title: Analysis of Mycobacterium ulcerans-specific T-cell cytokines for diagnosis of Buruli ulcer disease and as potential indicator for disease progression.
abstract: Buruli ulcer disease (BUD), caused by Mycobacterium (M.) ulcerans, is the third most common mycobacterial disease after tuberculosis and leprosy. BUD causes necrotic skin lesions and is a significant problem for health care in the affected countries. As for other mycobacterial infections, T cell mediated immune responses are important for protection and recovery during treatment, but detailed studies investigating these immune responses in BUD patients are scarce. In this study, we aimed to characterise M. ulcerans-specific CD4+ T cell responses in BUD patients and to analyse specific cytokine-producing T cells in the context of disease severity and progression.
  
  
  
  For this case-control study, whole blood samples of BUD patients (N = 36, 1.5-17 years of age) and healthy contacts (N = 22, 3-15 years of age) were stimulated with antigen prepared from M. ulcerans and CD4+ T cells were analysed for the expression of TNFα, IFNγ and CD40L by flow cytometry. The proportions and profile of cytokine producing CD4+ T cells was compared between the two study groups and correlated with disease progression and severity. Proportions of cytokine double-positive IFNγ+TNFα+, TNFα+CD40L+, IFNγ+CD40L+ (p = 0.014, p = 0.010, p = 0.002, respectively) and triple positive IFNγ+TNFα+CD40L+ (p = 0.010) producing CD4+ T cell subsets were increased in BUD patients. In addition, TNFα+CD40L-IFNγ- CD4+ T cells differed between patients and controls (p = 0.034). TNFα+CD40L-IFNγ- CD4+ T cells were correlated with lesion size (p = 0.010) and proportion were higher in 'slow' healers compared to 'fast healers' (p = 0.030).
  
  
  
  We were able to identify M. ulcerans-specific CD4+ T cell subsets with specific cytokine profiles. In particular a CD4+ T cell subset, producing TNFα but not IFNγ and CD40L, showed association with lesion size and healing progress. Further studies are required to investigate, if the identified CD4+ T cell subset has the potential to be used as biomarker for diagnosis, severity and/or progression of disease.
authors.affiliation: Pediatric Pneumology and Infectious Diseases Group, Department of General Pediatrics, Neonatology and Pediatric Cardiology, University Children's Hospital, Heinrich-Heine University, Dusseldorf, Germany.
authors.forename: Norman
authors.identifier: 0000-0002-9704-2148
authors.initials: N
authors.lastname: Nausch
authors.affiliation: Kumasi Centre for Collaborative Research in Tropical Medicine, KNUST, Kumasi, Ghana.
authors.forename: Daniel
authors.initials: D
authors.lastname: Antwi-Berko
authors.affiliation: Kumasi Centre for Collaborative Research in Tropical Medicine, KNUST, Kumasi, Ghana.
authors.forename: Yusif
authors.initials: Y
authors.lastname: Mubarik
authors.affiliation: Agogo Presbyterian Hospital, Agogo, Ghana.
authors.forename: Kabiru Mohammed
authors.initials: KM
authors.lastname: Abass
authors.affiliation: Kumasi Centre for Collaborative Research in Tropical Medicine, KNUST, Kumasi, Ghana.
authors.forename: Wellington
authors.initials: W
authors.lastname: Owusu
authors.affiliation: Kumasi Centre for Collaborative Research in Tropical Medicine, KNUST, Kumasi, Ghana.|Department of Global Health, School of public health, College of Health Sciences, KNUST, Kumasi, Ghana.
authors.forename: Ellis
authors.initials: E
authors.lastname: Owusu-Dabo
authors.affiliation: Kumasi Centre for Collaborative Research in Tropical Medicine, KNUST, Kumasi, Ghana.|School of Medical Sciences, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana.
authors.forename: Linda Batsa
authors.initials: LB
authors.lastname: Debrah
authors.affiliation: Kumasi Centre for Collaborative Research in Tropical Medicine, KNUST, Kumasi, Ghana.|Faculty of Allied Health Sciences of Kwame Nkrumah University of Science and Technology, Kumasi, Ghana.
authors.forename: Alexander Yaw
authors.initials: AY
authors.lastname: Debrah
authors.affiliation: Pediatric Pneumology and Infectious Diseases Group, Department of General Pediatrics, Neonatology and Pediatric Cardiology, University Children's Hospital, Heinrich-Heine University, Dusseldorf, Germany.
authors.forename: Marc
authors.initials: M
authors.lastname: Jacobsen
authors.affiliation: Kumasi Centre for Collaborative Research in Tropical Medicine, KNUST, Kumasi, Ghana.|School of Medical Sciences, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana.
authors.forename: Richard O
authors.initials: RO
authors.lastname: Phillips
mesh_terms: D000293:Adolescent; D015415:Biomarkers / Q000032:analysis; D054312:Buruli Ulcer / Q000175:diagnosis* / Q000473:pathology*; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology*; D023201:CD40 Ligand / Q000032:analysis*; D016022:Case-Control Studies; D002478:Cells, Cultured; D002648:Child; D002675:Child, Preschool; D016207:Cytokines / Q000032:analysis*; D018450:Disease Progression; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D019911:Mycobacterium ulcerans / Q000276:immunology*; D016176:T-Lymphocyte Subsets / Q000276:immunology*
chemical_list: D015415:Biomarkers; D016207:Cytokines; D023201:CD40 Ligand