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Optimisation of a flow cytometry antibody panel to detect BCG-induced innate responses in infants

The outcome of exposure to Mycobacterium tuberculosis is highly variable ranging from clearance, latency to a wide spectrum of subclinical and clinical tuberculosis (TB) disease. The underlying basis of the variable disease outcomes to mycobacterial exposure is largely unknown and is thought to invo...

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Main Author: Mwambene, Temwa Dango
Other Authors: Scriba, Thomas
Format: Thesis
Language:English
Published: Department of Pathology 2024
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access_status_str Open Access
author Mwambene, Temwa Dango
author2 Scriba, Thomas
author_browse Mwambene, Temwa Dango
Scriba, Thomas
author_facet Scriba, Thomas
Mwambene, Temwa Dango
author_sort Mwambene, Temwa Dango
collection Thesis
description The outcome of exposure to Mycobacterium tuberculosis is highly variable ranging from clearance, latency to a wide spectrum of subclinical and clinical tuberculosis (TB) disease. The underlying basis of the variable disease outcomes to mycobacterial exposure is largely unknown and is thought to involve a complex interplay between genetic variation in both host and pathogen. This is further convoluted by factors such as age, geography, coinfections including human immunodeficiency virus (HIV) and previous Bacillus Calmette–Guérin (BCG) vaccination. As it stands, other than inborn errors in key mycobacterial susceptibility genes both animal and human studies have not found many genetic polymorphisms that are strongly and reproducibly associated with increased mycobacterial disease susceptibility and/or BCG vaccine efficacy. Given the complexity of the interplay between the variability in disease susceptibility, BCG vaccine efficacy and human exposure to genetically diverse pathogens there is a need to study both host and pathogen genetic factors that contribute to increased TB disease susceptibility. This will facilitate rational design of more broadly efficacious interventions. This MSc project is nested in a project which aims to uncover the genetic factors that result in variable responses to BCG vaccination and in so doing, expand the basis of learning for novel TB vaccine candidates. The overall aim of this MSc was to optimise a flow cytometry panel to measure the BCG-induced innate immune responses in infants. The innate response to BCG was characterised by whole blood intracellular cytokine staining of banked, previously stimulated immune cells from 25, 10-week-old, HIV-uninfected, infants. The cohort is a subset of participants of a randomised control trial conducted in Worcester, South Africa. A 13-colour flow cytometry antibody panel was successfully optimised for enumerating and measuring cytokine and cell maturation marker expression by neutrophils, monocytes, pDCs, mDCs and T cells in response to BCG stimulation. Expression of cytokines (IFNg, IL-6, TNF) and maturation markers (CD40, PD-L1) by these cell subsets to BCG stimulation were quantified, allowing identification of single nucleotide polymorphisms that associate with variability in innate responses to BCG. Results from this MSc thus inform the bigger project which aims to determine genetic determinants of innate responses to BCG and TB disease risk.
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institution University of Cape Town (South Africa)
language eng
last_indexed 2026-06-10T12:31:53.390Z
license_str Not specified — see source repository
provenance_str_mv Harvested via OAI-PMH from UCTD — University of Cape Town Open Access Repository
publishDate 2024
publishDateRange 2024
publishDateSort 2024
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publisherStr Department of Pathology
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source_str UCTD — University of Cape Town Open Access Repository
spelling oai:open.uct.ac.za:11427/39736 Optimisation of a flow cytometry antibody panel to detect BCG-induced innate responses in infants Mwambene, Temwa Dango Scriba, Thomas Medicine The outcome of exposure to Mycobacterium tuberculosis is highly variable ranging from clearance, latency to a wide spectrum of subclinical and clinical tuberculosis (TB) disease. The underlying basis of the variable disease outcomes to mycobacterial exposure is largely unknown and is thought to involve a complex interplay between genetic variation in both host and pathogen. This is further convoluted by factors such as age, geography, coinfections including human immunodeficiency virus (HIV) and previous Bacillus Calmette–Guérin (BCG) vaccination. As it stands, other than inborn errors in key mycobacterial susceptibility genes both animal and human studies have not found many genetic polymorphisms that are strongly and reproducibly associated with increased mycobacterial disease susceptibility and/or BCG vaccine efficacy. Given the complexity of the interplay between the variability in disease susceptibility, BCG vaccine efficacy and human exposure to genetically diverse pathogens there is a need to study both host and pathogen genetic factors that contribute to increased TB disease susceptibility. This will facilitate rational design of more broadly efficacious interventions. This MSc project is nested in a project which aims to uncover the genetic factors that result in variable responses to BCG vaccination and in so doing, expand the basis of learning for novel TB vaccine candidates. The overall aim of this MSc was to optimise a flow cytometry panel to measure the BCG-induced innate immune responses in infants. The innate response to BCG was characterised by whole blood intracellular cytokine staining of banked, previously stimulated immune cells from 25, 10-week-old, HIV-uninfected, infants. The cohort is a subset of participants of a randomised control trial conducted in Worcester, South Africa. A 13-colour flow cytometry antibody panel was successfully optimised for enumerating and measuring cytokine and cell maturation marker expression by neutrophils, monocytes, pDCs, mDCs and T cells in response to BCG stimulation. Expression of cytokines (IFNg, IL-6, TNF) and maturation markers (CD40, PD-L1) by these cell subsets to BCG stimulation were quantified, allowing identification of single nucleotide polymorphisms that associate with variability in innate responses to BCG. Results from this MSc thus inform the bigger project which aims to determine genetic determinants of innate responses to BCG and TB disease risk. 2024-05-27T08:48:18Z 2024-05-27T08:48:18Z 2023 2024-05-23T12:59:40Z Thesis / Dissertation Masters MSc http://hdl.handle.net/11427/39736 eng application/pdf Department of Pathology Faculty of Health Sciences
spellingShingle Medicine
Mwambene, Temwa Dango
Optimisation of a flow cytometry antibody panel to detect BCG-induced innate responses in infants
thesis_degree_str Master's
title Optimisation of a flow cytometry antibody panel to detect BCG-induced innate responses in infants
title_full Optimisation of a flow cytometry antibody panel to detect BCG-induced innate responses in infants
title_fullStr Optimisation of a flow cytometry antibody panel to detect BCG-induced innate responses in infants
title_full_unstemmed Optimisation of a flow cytometry antibody panel to detect BCG-induced innate responses in infants
title_short Optimisation of a flow cytometry antibody panel to detect BCG-induced innate responses in infants
title_sort optimisation of a flow cytometry antibody panel to detect bcg induced innate responses in infants
topic Medicine
url http://hdl.handle.net/11427/39736
work_keys_str_mv AT mwambenetemwadango optimisationofaflowcytometryantibodypaneltodetectbcginducedinnateresponsesininfants