Kymera Therapeutics

Ubiquitination is a pivotal regulatory mechanism in host-virus interactions, playing essential roles in both antiviral defense and viral immune evasion, with E3 ubiquitin ligases serving as critical regulatory nodes. In this study, we systematically evaluated 26 candidate host E3 ubiquitin ligases for their involvement in influenza A virus (IAV) infection. Among these, potassium channel modulatory factor 1 (KCMF1) was identified as a novel negative regulator of IAV replication in vitro and in vivo. Mechanistically, KCMF1 interacts with the viral polymerase subunit PB1 and mediates its ubiquitination at lysine 653 (K653), triggering proteasomal degradation and consequent impairment of polymerase activity. A recombinant PR8 (H1N1) virus carrying a K653R substitution in PB1 exhibits enhanced replication and increased pathogenicity in both cells and mice. Furthermore, the inhibitory effect of KCMF1 on PR8 virus replication is dependent on the K653 residue of PB1. Importantly, viruses harboring the PB1 K653 mutation display marked resistance to favipiravir (T-705), an inhibitor of viral RNA-dependent RNA polymerase, suggesting that mutations at this site may influence antiviral drug sensitivity in circulating strains, and have potential implications for clinical treatment and viral surveillance. In conclusion, our findings identify KCMF1 as a host restriction factor that suppresses IAV replication via ubiquitination of PB1 at K653.IMPORTANCEInfluenza A virus (IAV) continues to pose a major global health threat, and host factors that regulate viral replication are critical for understanding pathogenesis and guiding antiviral interventions. Here, we identify KCMF1 as a host E3 ubiquitin ligase that restricts IAV replication by promoting ubiquitination-dependent degradation of the viral polymerase subunit PB1. We further define lysine 653 (K653) of PB1 as a critical residue for this regulatory mechanism. Notably, mutation at this site enhances viral replication and pathogenicity while conferring resistance to favipiravir, a clinically approved inhibitor of viral RNA-dependent RNA polymerase. Collectively, these findings provide new mechanistic insights into host-virus interactions and highlight important considerations for antiviral drug use and surveillance of emerging viral variants.

Tumor matrix stiffness, a pivotal physical attribute of the tumor microenvironment, has evolved from a passive physical barrier to an active immunoregulatory platform, profoundly impacting the initiation and effector phases of anti-tumor immune responses. This review systematically elaborates on the dual mechanisms that drive immunosuppression. Directly, stiffness attenuates T-cell and natural killer (NK) cell functions by activating pathways such as Yes-associated protein (YAP)/Transcriptional co-activator with PDZ-binding motif (TAZ) and Piezo-type mechanosensitive ion channel component 1 (Piezo1). It also drives the polarization of macrophages and dendritic cells towards immunosuppressive phenotypes. Indirectly, stiffness fosters an immune escape ecosystem by persistently activating cancer-associated fibroblasts, inducing tumor cell epithelial-mesenchymal transition, and upregulating immune checkpoints. Consequently, strategies such as enzymatic degradation, targeting mechanotransduction pathways, employing anti-fibrotic drugs, and developing intelligent combination therapies have emerged, aiming to soften tumors and reverse immunosuppression. Clinical studies confirm that high expression of the mechanosignaling hub Yes-associated protein 1 (YAP1) is associated with resistance to immunotherapy. In the future, integrating mechanobiology, immunometabolism, and smart materials to develop precise multimodal combination strategies holds promise for reversing the "cold tumor" microenvironment and opening new avenues to overcome immunotherapy resistance in solid tumors.

TRIM47 is a core member of the tripartite motif (TRIM) family of E3 ubiquitin ligases, characterized by an N-terminal RBCC motif and a C-terminal PRY-SPRY domain that flexibly catalyze both K48- and K63-linked ubiquitination. Under physiological conditions, TRIM47 functions as a crucial safety valve for immunological and neurovascular homeostasis, primarily by degrading innate immune signaling hubs (such as MAVS) to prevent hematopoietic stem cell exhaustion and by stabilizing antioxidant responses in the central nervous system. However, in the tumor microenvironment (TME), TRIM47 undergoes profound functional reprogramming driven by specific post-translational modifications (PTMs) and altered substrate availability. This pathogenic shift redirects its ubiquitin ligase activity toward the targeted degradation of critical tumor suppressors and metabolic enzymes, while persistently activating pro-survival signaling cascades, such as the NF-κB and Wnt/β-catenin pathways. Consequently, TRIM47 drives malignant progression, metabolic reprogramming, and multidrug resistance across diverse anatomical systems, concurrently remodeling the TME toward an immunosuppressive state via altered metabolic byproducts. Clinically, elevated TRIM47 expression strongly correlates with advanced tumor stage, metastasis, and poor prognosis, establishing its robust potential as a pan-cancer predictive biomarker. Despite this, direct systemic therapeutic targeting of TRIM47 remains conceptually challenged by substantial on-target toxicities, including lethal autoimmune inflammation and blood-brain barrier disruption. This review systematically delineates the structural basis and context-dependent regulatory networks of TRIM47, critically evaluates its transition from a physiological guardian to a pathological driver, and assesses the translational feasibility and distinct obstacles of TRIM47-targeted precision nanomedicine.

