Related Experiment Video
Updated: Oct 15, 2025
Depletion and Reconstitution of Macrophages in Mice
Published on: August 1, 2012
Heightened turnover and failed maturation of monocyte-derived macrophages in murine chronic granulomatous disease
Sophie L Gibbings1, Kelsey C Haist1,2, Heidi Nick1
1Department of Pediatrics, National Jewish Health, Denver, CO.
Abstract:
Loss of NADPH oxidase activity leads to altered phagocyte responses and exaggerated inflammation in chronic granulomatous disease (CGD). We sought to assess the effects of Nox2 absence on monocyte-derived macrophages (MoMacs) in gp91phox-/y mice during zymosan-induced peritonitis. MoMacs from CGD and wild-type (WT) peritonea were characterized over time after zymosan injection. Although numbers lavaged from both genotypes were virtually identical, there were marked differences in maturation: newly recruited WT MoMacs rapidly enlarged and matured, losing Ly6C and gaining MHCII, CD206, and CD36, whereas CGD MoMacs remained small and were mostly Ly6C+MHCII-. RNA-sequencing analyses showed few intrinsic differences between genotypes in newly recruited MoMacs but significant differences with time. WT MoMacs displayed changes in metabolism, adhesion, and reparative functions, whereas CGD MoMacs remained inflammatory. PKH dye labeling revealed that although WT MoMacs were mostly recruited within the first 24 hours and remained in the peritoneum while maturing and enlarging, CGD monocytes streamed into the peritoneum for days, with many migrating to the diaphragm where they were found in fibrin(ogen) clots surrounding clusters of neutrophils in nascent pyogranulomata. Importantly, these observations seemed to be driven by milieu: adoptive transfer of CGD MoMacs into inflamed peritonea of WT mice resulted in immunophenotypic maturation and normal behavior, whereas altered maturation/behavior of WT MoMacs resulted from transfer into inflamed peritonea of CGD mice. In addition, Nox2-deficient MoMacs behaved similarly to their Nox2-sufficient counterparts within the largely WT milieu of mixed bone marrow chimeras. These data show persistent recruitment with fundamental failure of MoMac maturation in CGD.
Insights
Mice lacking NADPH oxidase (Nox2) show persistent monocyte recruitment and failed maturation of macrophages in chronic granulomatous disease (CGD). This highlights the crucial role of Nox2 in macrophage development and inflammation resolution.
Area of Science:
- Immunology
- Cell Biology
- Inflammation Research
Background:
- Chronic granulomatous disease (CGD) is characterized by impaired NADPH oxidase activity in phagocytes, leading to exaggerated inflammation.
- The role of Nox2, a key component of NADPH oxidase, in monocyte-derived macrophage (MoMac) maturation and function during inflammation is not fully understood.
Purpose of the Study:
- To investigate the impact of Nox2 absence on MoMacs in gp91phox-/- mice during zymosan-induced peritonitis.
- To elucidate the mechanisms underlying altered inflammatory responses and MoMac behavior in a mouse model of CGD.
Main Methods:
- Characterization of MoMacs from wild-type (WT) and CGD (gp91phox-/-) mice over time following zymosan injection.
- Flow cytometry for MoMac surface markers (Ly6C, MHCII, CD206, CD36).
- RNA-sequencing to analyze gene expression differences.
- PKH dye labeling for cell tracking and migration studies.
- Adoptive transfer experiments to assess the influence of the microenvironment.
Main Results:
- CGD MoMacs exhibited impaired maturation, remaining small and Ly6C+MHCII-, unlike WT MoMacs which matured rapidly.
- RNA-seq revealed distinct transcriptional profiles over time, with WT MoMacs showing metabolic and reparative changes, while CGD MoMacs remained inflammatory.
- CGD monocytes showed persistent recruitment and migration to the diaphragm, forming pyogranulomata, whereas WT MoMacs were recruited early and matured in situ.
- Adoptive transfer studies indicated that the microenvironment, not intrinsic defects alone, significantly influenced MoMac maturation and behavior.
Conclusions:
- Nox2 deficiency in MoMacs leads to a fundamental failure in their maturation and resolution of inflammation.
- The local microenvironment plays a critical role in modulating MoMac phenotype and function, even in the absence of Nox2.
- These findings underscore the importance of Nox2 in regulating MoMac development and inflammatory processes relevant to CGD.
More Related Videos
09:57Quantification of Monocyte Chemotactic Activity In Vivo and Characterization of Blood Monocyte Derived Macrophages
Published on: August 12, 2019
06:53Author Spotlight: Developing a Reproducible Method for Isolating Bone Marrow-Derived Macrophages from Neonatal Mice to Advance Early Life Immune Responses
Published on: May 24, 2024
