Telma Miyuki Oshiro

Despite the effectiveness of antiretroviral therapy (ART) in suppressing HIV‐1 replication and reducing morbidity, viral eradication remains unachievable due to the persistence of latent reservoirs, particularly within memory CD4 ⁺ T cells. Dendritic cell (DC)‐based immunotherapeutic approaches have emerged as potential strategies to enhance antigen‐specific immune responses against HIV‐1. In this context, alpha‐type‐1 polarized DCs (αDC1) are notable for their capacity to produce interleukin‐12p70 (IL‐12p70) and induce robust Th1 and cytotoxic T lymphocyte (CTL) responses. However, clinical outcomes have been inconsistent, often influenced by host factors and methodological variability in DC generation and antigen delivery. The high genetic diversity of HIV poses challenges for vaccine development, whereas conserved regions such as gag and pol represent promising immunogenic targets. The present study aimed to evaluate a set of previously identified conserved HIV‐1 peptides for their ability to stimulate HIV‐specific T cell responses when presented by αDC1 in vitro in coculture assays using samples from a Brazilian cohort, as part of a preparatory phase for a clinical trial. For this purpose, monocytes were differentiated into αDC1 using IL‐4 and GM‐CSF. On Day 5, the cells were pulsed with 14–21mer HIV‐1 peptide pools (gag and pol) and matured by the addition of IFN‐α, IFN‐γ, IL‐1β, and TNF‐α. After 48 h, αDC1 were harvested and cocultured with autologous T cells for 6 or 20 days. Pulsed‐αDC1 were able to induce immune responses through the production of IFN‐γ in T cells, with the subpopulation of effector memory CD4 ⁺ T cells ( T _EM ) being responsible for the production of this cytokine after reexposure to the HIV antigens.

The prevalence of fragrances in various hygiene products contributes to their sensorial allure. However, fragrances can induce sensitization in the skin or respiratory system, and the mechanisms involved in this process are incompletely understood. This study investigated the intricate mechanisms underlying the fragrance's effects on sensitization response, focusing on the interplay between CYP450 enzymes, a class of drug‐metabolizing enzymes, and the adaptive immune system. Specifically, we assessed the expression of CYP450 enzymes and cytokine profiles in culture of BEAS‐2B and mature dendritic cells (mDC) alone or in co‐culture stimulated with 2 mM of a common fragrance, cinnamyl alcohol (CA) for 20 h. CYP1A1, CYP1A2, CYP1B1, CYP2A6, and CYP2A13 were analyzed by RT‐PCR and IL‐10, IL‐12p70, IL‐18, IL‐33, and thymic stromal lymphopoietin (TSLP) by Cytometric Bead Array (CBA). Through RT–PCR analysis, we observed that CA increased CYP1A2 and CYP1B1 expression in BEAS‐2B, with a further increased in BEAS‐2B‐mDC co‐culture. Additionally, exposure to CA increased IL‐12p70 levels in mDC rather than in BEAS‐2B‐mDC co‐culture. In regards to IL‐18, level was higher in BEAS‐2B than in BEAS‐2B‐mDC co‐culture. A positive correlation between the levels of IL‐10 and CYP1B1 was found in mDC‐CA‐exposed and between IL‐12p70 and CYP1A1 was found in BEAS‐2B after CA exposure. However, IL‐12p70 and CYP1A2 as well as IL‐18, IL‐33, and CYP1A1 levels were negative, correlated mainly in co‐culture control. These correlations highlight potential immunomodulatory interactions and complex regulatory relationships. Overall, exposure to CA enhances CYP450 expression, suggesting that CA can influence immune responses by degrading ligands on xenosensitive transcription factors.

