JoeyKelly

Cancer Cell. 2025 Jun 4:S1535-6108(25)00215-6. doi: 10.1016/j.ccell.2025.05.006. Online ahead of print.

ABSTRACT

Despite the success of chimeric antigen receptor (CAR)-T cell therapies in hematological malignancies, clinical success against solid tumors is limited due to low therapeutic efficacy or dose-limiting toxicity. Developing therapies that trigger potent, yet manageable, immune responses capable of eliminating highly heterogeneous and immunosuppressive tumor cell populations remains a key challenge. Here, we harness multiple genetic approaches to develop a CAR-T cell therapy targeting tumors. First, we screen binders targeting oncogenic KRAS G12V mutations presented by peptide-MHC complexes. Subsequently, we incorporate these neoantigen binders into CAR-T cells (mKRAS NeoCARs) and demonstrate their efficacy in xenograft models of metastatic lung, pancreatic, and renal cell cancer. Finally, we enhance the in vivo efficacy and safety profile of mKRAS NeoCARs via inducible secretion of IL-12 and T cell receptor deletion. Together, these screening and engineering processes provide a modular platform for expanding the therapeutic index of cellular immunotherapies that target cancer.

PMID:40480232 | DOI:10.1016/j.ccell.2025.05.006

ACS Infect Dis. 2025 Jul 11;11(7):1893-1906. doi: 10.1021/acsinfecdis.4c01062. Epub 2025 Jun 5.

ABSTRACT

The recalcitrance of Mycobacterium tuberculosis to antibiotic treatment has been broadly attributed to the impermeability of the organism's outer mycomembrane. However, the studies that support this inference have been indirect or reliant on bulk population measurements. We previously developed the Peptidoglycan Accessibility Click-Mediated AssessmeNt (PAC-MAN) method to covalently trap azide-modified small molecules in the peptidoglycan cell wall of live mycobacteria after they have traversed the mycomembrane. Using PAC-MAN, we now show that the mycomembrane differentially restricts access to fluorophores and antibiotic derivatives. Mycomembranes of both M. tuberculosis and the model organism Mycobacterium smegmatis discriminate between divergent classes of antibiotics as well as between antibiotics within a single family, the fluoroquinolones. By analyzing subpopulations of M. tuberculosis and M. smegmatis, we also found that some fluorophores and vancomycin are heterogeneously restricted by the mycomembrane. Our data indicate that the mycomembrane is a molecule- and cell-specific barrier to antibiotic permeation.

PMID:40471697 | DOI:10.1021/acsinfecdis.4c01062

bioRxiv [Preprint]. 2025 May 19:2025.05.14.654109. doi: 10.1101/2025.05.14.654109.

ABSTRACT

The antigen presenting molecule MHC class I-related protein 1 (MR1) binds small molecule metabolites derived from microbial riboflavin biosynthetic pathways and presents them at the cell surface for surveillance by MR1-restricted mucosal-associated invariant T cells (MAIT cells). MR1 ligands can originate in the extracellular space or in endosomal compartments that contain microbial pathogens. Distinct, complementary antigen processing and presentation pathways enable MR1 to survey diverse intracellular locations and present both exogenous and intracellular antigens. Here, we generated a panel of BEAS-2B MR1 KO cells reconstituted with MR1 proteins mutated at amino acids 9 - 16. The mutated MR1 molecules differentially translocated to the cell surface in response to 6-formylpterin and differed in their ability to present mycobacterial antigens to MAIT cell clones. While they barely presented Mycobacterium smegmatis supernatant and other exogenous MAIT cell antigens, their ability to present antigens derived from mycobacterial infection and a 5-A-RU prodrug requiring endosomal processing remained largely intact. Protein co-immunoprecipitation and mass spectrometry-based proteomic analysis showed that mutated MR1 differentially associated with calnexin and β ₂ -microglobulin (B2M). Knock-down of B2M in cells over-expressing MR1 phenocopied the loss of exogenous antigen presentation but did not impact presentation of intracellular antigens. Thus, the MR1-mediated presentation of exogenous antigen appears to be limited by binding to B2M whereas the lower sensitivity to B2M deficiency implies that MAIT cell activation via the endosomal antigen presentation pathway may be limited by the availability of MR1 itself.

