Protocol to phenotype and quantify mycobacteria-specific myeloid cells from human airways by mass cytometry.

Alveolar macrophages and other myeloid cells in the human airways are the primary cell types responding to respiratory pathogens. Here, we present a protocol for in vitro stimulation of cryopreserved human bronchoalveolar lavage (BAL) cells with mycobacterial antigens for phenotyping and quantifying proinflammatory cytokine responses in myeloid cells by mass cytometry. We demonstrate that the measure of markers of myeloid lineage and function is stable after freezing stained cells thereby allowing for batched analyses and/or machine downtime.

Age and sex influence antibody profiles associated with tuberculosis progression.

Antibody features vary with tuberculosis (TB) disease state. Whether clinical variables, such as age or sex, influence associations between Mycobacterium tuberculosis-specific antibody responses and disease state is not well explored. Here we profiled Mycobacterium tuberculosis-specific antibody responses in 140 TB-exposed South African individuals from the Adolescent Cohort Study.

OMIP-101: 27-color flow cytometry panel for immunophenotyping of major leukocyte populations in fixed whole blood.

This 27-color flow cytometry antibody panel allows broad immune-profiling of major leukocyte subsets in human whole blood (WB). It includes lineage markers to identify myeloid and lymphoid cell populations including granulocytes, monocytes, myeloid dendritic cells (mDCs), natural killer (NK) cells, NKT-like cells, B cells, conventional CD4 and CD8 T cells, γδ T cells, mucosa-associated invariant T (MAIT) cells and innate lymphoid cells (ILC). To further characterize each of these populations, markers defining stages of cell differentiation (CCR7, CD27, CD45RA, CD127, CD57), cytotoxic potential (perforin, granzyme B) and cell activation/proliferation (HLA-DR, CD38, Ki-67) were included.

World Tuberculosis Day 2023 theme "Yes! We Can End TB!".

Intro: Viruses, including SARS-CoV-2, which causes COVID-19, are constantly changing. These genetic changes (aka mutations) occur over time and can lead to the emergence of new variants that may have different characteristics. After the first SARS-CoV-2 genome was published in early 2020, scientists all over the world soon realized the immediate need to obtain as much genetic information from as many strains as possible.

Qualification of the differential leukocyte count and immunophenotyping in cryopreserved ex vivo whole blood assay.

We developed a flow cytometry-based assay, termed Differential Leukocyte Counting and Immunophenotyping in Cryopreserved Ex vivo whole blood (DLC-ICE), that allows quantification of absolute counts and frequencies of leukocyte subsets and measures expression of activation, phenotypic and functional markers. We evaluated the performance of the DLC-ICE assay by determining inter-operator variability for processing fresh whole blood (WB) from healthy donors collected at multiple clinical sites. In addition, we assessed inter-operator variability for staining of fixed cells and robustness across different anticoagulants.

Newborn bacille Calmette-Guérin vaccination induces robust infant interferon-γ-expressing natural killer cell responses to mycobacteria.

Objectives: The bacille Calmette-Guérin (BCG) vaccine is usually administered at birth to protect against severe forms of tuberculosis in children. BCG also confers some protection against other infections, possibly mediated by innate immune training. We investigated whether newborn BCG vaccination modulates myeloid and natural killer (NK) cell responses to mycobacteria.

Tuberculosis alters immune-metabolic pathways resulting in perturbed IL-1 responses.

Tuberculosis (TB) remains a major public health problem and we lack a comprehensive understanding of how () infection impacts host immune responses. We compared the induced immune response to TB antigen, BCG and IL-1β stimulation between latently infected individuals (LTBI) and active TB patients. This revealed distinct responses between TB/LTBI at transcriptomic, proteomic and metabolomic levels.

What's Old and New in Tuberculosis Vaccines for Children.

Tuberculosis (TB) is a leading cause of global child mortality. Until the turn of the 21st century, Mycobacterium bovis bacille Calmette-Guerin (BCG) was the only vaccine to prevent TB. The pediatric TB vaccine pipeline has advanced in the past decade to include the evaluation of novel whole cell vaccines to replace infant BCG and investigation of subunit and whole cell vaccines to boost TB immunity during adolescence.

Developing tuberculosis vaccines for people with HIV: consensus statements from an international expert panel.

New tuberculosis vaccine candidates that are in the development pipeline need to be studied in people with HIV, who are at high risk of acquiring Mycobacterium tuberculosis infection and tuberculosis disease and tend to develop less robust vaccine-induced immune responses. To address the gaps in developing tuberculosis vaccines for people with HIV, a series of symposia was held that posed six framing questions to a panel of international experts: What is the use case or rationale for developing tuberculosis vaccines? What is the landscape of tuberculosis vaccines? Which vaccine candidates should be prioritised? What are the tuberculosis vaccine trial design considerations? What is the role of immunological correlates of protection? What are the gaps in preclinical models for studying tuberculosis vaccines? The international expert panel formulated consensus statements to each of the framing questions, with the intention of informing tuberculosis vaccine development and the prioritisation of clinical trials for inclusion of people with HIV.

End-point definition and trial design to advance tuberculosis vaccine development.

Tuberculosis (TB) remains a leading infectious cause of death worldwide and the coronavirus disease 2019 pandemic has negatively impacted the global TB burden of disease indicators. If the targets of TB mortality and incidence reduction set by the international community are to be met, new more effective adult and adolescent TB vaccines are urgently needed. There are several new vaccine candidates at different stages of clinical development.

Evaluation of a transcriptomic signature of tuberculosis risk in combination with an interferon gamma release assay: A diagnostic test accuracy study.

