Metabolism and metabolic processes have long been considered to shape the tumour immunosuppressive microenvironment. Recent research has demonstrated that T regulatory cells (Tregs) display high rates of fatty acid oxidation (FAO) and a relatively low rate of glycolysis. Sphingosine 1-phosphate (S1P), which is a G protein signalling activator involved in immune regulation and FAO modulation, has been implicated in Treg differentiation. However, the precise relation between Treg differentiation and S1P remains unclear. In this study, we isolated naïve CD4+ T cells from the spleens of 6-8-week-old BALB/c mice using magnetic bead sorting, which was used in our study for Treg differentiation. S1P stimulation was performed during Treg differentiation. We examined the oxygen consumption and palmitic acid metabolism of the differentiated Tregs and evaluated the expression levels of various proteins, including Nrf2, CPT1A, Glut1, ACC1 and PPARα, through Western blotting. Our results demonstrate that S1P promotes Treg differentiation and enhances FAO, and that the expression of nuclear factor (erythroid-derived 2)-like 2 (Nrf2) and peroxisome proliferator-activated receptor α (PPARα) is upregulated. Furthermore, Nrf2 or PPARα knockdown dampened the Treg differentiation and FAO that were promoted by S1P, confirming that S1P can bind with S1PR4 to promote Treg differentiation through the Nrf2/PPARα signalling pathway, which may be related to FAO facilitation.
In-depth immunophenotyping by flow cytometry of peripheral blood dendritic cell (DC) populations of psoriasis vulgaris without (PsO; N = 23) or with psoriatic arthritis (PsA; N = 15), before (T1) and after 12 months (T2) therapy with the anti-TNF drugs infliximab, etanercept, the anti-IL-17A secukinumab and the anti-IL12/IL-23 ustekinumab. Compared to healthy donors (N = 38), patients with PsA displayed lower frequencies of dendritic cell subsets pDC, cDC1 and cDC2, which were normalized following treatment except pDC. In contrast, patients with PsO only displayed lower frequencies of pDC which were normalized following treatment. Figure created with BioRender.com.
Targeted therapy with tumour-associated macrophages (TAMs) has emerged as a new paradigm for immunotherapy of cervical cancer. Nocardia rubra cell wall skeleton (Nr-CWS) for external use is an immunotherapeutic agent. In this study, we aimed to explore the effects of Nr-CWS on TAMs and the potential mechanisms. Cervical tissue samples were collected before and after Nr-CWS treatment from patients with high-risk HPV infection and cervical intraepithelial neoplasia (CIN). The effect of Nr-CWS on macrophages in vivo was examined by immunohistochemistry and double-labeling immunofluorescence histochemistry. In vitro experiments were performed using a TAM model established by THP-1 cells under Nr-CWS treatment. We found that Nr-CWS treatment significantly reduced the numbers of total macrophages and M2 macrophages, increased the proportion of M1 macrophages and decreased the proportion of M2 macrophages in cervical tissues. After Nr-CWS treatment in vitro, the expression levels of the M1 macrophage markers were increased, while the expression levels of the M2 macrophage markers were decreased. Nr-CWS treatment also activated STAT1 pathways but inhibited STAT6 pathways. These results indicated that Nr-CWS may improve local immune response and reverse immunosuppression by regulating the M2 to M1 polarization of TAMs via STAT1/STAT6 pathways.