A Computationally Optimized Broadly Reactive Antigen Subtype-Specific Influenza Vaccine Strategy Elicits Unique Potent Broadly Neutralizing Antibodies against Hemagglutinin.

Computationally optimized broadly reactive Ags (COBRA) targeting H1 elicit a broad cross-reactive and cross-neutralizing Ab response against multiple H1N1 viral strains. To assess B cell breadth, Mus musculus (BALB/c) Ab-secreting cells elicited by a candidate COBRA hemagglutinin (HA) (termed P1) were compared with Ab-secreting cells elicited by historical H1N1 vaccine strains. In addition, to evaluate the Ab response elicited by P1 HA at increased resolution, a panel of P1 HA-specific B cell hybridomas was generated following immunization of mice with COBRA P1 and the corresponding purified mAbs were characterized for Ag specificity and neutralization activity. Both head- and stem-directed mAbs were elicited by the P1 HA Ag, with some mAbs endowed with Ab-dependent cell-mediated cytotoxicity activity. P1 HA-elicited mAbs exhibited a wide breadth of HA recognition, ranging from narrowly reactive to broadly reactive mAbs. Interestingly, we identified a P1 HA-elicited mAb (1F8) exhibiting broad hemagglutination inhibition activity against both seasonal and pandemic H1N1 influenza strains. Furthermore, mAb 1F8 recognized an overlapping, but distinct, epitope compared with other narrowly hemagglutination inhibition-positive mAbs elicited by the P1 or wild-type HA Ags. Finally, P1 HA-elicited mAbs were encoded by distinct H chain variable and L chain variable gene segment rearrangements and possessed unique CDR3 sequences. Collectively, the functional characterization of P1 HA-elicited mAbs sheds further insights into the underlying mechanism(s) of expanded Ab breadth elicited by a COBRA HA-based immunogen and advances efforts toward design and implementation of a more broadly protective influenza vaccine.

Functional antibody-dependent cell mediated cytotoxicity (ADCC) responses to vaccine and circulating influenza strains following vaccination.

Novel cell-based assays were developed to assess antibody-dependence cellular cytotoxicity (ADCC) antibodies against both vaccine and a representative circulation strain HA and NA proteins for the 2014-15 influenza season. The four assays using target cells stably expressing one of the four proteins worked well. In pre- and post-vaccine sera from 70 participants in a pre-season vaccine trial, we found ADCC antibodies and a rise in ADCC antibody titer against target cells expressing the 4 proteins but a much higher titer for the vaccine than the circulating HA in both pre-and post-vaccine sera. These differences in HA ADCC antibodies were not reflected in differences in HA binding antibodies. Our observations suggested that relatively minor changes on the subtype HA can result in large differences in ADCC activity.

Impaired memory B-cell recall responses in the elderly following recurrent influenza vaccination.

Influenza is a highly contagious viral respiratory disease that affects million of people worldwide each year. Annual vaccination is recommended by the World Health Organization with the goal of reducing influenza severity and limiting transmission through elicitation of antibodies targeting the hemagglutinin (HA) glycoprotein. The antibody response elicited by current seasonal influenza virus vaccines is predominantly strain-specific, but pre-existing influenza virus immunity can greatly impact the serological antibody response to vaccination. However, it remains unclear how B cell memory is shaped by recurrent annual vaccination over the course of multiple seasons, especially in high-risk elderly populations. Here, we systematically profiled the B cell response in young adult (18-34 year old) and elderly (65+ year old) vaccine recipients that received annual split inactivated influenza virus vaccination for 3 consecutive seasons. Specifically, the antibody serological and memory B-cell compartments were profiled for reactivity against current and historical influenza A virus strains. Moreover, multiparametric analysis and antibody landscape profiling revealed a transient increase in strain-specific antibodies in the elderly, but with an impaired recall response of pre-existing memory B-cells, plasmablast (PB) differentiation and long-lasting serological changes. This study thoroughly profiles and compares the immune response to recurrent influenza virus vaccination in young and elderly participants unveiling the pitfalls of current influenza virus vaccines in high-risk populations.