Background: We evaluated the diagnostic and prognostic performance of a transcriptomic signature of tuberculosis (TB) risk (RISK11) and QuantiFERON-TB Gold-plus (QFTPlus) as combination biomarkers of TB risk.

Methods: Healthy South Africans who were HIV-negative aged 18-60 years with baseline RISK11 and QFTPlus results were evaluated in a prospective cohort study conducted between Sept 20, 2016 and Dec 20, 2019. Prevalence and incidence-rate ratios were used to evaluate risk of TB.

Host transcriptomic signatures of tuberculosis can predict immune reconstitution inflammatory syndrome in HIV patients.

Immune reconstitution inflammatory syndrome (IRIS) can be a complication of antiretroviral therapy (ART) in patients with advanced HIV, but its pathogenesis is uncertain. In tuberculosis (TB) endemic countries, IRIS is often associated with mycobacterial infections or Bacille-Calmette-Guerin (BCG) vaccination in children. With no predictive or confirmatory tests at present, IRIS remains a diagnosis of exclusion.

Effects of BCG vaccination on donor unrestricted T cells in two prospective cohort studies.

Background: Non-protein antigen classes can be presented to T cells by near-monomorphic antigen-presenting molecules such as CD1, MR1, and butyrophilin 3A1. Such T cells, referred to as donor unrestricted T (DURT) cells, typically express stereotypic T cell receptors. The near-unrestricted nature of DURT cell antigen recognition is of particular interest for vaccine development, and we sought to define the roles of DURT cells, including MR1-restricted MAIT cells, CD1b-restricted glucose monomycolate (GMM)-specific T cells, CD1d-restricted NKT cells, and γδ T cells, in vaccination against Mycobacterium tuberculosis.

Innovative vaccine approaches-a Keystone Symposia report.

The rapid development of COVID-19 vaccines was the result of decades of research to establish flexible vaccine platforms and understand pathogens with pandemic potential, as well as several novel changes to the vaccine discovery and development processes that partnered industry and governments. And while vaccines offer the potential to drastically improve global health, low-and-middle-income countries around the world often experience reduced access to vaccines and reduced vaccine efficacy. Addressing these issues will require novel vaccine approaches and platforms, deeper insight how vaccines mediate protection, and innovative trial designs and models.

-Specific T Cell Functional, Memory, and Activation Profiles in QuantiFERON-Reverters Are Consistent With Controlled Infection.

Reversion of immune sensitization tests for (M.tb) infection, such as interferon-gamma release assays or tuberculin skin test, has been reported in multiple studies. We hypothesized that QuantiFERON-TB Gold (QFT) reversion is associated with a decline of M.

Multidimensional analysis of immune responses identified biomarkers of recent Mycobacterium tuberculosis infection.

The risk of tuberculosis (TB) disease is higher in individuals with recent Mycobacterium tuberculosis (M.tb) infection compared to individuals with more remote, established infection. We aimed to define blood-based biomarkers to distinguish between recent and remote infection, which would allow targeting of recently infected individuals for preventive TB treatment.

Antigen-Specific T-Cell Activation Distinguishes between Recent and Remote Tuberculosis Infection.

Current diagnostic tests fail to identify individuals at higher risk of progression to tuberculosis disease, such as those with recent infection, who should be prioritized for targeted preventive treatment. To define a blood-based biomarker, measured with a simple flow cytometry assay, that can stratify different stages of tuberculosis infection to infer risk of disease. South African adolescents were serially tested with QuantiFERON-TB Gold to define recent (QuantiFERON-TB conversion <6 mo) and persistent (QuantiFERON-TB+ for >1 yr) infection.

BCG Vaccination of Infants Confers Strain-Specific Immune Responses by Leukocytes.

The efficacy of bacille Calmette-Guerin (BCG) vaccination against tuberculosis is highly variable, and protective immunity elicited by BCG is poorly understood. We compared the cytokine/chemokine profiles of peripheral blood mononuclear cells (PBMC) obtained from infants BCG-vaccinated at birth to those of PBMC obtained from infants before (delayed) BCG vaccination. The PBMC from 10-week-old BCG-vaccinated infants released higher levels of pro-inflammatory molecules than PBMCs from the nonvaccinated counterpart.

Immune Profiling Enables Stratification of Patients With Active Tuberculosis Disease or Mycobacterium tuberculosis Infection.

Background: Tuberculosis (TB) is caused by Mycobacterium tuberculosis (Mtb) infection and is a major public health problem. Clinical challenges include the lack of a blood-based test for active disease. Current blood-based tests, such as QuantiFERON (QFT) do not distinguish active TB disease from asymptomatic Mtb infection.

Postnatal Expansion, Maturation, and Functionality of MR1T Cells in Humans.

MR1-restricted T (MR1T) cells are defined by their recognition of metabolite antigens presented by the monomorphic MHC class 1-related molecule, MR1, the most highly conserved MHC class I related molecule in mammalian species. Mucosal-associated invariant T (MAIT) cells are the predominant subset of MR1T cells expressing an invariant TCR α-chain, TRAV1-2. These cells comprise a T cell subset that recognizes and mediates host immune responses to a broad array of microbial pathogens, including .

Targeting Unconventional Host Components for Vaccination-Induced Protection Against TB.

The current tuberculosis (TB) vaccine, Bacille Calmette-Guerin (BCG), is effective in preventing TB in young children but was developed without a basic understanding of human immunology. Most modern TB vaccine candidates have targeted CD4 T cell responses, thought to be important for protection against TB disease, but not known to be sufficient or critical for protection. Advances in knowledge of host responses to TB afford opportunities for developing TB vaccines that target immune components not conventionally considered.