunology , Immunization/methods , Antibody Affinity , Antibodies, Bacterial/blood , Antibodies, Bacterial/immunology , Meningococcal Vaccines/immunology , Meningococcal Vaccines/administration & dosage , Immunologic Memory , Th1 Cells/immunologyABSTRACT
O Instituto Adolfo Lutz (IAL) foi criado em 1940 como resultado da unificação dos Institutos Bacteriológico e Bromatológico, um moderno laboratório voltado ao controle de doenças, inaugurando uma nova fase de laboratórios de saúde pública no estado de São Paulo. Os primeiros testes sorológicos oferecidos à população foram executados pelas "antigas" Seções de Sorologia e de Imunologia. Essas seções destacam-se no desenvolvimento científico do IAL pela realização de pesquisas, produção científica e inovação tecnológica, seguramente, fundamentais para a saúde pública no decorrer dos anos. O Centro de Imunologia do IAL (CIM-IAL) foi criado em 2010, com a unificação das Seções de Sorologia e Imunologia, quando ocorreu a reorganização institucional. O CIM-IAL contribuiu para importantes avanços científicos na área da saúde, reforçando sua capacidade de desenvolver pesquisas, executar e monitorar o diagnóstico e a vigilância de diferentes agravos. Este manuscrito tem como objetivo apresentar os principais acontecimentos que ressaltam o papel fundamental na busca de soluções para os problemas de saúde pública, desde a época das Seções de Sorologia e Imunologia até tornar-se o Centro de Imunologia. Na elaboração deste trabalho foram utilizadas bibliografias contendo dados históricos, científicos e relatos de profissionais da área.
A new phase of Public Health Laboratories in the state of São Paulo occurred in 1940, with the unification of Instituto Bacteriológico and Bromatológico, creating the Instituto Adolfo Lutz (IAL), a modern laboratory focused on solving problems in this area. The first diagnostic tests offered to the population were carried out by the "old" Serology and Immunology Sections. It's worth highlighting the importance of these sections in the scientific development of the IAL by carrying out research, scientific production and technological innovation, which have certainly been fundamental to public health over the years. The Immunology Center (CIM) of IAL was created in 2010, when organizational adaptation took place with the junction of the Serology and Immunology Sections. The CIM-IAL has undergone important advances in the health area, reinforcing its capacity to develop research, carry out and monitor the diagnosis and surveillance of different diseases. This manuscript aims to present the main events that highlight the fundamental role in the search for solutions to public health problems, from the time of the Serology and Immunology Sections until it became the CIM. In the preparation, bibliographies were used based on historical and scientific data and reports from professionals in the field.
ABSTRACT
Invasive meningococcal disease (IMD), caused by Neisseria meningitidis, is a public health problem, associated with high levels of morbidity and mortality, capable of causing outbreaks or epidemics, but preventable through vaccination. In Brazil, the main serogroups isolated are C and B. The last epidemic occurred in the '80s, in São Paulo, because of a B:4:P1.15 strain. Adult Swiss mice were immunized with outer membrane vesicles (OMV) of N. meningitidis strain C:4:P1.15, adjuvanted by the cationic lipid dioctadecyldimethylammonium bromide in bilayer fragments (DDA-BF), administered via prime-booster (intranasal/subcutaneous) scheme. The humoral response was assessed by Immunoblotting and ELISA, using homologous immunization strain and a different serogroup but equal serosubtype strain, N. meningitidis B:4:P1.15. Immunoblotting revealed the recognition of antigens associated with the molecular weight of Porin A and Opacity proteins, which are immunogenic but highly heterogeneous, and Tbp and NspA, which are more homogeneous between meningococci strains. ELISA results showed antibody production that persisted after 190 days and recognized the C:4:P1.15 and the B:4:P1.15 strains, with high avidity index. The adjuvanted group recognized antigens following the IN prime and had a higher avidity index against the heterologous strain. DDA-BF improved the humoral response, but the OMV alone induced high avidity index antibodies as well. Even though these are preliminary results, we see it as a promising approach for affordable meningococcal immunization in developing countries, at outbreak or epidemic situations. (AU)
Subject(s)
Bromides , Immunization , Cross Reactions , Meningitis, Meningococcal , Neisseria meningitidisABSTRACT
The avidity index (AI) measures the binding strength between the antibody and the antigen, reflecting the affinity maturation. It can be measured by a modified ELISA, adding a chaotropic agent to disrupt the antigen x antibody interaction. However, details of the protocols used affect the final results. We compared the AI of mice sera after a three-dose immunization with meningococcal antigens using different adjuvants. The AI was assessed using potassium thiocyanate (KSCN) and urea as chaotropic agents, incubated at 4 °C, room temperature (RT) and 37 °C. KSCN presented statistically different results when the incubation was set at 4 °C vs RT and 4 °C vs 37 °C, thus, the mean AI obtained were lower. For Urea, 4 °C vs 37 °C presented relevant differences. Using whole-cells suspensions or OMVs as coating antigen provided similar results in some protocols. Thus, the affinity maturation was assessed after each immunization dose and adjuvant use (aluminium hydroxide and dimethyldioctadecylammonium bromide) supported affinity maturation. It is important to study the AI as a functional parameter of humoral response, and both KSCN and Urea are suitable chaotropic agents, however, the protocols should be standardized considering the nature of the antigen, the chaotropic activity and overall laboratory conditions. Adjuvants are important tools to improve antibody avidity following immunization.
