Publications by authors named "Antonio C Freitas"

Background/objectives: DNA vaccines are rapidly produced and adaptable to different pathogens, but they face considerable challenges regarding stability and delivery to the cellular target. Thus, effective delivery methods are essential for the success of these vaccines. Here, we evaluated the efficacy of capsules derived from the cell wall of the yeast as a delivery system for DNA vaccines.

View Article and Find Full Text PDF

Extremophile organisms have been largely studied in Astrobiology. Among them, two antarctic plants emerge as good candidates to become colonizers of other celestial bodies, such as Mars and the Moon. The present research aimed to evaluate survival and growing capacity of Sanionia uncinata and Colobanthus quitensis on Martian (MGS-1) and Lunar (LMS-1) regolith simulants, under terrestrial conditions.

View Article and Find Full Text PDF

Lung cancer has the highest mortality rates worldwide, and Human Papillomavirus (HPV) has been associated with its carcinogenesis. In this study, HPV16 genes' expressions were investigated in patient samples, along with the immunological response promoted by lymphocytes and monocytes in A549 cells transfected with HPV oncogenes and co-cultured with PBMC. An increase in the expression of E5 was observed in the patients' samples.

View Article and Find Full Text PDF

BPV-2 infection can cause bladder infections in cattle that, when associated with bracken fern consumption, can progress to cancerous bladder tumors and also present as bovine enzootic hematuria (BEH). This study aimed to evaluate the prolonged natural BPV-2 infection in the blood and urine of cattle, excluding bracken fern consumption. Thirteen Girolando papillomatosis-affected cattle with no bracken fern contact history were monitored for 20 months.

View Article and Find Full Text PDF

The persistence of the human papillomavirus type 16 (HPV16) infection on the cervical epithelium contributes to the progression of cervical cancer. Studies have demonstrated that HPV16 genetic variants may be associated with different risks of developing cervical cancer. However, the E5 oncoprotein of HPV16, which is related to several cellular mechanisms in the initial phases of the infection and thus contributes to carcinogenesis, is still little studied.

View Article and Find Full Text PDF

Breast cancer risk factors include lifestyle, genetic-hormonal influences, and viral infections. Human papillomavirus (HPV), known primarily as the etiological agent of cervical cancer, also appears active in breast carcinogenesis, as evidenced in our study of 56 patients from northeastern Brazil. We assessed the clinical and sociodemographic characteristics, correlating them with various breast cancer tumor types.

View Article and Find Full Text PDF

Bovine Papillomaviruses (BPVs) constitute a diverse group within the Papillomaviridae family, playing a crucial role in bovine health and economic considerations. This study investigates the dynamics of vertical transmission of BPV in cattle, focusing on five cows and their reproductive tissues, as well as three gravid cows and their fetuses. DNA and RNA samples were extracted from the warts, fetal skin, placenta, uterus, ovary, and blood of cows, as well as the skin and blood of fetuses.

View Article and Find Full Text PDF

Breast cancer is the most common neoplasm worldwide. Viral infections are involved with carcinogenesis, especially those caused by oncogenic Human Papillomavirus (HPV) genotypes. Despite the detection of HPV in breast carcinomas, the virus's activity against this type of cancer remains controversial.

View Article and Find Full Text PDF

Background And Purpose: The employment of yeasts for biomedical purposes has become increasingly frequent for the delivery of prophylactic and therapeutic products. Its structural components, such as β-glucans, mannan, and chitin, can be explored as immunostimulators that show safety and low toxicity. Besides, this system minimizes antigen degradation after administration, facilitating the delivery to the target cells.

View Article and Find Full Text PDF

The understanding of the relationship between immunological responses and cancers, especially those related to HPV, has allowed for the study and development of therapeutic vaccines against these neoplasias. There is a growing number of studies about the composition and influence of the tumor microenvironment (TME) in the progression or establishment of the most varied types of cancer. Hence, it has been possible to structure immunotherapy approaches based on therapeutic vaccines that are even more specific and directed to components of TME and the immune response associated with tumors.

View Article and Find Full Text PDF

In the last decades, technological advances for RNA manipulation enabled and expanded its application in vaccine development. This approach comprises synthetic single-stranded mRNA molecules that direct the translation of the antigen responsible for activating the desired immune response. The success of RNA vaccines depends on the delivery vehicle.

View Article and Find Full Text PDF

Cervical cancer is associated with persistent infections by high-risk Human Papillomavirus (HPV) types that may have nucleotide polymorphisms and, consequently, different oncogenic potentials. Therefore, this study aimed to evaluate the genetic variability and structural effects of the E7 oncogene of HPV58 in cervical scraping samples from Brazilian women. The study was developed with patients from hospitals in the metropolitan area of Recife, PE, Brazil.

