IL-23-induced macrophage polarization and its pathological roles in mice with imiquimod-induced psoriasis

Macrophages acquire distinct phenotypes during tissue stress and inflammatory responses. Macrophages are roughly categorized into two different subsets named inflammatory M1 and anti-inflammatory M2 macrophages. We herein identified a unique pathogenic macrophage subpopulation driven by IL-23 with a distinct gene expression profile including defined types of cytokines. The freshly isolated resting mouse peritoneal macrophages were stimulated with different cytokines in vitro, the expression of cytokines and chemokines were detected by microarray, real-time PCR, ELISA and multiple colors flow cytometry. Adoptive transfer of macrophages and imiquimod-induced psoriasis mice were used. In contrast to M1- and M2-polarized macrophages, IL-23-treated macrophages produce large amounts of IL-17A, IL-22 and IFN-γ. Biochemical and molecular studies showed that IL-23 induces IL-17A expression in macrophages through the signal transducer and activator of transcription 3 (STAT3)-retinoid related orphan receptor-γ T (RORγT) pathway. T-bet mediates the IFN-γ production in IL-23-treated macrophages. Importantly, IL-23-treated macrophages significantly promote the dermatitis pathogenesis in a psoriasis-like mouse model. IL-23-treated resting macrophages express a distinctive gene expression prolife compared with M1 and M2 macrophages. The identification of IL-23-induced macrophage polarization may help us to understand the contribution of macrophage subpopulation in Th17-cytokines-related pathogenesis.

Multilevel pharmacological manipulation of adenosine-prostaglandin E2/cAMP nexus in the tumor microenvironment: a 'two hit' therapeutic opportunity.

Novel trends in cancer treatment research are focused on targeting the tumor microenvironment, thereby developing chemo-immunotherapeutic strategies which not only directly kill tumor cells, but also trigger the anti-tumor immune effector responses. Ectonucleotidases (CD39 and CD73)-generated extracellular adenosine and cyclooxygenase-2 (COX2)-derived prostaglandin E2 (PGE2) are amongst the tumor microenvironmental factors that have emerged as attractive targets in this regard. Both comprise a pivotal axis in tumor progression and immune escape via autocrine and paracrine activation of a common intracellular signaling pathway, the cAMP-protein kinase A (PKA) pathway, in cancer and immune cells. In this review, we venture a potential and realistic strategy that this adenosine-PGE2/cAMP nexus is targetable at different levels, thereby pointing out a 'two hit' chemo-immunotherapeutic proposition: direct killing of tumor cells on one hand, and the rescuing of endogenous anti-tumor immune response on the other. The reviewed experimental, preclinical and clinical data provide the proof of concept that 'two hit' multilevel pharmacological manipulation of adenosine-E2/cAMP nexus is achievable within the tumor microenvironment.