Subject(s)
Antigens , Immunoglobulin G , Animals , Mice , Temperature , Enzyme-Linked Immunosorbent Assay/methods , Antibody Affinity , Vaccination , UreaABSTRACT
Adjuvants are important components of vaccines, increasing immunogenicity and modulating the immune response. SARS-CoV-2 vaccines are still being developed in order to improve worldwide access to immunization. Specific populations should be addressed in these investigations, such as pregnant women-to protect both mothers and neonates. In this study, female adult mice were immunized with Receptor-binding domain (RBD) from SARS-CoV-2 adjuvanted by a mixture of DDA and Saponin and put to mating to verify the maternal transference of IgG. For comparison, other group received RBD adjuvanted by OMVs from Neisseria meningitidis and Alum. The adjuvants enhanced IgG production and neutralization. DDA/Sap contributed to increase IgG1, IgG2a, IgG2b, and IgG3 isotypes. Total IgG avidity was considered high, as well as IgG1, IgG2a, and IgG2b avidity. IgG antibodies were effectively transferred to the offspring, predominantly IgG2a, IgG2b, and IgG3. The passive transferred immunoglobulin maintained the neutralizing ability, although it lost avidity. ELISA data was confirmed in Dot-ELISA and immunoblotting assays. DDA and Saponin seem a promising adjuvant mixture to enhance the humoral response of SARS-CoV-2 antigens. Further studies considering the effects of maternal immunization in the protection of offspring are needed, regardless the platform used in COVID-19 vaccines.
Subject(s)
COVID-19 , Saponins , Animals , Female , Humans , Mice , Pregnancy , Adjuvants, Immunologic , Antibodies, Neutralizing , Antibodies, Viral , COVID-19/prevention & control , COVID-19 Vaccines , Immunoglobulin G , SARS-CoV-2ABSTRACT
BACKGROUND: Immunization is the key to prevent invasive meningococcal disease (IMD), caused by Neisseria meningitidis. Outer membrane vesicles (OMVs) can be used as meningococcal antigens. METHODS: Isogenic mice A/Sn (H2a) were immunized with low antigenic doses of OMVs of an N. meningitidis C:2a:P1.5 strain, via intranasal/intramuscular route, adjuvanted by cholera toxin subunit B (CTB) or via intramuscular route only, adjuvanted by aluminium hydroxide (AH). Mice were followed until old age and humoral and cellular responses were assessed by ELISA, Immunoblotting, Dot-blot, Serum-bactericidal assay, Immunohistochemistry and ELISpot. RESULTS: OMV+CTB and OMV+AH groups presented statistically higher antibodies titers, which persisted until middle and old ages. IgG isotypes point to a Th2 type of response. Avidity indexes were considered high, regardless of adjuvant use, but only groups immunized with OMVs and adjuvants (OMV+CTB and OMV+AH) presented bactericidal activity. The antibodies recognized antigens of molecular weights attributed to porin and cross-reactivity proteins. Although the spleen of old mice did not present differences in immunohistochemistry marking of CD68+, CD4+, CD79+ and CD25+ cells, splenocytes of immune groups secreted IL-4 and IL-17 when stimulated with OMVs and meningococcal C polysaccharide. CONCLUSION: We concluded that both adjuvants, CTB and AH, improved the immunogenicity of low doses of OMVs and contributed to a persistent immune response. Even though AH is well established in the vaccinology area, CTB seems to be a promising adjuvant candidate for meningococcal vaccines: it is suitable for mucosal delivery and supports a Th2 type of response. Therefore, OMVs are still a relevant vaccine platform.
