Publications by authors named "Cecilia Lindestam Arlehamn"

Background: Despite immune restoration after initiation of antiretroviral treatment (ART), the risk of tuberculosis (TB) persists in children living with HIV (CLHIV). We determined patterns of immune restoration of mycobacteria-specific T cells following ART in CLHIV.

Methods: CD4 and CD8 T cell activation and memory phenotype and functional profiles before and 6 months after ART were evaluated in peripheral blood mononuclear cells (PBMCs) from CLHIV enrolled in the PUSH study (NCT02063880) in Nairobi, Kenya.

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Parkinson's disease (PD) is the second most prevalent neurodegenerative disorder. While there is no curative treatment, the immune system's involvement with autoimmune T cells that recognize the protein alpha-synuclein (α-syn) in a subset of individuals suggests new areas for therapeutic strategies. As not all patients with PD have T cells specific for α-syn, we explored additional autoantigenic targets of T cells in PD.

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Article Synopsis
  • Researchers developed a new high-throughput method to analyze the transcriptomes of immune cell complexes without needing complex data processing, focusing on T cells and monocytes during active infections.
  • The study revealed distinct gene expression patterns in T cells and monocytes in blood samples from patients with active tuberculosis (TB) and dengue, highlighting their immune interactions.
  • Findings indicated that T cells in these complexes displayed characteristics of active immune responses, including effector cell traits and RNA exchange with monocytes, which suggests a deeper understanding of immune interactions during infections.
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Neurodegenerative diseases represent a huge healthcare challenge which is predicted to increase with an aging population. Synucleinopathies, including Parkinson's disease (PD), dementia with Lewy bodies (DLB), and multiple system atrophy (MSA), present complex challenges in understanding their onset and progression. They are characterized by the abnormal aggregation of α-synuclein in the brain leading to neurodegeneration.

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  • The study investigates how inflammatory responses affect pulmonary disease during SARS-CoV-2 infection, specifically using the rhesus macaque model of mild COVID-19.
  • It highlights the contrasting roles of the cytokines IFNγ and IL-10, where IFNγ contributes to lung lesions but isn't necessary for viral replication suppression, while IL-10 reduces inflammation and aids in T cell memory without hindering viral clearance.
  • The research reveals that IL-10 plays a key role in fostering airway memory T cells, indicating its importance in the immune response during SARS-CoV-2 infection.
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  • Researchers studied how genetic variation affects vaccine responses in infants from African countries, finding specific HLA associations with antibody responses to vaccines like pertussis and hepatitis B.
  • They used genetic data from over 1,700 individuals to identify patterns in HLA types that could explain up to 10% of the response variability in infants to these vaccines.
  • The study highlighted differences in immune responses based on ancestry, indicating that understanding HLA-DRB1 expression could help refine vaccine design for better effectiveness in diverse populations.
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Background: Interleukin-17-producing CD4 T cells contribute to the control of () infection in humans; whether infection with human immunodeficiency virus (HIV) disproportionately affects distinct Th17-cell subsets that respond to is incompletely defined.

Methods: We performed high-definition characterization of circulating -specific Th17 cells by spectral flow cytometry in people with latent TB and treated HIV (HIV-ART). We also measured kynurenine pathway activity by liquid chromatography-mass spectrometry (LC/MS) on plasma and tested the hypothesis that tryptophan catabolism influences Th17-cell frequencies in this context.

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Blockade of the co-inhibitory receptor PD-1 enhances antitumor responses by boosting the function of antigen-specific T cells. Although rare, PD-1 blockade in patients with cancer can lead to exacerbation of infection-associated pathology. Here, we detail the case of a 38-year-old man who was enrolled in a clinical trial for assessment of the safety and activity of anti-PD-1 therapy for Kaposi sarcoma in people with HIV well-controlled on antiretroviral therapy.

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Clinical prediction of nontuberculous mycobacteria lung disease (NTM-LD) progression remains challenging. We aimed to evaluate antigen-specific immunoprofiling utilizing flow cytometry (FC) of activation-induced markers (AIM) and IFN-γ enzyme-linked immune absorbent spot assay (ELISpot) accurately identifies patients with NTM-LD, and differentiate those with progressive from nonprogressive NTM-LD. A Prospective, single-center, and laboratory technician-blinded pilot study was conducted to evaluate the FC and ELISpot based immunoprofiling in patients with NTM-LD (n = 18) and controls (n = 22).

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CD4 T cells are essential for immunity to (), and emerging evidence indicates that IL-17-producing Th17 cells contribute to immunity to . While identifying protective T cell effector functions is important for TB vaccine design, T cell antigen specificity is also likely to be important. To identify antigens that induce protective immunity, we reasoned that as in other pathogens, effective immune recognition drives sequence diversity in individual antigens.

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Post-acute sequelae of COVID-19 (PASC), or Long COVID, is a chronic condition following acute SARS-CoV-2 infection. Symptoms include exertion fatigue, respiratory issues, myalgia, and neurological manifestations such as 'brain fog,' posing concern for their debilitating nature and potential role in other neurological disorders. However, the underlying potential pathogenic mechanisms of the neurological complications of PASC is largely unknown.