PMID:40475583 | PMC:PMC12139987 | DOI:10.1101/2025.05.14.654109

J Cancer Res Clin Oncol. 2025 May 24;151(5):174. doi: 10.1007/s00432-025-06227-5.

ABSTRACT

BACKGROUND: Histone deacetylases (HDAC) are involved in chromatin remodelling, and histone deacetylases inhibitors have become the interest of research and shown promising antitumor effects against various cancer.

METHODS: In the current study, an attempt was made to characterize the preclinical ADME properties of a novel hydroxamic based HDAC inhibitor, PAT-1102, with the help of in vitro assays and in vivo pharmacokinetic experiments in rats.

RESULTS: PAT-1102 showed high aqueous solubility and high Caco-2 permeability in the in vitro assays. It was found to be not a substrate of efflux protein P-gp, found stable in metabolism experiments with incubations of rat and human liver microsomes. Inhibition experiments of human recombinant CYP enzymes revealed that PAT-1102 was not considerably inhibited the major CYP enzymes. PAT-1102 exhibited low plasma protein binding of 58.1% and 54.5% in humans and rats, respectively. In vivo pharmacokinetic studies of PAT-1102 in male and female rats showed bioavailability of 3.7% and 3.0% by oral route, respectively. Previous research findings suggested that PAT-1102 is a potent pan-HDAC inhibitor with good preclinical efficacy.

CONCLUSION: Considering the overall ADME and pharmacokinetic profile of PAT-1102, as indicated by in vitro and in vivo experiments, the PAT-1102 could be considered as a potential candidate for the advancement of cancer therapy.

PMID:40411569 | PMC:PMC12103360 | DOI:10.1007/s00432-025-06227-5

Oncoimmunology. 2025 Dec;14(1):2508050. doi: 10.1080/2162402X.2025.2508050. Epub 2025 May 27.

ABSTRACT

Antibody-epitope conjugates (AECs) proved to be a promising new therapeutic strategy to redirect virus-specific CD8⁺ T cells toward cancer cells by delivering T-cell epitopes. To be able to redirect a larger fraction of the virus-specific T-cell population, it is beneficial to deliver a broader selection of T-cell epitopes. We investigated two different methods to generate AECs with two distinct virus-specific T-cell epitopes fused to one antibody. Epitopes were either placed in a tandem-like fashion at the C-terminus of the AEC (t-AEC) or bispecific-AECs (bs-AECs) were generated via controlled Fab-arm exchange to generate bs-AECs with two identical antigen binding domains, but two distinct epitopes on each Fab-arm. Our study revealed that maintaining a free epitope terminus was required for efficient delivery of the virus-specific T-cell epitopes. Consequently, viral-epitope delivery using t-AECs was suboptimal as the concatenated epitopes were less effectively delivered to the target cells. However, well-defined bs-AECs containing both CMV and EBV epitopes were successfully generated and both in vitro and in vivo efficacy was evaluated. Our results demonstrate that bispecific-AECs can efficiently deliver EBV and CMV epitopes simultaneously to multiple cancer cell lines from different origins, thereby redirecting and activating two distinct populations of virus-specific T cells. Furthermore, our in vivo findings indicate that when both virus-specific T-cell populations are present and tumor cells express the proteases required for efficient epitope delivery, bs-AECs exhibit similar efficacy in reducing tumor burden compared to AECs. To conclude, our study demonstrates the feasibility of redirecting two groups of virus-specific T cells using a single antibody and highlights the potential of bs-AECs both in vitro and in vivo.

