Identification and characterization of three novel LytM proteins of non-typeable Haemophilus influenzae involved in cell division, Outer Membrane Vesicles production and pathogenesis

Metalloproteases are a class of proteins very important for bacterial physiology, they are involved in many different aspects of microbial life and in the recent years they are target of many relevant studies. Through a genomic approach, we identified three hypothetical metalloprotease in Non-typeable Haemophilus influenzae (NTHi): NT013, NT017 and NT022. These proteins belong to LytM family, which is composed by factors mainly involved in cell division and in pathogenesis. The analysis of knockout mutant strains phenotypes confirms the role of protein NT013 and NT022 in cell splitting process; in particular we observed defective phenotypes in terms of cell morphology, formation of chains and bacterial aggregates. Moreover, we demonstrated a direct activity of protein NT013 in peptidoglycan cleavage, meanwhile NT022 seems to have a regulatory function. Furthermore, the alteration in the cell division in the KO strains resulted in an increase in the release of Outer Membrane Vesicles (OMVs), probably due to a decrease in membrane stability. NT017 does not seem to be involved in cell division process, but has a possible role in host colonization, since NT017 deletion reduces the capacity of NTHi to adhere to epithelial cells, to form biofilm and shows a susceptibility to human serum mediated killing. The results obtained so far clearly highlight the importance of LytM factors in NTHi physiology and pathogenesis

Identification and characterization of three novel LytM proteins of non-typeable Haemophilus influenzae involved in cell division, Outer Membrane Vesicles production and pathogenesis

Metalloproteases are a class of proteins very important for bacterial physiology, they are involved in many different aspects of microbial life and in the recent years they are target of many relevant studies. Through a genomic approach, we identified three hypothetical metalloprotease in Non-typeable Haemophilus influenzae (NTHi): NT013, NT017 and NT022. These proteins belong to LytM family, which is composed by factors mainly involved in cell division and in pathogenesis. The analysis of knockout mutant strains phenotypes confirms the role of protein NT013 and NT022 in cell splitting process; in particular we observed defective phenotypes in terms of cell morphology, formation of chains and bacterial aggregates. Moreover, we demonstrated a direct activity of protein NT013 in peptidoglycan cleavage, meanwhile NT022 seems to have a regulatory function. Furthermore, the alteration in the cell division in the KO strains resulted in an increase in the release of Outer Membrane Vesicles (OMVs), probably due to a decrease in membrane stability. NT017 does not seem to be involved in cell division process, but has a possible role in host colonization, since NT017 deletion reduces the capacity of NTHi to adhere to epithelial cells, to form biofilm and shows a susceptibility to human serum mediated killing. The results obtained so far clearly highlight the importance of LytM factors in NTHi physiology and pathogenesis

Sacrocolpopexy after sub-total hysterectomy vs. sacral hysteropexy for advanced urogenital prolapse: A propensity-matched study

ObjectiveTo compare objective and subjective outcomes of laparoscopic sacral colpopexy with supracervical hysterectomy (L-SCP) and robotic sacral hysteropexy (R-SHP). MethodsThis is a multicenter retrospective propensity score matched study. In the period between January 2014 and December 2018, we enrolled 161 patients with apical prolapse stage 2 or above, alone or with multicompartment descensus. ResultsAfter propensity-match analysis, there were 44 women for each group. Patients of the two groups had similar preoperative characteristics. No difference was found in terms of estimated blood loss, hospital stay, operative time, and intraoperative or postoperative complications. Subjective success rate, 12 months after surgery, was statistically better in the L-SCP group (P = 0.034): 81.8% and 97.8% women had Patient Global Impression of Improvement scores less than 3, in R-SHP and L-SCP, respectively. The objective cure rate was high in both groups without any significant differences in recurrence rate (P = 0.266). ConclusionBoth procedures are safe and effective in pelvic organ prolapse treatment. Patients who no longer desire uterine preservation could be encouraged to consider L-SCP. R-SHP is an alternative in women who are strongly motivated to preserve their uterus in the absence of abnormal uterine findings

The B-cell inhibitory receptor CD22 is a major factor in host resistance to Streptococcus pneumoniae infection

Streptococcus pneumoniae is a major human pathogen, causing pneumonia and sepsis. Genetic components strongly influence host responses to pneumococcal infections, but the responsible loci are unknown. We have previously identified a locus on mouse chromosome 7 from a susceptible mouse strain, CBA/Ca, to be crucial for pneumococcal infection. Here we identify a responsible gene, Cd22, which carries a point mutation in the CBA/Ca strain, leading to loss of CD22 on B cells. CBA/Ca mice and gene-targeted CD22-deficient mice on a C57BL/6 background are both similarly susceptible to pneumococcal infection, as shown by bacterial replication in the lungs, high bacteremia and early death. After bacterial infections, CD22-deficient mice had strongly reduced B cell populations in the lung, including GM-CSF producing, IgM secreting innate response activator B cells, which are crucial for protection. This study provides striking evidence that CD22 is crucial for protection during invasive pneumococcal disease.info:eu-repo/semantics/publishedVersio

Corrected and Republished from: "A Novel, Multiple-Antigen Pneumococcal Vaccine Protects against Lethal Streptococcus pneumoniae Challenge"