Seasonal influenza vaccination does not effectively expand H2 cross-reactive antibodies in humans.

Influenza viruses cause millions of infections and hundreds of thousands of deaths every year. Influenza virus vaccinations are produced every year and contain H1N1 and H3N2 influenza A viruses and either one or two influenza B viruses. In this study, we examined the effects of seasonal influenza vaccinations in people on both circulating serum antibody titers and memory B-cell activation to H2Nx influenza viruses. In addition to evaluating the human cohort as a whole, participants were also divided into three separate groups based upon their likelihood of being either exposed to or imprinted with H2N2 influenza viruses in the 1950s and 1960s. While participants born after H2N2 influenza viruses left the human population had lower HAI, ELISA and neutralizing antibody titers to these viruses, a select number of cross-reactive antibodies to some of the H2 HA proteins were boosted after seasonal influenza vaccination. However, these results varied and were not consistent by age group or specific H2 HA protein. Overall, seasonal influenza vaccination did not significantly expand cross-reactive antibodies to H2 HA antigens.

SARS-CoV-2 mRNA Vaccines Elicit Different Responses in Immunologically Naïve and Pre-Immune Humans.

As the COVID-19 pandemic continues, the authorization of vaccines for emergency use has been crucial in slowing down the rate of infection and transmission of the SARS-CoV-2 virus that causes COVID-19. In order to investigate the longitudinal serological responses to SARS-CoV-2 natural infection and vaccination, a large-scale, multi-year serosurveillance program entitled SPARTA (SARS SeroPrevalence and Respiratory Tract Assessment) was initiated at 4 locations in the U.S. The serological assay presented here measuring IgG binding to the SARS-CoV-2 receptor binding domain (RBD) detected antibodies elicited by SARS-CoV-2 infection or vaccination with a 95.5% sensitivity and a 95.9% specificity. We used this assay to screen more than 3100 participants and selected 20 previously infected pre-immune and 32 immunologically naïve participants to analyze their antibody binding to RBD and viral neutralization (VN) responses following vaccination with two doses of either the Pfizer-BioNTech BNT162b2 or the Moderna mRNA-1273 vaccine. Vaccination not only elicited a more robust immune reaction than natural infection, but the level of neutralizing and anti-RBD antibody binding after vaccination is also significantly higher in pre-immune participants compared to immunologically naïve participants (p<0.0033). Furthermore, the administration of the second vaccination did not further increase the neutralizing or binding antibody levels in pre-immune participants (p=0.69). However, ~46% of the immunologically naïve participants required both vaccinations to seroconvert.

Functional characterization of SARS-CoV-2 vaccine elicited antibodies in immunologically naïve and pre-immune humans.

As the COVID-19 pandemic continues, the authorization of vaccines for emergency use has been crucial in slowing down the rate of infection and transmission of the SARS-CoV-2 virus that causes COVID-19. In order to investigate the longitudinal serological responses to SARS-CoV-2 natural infection and vaccination, a large-scale, multi-year serosurveillance program entitled SPARTA (SARS SeroPrevalence and Respiratory Tract Assessment) was initiated at 4 locations in the U.S. The serological assay presented here measuring IgG binding to the SARS-CoV-2 receptor binding domain (RBD) detected antibodies elicited by SARS-CoV-2 infection or vaccination with a 95.5% sensitivity and a 95.9% specificity. We used this assay to screen more than 3100 participants and selected 20 previously infected pre-immune and 32 immunologically naïve participants to analyze their antibody binding to RBD and viral neutralization (VN) responses following vaccination with two doses of either the Pfizer-BioNTech BNT162b2 or the Moderna mRNA-1273 vaccine. Vaccination not only elicited a more robust immune reaction than natural infection, but the level of neutralizing and anti-RBD antibody binding after vaccination is also significantly higher in pre-immune participants compared to immunologically naïve participants (p<0.0033). Furthermore, the administration of the second vaccination did not further increase the neutralizing or binding antibody levels in pre-immune participants (p=0.69). However, ~46% of the immunologically naïve participants required both vaccinations to seroconvert.

