Infectious disease
Abstract
BACKGROUND. Symptoms of early-onset sepsis (EOS) in preterm infants are nonspecific, overlapping with normal postnatal physiological adaptations and noninfectious pathologies. This clinical uncertainty and the lack of reliable EOS diagnostics results in liberal use of antibiotics in the first days to weeks of life, leading to increased risk of antibiotic-related morbidities in infants who do not have an invasive infection. METHODS. To identify potential biomarkers for EOS in newborn infants, we used unlabelled tandem mass spectrometry proteomics to identify differentially abundant proteins in the umbilical cord blood of infants with and without culture-confirmed EOS. Proteins were then confirmed using immunoassay, and logistic regression and random forest models were built including both biomarker concentration and clinical variables to predict EOS. RESULTS. These data identified five proteins that were significantly upregulated in infants with EOS, three of which (serum amyloid A, C-reactive protein, and lipopolysaccharide-binding protein) were confirmed using a quantitative immunoassay. The random forest classifier for EOS was applied to a cohort of infants with culture-negative presumed sepsis (PS). Most PS infants were classified as resembling control infants, having low EOS biomarker concentrations. CONCLUSION. These results suggest that cord blood biomarker screening may be useful for early stratification of EOS risk among neonates, improving targeted, evidence-based use of antibiotics early in life. FUNDING. National Institutes of Health, Gerber Foundation, Friends of Prentice, Thrasher Research Fund, Ann & Robert H. Lurie Children’s Hospital, Stanley Manne Children’s Research Institute of Lurie Children’s.
Authors
Leena B. Mithal, Mark E. Becker, Ted Ling-Hu, Young Ah Goo, Sebastian Otero, Aspen Kremer, Surya Pandey, Nicola Lancki, Yawei Li, Yuan Luo, William Grobman, Denise Scholtens, Karen K. Mestan, Patrick C. Seed, Judd F. Hultquist
Abstract
Bacterial pneumonia is the most common cause of acute respiratory distress syndrome (ARDS), characterized by disrupted pulmonary endothelial barrier function, hyperinflammation, and impaired alveolar epithelial fluid clearance. ARDS has a high mortality rate and no proven pharmacological treatments, stressing the need for new targeted therapies. The TIP peptide, mimicking the lectin-like domain of TNF, directly binds to the α subunit of the epithelial Na+ channel, expressed in both alveolar epithelial and capillary endothelial cells, and may increase lung endothelial barrier function and alveolar fluid clearance during bacterial infection. This study tested these potential therapeutic mechanisms of the TIP peptide in a clinically relevant preparation of the ex vivo–perfused human lung injured by Streptococcus pneumoniae. Therapeutic administration of the TIP peptide reduced pulmonary barrier permeability to protein and lung edema formation, increased alveolar edema fluid clearance, and produced an antiinflammatory effect in the airspaces with reductions in IL-6 and IL-8 levels. Additionally, the TIP peptide reduced the translocation of bacteria into the circulation. These findings establish 3 mechanisms of benefit with the TIP peptide to reduce injury in the human lung and support the clinical relevance as a potential therapeutic for pneumococcal bacterial pneumonia.
Authors
Mazharul Maishan, Hiroki Taenaka, Bruno Evrard, Shotaro Matsumoto, Angelika Ringor, Carolyn Leroux, Rudolf Lucas, Michael A. Matthay
Abstract
Background. NK cell function is impaired in people with HIV (PWH), hindering their potential to reduce the lymphoid tissue (LT) reservoir. The IL-15 superagonist N-803 has been shown to enhance NK and T cell function, and thus may reduce viral reservoirs. Methods. To determine the impact of N-803 on LTs, we conducted a clinical trial where 10 PWH on effective antiretroviral therapy (ART) were given three 6 mcg/kg doses of N-803 subcutaneously. We obtained PBMCs and lymph node (LN) and gut biopsies at baseline and after the last N-803 dose. Results. We found a non-statistically significant ~0.50 median log reduction in the frequency of viral(v)RNA+ and vDNA+ cells/g in the 6 participants with baseline and post-treatment LNs. In the ileum, we observed reductions of vRNA+ cells in 8/10 participants and vDNA+ cells in all participants. We also found significant inverse correlations between NK cell proliferation and the frequency of vRNA+ cells, and between NKG2A expression on NK cells and the frequency of vRNA+ cells. Conclusions. Our findings suggest N-803 may reduce the HIV reservoir in LTs of PWH on ART, an effect likely mediated by enhanced NK cell function. Controlled studies assessing the impact of NK cell therapy on HIV LTs are needed.