Subject(s)
Meningococcal Vaccines , Neisseria meningitidis, Serogroup C , Neisseria meningitidis , Adjuvants, Immunologic , Aluminum Hydroxide , Animals , Antibodies, Bacterial , Cholera Toxin , Immunization , Immunoglobulin G , Immunologic Memory , Interleukin-17 , Interleukin-4 , Mice , Polysaccharides , Porins , SerogroupABSTRACT
The meningococcal disease is a global health threat, but is preventable through vaccination. Adjuvants improve meningococcal vaccines and are able to trigger different aspects of the immune response. The present work evaluated the immune response of mice against Neisseria meningitidis outer membrane vesicles (OMV) complexed with the adjuvants aluminium hydroxide (AH), via subcutaneous route; and dimethyldioctadecylammonium bromide (DDA) or Saponin (Sap), via intranasal/subcutaneous routes. ELISA demonstrated that all adjuvants increased IgG titers after the booster dose, remaining elevated for 18 months. Additionally, adjuvants increased the avidity of the antibodies and the bactericidal titer: OMVs alone were bactericidal until 1:4 dilution but, when adjuvanted by Alum, DDA or Sap, it increased to 1/32. DDA and Sap increased all IgG isotypes, while AH improved IgG1 and IgG2a levels. Thus, Sap led to the recognition of more proteins in Immunoblot, followed by DDA and AH. Sap and AH induced higher IL-4 and IL-17 release, respectively. The use of adjuvants improved both cellular and humoral immune response, however, each adjuvant contributed to particular parameters. This demonstrates the importance of studying different adjuvant options and their suitability to stimulate different immune mechanisms, modulating the immune response.
ABSTRACT
Vaccines are the most effective tool to control infectious diseases, which provoke significant morbidity and mortality rates. Most vaccines are administered through the parenteral route and can elicit a robust systemic humoral response, but they induce a weak T-cell-mediated immunity and are poor inducers of mucosal protection. Considering that most pathogens enter the body through mucosal surfaces, a vaccine that elicits protection in the first site of contact between the host and the pathogen is promising. However, despite the advantages of mucosal vaccines as good options to confer protection on the mucosal surface, only a few mucosal vaccines are currently approved. In this review, we discuss the impact of vaccine administration in different mucosal surfaces; how appropriate adjuvants enhance the induction of protective mucosal immunity and other factors that can influence the mucosal immune response to vaccines.
Subject(s)
Immunity, Mucosal , Vaccines , Adjuvants, Immunologic , Mucous Membrane , VaccinationSubject(s)
COVID-19 Vaccines , COVID-19 , COVID-19/prevention & control , Humans , Immunity, Innate , SARS-CoV-2 , VaccinationABSTRACT
The Enzyme-Linked Immunosorbent Assay is a versatile technique, which can be used for several applications. It has enormously contributed to the study of infectious diseases. This review highlights how this methodology supported the science conducted in COVID-19 pandemics, allowing scientists to better understand the immune response against SARS-CoV-2. ELISA can be modified to assess the functionality of antibodies, as avidity and neutralization, respectively by the standardization of avidity-ELISA and surrogate-neutralization methods. Cellular immunity can also be studied using this assay. Products secreted by cells, like proteins and cytokines, can be studied by ELISA or its derivative Enzyme-linked immunospot (ELISpot) assay. ELISA and ELISA-based methods aided the area of immunology against infectious diseases and is still relevant, for example, as a promising approach to study the differences between natural and vaccine-induced immune responses against SARS-CoV-2.
