Immunology
Abstract
Immune checkpoint inhibitors (ICIs) have reshaped the treatment landscape of several cancer types. However, their effectiveness remains limited to a subset of patients, in part due to insufficient preexisting antitumor immunity. In this study, we hypothesized that intracellular delivery of noncoding dsDNA encapsulated in lipid nanoparticles (DNA-LNPs), which have recently been demonstrated to activate both STING and absent in melanoma 2 (AIM2) pathways, could enhance antitumor immune responses and potentiate ICI therapy. Using multiple animal models of cancer, including hepatocellular carcinoma, acute myeloid leukemia, melanoma, and melanoma lung metastasis, we show that DNA-LNP treatment triggered strong cytokine induction and robust CD8+ T cell recruitment to the tumor microenvironment. This immune activation mediated potent CD8+ T cell–dependent antitumor effects and prolonged animal survival across multiple models. Notably, empty LNPs did not elicit potent cytokine elevation or antitumor effects, suggesting that these responses are triggered by the activation of cytosolic DNA-sensing pathways. Moreover, DNA-LNPs synergized with anti–PD-L1, substantially extending animal survival in both ICI-responsive and ICI-resistant tumor models. These findings position DNA-LNPs as a promising immunotherapy strategy, either alone or in combination with ICI therapies, to enhance antitumor immunity across diverse cancer types.
Authors
Seoyun Yum, Alba Rodríguez-Garcia, Joan Castellsagué, Marta Giménez-Alejandre, Guillem Colell, Salut Colell, Teresa Lobo-Jarne, Mark A. LaRue, Michael A. Minnier, Mustafa N. Yazicioglu, Rui Zhang, Xavier M. Anguela, Ali Nahvi, Matthew C. Walsh, Sean M. Armour, Sonia Guedan, Pedro J. Cejas
Abstract
Cytotoxic T lymphocytes form a critical component of SARS-CoV-2 immunity by recognizing viral peptides bound to HLA class I molecules. Here, we identified the Spike-derived peptide NYNYLYRLF448-456 (NF9) as the immunodominant HLA-A*24:02-restricted epitope in both convalescent and vaccinated donors. Across cohorts, A24/NF9-specific responses were dominated by public TCR motifs featuring TRAV12-1 (or TRAV6-1) paired with TRBJ2-7 and a conserved CDR3β sequence (CASSXXXGYEQYF). Using a panel of thirteen TCRs, we mapped recognition of single amino acid substitutions within NF9 and identified residue 5 (L452) as the principal determinant of escape. The L452R substitution, characteristic of the Delta variant, abolished recognition across all tested TCRs despite preserved HLA binding. Crystallography of a representative public TCR (P1-15) revealed that mutation at position 5 reoriented the peptide within HLA-A*24:02, flipping the adjacent Y453 side chain into the peptide-binding groove and eliminating the dominant TCR contact. This position-5-driven conformational switch provided a structural mechanism for universal loss of NF9 recognition by HLA-A*24:02-restricted T-cells. Consistent with this, Delta-infected convalescents failed to mount de novo NF9-5R-specific responses while retaining responses to the conserved A24/QI9 Spike epitope. Together, these findings defined the basis of A24/NF9 recognition and showed how one mutation remodelled peptide presentation to abrogate TCR responses.
Authors
Takeshi Nakama, Aaron Wall, Garry Dolton, Li-Rong Tan, Hannah Thomas, Hiroshi Hamana, Yoshiki Aritsu, Toong Seng Tan, Mako Toyoda, Yoshihiko Goto, Huanyu Li, Mizuki Kitamatsu, Keiko Udaka, Yusuke Miyashita, Hiroyuki Oshiumi, Kimitoshi Nakamura, Yoji Nagasaki, Rumi Minami, Hirotomo Nakata, Pierre J. Rizkallah, Hiroyuki Kishi, Takamasa Ueno, Andrew K. Sewell, Chihiro Motozono
Abstract
Maternal opioid use disorder (OUD) poses substantial risks to maternal and fetal health. These adverse outcomes are believed to be mediated, in part, by changes in placenta structure and function; however, few studies have addressed this question. Here, we utilized flow cytometry, histology, spatial and single-cell transcriptomics to uncover the impact of OUD on placental tissues. Given that half of subjects with chronic OUD contract hepatitis C (HCV), we further stratified our findings by maternal HCV status. Our results indicate that OUD leads to higher incidence of vascular malperfusion accompanied by increased levels of inflammatory markers and dysregulated secretion of placental development factors. Spatial transcriptomics revealed that OUD disrupts the communication between trophoblasts and immune cells important for placental vascular development. Additionally, CellChat analysis revealed aberrant vascular remodeling, neuropeptide, and chemotactic signaling across trophoblast, endothelial, and myeloid cells. Processes associated with tissue homeostasis and repair were also upregulated across trophoblast and leukocytes. In addition, placental leukocytes were rewired towards regulatory/tissue surveillant phenotypes. Finally, frequencies and responses to ex-vivo stimulation of decidual macrophages and cytolytic NKcells, critical for tissue remodeling and fetal tolerance, were decreased. Altogether, these results highlight substantial disruptions to placental health by maternal OUD.
