The epidermal immune microenvironment plays a dominant role in psoriasis development,as revealed by mass cytometry

Psoriasis is a common chronic inflammatory skin disease.The diversity and heterogeneity of immune cells in human skin have been studied in recent years,but the spatial distribution of immune cells at the single-cell level in the human psoriatic epidermis and dermis remains unclear.In this study,we mapped psoriatic skin immune cells from paired lesional,perilesional,and nonlesional skin samples using mass cytometry.Phenotypic dendritic cells(DCs)were found in the psoriatic epidermis and dermis.Psoriatic dermal CD1c^(+)CD11b^(+)cDC2s migrated to the epidermis in the perilesional skin during the preinitiation stage.CD1c^(+)CD11b^(+)cDC2s rapidly replaced EpCAM^(+)CD11c^(low) LC cells and initiated inflammation.Simultaneously,CD207^(+)CD11c^(hi) LC and CD5^(+)T cells accumulated in the psoriatic epidermis and orchestrated epidermal inflammation in psoriasis.The immune cell pool in the psoriatic dermis primarily included APCs and T cells.However,unlike that in the dermis,the epidermal immune environment was more significant and coincided with the inflammation occurring during psoriasis.

Immunoprofiling of Drosophila Hemocytes by Single-cell Mass Cytometry

Single-cell mass cytometry(SCMC)combines features of traditional flow cytometry(i.e.,fluorescence-activated cell sorting)with mass spectrometry,making it possible to measure several parameters at the single-cell level for a complex analysis of biological regulatory mechanisms.In this study,we optimized SCMC to analyze hemocytes of the Drosophila innate immune system.We used metal-conjugated antibodies(against cell surface antigens H2,H3,H18,L1,L4,and P1,and intracellular antigens 3A5 and L2)and anti-IgM(against cell surface antigen L6)to detect the levels of antigens,while anti-GFP was used to detect crystal cells in the immune-induced samples.We investigated the antigen expression profile of single cells and hemocyte populations in naive states,in immune-induced states,in tumorous mutants bearing a driver mutation in the Drosophila homologue of Janus kinase(hopTum)and carrying a deficiency of the tumor suppressor gene lethal(3)malignant blood neoplasm-1[l(3)mbn1],as well as in stem cell maintenance-defective hdcD84 mutant larvae.Multidimensional analysis enabled the discrimination of the functionally different major hemocyte subsets for lamellocytes,plasmatocytes,and crystal cells,and delineated the unique immunophenotype of Drosophila mutants.We have identified subpopulations of L2^(+)/P1^(+)and L2^(+)/L4^(+)/P1^(+)transitional phenotype cells in the tumorous strains l(3)mbn1 and hopTum,respectively,and a subpopulation of L4^(+)/P1^(+)cells upon immune induction.Our results demonstrated for the first time that SCMC,combined with multidimensional bioinformatic analysis,represents a versatile and powerful tool to deeply analyze the regulation of cell-mediated immunity of Drosophila.

Aptamer-Based Cell-Surface Profiling with Single-Cell Resolution Enables Precise Cancer Characterization

Molecular profiling of cell-surface proteins is a powerful strategy for precise cancer diagnosis.While mass cytometry(MC)enables synchronous detection of over 40 cellular parameters,its full potential in disease classification is challenged by the limited types of recognition probes currently available.In this work,we synthesize a panel of heavy isotopeconjugated aptamers to profile cancer-associated signatures on the surface of hematological malignancy(HM)cells.Based on 15 molecular signatures,we performed cell-surface profiling that allowed the precise classification of 8 HM cell lines.Combined with machine-learning technology,this aptamer-based MC platform also achieved multiclass identification of HM subtypes in clinical sampleswith 100%accuracy in the training cohort and 80%accuracy in the test cohort.Therefore,we report an effective and practical strategy for precise cancer classification at the singlecell level,paving the way for its clinical use in the near future.

Self-assembling, pH-responsive nanoflowers for inhibiting PAD4 and neutrophil extracellular trap formation and improving the tumor immune microenvironment

Self-assembling carrier-free nanodrugs are attractive agents because they accumulate at tumor by an enhanced permeability and retention(EPR) effect without introduction of inactive substances,and some nanodrugs can alter the immune environment. We synthesized a peptidyl arginine deiminase 4(PAD4) molecular inhibitor, ZD-E-1 M. It could self-assembled into nanodrug ZD-E-1. Using confocal laser scanning microscopy, we observed its cellular colocalization, PAD4 activity and neutrophil extracellular traps(NETs) formation. The populations of immune cells and expression of immune-related proteins were determined by single-cell mass cytometry. ZD-E-1 formed nanoflowers in an acidic environment, whereas it formed nanospheres at pH 7.4. Accumulation of ZD-E-1 at tumor was pHresponsive because of its pH-dependent differences in the size and shape. It could enter the nucleus and bind to PAD4 to prolong the intracellular retention time. In mice, ZD-E-1 inhibited tumor growth and metastasis by inhibiting PAD4 activity and NETs formation. Besides, ZD-E-1 could regulate the ratio of immune cells in LLC tumor-bearing mice. Immunosuppressive proteins like LAG3 were suppressed,while IFN-γ and TNF-a as stimulators of tumor immune response were upregulated. Overall, ZD-E-1 is a self-assembling carrier-free nanodrug that responds to pH, inhibits PAD4 activity, blocks neutrophil extracellular traps formation, and improves the tumor immune microenvironment.

Systemic and single cell level responses to 1 nm size biomaterials demonstrate distinct biological effects revealed by multi-omics atlas

Although ultra-small nanoclusters(USNCs,<2 nm)have immense application capabilities in biomedicine,the investigation on body-wide organ responses towards USNCs is scant.Here,applying a novel strategy of single-cell mass cytometry combined with Nano Genome Atlas of multi-tissues,we systematically evaluate the interactions between the host and calcium phosphate(CaP)USNCs at the organism level.Combining single-cell mass cytometry,and magnetic luminex assay results,we identify dynamic immune responses to CaP USNCs at the single cell resolution.The innate immune is initially activated and followed by adaptive immune activation,as evidenced by dynamic immune cells proportions.Furthermore,using Nano Genome Atlas of multi-tissues,we uncover CaP USNCs induce stronger activation of the immune responses in the cartilage and subchondral bone among the five local tissues while promote metabolic activities in the liver and kidney.Moreover,based on the immunological response profiles,histological evaluation of major organs and local tissue,and a body-wide transcriptomics,we demonstrate that CaP USNCs are not more hazardous than the Food and Drug Administration-approved CaP nanoparticles after 14 days of injection.Our findings provide valuable information on the future clinical applications of USNCs and introduce an innovative strategy to decipher the whole body response to implants.