Highlights from 2024 Conferences
Taconic scientists demonstrate how NK-engrafted hIL-15 NOG and FcResolv® hIL-15 NOG mice are important tools for research directed at NK cell-modulating therapies.
Scroll through the poster below, or download to learn more.
Have questions on the FcResolv NOG Mouse Portfolio? Connect with an expert today.
Ditte Olsen, Philip Dubé , Nicholas Smith, Monika Buczek, Megan MacBride, Debra Freer, Esther Andino, Emily Sack, Debra Freer, Michelle Vedder, Kathleen Bott, Louise Baskin, and Janell Richardson
Taconic Biosciences, Inc., Rensselaer, NY, USA
Jump to: Background | Results | Conclusions
Fc gamma receptors (FcγRs) on residual murine immune cells can interact with human IgG-based therapeutics and confound preclinical results. This is critical for therapeutics with human NK cell mediated antibody-dependent cellular cytotoxicity (ADCC) as their primary mode of action. We compared humanization, kinetics, and persistence of NK cell reconstitution in human IL-15-expressing mice with or without FcγRs using intraperitoneal (IP) or intravenous (IV) administration of cells from multiple donors.
Methods: Negatively selected human NK cells were engrafted into hIL-15 NOG or FcResolv® hIL-15 NOG (FcγR knockout) with identical protocols. Human reconstitution, immune profile and persistence was evaluated via serial blood sampling and terminal collections for blood, spleen, and bone marrow.
Results: Human NK cell reconstitution and persistence was equivalent between strains. There was a significant difference in the overall chimerism in IV vs. IP administration (IV > IP). There was no significant difference in % body weight, body condition scores, morbidity or mortality across study duration. NK cell persistence and kinetics were consistent between strains, administration, and donors, with a peak at 4-5 WPE and persistence to 12+ WPE in the blood. The dominant circulating NK phenotype was CD56+CD16+.
Conclusions: huNK-engrafted hIL-15 NOG and FcResolv® hIL-15 NOG mice provide a 12+ week study window, with equivalent reconstitution, immune profiling and kinetics.
Fig 1. The Taconic NOG Portfolio of super immunodeficient and humanized immune system mice
Fig 2. The FcResolv® NOG model portfolio is based on the super immunodeficient NOG mouse. This highly versatile strain lacks adaptive immune cells and has an attenuated innate immune response, yet still retains some residual mouse immune cells tht can interact with therapeutic antibodies. FcResolv® NOG models eliminate this interaction by knocking out the activity of all murine FcγRs, including the FcγRI, IIB, III and IV types, along with the high affinity FcεRI receptor. The low affinity FcεRII receptor remains present.
Fig 3. FcResolv® NOG models eliminate various confounding effects attributable to mouse Fc gamma receptors on residual immune cells, and the FcResolv® hIL-15 NOG mouse enables specific detection of ADCC mediated by human NK cells.
Fig 4. huNK cells from two different donors were administered IP and peripheral blood was analyzed via flow cytometry. (A) Absolute NK cell counts and (B) % hCD45 in hIL-15 NOG mice over time (mean±SEM, n=3-20). No morbidity or mortality was observed during the study. (C) The human CD45 fraction was evaluated for NK cells by flow cytometry (mean±SEM) gated on mCD45-, hCD45+, hCD3-, HCD16+, hCD56+.
Fig 5. Human cells in the peripheral blood of hIL-15 NOG and FcResolv® hIL-15 NOG 4-6 WPE with human NK cells from two different donors (mean±SEM, n=10-23). There was no significant difference between the two strains within a given donor (unpaired t-test).
Fig 6. There was no significant difference between absolute human NK peak engraftment (4-6 WPE) and persistence (12-14 WPE) within a given donor between the two strains (mean±SEM)
Fig 7. (A) Increased human NK cell engraftment (at 5 WPE) in FcResolv® hIL-15 NOG in 2 of 3 donors (mean±SEM; ns=p>0.05, ****p<0.001; ***p<0.0001). (B) Human NK cell persistence following IV administration (lines show repeated bleeds of the same animal at each timepoint).
Fig 8. (A) Body weights of FcResolv® hIL-15 NOG and hIL-15 NOG following huNK engraftment (mean±SEM). There was no significant difference between strains within a given donor (multiple unpaired t-test). All study animals were clinically observed across the entire study duration; there was no significant difference in body conditioning scores (not shown) nor mortality. (B) Kaplan-Meier survival curves.
Fig 9. Peripheral blood was analyzed by flow cytometry across three different donors (E, F, G) using hCD56 and hCD16 (gated on mCD45-hCD45+hCD3-) at 5 WPE.
® refers to a US trademark registration
