Production of Zika virus-like particles (VLPs) by perfusion processes

Zika virus (ZIKV) emerged as a major international public health concern in 2015 and rapidly spread to more than 80 countries in Africa, Asia and the Americas. ZIKV infection has been shown to cause Guillain-Barré syndrome in adults, as well as severe congenital malformations in fetuses from as much as 42% of infected mothers (Brasil et al., 2016, doi:10.1056/NEJMoa1602412). While no ZIKV vaccine becomes approved for human use, periodic outbreaks will continue to occur in endemic regions and the risk of spreading to non-endemic regions will continue to exist, especially because ZIKV persists in body fluids for very long time after infection and can be transmitted via the sexual route. Among many different vaccine platforms currently under study, virus-like particles (VLPs) are a promising alternative for the development of vaccines, since three-dimensional structures, constituted by recombinant structural proteins of the virus but lacking the viral genome, are able to display the antigen in a repetitive pattern, triggering a robust immune response. In this work, we investigated the production of Zika virus-like particles by both intermittent and continuous perfusion processes, using a recombinant HEK293 cell pool previously generated in our laboratory, which constitutively expresses the VLPs. In order to improve production levels, we first enriched the recombinant cell pool for high producers by means of fluorescence-activated cell sorting (FACS). Using this FACS-enriched cell pool, small-scale shake flask studies showed that intermittent perfusion (also known as pseudoperfusion) with daily medium exchange enhanced viable cell density by 3.5 fold and VLP titer by 4 fold when compared to batch cultures. Continuous perfusion in a controlled stirred-tank bioreactor was carried out using an ATF-2 unit as cell retention device. A steady-state viable cell concentration of 25-30 × 106 cells/mL was maintained at a cell-specific perfusion rate (CSPR) of 50-60 pL/cell/day. VLP titers inside the bioreactor were higher than in the harvest, evidencing product retention by the ATF hollow fiber, especially from day 14 of cultivation on. Our results show that the use of cell lines constitutively expressing zika VLPs, cultured in stirred-tank perfusion bioreactors, represents a promising system for the production of a VLP-based Zika vaccine candidate. This process could potentially be more cost-effective than traditional viral vaccine platforms based on batch production of whole viruses, especially considering that VLPs can be produced in lower biosafety level plants, and that perfusion systems are characterized by higher volumetric productivities, reduced bioreactor sizes, smaller plant footprint and lower investment costs when compared to batch processes

Perfusion process for the production of a new, VLP-based yellow fever vaccine candidate

Yellow fever (YF) is an acute viral hemorrhagic disease endemic in tropical areas of Africa, Central and South America, which is transmitted by the bite of infected mosquitoes. It is a “historically devastating disease” (Paules and Fauci, 2017) that killed during outbreaks in past centuries, before the introduction of the current vaccine, approximately 10% of the population of cities like Philadelphia (USA) and Barcelona (Spain). According to Garske et al. (2014), YF caused in 2013 78,000 deaths worldwide, which is a disease burden comparable to influenza. In the past few years, outbreaks in Angola (2016) and in Brazil (2017-2018) led to the depletion of the WHO vaccine stockpile and to the introduction of the emergency use of a fractional dose (1/5). Furthermore, the Angola outbreak in 2016 caused the first cases of YF ever to occur in Asia (11 imported cases to China), rising the concern about approximately 2 billion immunologically naïve people who would be at high risk in Asia in case local transmission of the virus starts to occur (Wilder-Smith et al., 2019). The urgent need for a new YF vaccine becomes evident from two major issues concerning the current vaccine, which consists of a live-attenuated virus propagated in chicken embryos: (i) vaccine shortage due to limitations in the manufacturing technology; (ii) rare, but fatal adverse effects. Therefore, this work focuses on the development of a safe, non-replicating YF vaccine, produced by a high-productivity perfusion process. Stable recombinant HEK293 cell lines constitutively expressing the structural proteins prM (pre-membrane) and E (envelope) of YFV were generated, enabling long-term production and secretion of recombinant virus-like particles (VLPs). FACS (fluorescence activated cell sorting) was used to sort the transfected population for high producer cells and allowed obtaining an enriched cell pool producing significantly higher amounts of VLPs. Small scale kinetic studies under intermittent perfusion (pseudoperfusion) were performed in order to investigate possible feeding strategies and to evaluate the use of short-chain fatty acids as productivity enhancers. Subsequently, perfusion runs were carried out in stirred-tank bioreactors in order to investigate optimal conditions for VLP production, as well as to evaluate different cell retention devices (e.g. inclined lamella settler and ATF-2). Partial retention of the VLPs in the perfusion bioreactor system occurred when the ATF-2 was used. VLPs produced by perfusion were purified by a two-step chromatographic process, and transmission electron microscopy (TEM) images confirmed the expected size and morphology of the VLPs, enabling their use in mouse immunogenicity studies. References: Garske T, Van Kerkhove MD, Yactayo S, Ronveaux O, Lewis RF, Staples JE, Perea W, Ferguson NM, Yellow Fever Expert Committee (2014). Yellow fever in Africa: estimating the burden of disease and impact of mass vaccination from outbreak and serological data. PLoS Medicine 11:e1001638. Paules CI, Fauci AS (2017), Yellow fever - once again on the radar screen in the Americas, N Engl J Med 376: 1397-1399. Wilder-Smith A, Lee V, Gubler DJ (2019), Yellow fever: is Asia prepared for an epidemic? The Lancet 19:241-242