Authors
Heather E. True, Brianna M. Doratt, Sheridan B. Wagner, Delphine C. Malherbe, Nathan R. Shelman, Mahdi Eskandarian Boroujeni, Cynthia Cockerham, John M. O'Brien, Ilhem Messaoudi
Abstract
Dengue virus (DENV) vaccines should be designed to induce balanced protective immunity against all four dengue serotype to mitigate the risk of vaccine-mediated enhanced dengue disease. The first tetravalent vaccine (Dengvaxia) tested in humans was efficacious in children who were partially immune to DENV at baseline. In DENV-naive children, the vaccine was not efficacious and placed some naïve children at risk of experiencing more severe wild-type DENV breakthrough infections. To define dengue vaccine responses at the individual subject level and their relationship to mild and severe dengue infections, we prospectively studied a cohort of DENV-naive children who received one dose of Dengvaxia. The vaccine stimulated variable responses that neutralized 0, 1 (monotypic), or 2+ (multitypic) serotypes in individual children. We used a logistic regression model to evaluate whether vaccine status and serotype-specific NAb status at the end of study period 1 influenced the probability of experiencing a virologically confirmed dengue disease (VCD) case thereafter (months 20 - 60). Vaccinated children with NAb response to only one serotype were at greater risk of being a case compared to the DENV-naïve control group (Odds Ratio 5.07). This risk was not observed in vaccinated children with no NAb or NAb to 2 or more serotypes. We propose that individuals with durable NAb to one serotype have an abundance of serotype cross-reactive, non-neutralizing Abs implicated in the enhanced replication of heterologous serotypes. We discuss the implications of our findings for flagging vaccine candidates that are likely to pose a special risk to seronegative subjects.
Authors
Laura J. White, Lindsay D. Hein, Maria Abad Fernandez, Cameron Adams, Elizabeth Adams, Emily Freeman, Ruby Shah, Lakshmanane Premkumar, Kristal An Agrupis, Maria Vinna Crisostomo, Jedas Veronica Daag, Michelle Ylade, Jacqueline Deen, Ana Lena Lopez, Leah Katzelnick, Aravinda M. de Silva
Abstract
Allogeneic islet transplantation is an effective treatment for type 1 diabetes, but its clinical use is limited by rejection involving innate and adaptive immune responses, requiring life-long immunosuppression. We herein engineered islets by transiently display two immunomodulators chimeric with streptavidin (SA), thrombomodulin (SA-TM) and CD47 (SA-CD47) for localized modulation of both innate and adaptive immune responses. The engineering process did not impact islet viability, glucose responsiveness, and metabolic activity. Intraportal transplantation into allogeneic recipients achieved sustained survival, with 8/11 grafts surviving 120-330 days without immunosuppression. In contrast, non-engineered islets were acutely rejected [median survival time (MST) = 12 days], while islets engineered with SA-TM showed delayed rejection [Median survival time (MST) = 13.5 days], and those with SA-CD47 exhibited prolonged survival (MST = 24 days). Double-engineered islets generated a localized tolerogenic immune environment characterized by low frequencies of inflammatory innate immune cells and increased frequencies of M2 macrophages, myeloid-derived suppressor cells, and CD4+FoxP3+ T regulatory cells. The transcriptomic analysis showed downregulation of proinflammatory and upregulation of immune regulatory pathways. Our results demonstrate that transient co-display of immunomodulatory molecules on the islet surface is a versatile platform with significant translational potential for islet transplantation.