Convergent antibody evolution and clonotype expansion following influenza virus vaccination.

Recent advances in high-throughput single cell sequencing have opened up new avenues into the investigation of B cell receptor (BCR) repertoires. In this study, PBMCs were collected from 17 human participants vaccinated with the split-inactivated influenza virus vaccine during the 2016-2017 influenza season. A combination of Immune Repertoire Capture (IRCTM) technology and IgG sequencing was performed on ~7,800 plasmablast (PB) cells and preferential IgG heavy-light chain pairings were investigated. In some participants, a single expanded clonotype accounted for ~22% of their PB BCR repertoire. Approximately 60% (10/17) of participants experienced convergent evolution, possessing public PBs that were elicited independently in multiple participants. Binding profiles of one private and three public PBs confirmed they were all subtype-specific, cross-reactive hemagglutinin (HA) head-directed antibodies. Collectively, this high-resolution antibody repertoire analysis demonstrated the impact evolution can have on BCRs in response to influenza virus vaccination, which can guide future universal influenza prophylactic approaches.

IgA Responses Following Recurrent Influenza Virus Vaccination.

Influenza is a highly contagious viral respiratory disease that affects millions of people worldwide each year. Annual vaccination is recommended by the World Health Organization to reduce influenza severity and limit transmission through elicitation of antibodies targeting mainly the hemagglutinin glycoprotein of the influenza virus. Antibodies elicited by current seasonal influenza vaccines are predominantly strain-specific. However, continuous antigenic drift by circulating influenza viruses facilitates escape from pre-existing antibodies requiring frequent reformulation of the seasonal influenza vaccine. Traditionally, immunological responses to influenza vaccination have been largely focused on IgG antibodies, with almost complete disregard of other isotypes. In this report, young adults (18-34 years old) and elderly (65-85 years old) subjects were administered the split inactivated influenza vaccine for 3 consecutive seasons and their serological IgA and IgG responses were profiled. Moreover, correlation analysis showed a positive relationship between vaccine-induced IgA antibody titers and traditional immunological endpoints, exposing vaccine-induced IgA antibodies as an important novel immune correlate during influenza vaccination.

Preexisting subtype immunodominance shapes memory B cell recall response to influenza vaccination.

Influenza is a highly contagious viral pathogen with more than 200,000 cases reported in the United States during the 2017-2018 season. Annual vaccination is recommended by the World Health Organization, with the goal to reduce influenza severity and transmission. Currently available vaccines are about 60% effective, and vaccine effectiveness varies from season to season, as well as between different influenza subtypes within a single season. Immunological imprinting from early-life influenza infection can prominently shape the immune response to subsequent infections. Here, the impact of preexisting B cell memory in the response to quadrivalent influenza vaccine was assessed using blood samples collected from healthy subjects (18-85 years old) prior to and 21-28 days following influenza vaccination. Influenza vaccination increased both HA-specific antibodies and memory B cell frequency. Despite no apparent differences in antigenicity between vaccine components, most individuals were biased toward one of the vaccine strains. Specifically, responses to H3N2 were reduced in magnitude relative to the other vaccine components. Overall, this study unveils a potentially new mechanism underlying differential vaccine effectiveness against distinct influenza subtypes.

High-Yield Expression and Purification of Recombinant Influenza Virus Proteins from Stably-Transfected Mammalian Cell Lines.

Influenza viruses infect millions of people each year, resulting in significant morbidity and mortality in the human population. Therefore, generation of a universal influenza virus vaccine is an urgent need and would greatly benefit public health. Recombinant protein technology is an established vaccine platform and has resulted in several commercially available vaccines. Herein, we describe the approach for developing stable transfected human cell lines for the expression of recombinant influenza virus hemagglutinin (HA) and recombinant influenza virus neuraminidase (NA) proteins for the purpose of in vitro and in vivo vaccine development. HA and NA are the main surface glycoproteins on influenza virions and the major antibody targets. The benefits for using recombinant proteins for in vitro and in vivo assays include the ease of use, high level of purity and the ability to scale-up production. This work provides guidelines on how to produce and purify recombinant proteins produced in mammalian cell lines through either transient transfection or generation of stable cell lines from plasmid creation through the isolation step via Immobilized Metal Affinity Chromatography (IMAC). Collectively, the establishment of this pipeline has facilitated large-scale production of recombinant HA and NA proteins to high purity and with consistent yields, including glycosylation patterns that are very similar to proteins produced in a human host.