Therapeutic vaccines based on monocyte‐derived dendritic cells have been shown to be promising strategies and may act as complementary treatments for viral infections, cancers, and, more recently, autoimmune diseases. Alpha‐type‐1‐polarized dendritic cells (aDC1s) have been shown to induce type‐1 immunity with a high capacity to produce interleukin‐12p70 (IL‐12p70). In the clinical use of cell‐based therapeutics, injectable solutions can affect the morphology, immunophenotypic profile, and viability of cells before delivery and their survival after injection. In this sense, preparing a cell suspension that maintains the quality of aDC1s is essential to ensure effective immunotherapy. In the present study, monocytes were differentiated into aDC1s in the presence of IL‐4 and GM‐CSF. On day 5, the cells were matured by the addition of a cytokine cocktail consisting of IFN‐α, IFN‐γ, IL‐1β, TNF‐α, and Poly I:C. After 48 hr, mature aDC1s were harvested and suspended in two different solutions: normal saline and Ringer’s lactate. The maintenance of cells in suspension was evaluated after 4, 6, and 8 hr of storage. Cell viability, immunophenotyping, and apoptosis analyses were performed by flow cytometry. Cellular morphology was observed by electron microscopy, and the production of IL‐12p70 by aDC1s was evaluated by ELISA. Compared with normal saline, Ringer’s lactate solution was more effective at maintaining DC viability for up to 8 hr of incubation at 4 or 22°C.

We investigated the anti-SARS-CoV-2 post-vaccine response through serum and salivary antibodies, serum antibody neutralizing activity and cellular immune response in samples from health care workers who were immunized with two doses of an inactivated virus-based vaccine (CoronaVac) who had or did not have COVID-19 previously. IgA and IgG antibodies directed at the spike protein were analysed in samples of saliva and/or serum by ELISA and/or chemiluminescence assays; the neutralizing activity of serum antibodies against reference strain B, Gamma and Delta SARS-CoV-2 variants were evaluated using a virus neutralization test and SARS-CoV-2 reactive interferon-gamma T-cell were analysed by flow cytometry. CoronaVac was able to induce serum and salivary IgG anti-spike antibodies and IFN-γ producing T cells in most individuals who had recovered from COVID-19 and/or were vaccinated. Virus neutralizing activity was observed against the ancestral strain, with a reduced response against the variants. Vaccinated individuals who had previous COVID-19 presented higher responses than vaccinated individuals for all variables analysed. Our study provides evidence that the CoronaVac vaccine was able to induce the production of specific serum and saliva antibodies, serum virus neutralizing activity and cellular immune response, which were increased in previously COVID-19-infected individuals compared to uninfected individuals.

Background: We developed a personalized Monocyte-Derived Dendritic-cell Therapy (MDDCT) for HIV-infected individuals on suppressive antiretroviral treatment and evaluated HIV-specific T-cell responses.Methods: PBMCs were obtained from 10 HIV⁺individuals enrolled in trial NCT02961829. Monocytes were differentiated into DCs using IFN-α and GM-CSF. After sequencing each patient’s HIV-1 Gag and determining HLA profiles, autologous Gag peptides were selected based on the predicted individual immunogenicity and used to pulse MDDCs. Three doses of the MDDCT were administered every 15 days. To assess immunogenicity, patients’ cells were stimulated in vitro with autologous peptides, and intracellular IL-2, TNF, and interferon-gamma (IFN-γ) production were measured in CD4⁺and CD8⁺T-cells.Results: The protocol of ex-vivo treatment with IFN-α and GM-CSF was able to induce maturation of MDDCs, as well as to preserve their viability for reinfusion. MDDCT administration was associated with increased expression of IL-2 in CD4⁺and CD8⁺T-cells at 15 and/or 30 days after the first MDDCT administration. Moreover, intracellular TNF and IFN-γ expression was significantly increased in CD4⁺T-cells. The number of candidates that increased in vitro the cytokine levels in CD4⁺and CD8⁺T cells upon stimulation with Gag peptides from baseline to day 15 and from baseline to day 30 and day 120 after MDDCT was significant as compared to Gag unstimulated response. This was accompanied by an increasing trend in the frequency of polyfunctional T-cells over time, which was visible when considering both cells expressing two and three out of the three cytokines examined.Conclusions: MDDC had a mature profile, and this MDDCT promoted in-vitro T-cell immune responses in HIV-infected patients undergoing long-term suppressive antiretroviral treatment.Trial registrationNCT02961829: (Multi Interventional Study Exploring HIV-1 Residual Replication: a Step Towards HIV-1 Eradication and Sterilizing Cure,https://www.clinicaltrials.gov/ct2/show/NCT02961829, posted November 11th, 2016)

In this preliminary study we investigated cellular and humoral immune responses to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antigens in blood samples from 14 recovered coronavirus disease 2019 (COVID-19) patients and compared them ...