PMID:40426019 | PMC:PMC12118402 | DOI:10.1080/2162402X.2025.2508050

J Biol Chem. 2025 May 22:110253. doi: 10.1016/j.jbc.2025.110253. Online ahead of print.

ABSTRACT

Major Histocompatibility Complex I (MHC-I) and MHC-I-like molecules play a central role in mediating immunity. Through their conservation across all taxa of jawed vertebrates, the MHC-I-like proteins have adapted to present non-peptidic antigens to distinct T cell populations. While our understanding of the structure-function relationship of MHC-I and MHC-I-like molecules in humans and mice is well established, the nature of the antigens presented by MHC-I- like molecules in 'non-model' species remains unclear. Here, using a mammalian recombinant expression system combined with mass spectrometry approaches, we identified N-myristoylated peptides as endogenous ligands for the chicken MHC-I-like protein YF1*7.1. Given the importance of N-myristoylation in viral pathogenesis, we determined the crystal structure of YF1*7.1 in complex with two N-myristoylated peptides derived from Marek's disease virus (MDV), demonstrating the molecular basis that underpins the presentation of N-myristoylated peptides from MDV, a highly contagious and fatal viral neoplastic disease in chickens. Thus, the identified ligands are distinct from unmodified peptides found in classical MHC-I and -II as well as diverse amphipathic lipids captured by CD1 proteins. Collectively, our study lays the foundation for further molecular and functional characterization of YF1*7.1 and more broadly of the role of the MHC-I encoded by the MHC-Y gene cluster in protection against highly contagious viral neoplastic diseases in chickens.

PMID:40412526 | DOI:10.1016/j.jbc.2025.110253

Nat Cancer. 2025 May 22. doi: 10.1038/s43018-025-00979-2. Online ahead of print.

ABSTRACT

Melanoma and non-small cell lung cancer (NSCLC) display exceptionally high mutational burdens. Hence, immune targeting in these cancers has primarily focused on tumor antigens (TAs) predicted to derive from nonsynonymous mutations. Using comprehensive proteogenomic analyses, we identified 589 TAs in cutaneous melanoma (n = 505) and NSCLC (n = 90). Of these, only 1% were derived from mutated sequences, which was explained by a low RNA expression of most nonsynonymous mutations and their localization outside genomic regions proficient for major histocompatibility complex (MHC) class I-associated peptide generation. By contrast, 99% of TAs originated from unmutated genomic sequences specific to cancer (aberrantly expressed tumor-specific antigens (aeTSAs), n = 220), overexpressed in cancer (tumor-associated antigens (TAAs), n = 165) or specific to the cell lineage of origin (lineage-specific antigens (LSAs), n = 198). Expression of aeTSAs was epigenetically regulated, and most were encoded by noncanonical genomic sequences. aeTSAs were shared among tumor samples, were immunogenic and could contribute to the response to immune checkpoint blockade observed in previous studies, supporting their immune targeting across cancers.

PMID:40405018 | DOI:10.1038/s43018-025-00979-2

Front Immunol. 2025 May 8;16:1595764. doi: 10.3389/fimmu.2025.1595764. eCollection 2025.