ABSTRACT
Since late 2019 and early 2020, with the emergence of the COVID-19 pandemic, scientists are rushing to develop treatment and prevention methods to combat SARS-CoV-2. Among these are vaccines. In view of this, the use of animals as experimental models, both to investigate the immunopathology of the disease and to evaluate the efficacy and safety of vaccines, is mandatory. This work aims to describe, through recent scientific articles found in reliable databases, the animal models used for the in vivo testing of COVID-19 vaccines, demonstrating some possibilities of more advantageous/gold-standard models for SARS-CoV-2 vaccines. The majority of the studies use rodents and primates. Meanwhile, the most adequate model to be used as the gold standard for in vivo tests of COVID-19 vaccines is not yet conclusive. Promising options are being discussed as new tests are being carried out and new SARS-CoV-2 variants are emerging.
ABSTRACT
Many aspects of the humoral immune response to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), such as its role in protection after natural infection, are still unclear. We evaluated IgA and IgG response to spike subunits 1 and 2 (S1 and S2) and Nucleocapsid proteins of SARS-COV-2 in serum samples of 109 volunteers with viral RNA detected or seroconversion with different clinical evolution (asymptomatic, mild, moderate, and severe coronavirus disease 2019), using the ViraChip® Test Kit. We observed that the quantification of antibodies to all antigens had a positive correlation to disease severity, which was strongly associated with the presence of comorbidities. Seroreversion was not uncommon even during the short (median of 77 days) observation, occurring in 15% of mild-asymptomatic cases at a median of 55 days for IgG and 46 days for IgA. The time to reach the maximal antibody response did not differ significantly among recovered and deceased volunteers. Our study illustrated the dynamic of anti-S1, anti-N, and anti-S2 IgA and IgG antibodies, and suggests that high production of IgG and IgA does not guarantee protection to disease severity and that functional responses that have been studied by other groups, such as antibody avidity, need further attention.
Subject(s)
Antibodies, Viral/blood , COVID-19/immunology , Coronavirus Nucleocapsid Proteins/immunology , SARS-CoV-2/immunology , Spike Glycoprotein, Coronavirus/immunology , Adult , Aged , Aged, 80 and over , Female , Humans , Immunoglobulin A/blood , Immunoglobulin G/blood , Male , Middle Aged , Phosphoproteins/immunology , Seroconversion , Young AdultABSTRACT
Many aspects of the humoral immune response to severe acute respiratory syn-drome coronavirus 2 (SARSCoV2), such as its role in protection after natural in-fection, are still unclear. We evaluated IgA and IgG response to spike subunits 1 and2 (S1 and S2) and Nucleocapsid proteins of SARSCOV2 in serum samples of 109volunteers with viral RNA detected or seroconversion with different clinical evolu-tion (asymptomatic, mild, moderate, and severe coronavirus disease 2019), using theViraChip®Test Kit. We observed that the quantification of antibodies to all antigenshad a positive correlation to disease severity, which was strongly associated with thepresence of comorbidities. Seroreversion was not uncommon even during the short(median of 77 days) observation, occurring in 15% of mildasymptomatic cases at amedian of 55 days for IgG and 46 days for IgA. The time to reach the maximalantibody response did not differ significantly among recovered and deceased vo-lunteers. Our study illustrated the dynamic of antiS1, antiN, and antiS2 IgA andIgG antibodies, and suggests that high production of IgG and IgA does not guaranteeprotection to disease severity and that functional responses that have been studiedby other groups, such as antibody avidity, need further attention. (AU)
Subject(s)
Nucleocapsid , Protein Array Analysis , Spike Glycoprotein, Coronavirus , SARS-CoV-2 , COVID-19ABSTRACT
SARS-CoV-2 is considered a global emergency, resulting in an exacerbated crisis in the health public in the world. Although there are advances in vaccine development, it is still limited for many countries. On the other hand, an immunological response that mediates protective immunity or indicates that predict disease outcome in SARS-CoV-2 infection remains undefined. This work aimed to assess the antibody levels, avidity, and subclasses of IgG to RBD protein, in symptomatic patients with severe and mild forms of COVID-19 in Brazil using an adapted in-house RBD-IgG ELISA. The RBD IgG-ELISA showed 100% of specificity and 94.3% of sensibility on detecting antibodies in the sera of hospitalized patients. Patients who presented severe COVID-19 had higher anti-RBD IgG levels compared to patients with mild disease. Additionally, most patients analyzed displayed low antibody avidity, with 64.4% of the samples of patients who recovered from the disease and 84.6% of those who died in this avidity range. Our data also reveals an increase of IgG1 and IgG3 levels since the 8th day after symptoms onset, while IgG4 levels maintained less detectable during the study period. Surprisingly, patients who died during 8-14 and 15-21 days also showed higher anti-RBD IgG4 levels in comparison with the recovered (P < 0.05), suggesting that some life-threatening patients can elicit IgG4 to RBD antibody response in the first weeks of symptoms onset. Our findings constitute the effort to clarify IgG antibodies' kinetics, avidity, and subclasses against SARS-CoV-2 RBD in symptomatic patients with COVID-19 in Brazil, highlighting the importance of IgG antibody avidity in association with IgG4 detection as tool laboratory in the follow-up of hospitalized patients with more significant potential for life-threatening.