Current vaccination against Streptococcus pneumoniae uses vaccines based on capsular polysaccharides from selected serotypes and has led to nonvaccine serotype replacement disease. We have investigated an alternative serotype-independent approach, using multiple-antigen vaccines (MAV) prepared from S. pneumoniae TIGR4 lysates enriched for surface proteins by a chromatography step after culture under conditions that induce expression of heat shock proteins (Hsp; thought to be immune adjuvants). Proteomics and immunoblot analyses demonstrated that, compared to standard bacterial lysates, MAV was enriched with Hsps and contained several recognized protective protein antigens, including pneumococcal surface protein A (PspA) and pneumolysin (Ply). Vaccination of rodents with MAV induced robust antibody responses to multiple serotypes, including nonpneumococcal conjugate vaccine serotypes. Homologous and heterologous strains of S. pneumoniae were opsonized after incubation in sera from vaccinated rodents. In mouse models, active vaccination with MAV significantly protected against pneumonia, while passive transfer of rabbit serum from MAV-vaccinated rabbits significantly protected against sepsis caused by both homologous and heterologous S. pneumoniae strains. Direct comparison of MAV preparations made with or without the heat shock step showed no clear differences in protein antigen content and antigenicity, suggesting that the chromatography step rather than Hsp induction improved MAV antigenicity. Overall, these data suggest that the MAV approach may provide serotype-independent protection against S. pneumoniae

How BRCA and homologous recombination deficiency change therapeutic strategies in ovarian cancer: a review of literature

About 50% of High Grade Serous Ovarian Cancer exhibit a high degree of genomic instability due to mutation of genes involved in Homologous Recombination (HRD) and such defect accounts for synthetic lethality mechanism of PARP inhibitors (PARP-i). Several clinical trials have shown how BRCA and HRD mutational status profoundly affect first line chemotherapy as well as response to maintenance therapy with PARP-i, hence Progression Free Survival and Overall Survival. Consequently, there is urgent need for the development of increasingly reliable HRD tests, overcoming present limitations, as they play a key role in the diagnostic and therapeutic process as well as have a prognostic and predictive value. In this review we offer an overview of the state of the art regarding the actual knowledge about BRCA and HRD mutational status, the rationale of PARPi use and HRD testing (current and in development assays) and their implications in clinical practice and in the treatment decision process, in order to optimize and choose the best tailored therapy in patients with ovarian cancer

The metabolic, virulence and antimicrobial resistance profiles of colonising Streptococcus pneumoniae shift after PCV13 introduction in urban Malawi

Streptococcus pneumoniae causes substantial mortality among children under 5-years-old worldwide. Polysaccharide conjugate vaccines (PCVs) are highly effective at reducing vaccine serotype disease, but emergence of non-vaccine serotypes and persistent nasopharyngeal carriage threaten this success. We investigated the hypothesis that following vaccine, adapted pneumococcal genotypes emerge with the potential for vaccine escape. We genome sequenced 2804 penumococcal isolates, collected 4-8 years after introduction of PCV13 in Blantyre, Malawi. We developed a pipeline to cluster the pneumococcal population based on metabolic core genes into “Metabolic genotypes” (MTs). We show that S. pneumoniae population genetics are characterised by emergence of MTs with distinct virulence and antimicrobial resistance (AMR) profiles. Preliminary in vitro and murine experiments revealed that representative isolates from emerging MTs differed in growth, haemolytic, epithelial infection, and murine colonisation characteristics. Our results suggest that in the context of PCV13 introduction, pneumococcal population dynamics had shifted, a phenomenon that could further undermine vaccine control and promote spread of AMR

Pericyte derived chemokines amplify neutrophil recruitment across the cerebrovascular endothelial barrier

Excessive neutrophil extravasation can drive immunopathology, exemplified in pyogenic meningitis caused by Streptococcus pneumoniae infection. Insufficient knowledge of the mechanisms that amplify neutrophil extravasation has limited innovation in therapeutic targeting of neutrophil mediated pathology. Attention has focussed on neutrophil interactions with endothelia, but data from mouse models also point to a role for the underlying pericyte layer, as well as perivascular macrophages, the only other cell type found within the perivascular space in the cerebral microvasculature. We tested the hypothesis that human brain vascular pericytes (HBVP) contribute to neutrophil extravasation in a transwell model of the cerebral post-capillary venule. We show that pericytes augment endothelial barrier formation. In response to inflammatory cues, they significantly enhance neutrophil transmigration across the endothelial barrier, without increasing the permeability to small molecules. In our model, neither pericytes nor endothelia responded directly to bacterial stimulation. Instead, we show that paracrine signalling by multiple cytokines from monocyte derived macrophages drives transcriptional upregulation of multiple neutrophil chemokines by pericytes. Pericyte mediated amplification of neutrophil transmigration was independent of transcriptional responses by endothelia, but could be mediated by direct chemokine translocation across the endothelial barrier. Our data support a model in which microbial sensing by perivascular macrophages generates an inflammatory cascade where pericytes serve to amplify production of neutrophil chemokines that are translocated across the endothelial barrier to act directly on circulating neutrophils. In view of the striking redundancy in inflammatory cytokines that stimulate pericytes and in the neutrophil chemokines they produce, we propose that the mechanism of chemokine translocation may offer the most effective therapeutic target to reduce neutrophil mediated pathology in pyogenic meningitis