Biology subjects

Pihl, R.

Publications and source records attributed to Pihl, R..

3 recordsLinked to original sources

bioRxiv2025

Neutrophils respond with pathogen-specific defenses during bacterial pneumonia

Neutrophils have historically been envisioned as a homogenous population of short-lived innate immune cells that migrate to sites of infection, kill pathogens, and die. Recent work, including studies in pneumonia models, has shown that neutrophil transcriptomes reflect the environment from which they were isolated. We used high-parameter spectral flow cytometry to compare and contrast a wide array of surface proteins on neutrophils from different tissues, infections, host age, pathogen virulence, and across multiple time-points of pneumonia. Circulating and airspace neutrophils consistently differed, and surface protein phenotypes unique to each infection setting were identified, revealing tissue-specific and microbe-specific neutrophil plasticity. Phenotypic differences in circulating neutrophils from mice infected with different pathogens (E. coli, S. pneumoniae, S. aureus, and P. aeruginosa) identified, even in the absence of bacteremia. Neutrophil activation state was diminished with less virulent pathogens and host age. In the airspace, VISTA, CD200R, and PD-L1 were selectively high on BAL neutrophils (BALN) during S. pneumoniae infection, and we identified pro-degranulation-like (CD88High VISTAHigh PD-L1+ CD101-) neutrophils in S. pneumoniae and pro-phagocytosis-like (CD101+ CD18Low PD-L1-) neutrophils in E. coli infections. Stimulation of VISTA with its ligand VISG-3 enhanced the neutrophil respiratory burst, degranulation, and killing of S. pneumoniae but not E. coli. We conclude that neutrophil cell surface protein expression depends on anatomic location and infection type, resulting in pathogen-specific neutrophil-mediated immune defense in discreet areas of the pneumonic lung. Graphical AbstractIn brief, Pihl et al. have found that neutrophil cell surface phenotype varies drastically based on tissue, time post-infection, and infection. BALN from early infections have higher activation and maturation statuses, while blood neutrophils are more migration primed, and late infections have more immune-suppressive and altered pathogen killing statuses. Neutrophil phenotype is skewed towards pro-phagocytosis associated marker expression on BALN from E. coli-infected mice while S. pneumoniae results in a pro-degranulation phenotype. In vitro BMN stimulation of VISTA with VSIG-3 results in degranulation, respiratory burst, and pathogen specific killing of S. pneumoniae but not E. coli. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=186 SRC="FIGDIR/small/649365v1_ufig1.gif" ALT="Figure 1"> View larger version (32K): org.highwire.dtl.DTLVardef@4e4829org.highwire.dtl.DTLVardef@1638108org.highwire.dtl.DTLVardef@1ac413dorg.highwire.dtl.DTLVardef@1ef36b5_HPS_FORMAT_FIGEXP M_FIG C_FIG

immunology↗

bioRxiv2022

Probing lung function at high spatiotemporal resolution using a novel crystal ribcage

Understanding the dynamic pathogenesis and treatment response in pulmonary diseases requires probing the lung at cellular resolution in real-time. Despite recent progress in intravital imaging, optical imaging of the lung during active respiration and circulation has remained challenging. Here, we introduce the crystal ribcage: a transparent ribcage that (i) allows truly multiscale optical imaging of the lung in health and disease from whole-organ to single cell, (ii) enables the modulation of lung biophysics and immunity through intravascular, intrapulmonary, intraparenchymal, and optogenetic interventions, and (iii) preserves the 3-D architecture, air-liquid interface, cellular diversity, and respiratory-circulatory functions of the lung. Utilizing these unprecedented capabilities on murine models of primary and metastatic lung tumors, respiratory infection, pulmonary fibrosis, emphysema, and acute lung injury we probed how disease progression remodels the respiratory-circulatory functions at the single alveolus and capillary levels. In cancer, we identified the earliest stage of tumorigenesis that compromises alveolar and capillary functions, a key state with consequences on tumor progression and treatment response. In pneumonia, we mapped mutual links between the recruited immune cells and the alveolar-capillary functions. We found that neutrophil migration is strongly and reversibly responsive to vascular pressure with implications for understanding of how lung physiology, altered by disease and anatomical location, affects immune cell activities. The crystal ribcage and its broad applications presented here will facilitate further studies of real-time remodeling of the alveoli and capillaries during pathogenesis of nearly any pulmonary disease, leading to the identification of new targets for treatment strategies.

bioengineering↗

bioRxiv2018

Multivariate Computational Analysis of Gamma Delta T cell Inhibitory Receptor Signatures Reveals the Divergence of Healthy and ART-Suppressed HIV+ Aging

Even with effective viral control, HIV-infected individuals are at a higher risk for morbidities associated with older age than the general population, and these serious non-AIDS events (SNAEs) track with plasma inflammatory and coagulation markers. The cell subsets driving inflammation in aviremic HIV infection are not yet elucidated. Also, whether ART-suppressed HIV infection causes premature induction of the inflammatory events found in uninfected elderly or if a novel inflammatory network ensues when HIV and older age co-exist is unclear. In this study we measured combinational expression of five inhibitory receptors (IRs) on seven immune cell subsets and 16 plasma markers from peripheral blood mononuclear cells (PBMC) and plasma samples, respectively, from a HIV and Aging cohort comprised of ART-suppressed HIV-infected and uninfected controls stratified by age ([≤]35 or [≥]50 years old). For data analysis, multiple multivariate computational algorithms (cluster identification, characterization, and regression (CITRUS), partial least squares regression (PLSR), and partial least squares-discriminant analysis (PLS-DA)) were used to determine if immune parameter disparities can distinguish the subject groups and to investigate if there is a cross-impact of aviremic HIV and age on immune signatures. IR expression on gamma delta ({gamma}{delta}) T cells exclusively separated HIV+ subjects from controls in CITRUS analyses and secretion of inflammatory cytokines and cytotoxic mediators from {gamma}{delta} T cells tracked with TIGIT expression among HIV+ subjects. Also, plasma markers predicted the percentages of TIGIT+ {gamma}{delta} T cells in subjects with and without HIV in PSLR models, and a PLS-DA model of {gamma}{delta} T cell IR signatures and plasma markers significantly stratified all four of the subject groups (uninfected younger, uninfected older, HIV+ younger, and HIV+ older). These data implicate {gamma}{delta} T cells as an inflammatory driver in ART-suppressed HIV infection and provide evidence of distinct inflamm-aging processes with and without ART-suppressed HIV infection.

immunology↗