Viral-associated pulmonary aspergillosis (VAPA) is a severe complication of viral pneumonia (VP) that is associated with pronounced inflammatory amplification, immune dysregulation, and increased mortality. However, systemic metabolic and immune response patterns accompanying VAPA remain incompletely understood. Plasma samples were obtained from 35 patients with viral pneumonia (VP group) and 20 with viral-associated pulmonary aspergillosis (VAPA group). An integrated multi-omics strategy combining data-independent acquisition (DIA)-based proteomics and untargeted metabolomics was used. In total, 1,930 proteins and 1,532 metabolites were identified. Differential analyses along with Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses were conducted to characterize host immune and metabolic alterations associated with viral-fungal coinfection. Compared to patients with VP, those with VAPA showed more pronounced systemic inflammatory activity, immune dysregulation, hepatic and renal impairment, and coagulation abnormalities. Proteomic profiling revealed a higher abundance of proteins related to antioxidant responses, protein degradation pathways, and inflammatory and immune signaling in patients with VAPA. Metabolomic analyses indicated substantial alterations in lipid metabolism, increased oxidative stress-related metabolites, and dysregulation of hormone- and vitamin-associated metabolic pathways. Together, these proteomic and metabolomic patterns were associated with enhanced inflammatory burden, disrupted immune regulation, and greater disease severity. This study provides a systematic overview of immune and metabolic alterations in patients with VAPA. The observed multi-omics features offer insights into host responses associated with viral-fungal coinfection and provide potential theoretical support for early identification and targeted intervention of VAPA.

Cervical cancer (CC) is characterized by tumor immune escape, which underlies suboptimal therapy responses and an increased recurrence risk. Despite the established role of LAT1 in cancer progression, its regulatory mechanism in the CC immune microenvironment remains elusive. LAT1 expression in cervical squamous cell carcinoma and its correlation with CD8+ T cell infiltration were assessed through the bioinformatic approach. LAT1 mRNA and protein expression were examined by qRT-PCR and Western blot, respectively. In a co-culture system with CC cells, CD8+ T cell antitumor activity was measured by lactate dehydrogenase release, ELISA, CCK-8, colony formation, and flow cytometry. The LAT1/TRIM67 interaction was identified through bioinformatics and validated by Co-IP and immunofluorescence. Potential ubiquitination substrates of TRIM67 were screened through bioinformatics. CHX chase assays combined with ubiquitination analysis were employed to verify the IRF3 degradation pathway. Finally, in vivo functional validation was conducted in a mouse xenograft model. LAT1 was overexpressed in CC tissues and cell lines. LAT1 expression negatively correlated with CD8+ T cell infiltration. LAT1 knockdown enhanced CD8+ T cell antitumor activity. Mechanistically, LAT1 suppressed CD8+ T cell antitumor function in CC by interacting with TRIM67 to promote ubiquitination and degradation of IRF3. LAT1 recruits TRIM67 to mediate IRF3 ubiquitination and degradation, ultimately suppressing CD8+ T cell function and promoting immune escape. These findings provide a theoretical basis for targeting the LAT1/TRIM67 axis to enhance immunotherapy in CC.

The interplay between host and parasite determines parasite burden and disease outcome. Parasite exploits host signaling pathways like p38-MAPK for its survival and pathogenesis. Here we have used NR-7h, a proteolysis-targeting chimera (PROTAC) targeting human p38-MAPK to assess p38-MAPK's role in Leishmania donovani and Plasmodium falciparum infection in their respective host cells. NR-7h degrades host p38-MAPK in a time- and dose-dependent manner. Degradation of host p38-MAPK by NR-7h reduces parasite load in host cells dose-dependently, implicating the role of p38-MAPK in parasite survival. During Leishmania infection, the modulation of cytokine profiling and oxidative burst upon NR-7h mediated degradation of host p38-MAPK is further correlated with parasite death. The effect of host p38-MAPK degradation by NR-7h with Amphotericin B enhances the efficacy of parasite-directed therapy. For Plasmodium infection, growth inhibition and invasion assays reveal impaired growth and merozoite invasion, suggesting that host p38-MAPK signaling contributes to both parasite invasion and intraerythrocytic development. This study underscores the importance of host p38-MAPK for L. donovani and P. falciparum progression and highlights NR-7h's potential in antiparasitic therapy by targeting this pathway.

Chimeric antigen receptor (CAR) T cell therapy has shown promise in solid tumours, but its efficacy is limited by dense extracellular matrix (ECM) that blocks T cell entry. We engineered mesothelin-targeted CAR T cells to express heparanase (HPSE) fused to the truncated hepatitis A virus pX domain (pX-Δ1-30), enabling surface display of HPSE on extracellular vesicles for localized, pH-dependent ECM degradation within the acidic tumour microenvironment while limiting systemic exposure. HPSE-pX-Δ1-30 CAR T (referred to as HPSE CAR T) cells penetrated ECM mimics nearly fourfold more effectively than standard CAR T cells. They also expressed more TNF-related apoptosis-inducing ligand (TRAIL), Fas ligand (FasL), and perforin, leading to stronger tumour killing in 2D and 3D colorectal cancer models. HPSE-pX-Δ1-30 CAR T-derived extracellular vesicles (EVs) retained CAR and chemokine receptors (CCR5/CCR7), carried apoptotic ligands, and were efficiently taken up by tumour cells and T cells. EV exposure promoted T cell proliferation, CCR5 expression, and central/stem-like memory formation while lowering PD-1 and CD57. In HCT116 xenografts, HPSE CAR T cells showed increased intratumoral infiltration, and EVs from these cells promoted infiltration of host T cells. Treatment reduced tumour burden, extended survival beyond 70 days, and did not cause systemic toxicity. These results highlight a dual strategy of ECM remodelling and immune modulation, offering a translational approach to overcome barriers to CAR T therapy in colorectal cancer.