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Objectives: Tuberculosis (TB) remains a global health challenge due to various factors, including delayed diagnoses leading to the spread of infection, limited efficacy of current vaccination strategies, and emergence of drug-resistant strains. Here, we explore the significance of Mycobacterium tuberculosis (Mtb)-specific antigens to overcome these challenges.

Methods: A narrative review exploring the dynamics of Mtb-specific antigens and the related T cell immune responses across the TB spectrum.

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Here we describe the case of a 51 years old Italian woman with acute lymphoblastic leukemia who underwent to hematopoietic stem cell transplantation (HSCT) during SARS-COV-2 infection. She presented a prolonged COVID-19 successfully treated with dual anti SARS-COV-2 antiviral plus monoclonal antibody therapy.

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Article Synopsis
  • Parkinson's disease (PD) is related to autoimmune T cells that target alpha-synuclein and other neuroantigens linked to PD pathology.
  • Researchers explored additional autoantigen targets by studying various proteins connected to PD, including GBA, SOD1, PINK1, and others.
  • The study found that T cells, particularly in male PD patients, reacted to the mitochondrial protein PINK1, suggesting that understanding these targets could lead to new diagnostics and treatments for PD.
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There is still incomplete knowledge of which Mycobacterium tuberculosis (Mtb) antigens can trigger distinct T cell responses at different stages of infection. Here, a proteome-wide screen of 20,610 Mtb-derived peptides in 21 patients mid-treatment for active tuberculosis (ATB) reveals IFNγ-specific T cell responses against 137 unique epitopes. Of these, 16% are recognized by two or more participants and predominantly derived from cell wall and cell processes antigens.

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Epitopes recognized by T cells are a collection of short peptide fragments derived from specific antigens or proteins. Immunological research to study T cell responses is hindered by the extreme degree of heterogeneity of epitope targets, which are usually derived from multiple antigens; within a given antigen, hundreds of different T cell epitopes can be recognized, differing from one individual to the next because T cell epitope recognition is restricted by the epitopes' ability to bind to MHC molecules, which are extremely polymorphic in different individuals. Testing large pools encompassing hundreds of peptides is technically challenging because of logistical considerations regarding solvent-induced toxicity.

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Heterogeneity in human immune responses is difficult to model in standard laboratory mice. To understand how host variation affects Bacillus Calmette Guerin-induced (BCG-induced) immunity against Mycobacterium tuberculosis, we studied 24 unique collaborative cross (CC) mouse strains, which differ primarily in the genes and alleles they inherit from founder strains. The CC strains were vaccinated with or without BCG and challenged with aerosolized M.

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The only licensed tuberculosis (TB) vaccine, Bacillus Calmette Guerin (BCG), fails to reliably protect adolescents and adults from pulmonary TB, resulting in ~1.6 million deaths annually. Protein subunit vaccines have shown promise against TB in clinical studies.

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Antigen-specific T cells play a central role in the adaptive immune response and come in a wide range of phenotypes. T cell receptors (TCRs) mediate the antigen-specificities found in T cells. Importantly, high-throughput TCR sequencing provides a fingerprint which allows tracking of specific T cells and their clonal expansion in response to particular antigens.

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Tuberculosis caused by is one of the leading causes of death from a single infectious agent. Identifying dominant epitopes and comparing their reactivity in different tuberculosis (TB) infection states can help design diagnostics and vaccines. We performed a proteome-wide screen of 20,610 derived peptides in 21 Active TB (ATB) patients 3-4 months post-diagnosis of pulmonary TB (mid-treatment) using an IFNγ and IL-17 Fluorospot assay.

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Article Synopsis
  • A study comparing two methods of BCG vaccination for tuberculosis in rhesus macaques found that intradermal (ID) delivery offers better immune responses in the airways than intragastric gavage vaccination.
  • Both vaccination methods elicited similar T cell responses in the blood; however, gavage vaccination led to weaker immune responses in the airways due to gut-homing receptors being activated.
  • This research highlights that while both vaccination methods create functional T cells, ID vaccination is more effective for generating airway immune protection against Mycobacterium tuberculosis.
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The induction of proinflammatory T cells by dendritic cell (DC) subtypes is critical for antitumor responses and effective immune checkpoint blockade (ICB) therapy. Here, we show that human CD1cCD5 DCs are reduced in melanoma-affected lymph nodes, with CD5 expression on DCs correlating with patient survival. Activating CD5 on DCs enhanced T cell priming and improved survival after ICB therapy.

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Background: Interleukin 17 producing CD4 T cells contribute to the control of infection in humans; whether infection with Human Immunodeficiency Virus (HIV) disproportionately affects distinct Th17 cell subsets that respond to is incompletely defined.

Methods: We performed high-definition characterization of circulating -specific Th17 cells by spectral flow cytometry in people with latent TB and treated HIV (HIV-ART). We also measured kynurenine pathway activity by LC/MS on plasma and tested the hypothesis that tryptophan catabolism influences Th17 cell frequencies in this context.

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