Monocyte Subsets: Phenotypes and Function in Tuberculosis Infection.
Monocytes are critical defense components that play an important role in the primary innate immune response. The heterogeneous nature of monocytes and their ability to differentiate into either monocyte-derived macrophages or monocyte-derived dendritic cells allows them to serve as a bridge between the innate and adaptive immune responses. Current studies of monocytes based on immunofluorescence, single-cell RNA sequencing and whole mass spectrometry finger printing reveals different classification systems for monocyte subsets. In humans, three circulating monocyte subsets are classified based on relative expression levels of CD14 and CD16 surface proteins, namely classical, intermediate and non-classical subsets. Transcriptomic analyses of these subsets help to define their distinct functional properties. Tuberculosis (TB) is a disease instigated by the deadly pathogen Mycobacterium tuberculosis. Current research on monocytes in TB has indicated that there are alterations in the frequency of intermediate and non-classical subsets suggesting their impact in bacterial persistence. In this review, we will focus on these monocyte subsets, including their classification, frequency distribution, cytokine profiles, role as a biomarker and will comment on future directions for understanding the salient phenotypic and functional properties relevant to TB pathogenesis.
['Sampath|Pavithra|P|', 'Moideen|Kadar|K|', 'Ranganathan|Uma Devi|UD|', 'Bethunaickan|Ramalingam|R|']
D000818:Animals D015415:Biomarkers D016207:Cytokines D054884:Host-Pathogen Interactions D006801:Humans D007958:Leukocyte Count D018655:Lymphocyte Count D008214:Lymphocytes D009000:Monocytes D009169:Mycobacterium tuberculosis D010641:Phenotype D020543:Proteome D012106:Research D059467:Transcriptome D014376:Tuberculosis
monocyte subsets Mycobacterium tuberculosis CD14+ monocytes CD16+ monocytes biomarkers for tuberculosis monocyte signatures monocyte to lymphocyte ratio