Beyond Autoantibodies: Biologic Roles of Human Autoreactive B Cells in Rheumatoid Arthritis Revealed by RNA-Sequencing.

Objective: To obtain the comprehensive transcriptome profile of human citrulline-specific B cells from patients with rheumatoid arthritis (RA).

Methods: Citrulline- and hemagglutinin-specific B cells were sorted by flow cytometry using peptide-streptavidin conjugates from the peripheral blood of RA patients and healthy individuals. The transcriptome profile of the sorted cells was obtained by RNA-sequencing, and expression of key protein molecules was evaluated by aptamer-based SOMAscan assay and flow cytometry.

Dysregulated human Tyrosyl-DNA phosphodiesterase I acts as cellular toxin.

Tyrosyl-DNA phosphodiesterase I (TDP1) hydrolyzes the drug-stabilized 3'phospho-tyrosyl bond formed between DNA topoisomerase I (TOPO1) and DNA. TDP1-mediated hydrolysis uses a nucleophilic histidine (Hisnuc) and a general acid/base histidine (Hisgab). A Tdp1Hisgab to Arg mutant identified in patients with the autosomal recessive neurodegenerative disease SCAN1 causes stabilization of the TDP1-DNA intermediate.

Simple regression for correcting ΔCt bias in RT-qPCR low-density array data normalization.

Background: Reverse transcription quantitative PCR (RT-qPCR) is considered the gold standard for quantifying relative gene expression. Normalization of RT-qPCR data is commonly achieved by subtracting the Ct values of the internal reference genes from the Ct values of the target genes to obtain ΔCt. ΔCt values are then used to derive ΔΔCt when compared to a control group or to conduct further statistical analysis.

Tyrosyl-DNA phosphodiesterase I catalytic mutants reveal an alternative nucleophile that can catalyze substrate cleavage.

Tyrosyl-DNA phosphodiesterase I (Tdp1) catalyzes the repair of 3'-DNA adducts, such as the 3'-phosphotyrosyl linkage of DNA topoisomerase I to DNA. Tdp1 contains two conserved catalytic histidines: a nucleophilic His (His(nuc)) that attacks DNA adducts to form a covalent 3'-phosphohistidyl intermediate and a general acid/base His (His(gab)), which resolves the Tdp1-DNA linkage. A His(nuc) to Ala mutant protein is reportedly inactive, whereas the autosomal recessive neurodegenerative disease SCAN1 has been attributed to the enhanced stability of the Tdp1-DNA intermediate induced by mutation of His(gab) to Arg.

Epstein-Barr virus nuclear antigen 3A promotes cellular proliferation by repression of the cyclin-dependent kinase inhibitor p21WAF1/CIP1.

Latent infection by Epstein-Barr virus (EBV) is highly associated with the endemic form of Burkitt lymphoma (eBL), which typically limits expression of EBV proteins to EBNA-1 (Latency I). Interestingly, a subset of eBLs maintain a variant program of EBV latency - Wp-restricted latency (Wp-R) - that includes expression of the EBNA-3 proteins (3A, 3B and 3C), in addition to EBNA-1. In xenograft assays, Wp-R BL cell lines were notably more tumorigenic than their counterparts that maintain Latency I, suggesting that the additional latency-associated proteins expressed in Wp-R influence cell proliferation and/or survival.

Glycan shielding of the influenza virus hemagglutinin contributes to immunopathology in mice.

Rationale: Pandemic influenza viruses historically have had few potential sites for N-linked glycosylation on the globular head of the hemagglutinin (HA) on emergence from the avian reservoir. Gain of glycans within antigenic sites of the HA during adaptation to the mammalian lung facilitates immune evasion.

Objectives: In this study, we sought to determine in mice how exposure to highly glycosylated viruses affects immunity to poorly glycosylated variants to model the emergence of a novel pandemic strain of a circulating subtype.