View Article and Find Full Text PDF
Article Synopsis
  • Improving antigen presentation is essential for effective immunization, and yeasts serve as both a protein production factory and a delivery system for antigens, with potential adjuvant effects.
  • Despite no current Zika virus outbreaks, ongoing vaccine development is critical due to the serious health risks associated with the virus, particularly its neurotropic effects.
  • The study shows that yeast-based vaccines with Zika virus epitopes enhance immune responses in mice, promoting the activation of T cells and significant antibody production while confirming the safety of these vaccine vehicles.
View Article and Find Full Text PDF

The human papillomavirus (HPV) represents the most prevalent sexually transmitted infectious agent worldwide. HPV penetrates the epithelium through microlesions and establishes an infectious focus that can lead to the development of cervical cancer. Prophylactic HPV vaccines are available, but do not affect already-established infections.

View Article and Find Full Text PDF
Article Synopsis
  • Healthcare workers are at a higher risk of SARS-CoV-2 infection due to their exposure to infected patients, necessitating a study of their clinical and immunological status.
  • A study involving 50 healthcare professionals in Brazil revealed that most participants were women over 50 years old working as nursing technicians, with around 56% testing positive for previous COVID-19 infection.
  • Immunological findings indicated signs of light inflammation and a distinct immune response in positive workers, highlighting the need for further research on the long-term effects of continuous virus exposure in this group.
View Article and Find Full Text PDF

In the context of vaccine development, improving antigenic presentation is critical for the activation of specific immune responses and the success of immunization, in addition to selecting an appropriate target. In this sense, different strategies have been developed and improved. Among them is the use of yeast cells as vehicles for the delivery of recombinant antigens.

View Article and Find Full Text PDF

Prophylactic vaccines against human papillomavirus (HPV) have proven efficacy in those who have not been infected by the virus. However, they do not benefit patients with established tumors. Therefore, the development of therapeutic options for HPV-related malignancies is critical.

View Article and Find Full Text PDF

Gene immunization comprises mRNA and DNA vaccines, which stand out due to their simple design, maintenance, and high efficacy. Several studies indicate promising results in preclinical and clinical trials regarding immunization against ebola, human immunodeficiency virus (HIV), influenza, and human papillomavirus (HPV). The efficiency of nucleic acid vaccines has been highlighted in the fight against COVID-19 with unprecedented approval of their use in humans.

View Article and Find Full Text PDF

Health professionals working to mitigate the COVID-19 pandemic are one of the main risk groups for the disease, being prioritized for vaccination. Considering this, the aim of this study was to analyze the immune response of these professionals immunized with CoronaVac in the first and second doses. Blood samples were collected after the first and second doses of the vaccine (CoronaVac) and used to investigate hematological and biochemical parameters, analysis of immunoglobulin production, cytokines, and gene expression profile, as well as the identification of subsets of immune cells.

View Article and Find Full Text PDF

This study evaluated the presence of Human Papillomavirus (HPV) DNA in the cervix and peripheral blood of women with cervical intraepithelial neoplasia (CIN I, II, and III) and healthy individuals. Overall, 139 paired peripheral blood and cervix samples of healthy women and women with CIN I, II, and III ( = 68) were tested for HPV DNA by using standard procedures. Polymerase chain reaction (PCR) sequencing determined HPV types.

View Article and Find Full Text PDF

The current pandemic called COVID-19 caused by the SARS-CoV-2 virus brought the need for the search for fast alternatives to both control and fight the SARS-CoV-2 infection. Therefore, a race for a vaccine against COVID-19 took place, and some vaccines have been approved for emergency use in several countries in a record time. Ongoing prophylactic research has sought faster, safer, and precise alternatives by redirecting knowledge of other vaccines, and/or the development of new strategies using available tools, mainly in the areas of genomics and bioinformatics.

View Article and Find Full Text PDF

We present a novel entropy-based computational tool that selects phylogenetic informative genomic regions associated with degenerate primer design. This tool identifies proper phylogenetic markers and proposes suitable degenerate primers to amplify and sequence them. The algorithm calculates the entropy value per site, and the selected region is used for primer design.

View Article and Find Full Text PDF

Yeasts are considered a useful system for the development of vaccines for human and veterinary health. Species such as Saccharomyces cerevisiae and Pichia pastoris have been used successfully as host organisms for the production of subunit vaccines. These organisms have been also explored as vaccine vehicles enabling the delivery of antigens such as proteins and nucleic acids.

View Article and Find Full Text PDF

The severe consequences of ZIKV infection and its emergence and re-emergence in several countries have boosted vaccines' development. Yeasts such as Pichia pastoris has been widely employed as antigen carriers for immunization against infectious agents. Components of the yeast cell wall have immunostimulatory properties, and recombinant antigens can be anchored to the cell surface to enhance the presentation to the immune system.

View Article and Find Full Text PDF

Persistent infections by high-risk human papillomavirus (HR-HPV) are a necessary condition, but not sufficient for cervical cancer development. Genetic variants of HR-HPV appear to be related to the risk of persistent infections. The study performed a functional evaluation of variants of the HPV-31 promoter region (LCR).

View Article and Find Full Text PDF