Authors
Shadab Kazmi, Mohammad Tarique, Darshan Badal, Vahap Ulker, Ali Turan, Kathleen M. Yee-Flores, Abdalmonam Jadou Nejma, Esma S. Yolcu, Haval Shirwan
Abstract
Introduction: BK polyomavirus (BKV) infection is associated with injury and subsequent graft loss due to the extent of injury or rejection. However, the molecular mechanisms driving injury and subsequent adverse outcomes remain poorly understood. Methods: In a cross-sectional study, single-cell RNA sequencing from kidney allograft biopsies was used to assess cell type-specific responses between uninfected controls and two distinct phases of BKV infection: peaking (increasing viral blood titers) and resolving (decreasing viral titers following immunosuppression reduction). Results: Genes upregulated in BK viral nephropathy (BKVN) were enriched for polyomavirus infection hallmarks, including ribosome biogenesis, translation, and energy restructuring. Additionally enriched pathways included wound healing, cellular stress, antigen presentation and immune signaling. Even without BKVN (peaking BK viremia alone), epithelial cells expressed signatures for wound healing, cellular stress, and extracellular matrix remodeling. In vivo tubular cell responses at single-cell resolution were validated against single cell transcriptomic data of BKV infected cells in a cell culture model. Despite similarities, in vivo tubular cells underwent metabolic adaptation favoring fatty acid oxidation and proinflammatory responses not observed in culture models likely due to an absent innate and adaptive immune system. Despite lymphopenia and immunosuppressive therapies, the proportion of recipient derived intrarenal adaptive immune cells was increased in biopsies associated with peaking viremia alongside activation of innate immune responses. Adaptive immune cells exhibited persistent inflammatory signaling and remodeling of energy metabolism during the resolving phase of infection. Conclusion: These not previously reported insights into BKV-associated injury may have implications for clinical management and improved allograft outcomes.
Authors
Tess Marvin, Rachel Sealfon, Phillip J. McCown, Fadhl AlAkwaa, Evan A. Farkash, Edgar A. Otto, Felix Eichinger, Ping An, Rajasree Menon, Celine C. Berthier, Tavis J. Reed, Paula Arrowsmith, Lalita Subramanian, Kelly J. Shaffer, Silas P. Norman, Ramnika Gumber, Michael J. Imperiale, James M. Pipas, Olga G. Troyanskaya, Matthias Kretzler, Chandra L. Theesfeld, Abhijit S. Naik
Abstract
The molecular mechanisms responsible for the “atopic march” of allergic skin disease to allergic airway disease are incompletely understood. Secreted phospholipase A2 group X (sPLA2-X) is implicated in human asthma and modulates airway hyperresponsiveness (AHR) and inflammation in murine models of allergic asthma. We developed a complete proteolytic allergen model of dermal sensitization followed by airway challenge to mimic the “atopic march” and examined the role of sPLA2-X in regulating peripheral allergen sensitization, AHR, and airway inflammation. Pla2g10-/- mice receiving both house dust mite (HDM) peripheral sensitization and airway challenge had attenuated AHR relative to WT mice and lower airway eosinophils. Transgenic C57BL/6 PLA2G10 mice (only expressing the human sPLA2-X gene) receiving treatment with a small molecule inhibitor of sPLA2-X (ROC0929) during the dermal sensitization phase demonstrated attenuated AHR and a reduction in lung tissue dust mite-specific tissue resident memory CD4+ T cells. Thus, sPLA2-X acts as an endogenous adjuvant to facilitate allergic sensitization in the periphery, which leads to AHR and airway inflammation following inhalation of the allergen. These results provide proof of concept that inhibition of sensitization in the periphery with a sPLA2-X inhibitor modulates subsequent allergen-induced airway dysfunction.
Authors
Ryan C. Murphy, Ying Lai, Yu-Hua Chow, Matt Liu, Brian D. Hondowicz, Dowon An, Marion Pepper, William A. Altemeier, Teal S. Hallstrand
Abstract
Macrophages (MΦ), endowed with remarkable phenotypic plasticity are essential for orchestrating injury responses and regulating iron homeostasis. Given the central role of ferritin heavy chain (FtH) as a molecular rheostat linking iron sequestration to redox-dependent signaling, we examined how myeloid FtH governs renal iron trafficking and ensuing oxidative-stress pathways during acute kidney injury (AKI). Transcriptome analysis revealed coupling of FtH deficiency in monocytes and MΦ with ferroptosis activation, a regulated cell death associated with iron accumulation. Moreover, myeloid FtH deletion worsened AKI, increasing leukocyte infiltration and iron deposition, together with ferroptosis‐associated gene induction, oxidative stress, and lipid peroxidation. Notably, ⍺-synuclein (SNCA), an iron-binding protein and the main pathological driver of Parkinson’s disease, was robustly induced by both FtH deficiency and following AKI. Mechanistic studies showed that monomeric SNCA exhibits ferrireductase activity, amplifying redox cycling and promoting ferroptotic cell death. Furthermore, SNCA expression was elevated in kidney pathologies characterized by leukocyte expansion in both mouse models and human cohorts, suggesting that inflammatory microenvironments promote SNCA accumulation and redox imbalance. These findings define a MΦ FtH-SNCA regulatory axis as a key driver of ferroptosis in AKI, implicating SNCA as a pathological nexus between iron dyshomeostasis and inflammatory kidney injury.