Pan-cirurgia ocular com um novo tipo de ceratoprótese temporária / Ocular surgery with a new model of temporary keratoprosthesis

Apresenta-se um tipo de ceratoprótese temporária que utilizou-se do modelo previamente proposto por Eckardt, moldado empolimetilmetacrilato, para ser usado em casos cirúrgicos que necessitem de boa visibilidade das estruturas de fundo de olho ocular, a qual estaria prejudicada, pelo dano ocorrido à córnea

Síndrome iridocórneo endotelial: novas opçöes para o tratamento / Endothelial iridocorneal syndrome: new option for treatment

Atrofia Essencial da Iris, Síndrome de Chandler e Síndrome de Coogan-Reese säo, atualmente, consideradas variaçöes de uma mesma patologia: Síndrome %) e seu controle é defícil. Portanto, o tratamento visa o controle da PIO e a manutençäo de uma boa acuidade visual. Os autores apresentam um caso de Síndrome de Coogan-Reese em uma paciente de 27 anos onde conseguiram restabelecer uma boa visäo através de uma pupiloplastia com Nd Yag Laser e o controle da PIO foi alcançado através do Implante de Molteno

Vitreo-retinopatia familial exsudativa: relato de uma família / Familial exudative vitreoretinopathy: report of a family

Os aa. apresentam 6 casos de vítreo-retinopatia familial exsudativa enfatizando os principais aspectos clínicos, oftalmoscópicos, angiográficos e ecográficos que permitiram o diagnóstico desta rara patologia. Fazem uma revisäo do assunto e concluem ser esta patologia de diagnótico fácil se analisada em conjunto, porém, em casos isolados o diagnóstico diferencial deve ser feito com a fibroplasia retrocristaliana e Doença de Coats, devendo sempre ser lembrada frente a um caso de leucocoria na infância

Atrofia girata de coróide e retina / Gyrate atrophy of choroid and retina

Os autores tecem comentários a respeito da atrofia girata da coróide e retina, com ênfase para os distúrbios genéticos e metabólicos como a hiperornitinemia. Apresentam um caso bastante avançado e discutem as possibilidades terapêuticas com doses elevadas de piridoxina

Retirada de lio via pars plana / Pars plana iol extraccion

Os autores apresentam, os resultados de 5 olhos com deslocamento de LIO de camara posterior para a cavidade vítrea, que foram submetidos a retirada da mesma via pars plana, enfatizando as poucas complicaçöes (hemorragia intra-ocular no pós-operatório 3/5) e o bom prognóstico visual. (1.0 em 3/5 e acima de 0.2 em 2/5)

Esclerite posterior; aspectos clínicos e ultra-sonográficos em dois casos / Posterior sclerits; clinicals and echograpic features in two cases

Apresentaçäo de 2 casos de esclerite posteiror. Abordam os principais aspectos clínicos e ecográficos que permitem o seu diagnóstico. Ressaltam a importância da ultra-sonografia como o exame complementar de maior utilidade para a confirmaçäo desta patologia

Edema macular cistóide / Cystoid macular edema

Dez casos de Edema Macular Cistóide de etiologia variável foram tratados com Triamcinolona e Acetazolamida. Houve melhora objetiva (uma a duas linhas na tabela de Snellen) e/ou subjetiva em todos eles

Cirurgia do descolamento da retina: revisäo de 76 olhos operados no IPB / Retinal detachment surgery: folow-up of 76 eyes

Os autores apresentam sua experiência de descolamento da retina usando a técnica de Michels, em 76 pacientes no Instituto Penido Burnier. Apresenta-se a análise estatística dos resultados, segundo o tipo específico de descolamento, motivo das conclusöes