Corrigendum: Escape of TLR5 recognition by spp.: A rationale for atypical endoflagella.

[This corrects the article DOI: 10.3389/fimmu.2020.

Penicillin resistance compromises Nod1-dependent proinflammatory activity and virulence fitness of neisseria meningitidis.

Neisseria meningitidis is a life-threatening human bacterial pathogen responsible for pneumonia, sepsis, and meningitis. Meningococcal strains with reduced susceptibility to penicillin G (Pen(I)) carry a mutated penicillin-binding protein (PBP2) resulting in a modified peptidoglycan structure. Despite their antibiotic resistance, Pen(I) strains have failed to expand clonally.

Downregulation of the Na/K-ATPase pump by leptospiral glycolipoprotein activates the NLRP3 inflammasome.

Leptospira interrogans is responsible for a zoonotic disease known to induce severe kidney dysfunction and inflammation. In this work, we demonstrate that L. interrogans induces NLRP3 inflammasome-dependent secretion of IL-1β through the alteration of potassium transport in bone marrow-derived macrophages.

TLR4- and TLR2-mediated B cell responses control the clearance of the bacterial pathogen, Leptospira interrogans.

Leptospirosis is a widespread zoonosis caused by pathogenic Leptospira interrogans that are transmitted by asymptomatic infected rodents. Leptospiral lipoproteins and LPS have been shown to stimulate murine cells via TLRs 2 and 4. Host defense mechanisms remain obscure, although TLR4 has been shown to be involved in clearing Leptospira.

Identification of a new cis-regulatory element of the terminal deoxynucleotidyl transferase gene in the 5' region of the murine locus.

Terminal deoxynucleotidyl transferase (TdT) expression is controlled at the transcriptional level, however, the TdT core promoter combining D, D', an initiator (Inr) and downstream basal elements (DBE) does not recapitulate the whole complex regulation of TdT expression. We hypothesized that important cis-regulatory elements of the gene are located outside of the TdT promoter. In an attempt to identify these elements, we performed DNase I hypersensitivity assays over 24kb including a 10kb region located upstream of the transcription start site (+1) and a 14kb region spanning exons and introns I to VI.

Methylation of the promoter region may be involved in tissue-specific expression of the mouse terminal deoxynucleotidyl transferase gene.

The terminal deoxynucleotidyl transferase gene (TdT) is expressed in mice only in early B and T lymphoid precursors a few days after birth. Transactivating factors have been shown to contribute to the lymphoid specific expression of TdT, but they do not account entirely for the restriction of its expression to early precursors. Since tissue-specific expression can be modulated by other mechanisms such as DNA methylation and DNA accessibility, we evaluated the methylation pattern of the TdT gene in various expressing and non-expressing tissues and cell lines.

Differential splicing in mouse thymus generates two forms of terminal deoxynucleotidyl transferase.

A new form of TdT mRNA has been identified by screening a mouse thymus cDNA library. It contains an open reading frame of 1527 base pairs corresponding to a protein containing 509 aminoacids, whereas the previously identified mouse TdT mRNA is composed of 1587 base pairs and encodes a protein of 529 aminoacids. Analysis of a mouse genomic clone containing the 3' portion of the TdT gene shows that these twenty additional aminoacids are encoded by an additional exon located between exons X and XI.

Demonstration of a divergent transcript from the bidirectional heavy chain immunoglobulin promoter VH441 in B-cells.

The mouse heavy chain immunoglobulin promoter VH441 can lead in vitro to bidirectional transcription, due to a symmetrical organization of immunoglobulin heavy chain promoters with two TATA-like sequences bracketing the upstream promoter element ATGCAAAT (the so called octamer). We demonstrate here that divergent transcription also occurs in vivo in mature B cells from a myeloma which expresses the VH441 gene and even from the spleen of BALB/c mice. The level of VH441 divergent transcript increases in the spleen of BALB/c mice after immunisation by beta-(1,6)-galactan, showing that it is expressed in B cells which actively transcribe the VH441 gene.