Faculty, Staff and Student Publications
Language
English
Publication Date
4-1-2025
Journal
Journal of Immunology
DOI
10.1093/jimmun/vkae051
PMID
40073090
PMCID
PMC12041766
PubMedCentral® Posted Date
3-9-2025
PubMedCentral® Full Text Version
Post-print
Abstract
Leukocytes migrate through the blood and extravasate into organs to surveil the host for infection or cancer. Recently, we demonstrated that intravenous (IV) anti-CD45.2 antibody labeling allowed for precise tracking of leukocyte migration. However, the narrow labeling window can make this approach challenging for tracking rare migration events. Here, we show that altering antibody administration route and fluorophore can significantly extend the antibody active labeling time. We found that while both IV and intraperitoneal (IP) anti-CD45.2 antibody labeled circulating leukocytes after injection, they had different kinetic properties that impacted labeling time and intensity. Quantification of circulating antibody revealed that while unbound IV anti-CD45.2 antibody rapidly decreased, unbound IP anti-CD45.2 antibody increased over 1 h. Using in vitro and in vivo serial dilution assays, we found that Alexa Fluor 647 and Brilliant Blue 700 (BB700) dyes had the greatest labeling sensitivity compared with other fluorophores. However, IP antibody injection with anti-CD45.2 BB700, but not Alexa Fluor 647, resulted in continuous blood leukocyte labeling for over 6 h. Finally, we leveraged IP anti-CD45.2 BB700 antibody to track slower migrating leukocytes into tumors. We found that IP anti-CD45.2 antibody injection allowed for the identification of ∼7 times as many tumor-specific CD8+ T cells that had recently migrated from blood into tumors. Our results demonstrate how different injection routes and fluorophores affect anti-CD45.2 antibody leukocyte labeling and highlight the utility of this approach for defining leukocyte migration in the context of homeostasis and cancer.
Keywords
Animals, Mice, Fluorescent Dyes, Leukocytes, Staining and Labeling, Leukocyte Common Antigens, Humans, Injections, Intraperitoneal, Mice, Inbred C57BL, Female, Cell Movement, Carbocyanines, blood contiguous organs, in vivo labeling, route of injection, T cell migration
Published Open-Access
yes
Recommended Citation
Hagan, Natalie B; Inaku, Charles; Kunder, Nikesh; et al., "In Vivo Antibody Labeling Route and Fluorophore Dictate Labeling Efficiency, Sensitivity, and Longevity" (2025). Faculty, Staff and Student Publications. 6398.
https://digitalcommons.library.tmc.edu/uthgsbs_docs/6398
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