Project description:Aim of this project was to examine the global gene expression profiles of mononuclear phagocytes recruited from peripheral blood to the alveolar space following alveolar deposition of the TLR2-ligand Pam3CSK4 in transgenic CX3CR1+/GFP mice.
Project description:Muscle injury triggers inflammation in which infiltrating mononuclear phagocytes are crucial for tissue regeneration. The interaction of the CCL2/CCR2 and CX3CL1/CX3CR1 chemokine axis that guides phagocyte infiltration is incompletely understood. Here, we show that CX3CR1 deficiency promotes muscle repair and rescues Ccl2-/- mice from impaired muscle regeneration as a result of altered macrophage function, not infiltration. Transcriptomic analysis of muscle mononuclear phagocytes reveals that Apolipoprotein E (ApoE) is up-regulated in mice with efficient regeneration. ApoE treatment enhances phagocytosis by mononuclear phagocytes in vitro, and restores phagocytic activity and muscle regeneration in Ccl2-/- mice. Because CX3CR1 deficiency may compensate for defective CCL2-dependant monocyte recruitment by modulating ApoE-dependent macrophage phagocytic activity, targeting CX3CR1 expressed by macrophages might be a powerful therapeutic approach to improve muscle regeneration.
Project description:Aim of this project was to examine the global gene expression profiles of mononuclear phagocytes recruited from peripheral blood to the alveolar space following alveolar deposition of the TLR2-ligand Pam3CSK4 in transgenic CX3CR1+/GFP mice. Experiment Overall Design: Alveolar macrophages (AM) and peripheral blood monocytes (PBM) were isolated from broncho-alveolar lavages and from blood, respectively, using FACS. Expression profiles from AM and PBM of the same mice were compared on the same slides. Each labeled RNA sample contained RNA pooled from six individuals. Four pairs of RNA from corresponding AM and PBM pools were hybridized, giving a total amount of 24 individual mice analyzed. Two hybridizations were performed with AM labeled with Cy3 and PBM with Cy5, two hybridizations were performed with swaped dyes.
Project description:We uesd single-cell transcriptome sequencing technology to sequence the mononuclear phagocytes in the mice kidney, blood and spleen after acute kidney injury, and comprehensively describe characteristics of mononuclear phagocytes.
Project description:Mononuclear phagocytes (MPs) comprise monocytes, macrophages and dendritic cells and play a crucial role in tissue homeostasis. However, accumulating evidence suggests that mononuclear phagocytes contribute to tumor progression and resistance to checkpoint blockade. Protein kinase C delta (PKCδ) is a serine/threonine kinase that plays a crucial role in regulating the immune response by preventing autoimmunity. However, the role of PKCδ in antitumor immunity is unknown. In this study, we found that PKCδ is abundantly expressed by MPs in several human and mouse tumors. PKCδ-/- mice were more resistant to growth of various cancers compared to wild-type mice and were more responsive to anti-PD-1 immunotherapy. Furthermore, we found that tumors from PKCδ-/- mice harbor a Th-1-skewed immune response including increased antigen cross-presentation and T cell activation. Depletion of MPs in vivo altered tumor growth in wild-type mice, but not in PKCδ-/- mice. In addition, co-injection of PKCδ-/- M2-like macrophages with cancer cells into wild-type mice markedly delayed tumor growth and significantly increased intratumoral T cell activation compared to wild-type M2-like macrophages co-injected with cancer cells. Finally, intrinsic loss of PKCδ functionally reprogrammed macrophages and dendritic cells by promoting their antigen presenting and cross-presenting capacity and triggered Type I and II interferon signaling. Our results suggest that PKCδ can be targeted to reprogram mononuclear phagocytes and augment checkpoint blockade efficacy.