Authors
Tanima Chatterjee, Sarah Machado, Kellen Cowen, Mary E. Miller, Bronte Johnson, Yanfeng Zhang, Laura A. Volpicelli-Daley, Lauren A. Fielding, Rudradip Pattanayak, Frida Rosenblum, László Potor, György Balla, Jozsef Balla, Christian Faul, Abolfazl Zarjou
Abstract
Heterogeneity in disease severity and treatment response in inflammatory bowel disease (IBD) likely evolve from individual differences in host-microbiota-immune interactions. Histological evaluation of intestinal biopsies is central to diagnosis, but histological parameters that define underlying immune mechanisms are limited. We investigated histological features that distinguish individual patient immune profiles in therapy-naive paediatric IBD patients (age 6‒18-years-old) using biopsy immunohistochemistry and transcriptomics and plasma proteomics across two cohorts. High colonic epithelial expression of Secretory Leukocyte Protease Inhibitor (SLPI), a microbiota-induced regulator of epithelial function, occurred in IBD patients with high clinical disease activity and more severe endoscopic and microscopic disease activity. SLPI expression related to increased neutrophil infiltration, transcriptomic signatures of activation and genes known to associate with therapeutic resistance. High SLPI co-localized with high densities of IL-17-secreting cells and was associated with high plasma concentrations of Th17-related immune proteins. Additionally, patients with high intestinal SLPI had an intrinsically different immunotype, in which circulating neutrophils exhibited altered transcription of genes involved in neutrophil granule formation, phagocytosis, oxidative phosphorylation, and interferon signalling. Thus, high colonic SLPI expression at diagnosis associates with severe IBD, increased IL-17A-neutrophil pathway responses and altered transcriptomic wiring of circulating neutrophils.
Authors
Sandrine Nugteren, Beatriz Calado, Ytje Simons-Oosterhuis, Daniëlle H. Hulleman-van Haaften, Willem K. Smits, Renz C.W. Klomberg, Bastiaan Tuk, Mohammed Charrout, Dicky J. Lindenbergh-Kortleve, Michail Doukas, Mathijs A. Sanders, Gregory van Beek, Johanna C. Escher, Lissy de Ridder, Maria Fernanda Pascutti, Janneke N. Samsom
Abstract
Viral lower respiratory tract infections are common early in life and are associated with long-term development of asthma, a chronic condition defined by reversible airflow obstruction secondary to inflammation. Understanding the immunologic mechanism connecting these two pathologies observed early in life becomes imperative to guide therapeutic measures. To investigate this connection, neonatal (day of life 4-6) or adult mice were infected with human metapneumovirus (HMPV) followed by a secondary HMPV infection 6 weeks later. Mice initially infected as neonates demonstrate increased mucus production, eosinophil recruitment, airway hyperresponsiveness, and Th2 T-cell differentiation following re-challenge compared to adult mice rechallenged with HMPV. Neonatal HMPV infection led to formation of Th2 clonally expanded tissue resident memory (TRM) T cells that were absent after adult HMPV. FTY720-mediated disruption of lymphocyte circulation demonstrated TRMs contribute to pathology. Local depletion of lung CD4+ T cells and JAK2-inhibition mitigated pathology. These findings suggest TRMs uniquely generated after early life viral infection can contribute to Th2-driven asthma pathology.
Authors
Emma E. Brown, Jie Lan, Olivia B. Parks, Li Fan, Dequan Lou, Alysia McCray, Lisa Mathews, Alexander J. Wardropper, Anna Shull, Michelle L. Manni, Hēth R. Turnquist, Kong Chen, Taylor Eddens
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