Immunology
Abstract
Sepsis is a leading cause of death for which host-directed therapies are urgently needed. We performed high-dimensional flow cytometry, measurement of soluble biomarkers, and lipopolysaccharide (LPS) stimulation of neutrophils to characterize neutrophil heterogeneity and function in patients with sepsis. We observed that in sepsis patients, low-density neutrophils (LDNs) are elevated and phenotypically diverse populations of innate immune cells with varying degrees of maturity and myeloperoxidase expression. Spleen tyrosine kinase (SYK) expression was found to be higher in whole blood neutrophils and LDNs of sepsis patients compared to healthy donors. Importantly, SYK+LDNs associated with increased levels of intracellular myeloperoxidase (MPO) and soluble biomarkers. Furthermore, SYK+LDNs correlated with clinical outcomes of sepsis disease severity including sequential organ failure assessment (SOFA) score, mechanical ventilation, and vasopressors. Functionally, the SYK inhibitor R406 suppressed changes in neutrophil features of activation from normal-density neutrophils and LDNs including the SYK+ and SYK- neutrophil subsets and MPO release from LDNs following LPS stimulation of sepsis neutrophils. Combined, these results establish LDNs as a heterogenous population of neutrophils that express high levels of SYK and support SYK inhibition as a novel therapeutic target aimed at suppressing overactive neutrophils in sepsis.
Authors
Heather L. Teague, Lauren Knabe, Raquel S. Da Cruz, Xianglan Yao, Kiana C. Allen, Trenton Williams, Cumhur Y. Demirkale, Merte Woldehanna, Ernest Evans, Amir Hobson, Jared D. Wilkinson, Steven D. Nathan, Christopher S. King, Jeffrey R. Strich
Abstract
BACKGROUND. IL-7 is a critical cytokine in T cell development, survival, and homeostasis. Previous preclinical and clinical studies reported that IL-7 treatment increased T cell counts, but its effect on peripheral blood T cells in cancer patients and molecular mechanisms have not been explored. METHODS. We investigated effects of long-acting recombinant human interleukin-7 (rhIL-7-hyFc) on peripheral T cells in patients with advanced solid tumors. Peripheral blood samples were collected before and after treatment, followed by analysis through single-cell transcriptomics and flow cytometry. RESULTS. We found that rhIL-7-hyFc induced marked expansion of proliferating T cells, and promoted transcriptional changes associated with immune activation, cell cycle progression, and anti-apoptosis. Trajectory analysis revealed that post-treatment T cells had distinct transcriptional states enriched for cytokine- and TCR-mediated signaling pathways. Notably, a second dose administered after three weeks yielded diminished proliferation and minimal transcriptional changes, which were independent of antidrug antibody or CD127 downmodulation. Examination of elements of the IL-7 signaling pathway revealed intact proximal signaling (e.g., STAT5 phosphorylation) but downregulation of distal elements, including PIM-1 kinase and c-Myc. CONCLUSIONS. Our results demonstrate that rhIL-7-hyFc induces robust peripheral T-cell expansion and activation in patients with solid tumors, supporting its potential use for lymphopenic patients treated with cancer immunotherapy. TRIAL REGISTRATION. NCT03478995, NCT03619239. FUNDING. NRF-2022R1A2C3007292, RS-2024-00439160, RS-2025-02213409, RS-2025-25460003
Authors
Ho Cheol Jang, Jeong Yeon Kim, Sojeong Kim, Heewon Kim, Mi-Sun Byun, Myung Ah Lee, Jong Hee Chang, Do-Hyun Nam, Tae Won Kim, Sin-Soo Jeun, Joohyuk Sohn, Su-Hyung Park, Eui-Cheol Shin
Abstract
