The Role of Interleukin-23 in the Early Development of Emphysema in HIV1⁺ Smokers

Figure 7

Proposed mechanism of IL-23 induced upregulation of AM MMP-9. IL-23 induced production of MMP-9 is indirect and requires the presence of non-AM cells such as T cells (“T”) in the alveolar environment. Memory T cells may express IL-23R and are known to be the target of IL-23. Upon stimulation with IL-23, T cells further induce the upregulation of MMP-9 in AM by a mechanism that likely requires direct cell-to-cell contact between T cells and AM.