Authors
Joshua Rhein, Jeffrey G. Chipman, Gregory J. Beilman, Ross Cromarty, Kevin Escandón, Jodi Anderson, Garritt Wieking, Jarrett Reichel, Rodolfo Batres, Alexander Khoruts, Christopher M. Basting, Peter Hinderlie, Zachary B. Davis, Anne Eaton, Byron P. Vaughn, Elnaz Eilkhani, Jeffrey T. Safrit, Patrick Soon-Shiong, Jason V. Baker, Nichole R. Klatt, Steven G. Deeks, Jeffrey S. Miller, Timothy W. Schacker
Abstract
H7N9 avian influenza virus is a zoonotic influenza virus of public health concern, with a 39% mortality rate in humans. H7N9-specific prevention or treatments for humans have not been approved. We previously isolated a human monoclonal antibody (mAb) designated H7-235 that broadly reacts to diverse H7 viruses and neutralizes H7N9 viruses in vitro. Here, we report the crystal structure of H7 HA1 bound to the fragment antigen-binding region (Fab) of recombinant H7-235 (rH7-235). The crystal structure revealed that rH7-235 recognizes residues near but outside of the receptor binding site (RBS). Nevertheless, the rH7-235 IgG potently inhibits hemagglutination mediated by H7N9 viruses due to avidity effect and Fc steric hindrance. This mAb prophylactically protects mice against weight loss and death caused by challenge with lethal H7N9 viruses in vivo. rH7-235 mAb neutralizing activity alone is sufficient for protection when used at high dosed in a prophylactic setting. This study provides insights into mechanisms of viral neutralization by protective broadly reactive anti-H7 antibodies informing the rational design of therapeutics and vaccines against H7N9 influenza virus.
Authors
Iuliia M. Gilchuk, Jinhui Dong, Ryan P. Irving, Cameron D. Buchman, Erica Armstrong, Hannah L. Turner, Sheng Li, Andrew B. Ward, Robert H. Carnahan, James E. Crowe Jr.
Abstract
Expanding the repertoire of CAR therapies to include intracellular antigens holds promise for treating a broad spectrum of malignancies. TCR-like T cells, capable of recognizing intracellular antigen–derived peptides in complex with HLA molecules (pHLA), represent a promising strategy in the field of engineered cellular therapy. This study introduced antibody-like TCR (abTCR) T cells that specifically targeted HLA-A*02:01–restricted LMP2426 peptides, a typical Epstein-Barr virus (EBV) latency II protein, for the treatment of EBV-associated lymphoproliferative diseases (EBV-LPDs). Compared with classic CAR T cells targeting the same epitope, abTCR T cells demonstrated superior efficiency, including increased CD107A expression, enhanced cytotoxicity, and elevated IFN-γ secretion, even when engaging with target cells that naturally present antigens. Moreover, a costimulatory signal–armed abTCR (Co-abTCR), which integrated a costimulatory structure with the abTCR, further enhanced the proliferation and in vivo tumoricidal efficacy of transfected T cells. Collectively, our study developed a potentially novel TCR-like T cell therapy that targets HLA-A*02/LMP2426 for the treatment of EBV-LPDs, providing a potential therapeutic solution for targeting of intracellular antigens in cancer immunotherapy.