BACKGROUND. Disseminated coccidioidomycosis (DCM) is an often fatal and otherwise intractable condition requiring lifelong antifungal treatment. We have previously shown that a deranged polarization of CD4+ T cells toward a Th2 phenotype can exist in the context of DCM. Here we studied a large population of subjects to determine the frequency of abnormal Th2 skewing of CD4+ T cells in patients with coccidioidomycosis and to identify underlying genetic mechanisms supporting this phenotype. METHODS. We collected peripheral blood mononuclear cells from 204 patients with coccidioidomycosis, including 96 patients with disseminated disease. We measured immune phenotypes and cytokine production by CD4+ T cells from patients and healthy controls, and comparisons between groups were made based on disease severity and demographics. Whole genome sequencing was conducted on 180 individuals who also had cytokine profiling. RESULTS. We found that ~25% of DCM patients had a CD4+ T-cell compartment that was abnormally skewed toward a Th2 phenotype, and Th2 skewing was highly correlated with male sex. Co-culture of T cells with the IL4R/IL13R-blocking antibody dupilumab reduced Th2 skewing. Sequencing revealed rare variants in genes involved in the IL-12-IFN-γ axis in several Th2-skewed patients, and we validated one such variant in IFNGR1 as hypomorphic. CONCLUSION. Patients with DCM, especially males, should be screened for Th2 skewing of CD4+ T cells. Patients with Th2 skewing should be additionally screened for genetic defects in the IL-12-IFN-γ axis. Our findings give a mechanistic rationale for blockade of IL4R in Th2-skewed patients with refractory coccidioidomycosis.
Authors
Timothy J. Thauland, Smriti S. Nagarajan, Alexis V. Stephens, Samantha L. Jensen, Anviksha Srivastava, Miguel A. Moreno Lastre, Terrie S. Ahn, Chantana Bun, Michael T. Trump, Royce H. Johnson, George R. Thompson III, Maria I. Garcia-Lloret, Valerie A. Arboleda, Manish J. Butte
Abstract
Background. Coccidioidomycosis ranges from self-limiting Uncomplicated Valley Fever (UVF) in most cases to life-threatening Disseminated Coccidioidomycosis (DCM) in rare individuals. A few patterns of immunologic deficits allowing for dissemination have been identified, though the specific defects in most individuals with DCM remain undefined. We hypothesized that chronic antigen exposure in DCM engenders a state of T cell exhaustion. Methods. From a cohort of over 300 subjects with confirmed diagnoses of coccidioidomycosis, circulating T cell phenotypes were characterized via flow cytometry and Coccidioides-specific T cell responses were measured by Activation-Induced Marker (AIM) assay. Results. Male sex was significantly associated with disseminated disease (odds ratio 2.5; 95% CI: 1.5 – 4.0). 52% of subjects showed Coccidioides-specific T cell responses in our AIM assay. We noted a significant difference in subjects sampled in the first year of diagnosis, where only 8% of DCM subjects had T cell responses during this time, as compared to 44% of UVF subjects (p = 0.04). Among DCM patients with detectable AIM responses, CD4+ T cells demonstrated an exhausted phenotype with elevated PD-1 expression compared to UVF subjects. In vitro PD-1 blockade augmented IFNγ production in most tested DCM subjects. Conclusion. These findings suggest that dissemination may occur in some individuals during a period of impaired antigen-specific T-cell activity. Importantly, these responses can be augmented in vitro by PD-1 blocking antibodies, supporting further study of immune checkpoint therapy as an adjunct to antifungal treatment in disseminated coccidioidomycosis.
