Publications by authors named "Iatm Ferreira"

HIV-1 antiretroviral therapy is highly effective but fails to eliminate a reservoir of latent proviruses, leading to a requirement for life-long treatment. How the site of integration of authentic intact latent proviruses might impact their own or neighboring gene expression or reservoir dynamics is poorly understood. Here, we report on proviral and neighboring gene transcription at sites of intact latent HIV-1 integration in cultured T cells obtained directly from people living with HIV, as well as engineered primary T cells and cell lines.

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Low-oxygen conditions (hypoxia) have been associated primarily with cell-cycle arrest in dividing cells. Macrophages are typically quiescent in G0 but can proliferate in response to tissue signals. Here we show that hypoxia (1% oxygen tension) results in reversible entry into the cell cycle in macrophages.

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HIV-1 anti-retroviral therapy is highly effective but fails to eliminate a reservoir of latent proviruses leading to a requirement for life-long treatment. How the site of integration of authentic intact latent proviruses might impact their own or neighboring gene expression or reservoir dynamics is poorly understood. Here we report on proviral and neighboring gene transcription at sites of intact latent HIV-1 integration in cultured T cells obtained directly from people living with HIV, as well as engineered primary T cells and cell lines.

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Article Synopsis
  • Elderly individuals (70 years and older) show weaker antibody responses to a COVID-19 booster compared to younger people after receiving an initial two-dose vaccine series with AZD1222 and a third mRNA booster.
  • The elderly have a specific type of B cells (anomalous spike-specific B cells) that may impair their ability to neutralize the virus effectively after the booster.
  • Interestingly, when elderly individuals receive three doses of mRNA vaccines, their antibody responses are comparable to those younger than 70, suggesting that different vaccine technologies influence immune memory formation.
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Real-world data on vaccine-elicited neutralising antibody responses for two-dose AZD1222 in African populations are limited. We assessed baseline SARS-CoV-2 seroprevalence and levels of protective neutralizing antibodies prior to vaccination rollout using binding antibodies analysis coupled with pseudotyped virus neutralisation assays in two cohorts from West Africa: Nigerian healthcare workers (n = 140) and a Ghanaian community cohort (n = 527) pre and post vaccination. We found 44 and 28% of pre-vaccination participants showed IgG anti-N positivity, increasing to 59 and 39% respectively with anti-receptor binding domain (RBD) IgG-specific antibodies.

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The SARS-CoV-2 Omicron BA.1 variant emerged in 2021 and has multiple mutations in its spike protein. Here we show that the spike protein of Omicron has a higher affinity for ACE2 compared with Delta, and a marked change in its antigenicity increases Omicron's evasion of therapeutic monoclonal and vaccine-elicited polyclonal neutralizing antibodies after two doses.

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(Mtb) bacilli readily aggregate. We previously reported that Mtb aggregates lead to phagocyte death and subsequent efficient replication in the dead infected cells. Here, we examined the transcriptional response of human monocyte derived macrophages to phagocytosis of aggregated Mtb relative to phagocytosis of non-aggregated single or multiple bacilli.

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Article Synopsis
  • The B.1.617.2 (Delta) variant of SARS-CoV-2 was first detected in Maharashtra, India, late 2020, and quickly outcompeted earlier variants like B.1.617.1 (Kappa) and B.1.1.7 (Alpha).
  • This variant shows significantly reduced sensitivity to neutralizing antibodies from both recovered individuals and vaccine recipients, with lower protection observed in those vaccinated with the ChAdOx1 serum compared to BNT162b2.
  • Due to its higher replication efficiency and ability to evade the immune response, B.1.617.2's dominance highlights the need for ongoing infection control measures even after vaccination.
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  • The SARS-CoV-2 B.1.617 variant was discovered in Maharashtra, India, in late 2020, raising concerns about its ability to evade antibodies.
  • Key mutations L452R and E484Q were studied to see if they together would increase this evasion effect.
  • The findings indicate that while these mutations do reduce the vaccine's effectiveness slightly, they do not work together to create a stronger resistance to the vaccines, behaving similarly to their effects when present individually.
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Although two-dose mRNA vaccination provides excellent protection against SARS-CoV-2, there is little information about vaccine efficacy against variants of concern (VOC) in individuals above eighty years of age. Here we analysed immune responses following vaccination with the BNT162b2 mRNA vaccine in elderly participants and younger healthcare workers. Serum neutralization and levels of binding IgG or IgA after the first vaccine dose were lower in older individuals, with a marked drop in participants over eighty years old.

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Article Synopsis
  • The study focuses on the ΔH69/V70 deletion in the SARS-CoV-2 spike protein, found in various lineages alongside mutations like N439K and Y453F that enhance the virus's ability to bind to the ACE2 receptor and evade antibodies.
  • While ΔH69/V70 does not directly help the virus escape antibodies, it increases overall infectivity by improving how the spike protein integrates into virus particles.
  • The research underscores the importance of monitoring such deletions, as they may help the virus maintain its infectivity despite other mutations that could weaken it.
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Transmission of SARS-CoV-2 is uncontrolled in many parts of the world; control is compounded in some areas by the higher transmission potential of the B.1.1.

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Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) transmission is uncontrolled in many parts of the world, compounded in some areas by higher transmission potential of the B1.1.7 variant now seen in 50 countries.

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The spike protein of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is critical for virus infection through the engagement of the human ACE2 protein and is a major antibody target. Here we show that chronic infection with SARS-CoV-2 leads to viral evolution and reduced sensitivity to neutralizing antibodies in an immunosuppressed individual treated with convalescent plasma, by generating whole-genome ultra-deep sequences for 23 time points that span 101 days and using in vitro techniques to characterize the mutations revealed by sequencing. There was little change in the overall structure of the viral population after two courses of remdesivir during the first 57 days.

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SARS-CoV-2 Spike protein is critical for virus infection via engagement of ACE2, and amino acid variation in Spike is increasingly appreciated. Given both vaccines and therapeutics are designed around Wuhan-1 Spike, this raises the theoretical possibility of virus escape, particularly in immunocompromised individuals where prolonged viral replication occurs. Here we report chronic SARS-CoV-2 with reduced sensitivity to neutralising antibodies in an immune suppressed individual treated with convalescent plasma, generating whole genome ultradeep sequences by both short and long read technologies over 23 time points spanning 101 days.

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Macrophages are the first line of defence against invading pathogens. They play a crucial role in immunity but also in regeneration and homeostasis. Their remarkable plasticity in their phenotypes and function provides them with the ability to quickly respond to environmental changes and infection.

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