ABSTRACT

Immunologists generally view the notion of self and non-self as part of a broader, more contextual understanding of immune function, rather than a rigid dogma. While the classical paradigm that the primary role of the immune system is to recognize and eliminate anything foreign once provided a unifying basis for explaining tolerance and rejection, numerous discoveries have focused attention on how immune responses are finely tuned by a range of contextual cues, including tissue signals, hygienist theory, molecular mimicry, symbiotic microbes, metabolic factors and epigenetic modifications. Maternal-fetal tolerance and the persistence of microchimeric cells in adults demonstrate that genetically foreign cells can be actively integrated into the host, challenging the simple assumption that 'foreign' equals unconditional attack. Similarly, research into the microbiome, the virome and the phenomenon of trained innate immunity has shown that there can be beneficial or even essential relationships between the body and what has traditionally been labelled 'non-self'. Over the last decade, the idea that the immune system strictly enforces a binary distinction has instead evolved towards a model in which it continuously interprets signals of damage or perturbation, manages complex ecological relationships with commensal or latent organisms, and recalibrates according to the organism's life stage and environment. There remains a recognition that clonal deletion and negative selection in the thymus, together with MHC-bound peptide recognition, still underlie many core processes, and in certain clinical contexts, such as acute transplant rejection or the prevention of autoimmunity, an approximate self-non-self-categorization is directly relevant. Overall, however, the field recognizes that 'self' is not a static attribute defined once and for all, but rather a dynamic and context-dependent state that continues to be shaped by microbial symbioses, epigenetic reprogramming and immunoregulatory networks throughout an individual's lifespan.

PMID:40406136 | PMC:PMC12095020 | DOI:10.3389/fimmu.2025.1595764

Biomed Pharmacother. 2025 May 16;188:118161. doi: 10.1016/j.biopha.2025.118161. Online ahead of print.

ABSTRACT

The overexpression of programmed cell death ligand 1 (PD-L1), a critical immune checkpoint protein, is associated with poor prognosis and reduced survival in lung cancer patients. Monoclonal antibodies targeting the PD-1/PD-L1 axis have been approved to disrupt this interaction and prevent immune cell exhaustion. Herein, to enhance the efficacy of PD-1/PD-L1 blockade, we investigated a bispecific αPD-L1 × αCD3 protein engager (αPD-L1 × αCD3 BIPE). The αPD-L1 × αCD3 BIPE consists of an anti-CD3 single-chain variable fragment (scFv) linked to an anti-PD-L1 scFv, allowing it to bind to CD3-positive T cells simultaneously and PD-L1-overexpressing cancer cells. In co-culture assays with T cells and non-small cell lung cancer (NSCLC) cell lines-A549, NCI-H460, and NCI-H1975-treatment with the BIPE significantly enhanced T-cell-mediated cytotoxicity. The killing efficiency correlated with PD-L1 expression levels, with the highest cytotoxic activity observed in NCI-H1975 (high PD-L1 expression), followed by NCI-H460 (moderate PD-L1 expression) and A549 (low PD-L1 expression). Furthermore, combining the BIPE with the standard chemotherapeutic agent gemcitabine further improved anti-tumor activity. This effect was likely due to gemcitabine-induced upregulation of PD-L1 and MHC class I expression on cancer cells, enhancing T-cell recognition and cytotoxicity. These findings suggest that combining αPD-L1 × αCD3 BIPE with gemcitabine is promising for enhancing immune checkpoint blockade and augmenting anti-tumor immunity in NSCLC.

PMID:40381506 | DOI:10.1016/j.biopha.2025.118161

Nat Commun. 2025 May 14;16(1):4454. doi: 10.1038/s41467-025-59622-4.

ABSTRACT

B cells engage in anti-tumor immunity but how they contribute to cancer suppression remains unclear. We report that inhibiting plasma cell differentiation either in IgMi mice lacking Igh elements needed for antibody secretion or in mice with B cell-specific knockout of Blimp-1 (Blimp-1 BcKO) promotes rather than inhibits antitumor immunity and increases numbers of activated B cells. Deficiency of Blimp-1 in tumor-infiltrating B cells generates a unique transcription profile associated with expansion of mutated clones targeting cognate tumor cells. Major histocompatibility complex class II (MHC II) is required for anti-tumor efficacy. Blimp-1-deficient B cells have increased expression of CD80 and CD86 costimulatory molecules that enhance effector T cell function. The Blimp-1 inhibitor valproic acid suppresses tumor growth in a B cell-dependent manner. Thus, inhibition of plasma cell differentiation results in enhanced tumor-specific antigen presentation by B cells and thereby tumor repression, suggesting a potential avenue of immunotherapy against cancer.