Brazilian Consensus on Photoprotection

Brazil is a country of continental dimensions with a large heterogeneity of climates and massive mixing of the population. Almost the entire national territory is located between the Equator and the Tropic of Capricorn, and the Earth axial tilt to the south certainly makes Brazil one of the countries of the world with greater extent of land in proximity to the sun. The Brazilian coastline, where most of its population lives, is more than 8,500 km long. Due to geographic characteristics and cultural trends, Brazilians are among the peoples with the highest annual exposure to the sun. Epidemiological data show a continuing increase in the incidence of nonmelanoma and melanoma skin cancers. Photoprotection can be understood as a set of measures aimed at reducing sun exposure and at preventing the development of acute and chronic actinic damage. Due to the peculiarities of Brazilian territory and culture, it would not be advisable to replicate the concepts of photoprotection from other developed countries, places with completely different climates and populations. Thus the Brazilian Society of Dermatology has developed the Brazilian Consensus on Photoprotection, the first official document on photoprotection developed in Brazil for Brazilians, with recommendations on matters involving photoprotection

Catálogo Taxonômico da Fauna do Brasil: setting the baseline knowledge on the animal diversity in Brazil

The limited temporal completeness and taxonomic accuracy of species lists, made available in a traditional manner in scientific publications, has always represented a problem. These lists are invariably limited to a few taxonomic groups and do not represent up-to-date knowledge of all species and classifications. In this context, the Brazilian megadiverse fauna is no exception, and the Catálogo Taxonômico da Fauna do Brasil (CTFB) (http://fauna.jbrj.gov.br/), made public in 2015, represents a database on biodiversity anchored on a list of valid and expertly recognized scientific names of animals in Brazil. The CTFB is updated in near real time by a team of more than 800 specialists. By January 1, 2024, the CTFB compiled 133,691 nominal species, with 125,138 that were considered valid. Most of the valid species were arthropods (82.3%, with more than 102,000 species) and chordates (7.69%, with over 11,000 species). These taxa were followed by a cluster composed of Mollusca (3,567 species), Platyhelminthes (2,292 species), Annelida (1,833 species), and Nematoda (1,447 species). All remaining groups had less than 1,000 species reported in Brazil, with Cnidaria (831 species), Porifera (628 species), Rotifera (606 species), and Bryozoa (520 species) representing those with more than 500 species. Analysis of the CTFB database can facilitate and direct efforts towards the discovery of new species in Brazil, but it is also fundamental in providing the best available list of valid nominal species to users, including those in science, health, conservation efforts, and any initiative involving animals. The importance of the CTFB is evidenced by the elevated number of citations in the scientific literature in diverse areas of biology, law, anthropology, education, forensic science, and veterinary science, among others

ATLANTIC EPIPHYTES: a data set of vascular and non-vascular epiphyte plants and lichens from the Atlantic Forest

