Proliferating cell nuclear antigen acts as a cytoplasmic platform controlling human neutrophil survival

Cytosolic proliferating cell nuclear antigen (PCNA) binds to procaspases and protects human neutrophils from apoptosis

XTX101, A Tumor-Activated, Fc-Enhanced Anti-ctla-4 Monoclonal Antibody, Demonstrates Tumor-Growth Inhibition and Tumor-Selective Pharmacodynamics in Mouse Models of Cancer

INTRODUCTION: The clinical benefit of the anti-CTLA-4 monoclonal antibody (mAb) ipilimumab has been well established but limited by immune-related adverse events, especially when ipilimumab is used in combination with anti-PD-(L)1 mAb therapy. To overcome these limitations, we have developed XTX101, a tumor-activated, Fc-enhanced anti-CTLA-4 mAb. METHODS: XTX101 consists of an anti-human CTLA-4 mAb covalently linked to masking peptides that block the complementarity-determining regions, thereby minimizing the mAb binding to CTLA-4. The masking peptides are designed to be released by proteases that are typically dysregulated within the tumor microenvironment (TME), resulting in activation of XTX101 intratumorally. Mutations within the Fc region of XTX101 were included to enhance affinity for FcγRIII, which is expected to enhance potency through antibody-dependent cellular cytotoxicity. RESULTS: Biophysical, biochemical, and cell-based assays demonstrate that the function of XTX101 depends on proteolytic activation. In human CTLA-4 transgenic mice, XTX101 monotherapy demonstrated significant tumor growth inhibition (TGI) including complete responses, increased intratumoral CD8+T cells, and regulatory T cell depletion within the TME while maintaining minimal pharmacodynamic effects in the periphery. XTX101 in combination with anti-PD-1 mAb treatment resulted in significant TGI and was well tolerated in mice. XTX101 was activated in primary human tumors across a range of tumor types including melanoma, renal cell carcinoma, colon cancer and lung cancer in an ex vivo assay system. CONCLUSIONS: These data demonstrate that XTX101 retains the full potency of an Fc-enhanced CTLA-4 antagonist within the TME while minimizing the activity in non-tumor tissue, supporting the further evaluation of XTX101 in clinical studies

From IL-15 to IL-33: the never-ending list of new players in inflammation. Is it time to forget the humble aspirin and move ahead?

The study of the inflammatory response has seen a tremendous expansion over the last 30 years. Advancements in technology and better knowledge of the ethiopathogenesis of several inflammatory conditions have facilitated this process allowing researchers to almost reach the core of problem. Thus, we now know that inflammation can be manifested in many different ways depending on the context that has elicited it. Viral and infectious, allergic and autoimmune, carcinogenic and resolutive are just a few examples of how inflammation can disguise itself. However, and most intriguingly, it appears that the more we try to discover "an ideal target" and delineate borders for a specific class of inflammatory conditions the more we find similarities, overlaps or often links that we did not predict. These somehow disappointing findings have pushed researchers towards a frantic search for new and more "reliable" targets. As result, we have recently seen a surge of many novel mediators of inflammation. If we just limit our focus to inflammatory cytokines, the main topic of this commentary, the list seems never-ending: IL-15, IL-17, IL-18, IL-21, IL-22, IL-23, IL-27 and IL-33. Are these cytokines destined to supersede prostaglandins and other autacoids for their key role in inflammation? Are we going to see a cheap and effective alternative to aspirin on the supermarket shelves in the next few years? Here we summarize the most recent findings on the biological effects of these new inflammatory cytokines and discuss how these discoveries might influence our current view on therapeutic approaches to treat inflammatio

From IL-15 to IL-33the never-ending list of new players in inflammation. Is it time to forget the humble aspirin and move ahead?

The study of the inflammatory response has seen a tremendous expansion over the last 30 years. Advancements in technology and better knowledge of the ethiopathogenesis of several inflammatory conditions have facilitated this process allowing researchers to almost reach the core of problem. Thus, we now know that inflammation can be manifested in many different ways depending on the context that has elicited it. Viral and infectious, allergic and autoimmune, carcinogenic and resolutive are just a few examples of how inflammation can disguise itself. However, and most intriguingly, it appears that the more we try to discover "an ideal target" and delineate borders for a specific class of inflammatory conditions the more we find similarities, overlaps or often links that we did not predict. These somehow disappointing findings have pushed researchers towards a frantic search for new and more "reliable" targets. As result, we have recently seen a surge of many novel mediators of inflammation. If we just limit our focus to inflammatory cytokines, the main topic of this commentary, the list seems never-ending: IL-15, IL-17, IL-18, IL-21, IL-22, IL-23, IL-27 and IL-33. Are these cytokines destined to supersede prostaglandins and other autacoids for their key role in inflammation? Are we going to see a cheap and effective alternative to aspirin on the supermarket shelves in the next few years? Here we summarize the most recent findings on the biological effects of these new inflammatory cytokines and discuss how these discoveries might influence our current view on therapeutic approaches to treat inflammation.</p

Design and characterization of a cleavage-resistant Annexin A1 mutant to control inflammation in the microvasculature

Human polymorphonuclear leukocytes adhesion to endothelial cells during the early stage of inflammation leads to cell surface externalization of Annexin A1 (AnxA1), an effector of endogenous anti-inflammation. The antiadhesive properties of AnxA1 become operative to finely tune polymorphonuclear leukocytes transmigration to the site of inflammation. Membrane bound proteinase 3 (PR3) plays a key role in this microenvironment by cleaving the N terminus bioactive domain of AnxA1. In the present study, we generated a PR3-resistant human recombinant AnxA1-named superAnxA1 (SAnxA1)-and tested its in vitro and in vivo properties in comparison to the parental protein. SAnxA1 bound and activated formyl peptide receptor 2 in a similar way as the parental protein, while showing a resistance to cleavage by recombinant PR3. SAnxA1 retained anti-inflammatory activities in the murine inflamed microcirculation (leukocyte adhesion being the readout) and in skin trafficking model. When longer-lasting models of inflammation were applied, SAnxA1 displayed stronger anti-inflammatory effect over time compared with the parental protein. Together these results indicate that AnxA1 cleavage is an important process during neutrophilic inflammation and that controlling the balance between AnxA1/PR3 activities might represent a promising avenue for the discovery of novel therapeutic approaches