Exploring the landscape of synthetic IL-6-type cytokines

High-yield production of recombinant CLCF1 protein fused with human serum albumin in animal cells and toxicity evaluation in rodents

Recombinant protein based biopharmaceutics have been developed as therapeutics of various diseases, especially cancer, diabetes, infectious diseases, and autoimmune diseases. In this study, we conducted a study for the development of biopharmaceuticals based on the CLCF1 protein. First, we established strategies for producing recombinant human CLCF1 protein by transient gene expression in ExpiCHO-S™ Cells and Expi293F™ Cells. For the secretion of CLCF1 protein, we established strategies that human CRLF1 or sCNTFR with CLCF1 protein were co-expressed. As a result, the CLCF1 protein formed a complex with CRLF1 or sCNTFR, which was successfully secreted. Furthermore, the productivity of CLCF1 protein was significantly increased. The ratio of co-transfected plasmids, temperature, CO2 level and time of harvest were explored, so that the productivity of CLCF1 was remarkably increased 7-fold from 3 mg/L to 22 mg/L. Next, we generated recombinant CLCF1 fusion protein with HSA (Albumin CLCF1) considering the improvement of pharmacokinetic properties and the proven production method in GMP facilities. We evaluated the biological activity of various CLCF1 proteins. In consideration of protein productivity, physical properties, and efficacy, we conducted a single intravenous administration of 4 types of proteins in Sprague-Dawley rats to evaluate the short-term toxicity. As a result, no toxicity related CLCF1 proteins was observed based on the behavior sign observation and body weight changes. In conclusion, we successfully established the strategies of production and characterization of biologically active recombinant CLCF1 proteins in mammalian cells as potential biotherapeutics.

Mechanism of disturbed endothelial cell function on angiogenesis following ischemic brain stroke (Review)

The present study focused on the mechanisms of post-ischemic stroke (IS) angiogenesis from the perspective of endothelial cells (ECs) dysfunction. First, it emphasized the importance of hypoxia-inducible factor-1α in the function of ECs under hypoxic conditions, particularly in promoting angiogenesis and improving cerebral blood supply. Secondly, inflammatory cytokines and adhesion factors (for example, selectins, the immunoglobulin superfamily and integrins) influence the function and angiogenesis of ECs through various mechanisms and signaling pathways following IS. In addition, the effects of oxidative stress on ECs function and angiogenesis were explored, along with the potential of antioxidant strategies to improve EC function and promote angiogenesis. Based on these insights, the present study proposed new therapeutic strategies to ameliorate endothelial dysfunction and promote angiogenesis following IS, including small-molecule drugs targeting specific molecules, gene therapy and traditional Chinese medicine treatments. Finally, the importance of translating these laboratory findings into clinical applications was emphasized, alongside the need for advanced imaging techniques to monitor the dynamic processes of post-IS angiogenesis and evaluate the efficacy of novel therapeutic interventions. These explorations aimed at providing a more comprehensive understanding of EC function and the regulatory mechanisms of a deeper understanding of angiogenesis following IS, offering new intervention strategies for IS treatment.

Integrative Bioinformatics Analysis of Pyroptosis-Related Genes and Analysis of Immune Cell Infiltration in Infantile Hemangioma Regression

Background

Infantile hemangiomas (IHs) are characterized by spontaneous regression, and their pathogenesis involves immune cell infiltration and programmed cell death. The molecular pathways and mechanisms involved in pyroptosis in IHs are still unclear. This study aimed to identify genes related to pyroptosis in IH regression by bioinformatics methods and to explore the effects of these pyroptosis-related genes (PRGs) on disease pathology and immune cell infiltration.

Methods

The microarray dataset GSE127487 was assessed to identify differentially expressed genes (DEGs) between proliferation-phase IH (PIHs) and involution-phase IH (IIHs). The DEGs that overlapped with PRGs were considered IH-PRGs. The IH-PRGs were validated and subjected to functional enrichment analysis and Genomes pathway analyses. Gene set enrichment analysis (GSEA) was also performed to analyse the biological significance of the DEGs. The NetworkAnalyst database was used to analyse the correlation network of IH-PRGs and miRNAs as well as that of IH-PRGs and transcription factors. The STRING online database and Cytoscape were used to identify the hub-IH-PRGs. Additionally, a single-sample GSEA algorithm was applied to assess immune cell infiltration in IHs, and correlation analysis was performed between the hub-IH-PRGs and infiltrating immune cells.

Results

Fourteen IH-PRGs were identified. IL6, EGFR, IRF1 and IL32 were identified as hub-IH-PRGs and displayed excellent diagnostic performance. Immune cell infiltration analysis revealed notable differences in CD8+ T cells, Tgd cells and Th17 cells between PIHs and IIHs. IL-6 was significantly positively correlated with Th17 cell infiltration and significantly negatively correlated with Tgd cell infiltration; EGFR was negatively correlated with Tgd cell infiltration; and IRF1 and IL32 were significantly negatively correlated with Th17 cell infiltration.

Conclusion

Four PRGs, namely, IL6, EGFR, IRF1 and IL32, may play a significant role in IH regression. This study provides insights into the molecular mechanisms underlying IH pathogenesis, highlighting the importance of pyroptosis and immune cell infiltration.

Unpaired cysteine insertions favor transmembrane dimerization and induce ligand-independent constitutive cytokine receptor signaling

Naturally occurring gain-of-function (GOF) mutants have been identified in patients for a variety of cytokine receptors. Although this constitutive activation of cytokine receptors is strongly associated with malignant disorders, ligand-independent receptor activation is also a useful tool in synthetic biology e.g. to improve adoptive cellular therapies with genetically modified T-cells. Balanced Interleukin (IL-)7 signaling via a heterodimer of IL-7 receptor (IL-7Rα) and the common γ-chain (γc) controls T- and B-cell development and expansion, whereas uncontrolled IL-7 signaling can drive acute lymphoid leukemia (ALL) development. The ALL-driver mutation PPCL in the transmembrane domain of IL-7Rα is a mutational insertion of the four amino acids proline-proline-cysteine-leucine and leads to ligand-independent receptor dimerization and constitutive activation. We showed here in the cytokine-dependent pre-B-cell line Ba/F3 that the PPCL-insertion in a synthetic version of the IL-7Rα induced γc-independent STAT5 and ERK phosphorylation and also proliferation of the cells and that booster-stimulation by arteficial ligands additionally generated non-canonical STAT3 phosphorylation via the synthetic IL-7Rα-PPCL-receptors. Transfer of the IL-7Rα transmembrane domain with the PPCL insertion into natural and synthetic cytokine receptor chains of the IL-6, IL-12 and Interferon families also resulted in constitutive receptor signaling. In conclusion, our data suggested that the insertion of the mutated PPCL IL-7Rα transmembrane domain is an universal approach to generate ligand-independent, constitutively active cytokine receptors.