Due to its leading role in fighting infections, the human immune system has been the focus of many studies in the context of Coronavirus disease 2019 (COVID-19). In a worldwide effort, the scientific community has transitioned from reporting about the effects of the novel coronavirus on the human body in the early days of the pandemic to exploring the body’s many immunopathological and immunoprotecting properties that have improved disease treatment and enabled the development of vaccines. The aim of this review is to explain what happens to the immune system after recovery from COVID-19 and/or vaccination against SARS-CoV-2, the virus that causes the disease. We detail the way in which the immune system responds to a SARS-CoV-2 infection, including innate and adaptive measures. Then, we describe the role of vaccination, the main types of COVID-19 vaccines and how they protect us. Further, we explain the reason why immunity after COVID-19 infection plus a vaccination appears to induce a stronger response compared with virus exposure alone. Additionally, this review reports some correlates of protection from SARS-CoV-2 infection. In conclusion, we reinforce that vaccination is safe and important in achieving herd immunity.

Coronavirus disease 19 (COVID-19) is caused by SARS-Cov-2 and the manifestations of this infection range from an absence of symptoms all the way up to severe disease leading to death. To estimate the prevalence of past infection in a population, the most readily available method is the detection of antibodies against the virus. This study has investigated the prevalence of anti-SARS-CoV-2 antibodies in outpatients of the Hospital das Clinicas, in Sao Paulo city (Brazil), which is a large university hospital belonging to the public health system that cares for patients with complex diseases who need tertiary or quaternary medical care. Our serological inquiry was carried out for 6 weeks, with once-a-week blood sampling and included 439 patients from several outpatient services. Overall, 61 patients tested positive for anti-SARS-CoV-2 IgG (13.9%); 56.1 % of the patients live in Sao Paulo city, with the remaining living in other towns of the metropolitan area; 32.8% of the patients testing positive for IgG antibodies to SARS-CoV-2 were asymptomatic, 55.7% developed mild or moderate disease and 11.5% had to be hospitalized. The prevalence of SARS-CoV-2 positive serology was lower among patients who had received the seasonal influenza vaccine compared to the ones who did not. These findings may indicate that those individuals care more about health issues, and/or that they have a better access to health care and/or a better quality of health care service. The large proportion of patients who were unaware of having had contact with SARS-CoV-2 deserves attention, reflecting the scarcity of tests performed in the population.

Dendritic cell (DC)-based immunotherapy is a promising strategy for the treatment of HIV-infected individuals. Different from the conventional protocol for DC differentiation based on the cytokine IL-4 (IL4-DCs), several studies have suggested obtaining DCs by culturing monocytes with type I IFN (IFN-α) to yield IFN-DCs, as performed in cancer therapy. To evaluate the phenotypic and functional characteristics, monocytes from HIV-infected subjects were differentiated into IFN-DCs or IL4-DCs, pulsed with chemically inactivated HIV and stimulated with pro-inflammatory cytokines. A comparative analysis between both types of monocyte-derived DCs (MoDCs) showed that immature IFN-DCs were phenotypically distinct from immature IL4-DCs at the baseline of differentiation, presenting a pre-activated profile. From the functional profile, we determined that IFN-DCs were capable of producing the cytokine IL-12 p70 and of inducing the production of IFN-γ by CD4 + T lymphocytes but not by TCD8+ lymphocytes. Our results suggest that IFN-DCs derived from HIV-infected individuals are able to recognize and present viral antigens to induce TCD4+ cellular immunity to HIV.