Role of natural killer cells in the progression of Mycobacterium tuberculosis infection to pulmonary disease

• Autor(a) principal: Abreu, Mónica Teresa Parente
• Data de Publicação: 2011
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/10316/25059
• topic: Doenças do pulmão; Mycobacterium tuberculosis; Células destruidoras naturais

Introduction: Natural killer (NK) cells are key components of the innate immune system and participate in the early response against infected or transformed cells. They are characterized by the expression of a varied repertoire of receptors, named inhibitors and activators, which balance mediates their function. NK cell contribution in infection remains unclear. Mycobacterium tuberculosis infection is still a significant health problem and it will probably become even more significant in coming years because of the high prevalence of human immunodeficiency virus (HIV). The main goal is to clarify the role of NK cells in immunopathogenesis and hypothetical contribution as targets for therapy interventions. Material and methods: Peripheral blood from 38 TB patients and 15 HC was analysed. Complete Blood Cells count as well as enumeration of lymphocyte subsets was made. NK cell surface expression of some important receptors and markers (CD56/CD16, CD27/CD11b, CD57, CD94/NKG2D, NKp30, NKp44, NKp46, NKp80, KIR2DL1, KIR2DL2, KIR3DL1, KIR2DS1) were evaluated and also the intracellular expression of IFN-γ. Results and Discussion: A moderate lymphopenia was observed in TB patients, with a decrease of all lymphocyte subsets, except for B cells. NK cells from TB patients present a higher level of maturation and IFN-γ production. The most marked increase in surface markers expression was observed for CD57. Conclusion: The general NK cells phenotyping here presented can help in the understanding of NK cell role in pulmonary tuberculosis infection and progression to disease, giving some highlights for further research.