Subject(s)
Antibodies, Viral , Antibody Affinity , COVID-19 , Immunoglobulin G , SARS-CoV-2 , Adult , Aged , Aged, 80 and over , Antibodies, Viral/blood , Antibodies, Viral/immunology , Brazil/epidemiology , COVID-19/blood , COVID-19/epidemiology , COVID-19/immunology , Female , Humans , Immunoglobulin G/blood , Immunoglobulin G/immunology , Male , Middle Aged , SARS-CoV-2/immunology , SARS-CoV-2/metabolismABSTRACT
Antibody avidity is an important parameter to evaluate immune response, being useful to evaluate vaccine responses and helping to distinguish acute and latent infection. The antibody avidity can be measured by different methods, yet the most common is a modified ELISA. The utilization of commercial kits or in-house methods to evaluate antibody avidity have been adopted more and more, although the lack of standardization between different assays may generate a lot of variation in the process, making it hard to compare the results generated.
Subject(s)
Immunoglobulin G , Antibody Affinity , Enzyme-Linked Immunosorbent Assay , Humans , Reference StandardsABSTRACT
Although COVID-19 vaccines have recently been approved for emergency use, search for new vaccines are still urgent, since the access of the countries, especially the poorest, to the vaccines, has shown to be slower than the necessary to rapidly control the pandemic. We proposed a novel platform for vaccine using recombinant receptor binding domain (rRBD) from Sars-Cov-2 spike protein and Neisseria meningitidis outer membrane vesicles (OMVs). The antigen preparation produced a humoral and cellular immune response. Taken together our findings suggest a good immunostimulatory patter in response to immunization with rRBD plus N. meningitidis OMV.
Subject(s)
COVID-19 , Meningococcal Vaccines , Vaccines , Bacterial Outer Membrane Proteins , COVID-19 Vaccines , Humans , SARS-CoV-2 , Spike Glycoprotein, CoronavirusABSTRACT
SARS-CoV-2 is considered a global emergency, resulting in an exacerbated crisis in the health public in the world. Although there are advances in vaccine development, it is still limited for many countries. On the other hand, an immunological response that mediates protective immunity or indicates that predict disease outcome in SARS-CoV-2 infection remains undefned. This work aimed to assess the antibody levels, avidity, and subclasses of IgG to RBD protein, in symptomatic patients with severe and mild forms of COVID-19 in Brazil using an adapted in-house RBD-IgG ELISA. The RBD IgG-ELISA showed 100% of specifcity and 94.3% of sensibility on detecting antibodies in the sera of hospitalized patients. Patients who presented severe COVID-19 had higher anti-RBD IgG levels compared to patients with mild disease. Additionally, most patients analyzed displayed low antibody avidity, with 64.4% of the samples of patients who recovered from the disease and 84.6% of those who died in this avidity range. Our data also reveals an increase of IgG1 and IgG3 levels since the 8th day after symptoms onset, while IgG4 levels maintained less detectable during the study period. Surprisingly, patients who died during 814 and 1521 days also showed higher anti-RBD IgG4 levels in comparison with the recovered (P< 0.05), suggesting that some life-threatening patients can elicit IgG4 to RBD antibody response in the frst weeks of symptoms onset. Our fndings constitute the efort to clarify IgG antibodies' kinetics, avidity, and subclasses against SARS-CoV-2 RBD in symptomatic patients with COVID-19 in Brazil, highlighting the importance of IgG antibody avidity in association with IgG4 detection as tool laboratory in the follow-up of hospitalized patients with more signifcant potential for life-threatening. (AU)