The Role of T Cells and Macrophages in Asthma Pathogenesis: A New Perspective on Mutual Crosstalk

Figure 1

Imbalance of T cells in asthma pathogenesis. In response to allergens, the naïve T (Tn) cells are activated by the macrophages and tend to differentiate into T helper (Th) 1, Th2, Th17, Th22, Th9, Th25, T regulatory (Treg), T follicular helper (Tfh), natural killer T (NKT), mucosal-associated invariant T (MAIT), γδT cells, cytotoxic CD8⁺T lymphocytes (CTLs), and memory T (Tm) cells. They secrete cytokines to activate and recruit the eosinophils, neutrophils, mast cells, and B cells. The arrows represent the secretions from these cells, affecting the progression of asthma. The transcriptional factors T-bet, Gata3, RAR-related orphan receptor (ROR) γt, Foxp3, and PU.1 are necessary to Th1, Th2, Th17, Treg, Th22, and Th9 cell activation. The signal transducer and activator of transcription (STAT) signals are involved in the process. Besides, caspase 8 and the Fas/FasL pathway are related to cell apoptosis mediated by CTLs.