Authors
Gregory D. Whitehill, Alexis V. Stephens, Timothy J. Thauland, Miguel A. Moreno Lastre, Matthew M. Tate, Sinem Beyhan, Royce H. Johnson, George R. Thompson III, Maria Garcia-Lloret, Manish J. Butte
Abstract
Systemic inflammation is now recognized as a key contributor to epilepsy pathophysiology, yet the role of innate immune cells, particularly neutrophils, remains poorly defined in epilepsy. While preclinical studies in rodent models have implicated neutrophils in seizure activity, their phenotype in human epilepsy has not been thoroughly investigated. In this study, we aimed to characterize systemic inflammatory profiles and neutrophil-associated immune signatures in the blood of patients with drug-resistant epilepsy, compared to healthy controls. We identified a systemic low-grade inflammatory profile in patients, characterized by elevated neutrophil-to-lymphocyte ratio, C-reactive protein, pro-inflammatory cytokines (IL-6, CXCL8/IL-8, TNF-α), and activated neutrophils (CXCR4+CD62Llow). Neutrophil phenotyping revealed two distinct immune profiles. Patients with longer disease duration exhibited a more immature systemic signature, characterized by immature neutrophils (CD15⁺CD10⁻), resting neutrophils (CXCR4⁺CD62L⁺), and elevated IL-6 levels. In contrast, patients with higher seizure frequency displayed a more inflammatory profile, marked by increased IL-12 and activated (CXCR4+CD62Llow) and hyperactivated (CXCR4highCD62Llow) neutrophil subsets. Moreover, elevated pre-surgical levels of inflammatory profile TNF-α, IL-6, and hyperactivated CXCR4high CD62Llow neutrophils were associated with seizure recurrence one year after surgery. This pioneering study highlights the heterogeneity of peripheral immune responses in drug-resistant epilepsy and identifies neutrophil-related signatures as promising prognostic biomarkers in this context.
Authors
Coraly Simoës Da Gama, Aurelie Hanin, Gwen Goudard, Veronique Masson, Aurore Besnard, Karim Dorgham, Guy Gorochov, Guillaume Dorothee, Valerio Frazzini, Vincent Navarro, Mélanie Morin-Brureau
Abstract
Malnutrition, gut inflammation, and antibiotic-induced dysbiosis (AID) are well-recognized risk factors for poor clinical outcomes among critically ill patients. We previously showed that commercially available plant-based enteral nutrition (PBEN) preserves a commensal microbiome compared with commonly used artificial enteral nutrition (AEN). In this study, PBEN was superior to AEN in promoting recovery from antibiotic-induced dysbiosis in mice and humans. PBEN effectively mitigated anemia and leukopenia, restored naïve lymphocyte populations, and reduced bone marrow myeloid expansion. Animals randomized to PBEN also exhibited improved responses to infectious challenges following antibiotic exposure. A pilot clinical study validated these findings, demonstrating increased gut commensals, reduced pathogens, and improved leukocyte balance in critically ill children receiving PBEN compared with AEN. Together, these results suggest that PBEN offers a practical dietary approach to mitigate antibiotic-associated complications and potentially improve clinical outcomes among hospitalized patients requiring supplemental nutrition.
Authors
Mona Chatrizeh, Jianmin Tian, Matthew Rogers, Firuz Feturi, Guojun Wu, Brian Firek, Roman Nikonov, Lauren Cass, Alexandra Sheppeck, Lavnish Ojha, Ali Carroll, Matthew Henkel, Justin Azar, Rajesh K. Aneja, Brian Campfield, Dennis Simon, Michael J. Morowitz
Loss of Tumor-Infiltrating Lymphocytes and Poor Response to Immunotherapy in IDH GOF Mutant Melanoma
Abstract
Recent innovations in melanoma treatment with immune checkpoint blockade (ICB) have improved overall outcomes for patients, however over 50% of patients still develop resistance to treatment. These patients either have intrinsic resistance, and never respond to therapy, or develop acquired resistance months or years into treatment. The mechanisms underlying ICB resistance remain poorly understood. Our data shows that isocitrate dehydrogenase gain of function (IDH GOF) mutant melanoma patients have a worse response to anti-PD1 immunotherapy. IDH mutations have been found to be oncogenic and associated with differential methylation in multiple cancers but are not yet characterized in human melanoma. Here, we investigate the clinical, immune, and transcriptional phenotypes of IDH GOF melanomas through analyses of clinical response, single-cell RNA sequencing, bulk RNA sequencing, and DNA methylation data. Single-cell data analysis shows decreased immune infiltrate and activity in the IDH GOF tumors. Bulk sequencing data demonstrates the association between IDH mutation, immune exclusion, and disruptions in global DNA methylation. The melanoma-derived genomic data presented supports previously described resistance mechanisms of IDH mutation in other cancer types and is the first demonstration of the role of IDH GOF in the human melanoma tumor microenvironment.
