OBJECTIVETo identify ubiquitinated proteins from complex human multiple myeloma (MM) U266 cells, a malignant disorder of differentiated human B cells.

METHODSEmploying a globally proteomic strategy combining of immunoprecipitation, LC-MS/MS and SCX-LC-MS analysis to identified ubiquitination sites, which were identified by detecting signature peptides containing a GG-tag (114.1 Da) and an LRGG-tag (383.2 Da).

RESULTSIn total, 52 ubiquitinated proteins containing 73 ubiquitination sites of which 14 and 59 sites contained LRGG-tag and GG-tag were identified, respectively.

CONCLUSIONClassification analysis by of the proteins identified in the study based on the PANTHER showed that they were associated with multiple functional groups. This suggested the involvement of many endogenous proteins in the ubiquitination in MM.

Cell Line, Tumor ; Gene Expression Profiling ; Gene Expression Regulation, Neoplastic ; physiology ; Humans ; Multiple Myeloma ; metabolism ; Neoplasm Proteins ; genetics ; metabolism ; Proteomics ; methods ; Ubiquitination

Age-associated changes in immune cells have been linked to an increased risk for infection. However, a global and detailed characterization of the changes that human circulating immune cells undergo with age is lacking. Here, we combined scRNA-seq, mass cytometry and scATAC-seq to compare immune cell types in peripheral blood collected from young and old subjects and patients with COVID-19. We found that the immune cell landscape was reprogrammed with age and was characterized by T cell polarization from naive and memory cells to effector, cytotoxic, exhausted and regulatory cells, along with increased late natural killer cells, age-associated B cells, inflammatory monocytes and age-associated dendritic cells. In addition, the expression of genes, which were implicated in coronavirus susceptibility, was upregulated in a cell subtype-specific manner with age. Notably, COVID-19 promoted age-induced immune cell polarization and gene expression related to inflammation and cellular senescence. Therefore, these findings suggest that a dysregulated immune system and increased gene expression associated with SARS-CoV-2 susceptibility may at least partially account for COVID-19 vulnerability in the elderly.
Adult ; Aged ; Aged, 80 and over ; Aging ; genetics ; immunology ; Betacoronavirus ; CD4-Positive T-Lymphocytes ; metabolism ; Cell Lineage ; Chromatin Assembly and Disassembly ; Coronavirus Infections ; immunology ; Cytokine Release Syndrome ; etiology ; immunology ; Cytokines ; biosynthesis ; genetics ; Disease Susceptibility ; Flow Cytometry ; methods ; Gene Expression Profiling ; Gene Expression Regulation, Developmental ; Gene Rearrangement ; Humans ; Immune System ; cytology ; growth & development ; immunology ; Immunocompetence ; genetics ; Inflammation ; genetics ; immunology ; Mass Spectrometry ; methods ; Middle Aged ; Pandemics ; Pneumonia, Viral ; immunology ; Sequence Analysis, RNA ; Single-Cell Analysis ; Transcriptome ; Young Adult