Molecular tracking devices quantify antigen distribution and archiving in the murine lymph node
- University of Colorado Anschutz Medical Campus, United States
Abstract
The detection of foreign antigens in vivo has relied on fluorescent conjugation or indirect read-outs such as antigen presentation. In our studies, we found that these widely used techniques had several technical limitations that have precluded a complete picture of antigen trafficking or retention across lymph node cell types. To address these limitations, we developed a 'molecular tracking device' to follow the distribution, acquisition, and retention of antigen in the lymph node. Utilizing an antigen conjugated to a nuclease-resistant DNA tag, acting as a combined antigen-adjuvant conjugate, and single-cell mRNA sequencing we quantified antigen abundance in lymph node. Variable antigen levels enabled the identification of caveolar endocytosis as a mechanism of antigen acquisition or retention in lymphatic endothelial cells. Thus, these molecular tracking devices enable new approaches to study dynamic tissue dissemination of antigen-adjuvant conjugates and identify new mechanisms of antigen acquisition and retention at cellular resolution in vivo.
Data availability
Raw and processed data for this study have been deposited at NCBI GEO under accession GSE150719. A reproducible analysis pipeline is available at https://github.com/rnabioco/antigen-tracking.
-
Molecular tracking devices quantify antigen distribution and archiving in the lymph nodeNCBI Gene Expression Omnibus, GSE150719.
-
Transcriptional basis of mouse and human dendritic cell heterogeneity revealed by single-cell profilingNCBI Gene Expression Omnibus, GSE137710.
-
ImmGen Microarray Phase 1NCBI Gene Expression Omnibus, GSE15907.
-
Single-cell RNA sequencing of lymph node stromal cells reveals niche-associated heterogeneityNCBI Gene Expression Omnibus, GSE112903.
-
Single-cell RNA-seq of the mouse lymph node lymphatic vasculature: Droplet-seqNCBI Gene Expression Omnibus, GSE145121.
-
ImmGen ULI: Systemwide RNA-seq profiles (#1)NCBI Gene Expression Omnibus, GSE109129.
Article and author information
Author details
Beth Ann Jiron Tamburini
Funding
National Institutes of Health (R01 AI121209)
- Beth Ann Jiron Tamburini
University of Colorado Department of Medicine Outstanding Early Career Scholar and RBI Clinical Scholar Award (Outstanding Early Career Scholar and RBI Clinical Scholar Award)
- Beth Ann Jiron Tamburini
American Cancer Society (Post-doctoral Fellowship)
- Shannon M Walsh
National Institutes of Health (T32 AI007405)
- Erin D Lucas
National Institutes of Health (R35 GM119550)
- Jay R Hesselberth
National Institutes of Health (T32 AI074491)
- Ryan M Sheridan
National Institutes of Health (R21 AI155929)
- Jay R Hesselberth
- Beth Ann Jiron Tamburini
The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.
Ethics
Animal experimentation: All animal procedures were approved by the Institutional Animal Care and Use Committee at the University of Colorado under protocol number 00067.
Copyright
© 2021, Walsh et al.
This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.
Download links
Further reading
-
- Cell Biology
- Developmental Biology
A study in mice reveals key interactions between proteins involved in fibroblast growth factor signaling and how they contribute to distinct stages of eye lens development.
-
- Cell Biology
- Evolutionary Biology
Maintenance of rod-shape in bacterial cells depends on the actin-like protein MreB. Deletion of mreB from Pseudomonas fluorescens SBW25 results in viable spherical cells of variable volume and reduced fitness. Using a combination of time-resolved microscopy and biochemical assay of peptidoglycan synthesis, we show that reduced fitness is a consequence of perturbed cell size homeostasis that arises primarily from differential growth of daughter cells. A 1000-generation selection experiment resulted in rapid restoration of fitness with derived cells retaining spherical shape. Mutations in the peptidoglycan synthesis protein Pbp1A were identified as the main route for evolutionary rescue with genetic reconstructions demonstrating causality. Compensatory pbp1A mutations that targeted transpeptidase activity enhanced homogeneity of cell wall synthesis on lateral surfaces and restored cell size homeostasis. Mechanistic explanations require enhanced understanding of why deletion of mreB causes heterogeneity in cell wall synthesis. We conclude by presenting two testable hypotheses, one of which posits that heterogeneity stems from non-functional cell wall synthesis machinery, while the second posits that the machinery is functional, albeit stalled. Overall, our data provide support for the second hypothesis and draw attention to the importance of balance between transpeptidase and glycosyltransferase functions of peptidoglycan building enzymes for cell shape determination.