PMID:40360528 | DOI:10.1038/s41467-025-59622-4

Clin Cancer Res. 2025 May 12. doi: 10.1158/1078-0432.CCR-24-4338. Online ahead of print.

ABSTRACT

PURPOSE: Tyrosine kinase inhibitors (TKIs) combined with immune checkpoint blockades (ICBs) produce enhanced anti-tumor activity in the treatment of advanced hepatocellular carcinoma (HCC). Sitravatinib is a novel multi-target TKI that targets TYRO3, AXL, MERTK (TAM) receptors, c-MET, etc. This study aimed to investigate the anti-tumor efficacy and immunomodulatory activity of sitravatinib in HCC.

EXPERIMENTAL DESIGN: Human HCC cell lines and xenograft models were used to explore the anti-tumor activity of sitravatinib. Subcutaneous and orthotopic immunocompetent murine HCC models were used to assess the therapeutic efficacy of sitravatinib and PD-1 blockade combination therapy. Co-cultures for tumor cells and T cells were performed to verify the immunomodulatory effect of sitravatinib in tumors.

RESULTS: Sitravatinib showed potent anti-tumor activity and immunomodulatory capabilities from in vitro to in vivo. Sitravatinib treatment synergized with PD-1 blockade to generate an increased anti-tumor efficacy, leading to significant enrichment of cytotoxic CD8+ T cells as well as reduction of Treg cells infiltration in tumors. Mechanically, on one hand, sitravatinib reinforced MHC-I expression by blocking TYRO3-STAT1 axis, thereby sensitizing tumor cells to T cell liking. On the other hand, sitravatinib suppressed tumor-secreted IL33 by inhibiting TYRO3 activity in HCC cells, resulting in reduced Treg cells differentiation and consequently liberating CD8+ T cell cytotoxic capacity. In the clinic, one advanced HCC patient treated with Sitravatinib plus PD-1 blockade achieved near complete response and remains disease progression-free for more than two years.

CONCLUSIONS: Collectively, we demonstrated a rationale for combining sitravatinib with PD-1 blockade in the treatment for HCC.

PMID:40353734 | DOI:10.1158/1078-0432.CCR-24-4338

Vaccines (Basel). 2025 Mar 25;13(4):346. doi: 10.3390/vaccines13040346.

ABSTRACT

Background/Objectives: The revolution for the treatment of melanoma came with the approval of checkpoint blockade antibodies. However, a substantial proportion of patients show primary or secondary resistance to this type of immunotherapy, indicating the need for alternative therapeutic strategies. Dendritic cells (DCs) of the skin are prime targets for vaccination approaches due to their potential to prime naïve T cells and their accessibility. This study aimed to develop and evaluate novel vaccines targeting the C-type lectin receptor DEC-205 to deliver melanoma-associated antigenic peptides to skin DCs. Methods: We cloned MHC-I-restricted peptides from the glycoprotein (gp)100_25-33 and Tyrosinase-related protein (trp)2_180-188 into the DEC-205 antibody sequence with modified peptide cutting sites from the OVA_257-264 SIINFEKL peptide. We tested their potential to induce CD8⁺ T cell responses in both in vitro and in vivo settings. Tumor growth inhibition was evaluated in the transplantable B16.OVA melanoma murine model using a multi-epitope DC-based vaccine combining both peptides. Results: The cross-presentation of both gp100 and trp2 peptides was confirmed in vivo when peptide sequences were flanked by the OVA_257-264 peptide cutting sites. Moreover, the combination of both antigenic peptides into a multi-epitope DC vaccine was required to inhibit B16.OVA melanoma growth. Conclusions: Our findings suggest that a DC-targeted vaccination approach using multiple epitopes deriving from melanoma antigens could represent a promising strategy for melanoma therapy.