Authors
Jiali Cheng, Xuelian Hu, Zhenyu Dai, Yuhao Zeng, Jin Jin, Wei Mu, Qiaoe Wei, Xiangyin Jia, Jianwei Liu, Meng Xie, Qian Luo, Guang Hu, Gaoxiang Wang, Xiaojian Zhu, Jianfeng Zhou, Min Xiao, Jue Wang, Taochao Tan, Liang Huang
Abstract
Community-acquired infectious meningoencephalitis is associated with high rates of mortality and morbidity, compounded by limited access to diagnostic resources. The current study assessed acute central nervous system (CNS) infections in patients with meningoencephalitis enrolled in a hospital-based diagnostic surveillance study in São Paulo, Brazil. Cerebrospinal fluid (CSF) was collected from 600 subjects between March 2018 and November 2019 and initially screened for a broad range of pathogens according to a local diagnostic algorithm. Standard microbiological and molecular diagnostic methods were applied. Metagenomic sequencing was used as a complementary approach to investigating etiology in cases where no pathogen was initially identified. Standard testing identified infectious etiologies in 292 cases (48.6%), with 227 (77.7%) confirmed as viral infections, predominantly caused by enteroviruses (n=144) and herpesviruses (n=40). Non-viral agents were identified in 65 cases (22.3%). Metagenomic sequencing (mNGS) of 279 out of 308 undiagnosed cases revealed several additional potential etiologies, including Parvovirus B19, Toxoplasma gondii, Picobirnavirus, other enterovirus species and Vesivirus, the latter being associated with CNS infection for the first time. These findings underscore the complexity of CNS infections and highlight the potential of metagenomics to improve diagnostic accuracy, inform treatment strategies, and support efforts to address future pandemics.
Authors
Noely Evangelista Ferreira, Michael G. Berg, Antonio C. da Costa, Mary A. Rodgers, Esper G. Kallas, Cassia G. Terrasani Silveira, Mateus Vailant Thomazella, Ana Carolina Soares de Oliveira, Layla Honorato, Heuder G.O. Paião, Renan Barros Domingues, Carlos Senne, Marina F. Côrtes, Tania R. Tozetto-Mendoza, Hélio R. Gomes, Maria Laura Mariano Matos, Geovani de Oliveria Ribeiro, Steven S. Witkin, Gavin A. Cloherty, Maria Cassia Mendes-Correa
Abstract
Severe asthma in children is notoriously difficult to treat, and its immunopathogenesis is complex. In particular, the contribution of T cells and relationships to antiviral immunity remain enigmatic. Here, we coupled deep phenotyping with machine learning methods to elucidate the dynamics of T cells in the lower airways of children with treatment-refractory recurrent wheeze, and examine rhinovirus (RV) as a driver. Our strategy revealed a T cell landscape dominated by type 1 and type 17 CD8+ signatures. Interrogation of phenotypic relationships coupled with trajectory mapping identified T cell migratory and differentiation pathways spanning the blood and airways that culminated in tissue residency, and involved transitions between type 1 and type 17 tissue-resident types. These dynamics were reflected in cytokine polyfunctionality. Use of machine learning tools to cross-compare T cell populations that were enriched in the airways of RV-positive children with those induced in the blood following experimental RV challenge precisely pinpointed RV-responsive signatures that contributed to T cell migratory and differentiation pathways. Despite their rarity, these signatures were also detected in the airways of RV-negative children. Together, our results underscore the aberrant nature of type 1 immunity in the airways of children with recurrent wheeze, and implicate an important viral trigger as a driver.
Authors
Naomi Bryant, Lyndsey M. Muehling, Kristin Wavell, W. Gerald Teague, Judith A. Woodfolk
Abstract
P.falciparum infection can trigger high levels of inflammation that lead to fever and sometimes severe disease. People living in malaria-endemic areas gradually develop resistance to symptomatic malaria and control both parasite numbers and the inflammatory response. We previously found that adaptive NK cells correlated with reduced parasite load and protection from symptoms. We also found that murine NK cell production of IL-10 protected mice from experimental cerebral malaria. Human NK cells can also secrete IL-10, but it is unknown what NK cell subsets produce IL-10 or if this is affected by malaria experience. We hypothesized that NK cell immunoregulation may lower inflammation and reduce fever induction. Here, we showed that NK cells from participants with malaria experience make significantly more IL-10 than participants with no malaria experience. We then determined the proportions of NK cells that are cytotoxic and produce IFN-γ and/or IL-10 and identified a signature of adaptive and checkpoint molecules on IL-10–producing NK cells. Lastly, we found that coculture with primary monocytes, Plasmodium-infected RBCs, and antibody induced IL-10 production by NK cells. These data suggest that NK cells may contribute to protection from malaria symptoms via IL-10 production.