Epiphytes are hyper-diverse and one of the frequently undervalued life forms in plant surveys and biodiversity inventories. Epiphytes of the Atlantic Forest, one of the most endangered ecosystems in the world, have high endemism and radiated recently in the Pliocene. We aimed to (1) compile an extensive Atlantic Forest data set on vascular, non-vascular plants (including hemiepiphytes), and lichen epiphyte species occurrence and abundance; (2) describe the epiphyte distribution in the Atlantic Forest, in order to indicate future sampling efforts. Our work presents the first epiphyte data set with information on abundance and occurrence of epiphyte phorophyte species. All data compiled here come from three main sources provided by the authors: published sources (comprising peer-reviewed articles, books, and theses), unpublished data, and herbarium data. We compiled a data set composed of 2,095 species, from 89,270 holo/hemiepiphyte records, in the Atlantic Forest of Brazil, Argentina, Paraguay, and Uruguay, recorded from 1824 to early 2018. Most of the records were from qualitative data (occurrence only, 88%), well distributed throughout the Atlantic Forest. For quantitative records, the most common sampling method was individual trees (71%), followed by plot sampling (19%), and transect sampling (10%). Angiosperms (81%) were the most frequently registered group, and Bromeliaceae and Orchidaceae were the families with the greatest number of records (27,272 and 21,945, respectively). Ferns and Lycophytes presented fewer records than Angiosperms, and Polypodiaceae were the most recorded family, and more concentrated in the Southern and Southeastern regions. Data on non-vascular plants and lichens were scarce, with a few disjunct records concentrated in the Northeastern region of the Atlantic Forest. For all non-vascular plant records, Lejeuneaceae, a family of liverworts, was the most recorded family. We hope that our effort to organize scattered epiphyte data help advance the knowledge of epiphyte ecology, as well as our understanding of macroecological and biogeographical patterns in the Atlantic Forest. No copyright restrictions are associated with the data set. Please cite this Ecology Data Paper if the data are used in publication and teaching events. © 2019 The Authors. Ecology © 2019 The Ecological Society of Americ

Intradermal Immunization of SARS-CoV-2 Original Strain Trimeric Spike Protein Associated to CpG and AddaS03 Adjuvants, but Not MPL, Provide Strong Humoral and Cellular Response in Mice

Despite the intramuscular route being the most used vaccination strategy against SARS-CoV-2, the intradermal route has been studied around the globe as a strong candidate for immunization against SARS-CoV-2. Adjuvants have shown to be essential vaccine components that are capable of driving robust immune responses and increasing the vaccination efficacy. In this work, our group aimed to develop a vaccination strategy for SARS-CoV-2 using a trimeric spike protein, by testing the best route with formulations containing the adjuvants AddaS03, CpG, MPL, Alum, or a combination of two of them. Our results showed that formulations that were made with AddaS03 or CpG alone or AddaS03 combined with CpG were able to induce high levels of IgG, IgG1, and IgG2a; high titers of neutralizing antibodies against SARS-CoV-2 original strain; and also induced high hypersensitivity during the challenge with Spike protein and a high level of IFN-γ producing CD4+ T-cells in mice. Altogether, those data indicate that AddaS03, CpG, or both combined may be used as adjuvants in vaccines for COVID-19

AMAZONIA CAMTRAP: A data set of mammal, bird, and reptile species recorded with camera traps in the Amazon forest

The Amazon forest has the highest biodiversity on Earth. However, information on Amazonian vertebrate diversity is still deficient and scattered across the published, peer-reviewed, and gray literature and in unpublished raw data. Camera traps are an effective non-invasive method of surveying vertebrates, applicable to different scales of time and space. In this study, we organized and standardized camera trap records from different Amazon regions to compile the most extensive data set of inventories of mammal, bird, and reptile species ever assembled for the area. The complete data set comprises 154,123 records of 317 species (185 birds, 119 mammals, and 13 reptiles) gathered from surveys from the Amazonian portion of eight countries (Brazil, Bolivia, Colombia, Ecuador, French Guiana, Peru, Suriname, and Venezuela). The most frequently recorded species per taxa were: mammals: Cuniculus paca (11,907 records); birds: Pauxi tuberosa (3713 records); and reptiles: Tupinambis teguixin (716 records). The information detailed in this data paper opens up opportunities for new ecological studies at different spatial and temporal scales, allowing for a more accurate evaluation of the effects of habitat loss, fragmentation, climate change, and other human-mediated defaunation processes in one of the most important and threatened tropical environments in the world. The data set is not copyright restricted; please cite this data paper when using its data in publications and we also request that researchers and educators inform us of how they are using these data