Authors
Emma Specht, Lakshmi Pakanati, Meng-Ju Wu, Russell W. Jenkins, Derek N. Effiom, Nabeel Bardeesy, Bradley E. Bernstein, Moshe Sade-Feldman, Christine G. Lian, Genevieve M. Boland, Elena Torlai Triglia, Sonia Cohen
Abstract
Authors
Xiangmei Hua, Pranali N. Shah, Gustavo A. Velasquez, Lillian Sidky, George A. Romar, Lydia W. Boer, Natalie Hickerson, Tracy Qiying Cui, Federico Repetto, Abigail Waldman, Marilyn G. Liang, J. Paul Marcoux, MacLean Sellars, Victor Barrera, Birgitta A.R. Schmidt, Arash Mostaghimi, Ruth K. Foreman, Christine G. Lian, Sherrie J. Divito
Abstract
At-home blood collection devices (ABCDs) can facilitate study participation for remote and rural cohorts. Previous studies used ABCDs to interrogate samples by proteomics and sequencing approaches. We wanted to address the question of whether this approach could be used to assess live immune cells with high-parameter flow cytometry to enable remote immune monitoring. We first compared blood from standard venipuncture with ABCD blood draws, followed by assessment of the impact of sample shipping on immune cell viability and phenotyping. We found that capillary blood collected with a Tasso+ device and concurrently drawn venipuncture blood samples had highly congruent immune cell composition and phenotype. Shipment of Tasso+ samples via the United States Postal Service altered the myeloid compartment, but T cell numbers, subsets, and phenotypes remained remarkably stable compared with non-shipped samples. Finally, we describe a flow cytometry analysis framework that allowed for direct sample comparison even when samples were stained and analyzed over a time period of 1.5 years. Overall, our data highlight the feasibility of using ABCDs combined with subsequent flow cytometry analysis for remote immune monitoring. Additionally, our study also identifies areas that could be improved to further promote the use of ABCDs for immune monitoring.
Authors
Andrew J. Konecny, Fang Yun Lim, Eva Domenjo-Vila, Erika Lovas, Rachel L. Blazevic, Louise E. Kimball, Michael Boeckh, Alpana Waghmare, Martin Prlic
Vancomycin eliminates gut deoxycholic acid, restoring ER proteostasis in ILC2s and relieving colitis
Abstract
Ulcerative colitis (UC) remission is marked by gut microbiota restructuring, but how microbial metabolites influence immune-mediated tissue repair is unclear. Here, we demonstrate that oral vancomycin alleviates colitis symptoms in murine models, mirroring its clinical efficacy in inducing remission in patients with UC. Mechanistically, vancomycin’s therapeutic effect is achieved by reducing deoxycholic acid (DCA). We reveal that DCA impairs mucosal repair driven by group 2 innate lymphoid cells (ILC2s) by inducing ER stress through direct binding to thioredoxin-related transmembrane protein 2 (TMX2). This interaction disrupts TMX2’s role in protein folding, triggering unresolved unfolded protein response via hyperactivation of PERK/eIF2α signaling, which suppresses the production of pro-healing molecules by ILC2s. Pharmacological inhibition of PERK phosphorylation restores ILC2 function and accelerates colitis resolution. Our work uncovers a pathogenic microbiota/DCA/ILC2 axis that obstructs mucosal healing and positions vancomycin as a targeted strategy to eliminate DCA, thereby promoting UC remission.
Authors
Qiuheng Tian, Han Liu, Xiang Gu, Jing Shen, Xi Yuan, Mengqi Zheng, Yunjiao Zhai, Yatai Chen, Penghu Han, Yangchun Ma, Wei Xin, Hongyue Ma, Yu Li, Sihan Wang, Lei Guo, Detian Yuan, Yanbo Yu, Shiyang Li
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