Authors
Sarah A. McNitt, Jenna K. Dick, Maria Andrea Hernandez-Castaneda, Jules Sangala, Mark Pierson, Marissa Macchietto, Kristina S. Burrack, Peter D. Crompton, Karl Seydel, Sara E. Hamilton, Geoffrey T. Hart
Abstract
Measles remains one of the most important causes of worldwide morbidity and mortality in children. Measles virus (MeV) replicates extensively in lymphoid tissue and most deaths are due to other infectious diseases associated with MeV-induced loss of circulating antibodies to other pathogens. To determine whether remdesivir, a broad-spectrum direct-acting antiviral, affects MeV-induced loss of antibody to other pathogens, we expanded the VirScan technology to detect antibody to both human and macaque pathogens. We measured the antibody reactivity to MeV and non-MeV viral peptides using plasma from MeV-infected macaques that received remdesivir either as post-exposure prophylaxis (d3-14, PEP) or as late treatment (d11-22, LT) in comparison with macaques that were not treated. Remdesivir PEP, but not LT, limited the loss of antibody to non-MeV pathogens. Remdesivir PEP also limited the antibody response to MeV with a decrease in both the magnitude and breadth of the epitopes recognized. LT had little effect on the magnitude of the MeV-specific antibody response but affected the breadth of the response. Therefore, early, but not late, treatment of measles with the direct-acting antiviral remdesivir prevents the loss of antibody to other pathogens but decreases the response to MeV.
Authors
Andy Kwan Pui Chan, Liting Liu, William R. Morgenlander, Manjusha Thakar, Nadine A. Peart Akindele, Jacqueline Brockhurst, Shristi Ghimire, Maggie L. Bartlett, Kelly A. Metcalf Pate, Victor C. Chu, Meghan S. Vermillion, Danielle P. Porter, Tomas Cihlar, Michael J. Mina, H. Benjamin Larman, Diane E. Griffin
Abstract
Human T-lymphotropic virus type 1 (HTLV-1)-associated myelopathy/tropical spastic paraparesis (HAM) is a rare neurodegenerative disease with largely elusive molecular mechanisms, impeding targeted therapeutic advancements. This study aimed to identify the critical molecule responsible for neuronal damage in HAM, its source, and the regulatory mechanisms controlling its expression. Utilizing patient-derived cells and established cell lines, we discovered that HTLV-1 Tax, in conjunction with Specificity Protein 1 (Sp1), enhanced the expression of repulsive guidance molecule A (RGMa), a molecule known to contribute to neuronal damage. RGMa expression was specifically upregulated in HTLV-1-infected cells from HAM patients, particularly in those expressing HTLV-1 Tax. Furthermore, in CD4+ cells from HAM patients, the level of H3K27me3 methylation upstream of the RGMA gene locus was reduced, making RGMA more prone to constitutive expression. We demonstrated that HTLV-1-infected cells in HAM inflict neuronal damage via RGMa. Crucially, the neutralizing antibody against RGMa, unasnemab/MT-3921, effectively mitigated this damage in a dose-responsive manner, highlighting RGMa's pivotal role in neuronal damage and its potential as a therapeutic target for alleviating neuronal damage in HAM.
Authors
Natsumi Araya, Makoto Yamagishi, Makoto Nakashima, Naomi Asahara, Kazuhiro Kiyohara, Satoko Aratani, Naoko Yagishita, Erika Horibe, Izumi Ishizaki, Toshiki Watanabe, Tomoo Sato, Kaoru Uchimaru, Yoshihisa Yamano
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