DOI: 10.5061/dryad.47d7wm3mw
title: Animal histological images for <em>in vivo</em> maximum tolerated dose and toxicity

description: The rising rate of antibiotic resistance is a widely acknowledged
 challenge, especially for gram-negative bacterial infections. Some drugs,
 such as the lipopeptide polymyxin B (PMB), have high antimicrobial
 activity against gram-negative organisms but also high toxicity owing to
 low specificity, resulting in a low therapeutic index and poor clinical
 utility. Due to the high rate of nephrotoxicity, systemic use of PMB is
 presently restricted to last-line therapy, with adverse clinical
 tradeoffs. To salvage such antibiotics, we propose specific drug delivery
 to bacterial cells using engineered phage as a carrier. We replaced the
 receptor-binding protein of phage M13 with an antibody fragment (scFab)
 recognizing the core antigen of lipopolysaccharide (LPS), creating a phage
 that bound a wide range of clinically important gram-negative pathogen
 species. We then cross-linked thousands of PMB molecules per virion,
 making ‘PMB-Phage’. PMB-Phage reduced the minimum inhibitory concentration
 (MIC) by up to 2 orders of magnitude for a variety of species, including
 the ESKAPEE pathogens Pseudomonas aeruginosa, Klebsiella pneumoniae,
 Escherichia coli, and Acinetobacter baumannii. To test efficacy,
 immunocompetent mice were infected with multidrug-resistant P. aeruginosa
 in a pneumonia model. PMB-Phage treatment was effective, causing
 bacteriostasis and up to 500-fold reduction in bacterial counts compared
 to a negative control, with a ~90-fold increase in potency compared to
 PMB. Similarly, P. aeruginosa infection of the cornea (keratitis) was
 treated effectively by PMB-Phage, with ~10,000-fold reduction in bacterial
 counts and a &gt;10-fold increase in potency compared to PMB.
 PMB-Phage was well-tolerated, with no toxic effects observed in vitro or
 in vivo, including by serum biomarkers and histology. This work
 demonstrates a proof-of-concept of phage-antibiotic conjugates as a
 strategy to improve cell targeting for bacteria over mammalian cells,
 combining engineerable phage-based targeting with large payload capacity.
 Phage-drug conjugates may represent a next-generation strategy to greatly
 improve potency and therapeutic index for otherwise toxic molecules.
description: README: Animal histological images for *in vivo* maximum tolerated dose
 and toxicity Associated article: Yang Y, Vexler S, Jordan MC, et al. “A
 Synthetic Phage-Peptide Conjugate as a Potent Antibacterial Agent for
 Pseudomonas aeruginosa Infections.” ACS Central Science. DOI:
 10.1021/acscentsci.5c00562 Contact: Irene A. Chen —
 [ireneachen@ucla.edu](mailto:ireneachen@ucla.edu) License: Data are
 released by Dryad under CC0 (public domain). 1\) Summary This dataset
 contains whole-slide histology images from a 7-day in vivo maximum
 tolerated dose (MTD) / toxicity study in mice exposed to polymyxin B
 (PMB), engineered phage–peptide conjugate (PMB-M13αLPS), 1× PBS vehicle,
 or no injection. For each animal, formalin-fixed, paraffin-embedded
 tissues (kidney, liver, spleen) were H&E-stained and scanned as
 whole-slide images. Slides were labeled so that the pathologist was
 blinded to treatment. The dataset is intended to enable independent
 inspection of tissue morphology for treatment-related toxicity. 2\) What’s
 included Files are at the top level and follow the naming scheme:
 \-.svs \: integer ID
 (see mapping below) \: one of Kidney, Liver, Spleen Each
 animal should have up to three slides (kidney, liver, spleen). Animals 4–6
 have no slides (animal death after a single PMB dose). 3\) Animal
 numbering → treatment (dose, route, schedule) Abbreviations: PMB =
 polymyxin B (sulfate); PMB-M13αLPS = engineered M13 phage targeted to LPS
 and conjugated with PMB; IV = intravenous (tail vein); QD = once daily;
 PBS = phosphate-buffered saline. All injections were IV, QD for 7 days in
 100 µL unless shown as “No injection”. 1–3 PMB 21 mg/kg 4–6 PMB 72 mg/kg
 (no histology; animals died after first dose) 7–9 PMB-M13αLPS 1.6×10^11
 virions/day 16–19 PBS (vehicle control) 20–22 PMB 2.5 mg/kg 23–25
 PMB-M13αLPS 6.85×10^9 virions/day 26–28 PMB-M13αLPS 1.37×10^10 virions/day
 29–31 PMB-M13αLPS 2.74×10^10 virions/day 32 No injection of substance
 (untreated control) 4\) How to access/open the data (free &
 open-source) Recommended: QuPath (v0.4+). QuPath is free, cross-platform,
 and supports .svs via Bio-Formats. Quick start: Install QuPath:
 [https://qupath.github.io](https://qupath.github.io) File → Open… → select
 any .svs file. If prompted, set Image type = “Brightfield (H&E)”. Use
 the zoom/pan tools to inspect tissue; toggle the scale bar (View → Show
 scale bar). For annotations or measurements: use the Tools panel; results
 export via Analyze → Measure… and File → Export…. Alternatives (also
 free/open): ASAP (Automated Slide Analysis Platform) — Windows/Linux;
 reads .svs. OpenSlide + openslide-viewer — lightweight viewer for .svs.
 5\) Data structure, variables, and conventions File format: .SVS
 (pyramidal TIFF-based whole-slide images). Tissues: Kidney, Liver, Spleen.
 Animal IDs: integers listed in Section 3. Missing data: No images for
 animals 4–6 (mortality after first PMB dose). Quality notes: Some slides
 may contain scanning artifacts near edges (tissue folds, pen marks). These
 do not affect central parenchyma review. Units/scale: Pixel size and
 magnification are embedded in the SVS metadata and read automatically by
 QuPath; use the QuPath scale bar for calibrated measurements. 6\) Methods
 (brief, for context) Male mice received daily IV tail-vein injections for
 7 days per Section 3. Twenty-four hours after the last injection, blood
 was collected for clinical chemistry and animals were euthanized; kidney,
 liver, and spleen were fixed, processed, H&E-stained, and scanned as
 whole-slide images. Blinded histopathology was performed to assess any
 treatment-related lesions. 7\) File inventory (as uploaded) For
 transparency, this version contains .svs files named for animals: 1, 2, 3;
 7, 8, 9; and 16–32 (three tissues per animal where available). If any
 filename differs by punctuation (e.g., 19_-Spleen.svs), treat it as the
 corresponding animal/tissue listed above. 8\) How to cite Please cite both
 the dataset and the associated article. Dataset (example, update with the
 final DOI once published): “Irene A. Chen Lab (2025). Animal Histological
 Images for In vivo Maximum Tolerated Dose and Toxicity." Dryad, DOI:
 10.5061/dryad.47d7wm3mw Article: Yang Y, Vexler S, Jordan MC, et al. “A
 Synthetic Phage-Peptide Conjugate as a Potent Antibacterial Agent for
 *Pseudomonas aeruginosa* Infections.” *ACS Central Science*. DOI:
 10.1021/acscentsci.5c00562 9\) Version history 2025-09-02: Initial upload
 of 24.66 GB of .svs slides and README. 10\) Support Questions or
 corrections: [ireneachen@ucla.edu](mailto:ireneachen@ucla.edu)