Anchoring of proteins to lactic acid bacteria

The anchoring of proteins to the cell surface of lactic acid bacteria (LAB) using genetic techniques is an exciting and emerging research area that holds great promise for a wide variety of biotechnological applications. This paper reviews five different types of anchoring domains that have been explored for their efficiency in attaching hybrid proteins to the cell membrane or cell wall of LAB. The most exploited anchoring regions are those with the LPXTG box that bind the proteins in a covalent way to the cell wall. In recent years, two new modes of cell wall protein anchoring have been studied and these may provide new approaches in surface display. The important progress that is being made with cell surface display of chimaeric proteins in the areas of vaccine development and enzyme- or whole-cell immobilisation is highlighted.

The phenotypic spectrum of WWOX-related disorders: 20 additional cases of WOREE syndrome and review of the literature

Purpose Germline WWOX pathogenic variants have been associated with disorder of sex differentiation (DSD), spinocerebellar ataxia (SCA), and WWOX-related epileptic encephalopathy (WOREE syndrome). We review clinical and molecular data on WWOX-related disorders, further describing WOREE syndrome and phenotype/genotype correlations. Methods We report clinical and molecular findings in 20 additional patients from 18 unrelated families with WOREE syndrome and biallelic pathogenic variants in the WWOX gene. Different molecular screening approaches were used (quantitative polymerase chain reaction/multiplex ligation-dependent probe amplification [qPCR/MLPA], array comparative genomic hybridization [array-CGH], Sanger sequencing, epilepsy gene panel, exome sequencing), genome sequencing. Results Two copy-number variations (CNVs) or two single-nucleotide variations (SNVs) were found respectively in four and nine families, with compound heterozygosity for one SNV and one CNV in five families. Eight novel missense pathogenic variants have been described. By aggregating our patients with all cases reported in the literature, 37 patients from 27 families with WOREE syndrome are known. This review suggests WOREE syndrome is a very severe epileptic encephalopathy characterized by absence of language development and acquisition of walking, early-onset drug-resistant seizures, ophthalmological involvement, and a high likelihood of premature death. The most severe clinical presentation seems to be associated with null genotypes. Conclusion Germline pathogenic variants in WWOX are clearly associated with a severe early-onset epileptic encephalopathy. We report here the largest cohort of individuals with WOREE syndrome.</p

BCL11A intellectual developmental disorder: defining the clinical spectrum and genotype-phenotype correlations

\ua9 The Author(s) 2024.An increasing number of individuals with intellectual developmental disorder (IDD) and heterozygous variants in BCL11A are identified, yet our knowledge of manifestations and mutational spectrum is lacking. To address this, we performed detailed analysis of 42 individuals with BCL11A-related IDD (BCL11A-IDD, a.k.a. Dias-Logan syndrome) ascertained through an international collaborative network, and reviewed 35 additional previously reported patients. Analysis of 77 affected individuals identified 60 unique disease-causing variants (30 frameshift, 7 missense, 6 splice-site, 17 stop-gain) and 8 unique BCL11A microdeletions. We define the most prevalent features of BCL11A-IDD: IDD, postnatal-onset microcephaly, hypotonia, behavioral abnormalities, autism spectrum disorder, and persistence of fetal hemoglobin (HbF), and identify autonomic dysregulation as new feature. BCL11A-IDD is distinguished from 2p16 microdeletion syndrome, which has a higher incidence of congenital anomalies. Our results underscore BCL11A as an important transcription factor in human hindbrain development, identifying a previously underrecognized phenotype of a small brainstem with a reduced pons/medulla ratio. Genotype-phenotype correlation revealed an isoform-dependent trend in severity of truncating variants: those affecting all isoforms are associated with higher frequency of hypotonia, and those affecting the long (BCL11A-L) and extra-long (-XL) isoforms, sparing the short (-S), are associated with higher frequency of postnatal microcephaly. With the largest international cohort to date, this study highlights persistence of fetal hemoglobin as a consistent biomarker and hindbrain abnormalities as a common feature. It contributes significantly to our understanding of BCL11A-IDD through an extensive unbiased multi-center assessment, providing valuable insights for diagnosis, management and counselling, and into BCL11A’s role in brain development

Inhibiting factors produced by lactic acid bacteria. 2. Bacteriocins and other antibacterial substances

International audienc

Inhibiting factors produced by lactic acid bacteria. 1. Oxygen metabolites and catabolism end-products

International audienc

Efficacy of a Lactococcus lactis ΔpyrG vaccine delivery platform expressing chromosomally integrated hly from Listeria monocytogenes

Listeria monocytogenes is a significant food-borne pathogen and the causative agent of listeriosis, a disease which manifests as meningitis in immunocompromised adults or infection of the fetus and miscarriage in pregnant women. We have previously used Lactococcus lactis, a GRAS (Generally Regarded As Safe) organism, as a vaccine vector against listeriosis by engineering plasmid-mediated expression of the immunodominant antigen from L. monocytogenes, listeriolysin O (LLO). However, the environmental release of an engineered vaccine vector carrying a replicating plasmid during clinical usage may raise safety concerns. Here we describe the integration of the LLO gene (hly) into the L. lactis chromosome through homologous double crossover to allow stable expression, in order to avoid the use of antibiotic selection markers and to eliminate the requirement for a plasmid-based system. The approach was designed to simultaneously eliminate the pyrG gene encoding the CTP synthase which is responsible for converting UTP to CTP in a unique step in the de novo pyrimidine synthesis in L. lactis. This gene was targeted in order to restrict bacterial replication outside of the host (biological containment). The resulting cytidine auxotroph was able to secrete LLO constitutively and could elicit LLO91–99-specific CD8+ T lymphocytes in the murine infection model. Moreover, protection against lethal challenge with L. monocytogenes was accomplished after intraperitoneal (IP) vaccination with the constructed strain. The implications for the use of cytidine auxotropy in biological containment are discussed