PMID:40333215 | PMC:PMC12031154 | DOI:10.3390/vaccines13040346

Nat Commun. 2025 Apr 28;16(1):3957. doi: 10.1038/s41467-025-58452-8.

ABSTRACT

Glioblastoma (GBM) is an aggressive primary brain cancer with few effective therapies. Stereotactic needle biopsies are routinely used for diagnosis; however, the feasibility and utility of investigative biopsies to monitor treatment response remains ill-defined. Here, we demonstrate the depth of data generation possible from routine stereotactic needle core biopsies and perform highly resolved multi-omics analyses, including single-cell RNA sequencing, spatial transcriptomics, metabolomics, proteomics, phosphoproteomics, T-cell clonotype analysis, and MHC Class I immunopeptidomics on standard biopsy tissue obtained intra-operatively. We also examine biopsies taken from different locations and provide a framework for measuring spatial and genomic heterogeneity. Finally, we investigate the utility of stereotactic biopsies as a method for generating patient-derived xenograft (PDX) models. Multimodal dataset integration highlights spatially mapped immune cell-associated metabolic pathways and validates inferred cell-cell ligand-receptor interactions. In conclusion, investigative biopsies provide data-rich insight into disease processes and may be useful in evaluating treatment responses.

PMID:40295505 | PMC:PMC12037860 | DOI:10.1038/s41467-025-58452-8

Phytomedicine. 2025 Apr 14;142:156731. doi: 10.1016/j.phymed.2025.156731. Online ahead of print.

ABSTRACT

BACKGROUND: Celastrol (CEL) has demonstrated promising anti-cancer properties, yet its specific mechanisms against melanoma remain insufficient. This study investigated the CEL's anti-tumor effects and determined its potential mechanisms in the regulation of MHC-I expression in melanoma. In addition, we also tested its efficacy in sensitizing immune checkpoint inhibitors (ICIs) to melanoma.

METHODS: CEL's anti-tumor activity was evaluated in B16F10 melanoma-bearing C57BL/6 mice across five groups (control, CEL 0.5 mg/kg, CEL 1 mg/kg, CEL 2 mg/kg, and ICIs), the tumor volume, histopathology, and body weight were assessed. Mechanistic insights were obtained through network pharmacology and RNA sequencing in B16F10 cells. Differential gene and pathway analysis were validated using qRT-PCR, Western blotting, and flow cytometry. CD8+T cell activation and cytotoxicity were analyzed in co-culture with CEL-pretreated B16F10 cells using flow cytometry and ELISA. CEL's interaction with potential targets was determined by molecular docking, surface plasmon resonance (SPR), and siRNA. The synergistic effect of CEL combined with ICIs was confirmed in B16F10-bearing C57BL/6 mice, and tumor-infiltrating T cells were assessed by flow cytometry across four groups (control, CEL, ICIs, CEL+ICIs).

RESULTS: CEL exhibited a significant anti-tumor effect in B16F10 melanoma-bearing mice. Mechanistically, CEL-pretreated B16F10 cells notably enhanced CD8+T cell activation and promoted IFNγ and TNFα secretion, leading to B16F10 cell death. CEL upregulated MHC-I expression through activation of the JAK/STAT1 pathway in B16F10 cells. The binding assay revealed that CEL interacted with SHP2, with an affinity of 37.93 μM. When SHP2 was silenced in B16F10 cells by siRNA, CEL failed to induce MHC-I upregulation. Moreover, CEL combined with ICIs produced superior antitumor efficacy compared to ICIs alone, which was accompanied by increased CD8+T cell infiltration in melanoma.

CONCLUSION: CEL enhanced CD8+T cell immunity by upregulating MHC-I expression in melanoma cells, these effects were at least partially through targeting SHP2 and activating JAK/STAT1 pathway. CEL might be a novel sensitizer for ICIs in melanoma.

PMID:40286748 | DOI:10.1016/j.phymed.2025.156731