Tissue-resident macrophage populations constitute a mosaic of phenotypes, yet how their metabolic states link to the range of phenotypes and functions in vivo is still poorly defined. Here, using... Show moreTissue-resident macrophage populations constitute a mosaic of phenotypes, yet how their metabolic states link to the range of phenotypes and functions in vivo is still poorly defined. Here, using high-dimensional spectral flow cytometry, we observe distinct metabolic profiles between different organs and functionally link acetyl CoA carboxylase activity to efferocytotic capacity. Additionally, differences in metabolism are evident within populations from a specific site, corresponding to relative stages of macrophage maturity. Immune perturbation with intestinal helminth infection increases alternative activation and metabolic rewiring of monocyte-derived macrophage populations, while resident TIM4+ intestinal macrophages remain immunologically and metabolically hyporesponsive. Similar metabolic signatures in alternatively-activated macrophages are seen from different tissues using additional helminth models, but to different magnitudes, indicating further tissue-specific contributions to metabolic states. Thus, our high-dimensional, flow-based metabolic analyses indicates complex metabolic heterogeneity and dynamics of tissue-resident macrophage populations at homeostasis and during helminth infection.Gauging the in vivo metabolism of immune cells at the single-cell level has proven challenging. Here the authors use spectral flow cytometry to investigate metabolic profiles in tissue-resident macrophages from several organs and changes in response to helminth infection. Show less
Innate mononuclear phagocytic system (MPS) cells preserve mucosal immune homeostasis. We investigated their role at nasal mucosa following allergen challenge with house dust mite. We combined... Show moreInnate mononuclear phagocytic system (MPS) cells preserve mucosal immune homeostasis. We investigated their role at nasal mucosa following allergen challenge with house dust mite. We combined single-cell proteome and transcriptome profiling on nasal immune cells from nasal biopsies cells from 30 allergic rhinitis and 27 non-allergic subjects before and after repeated nasal allergen challenge. Biopsies of patients showed infiltrating inflammatory HLA-DRhi/CD14(+) and CD16(+) monocytes and proallergic transcriptional changes in resident CD1C(+)/CD1A(+) conventional dendritic cells (cDC)2 following challenge. In contrast, non-allergic individuals displayed distinct innate MPS responses to allergen challenge: predominant infiltration of myeloid-derived suppressor cells (MDSC: HLA-DRlow/CD14(+) monocytes) and cDC2 expressing inhibitory/tolerogenic transcripts. These divergent patterns were confirmed in ex vivo stimulated MPS nasal biopsy cells. Thus, we identified not only MPS cell clusters involved in airway allergic inflammation but also highlight novel roles for non-inflammatory innate MPS responses by MDSC to allergens in non-allergic individuals. Future therapies should address MDSC activity as treatment for inflammatory airway diseases.Innate mononuclear phagocytic cells (MPS) in the nasal mucosa are the first to encounter inhaled allergens. MPS from allergic rhinitis patients showed a pro-inflammatory response during experimental allergen challenge, while clinically silent non-allergic controls displayed a tolerizing/anti-inflammatory response. Show less
Roukens, A.H.E.; Pothast, C.R.; Konig, M.; Huisman, W.; Dalebout, T.; Tak, T.; ... ; Collaboration COVID-19 LUMC Grp 2021
Systemic immune cell dynamics during coronavirus disease 2019 (COVID-19) are extensively documented, but these are less well studied in the (upper) respiratory tract, where severe acute respiratory... Show moreSystemic immune cell dynamics during coronavirus disease 2019 (COVID-19) are extensively documented, but these are less well studied in the (upper) respiratory tract, where severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) replicates(1-6). Here, we characterized nasal and systemic immune cells in individuals with COVID-19 who were hospitalized or convalescent and compared the immune cells to those seen in healthy donors. We observed increased nasal granulocytes, monocytes, CD11c(+) natural killer (NK) cells and CD4(+) T effector cells during acute COVID-19. The mucosal proinflammatory populations positively associated with peripheral blood human leukocyte antigen (HLA)-DRlow monocytes, CD38(+)PD1(+)CD4(+) T effector (T-eff) cells and plasmablasts. However, there was no general lymphopenia in nasal mucosa, unlike in peripheral blood. Moreover, nasal neutrophils negatively associated with oxygen saturation levels in blood. Following convalescence, nasal immune cells mostly normalized, except for CD127(+) granulocytes and CD38(+)CD8(+) tissue-resident memory T cells (T-RM). SARS-CoV-2-specific CD8(+) T cells persisted at least 2 months after viral clearance in the nasal mucosa, indicating that COVID-19 has both transient and long-term effects on upper respiratory tract immune responses. Show less
In Rhizobium leguminosarum biovar viciae, the nodABCand nodFEL operons are involved in the production of lipo-oligosaccharide signals which mediate host specificity. The structure of these... Show moreIn Rhizobium leguminosarum biovar viciae, the nodABCand nodFEL operons are involved in the production of lipo-oligosaccharide signals which mediate host specificity. The structure of these metabolites and those produced in nod mutants links the nodE and nodi genes to specific chemical features of the signal molecules. A nodE-determined, highly unsaturated fatty acid and a nod-determined O-acetyl substituent are essential for the ability of the signals to induce nodule meristems on the host plant Vicia sativa. Show less
A hybrid nodD gene consisting of 75% of the nodD1 gene of Rhizobium meliloti at the 5' end and 27% of the nodD gene of Rhizobium trifolii at the 3' end activates the six tested inducible nod... Show moreA hybrid nodD gene consisting of 75% of the nodD1 gene of Rhizobium meliloti at the 5' end and 27% of the nodD gene of Rhizobium trifolii at the 3' end activates the six tested inducible nod promoters of Rhizobium leguminosarum, R. trifolii, or R. meliloti to maximal levels, even in the absence of flavonoids. In strains containing such a constitutive activating nodD gene, transcription of nod genes started at the same site as in flavonoid-induced strains containing a wild-type nodD gene. In contrast to heterologous wild-type nodD products, the constitutive activating nodD gene does not cause a limitation of the host range. Furthermore, R. leguminosarum, R. trifolii, and R. meliloti strains containing the constitutive activating nodD gene induce (pseudo) nodules on tropical leguminous plants. Comparison of the symbiotic properties of rhizobia containing the constitutive nodD hybrid gene with those of rhizobia containing various wild-type nodD genes indicates that the activation of the nodD product by flavonoids is of crucial importance during the process of infection thread formation and, surprisingly, also during nitrogen fixation. Show less
