A Defined Terminal Region of the E. coli Chromosome Shows Late Segregation and High FtsK Activity

Background: The FtsK DNA-translocase controls the last steps of chromosome segregation in E. coli. It translocates sister chromosomes using the KOPS DNA motifs to orient its activity, and controls the resolution of dimeric forms of sister chromosomes by XerCD-mediated recombination at the dif site and their decatenation by TopoIV. Methodology: We have used XerCD/dif recombination as a genetic trap to probe the interaction of FtsK with loci located in different regions of the chromosome. This assay revealed that the activity of FtsK is restricted to a,400 kb terminal region of the chromosome around the natural position of the dif site. Preferential interaction with this region required the tethering of FtsK to the division septum via its N-terminal domain as well as its translocation activity. However, the KOPSrecognition activity of FtsK was not required. Displacement of replication termination outside the FtsK high activity region had no effect on FtsK activity and deletion of a part of this region was not compensated by its extension to neighbouring regions. By observing the fate of fluorescent-tagged loci of the ter region, we found that segregation of the FtsK high activity region is delayed compared to that of its adjacent regions. Significance: Our results show that a restricted terminal region of the chromosome is specifically dedicated to the last step

Asymmetry of Chromosome Replichores Renders the DNA Translocase Activity of FtsK Essential for Cell Division and Cell Shape Maintenance in Escherichia coli

Bacterial chromosomes are organised as two replichores of opposite polarity that coincide with the replication arms from the ori to the ter region. Here, we investigated the effects of asymmetry in replichore organisation in Escherichia coli. We show that large chromosome inversions from the terminal junction of the replichores disturb the ongoing post-replicative events, resulting in inhibition of both cell division and cell elongation. This is accompanied by alterations of the segregation pattern of loci located at the inversion endpoints, particularly of the new replichore junction. None of these defects is suppressed by restoration of termination of replication opposite oriC, indicating that they are more likely due to the asymmetry of replichore polarity than to asymmetric replication. Strikingly, DNA translocation by FtsK, which processes the terminal junction of the replichores during cell division, becomes essential in inversion-carrying strains. Inactivation of the FtsK translocation activity leads to aberrant cell morphology, strongly suggesting that it controls membrane synthesis at the division septum. Our results reveal that FtsK mediates a reciprocal control between processing of the replichore polarity junction and cell division

Avelumab, an anti-PD-L1 antibody, in patients with locally advanced or metastatic breast cancer: a phase 1b JAVELIN Solid Tumor study

PURPOSE: Agents targeting programmed death receptor 1 (PD-1) or its ligand (PD-L1) have shown antitumor activity in the treatment of metastatic breast cancer (MBC). The aim of this study was to assess the activity of avelumab, a PD-L1 inhibitor, in patients with MBC. METHODS: In a phase 1 trial (JAVELIN Solid Tumor; NCT01772004), patients with MBC refractory to or progressing after standard-of-care therapy received avelumab intravenously 10 mg/kg every 2 weeks. Tumors were assessed every 6 weeks by RECIST v1.1. Adverse events (AEs) were graded by NCI-CTCAE v4.0. Membrane PD-L1 expression was assessed by immunohistochemistry (Dako PD-L1 IHC 73-10 pharmDx). RESULTS: A total of 168 patients with MBC, including 58 patients with triple-negative breast cancer (TNBC), were treated with avelumab for 2-50 weeks and followed for 6-15 months. Patients were heavily pretreated with a median of three prior therapies for metastatic or locally advanced disease. Grade >/= 3 treatment-related AEs occurred in 13.7% of patients, including two treatment-related deaths. The confirmed objective response rate (ORR) was 3.0% overall (one complete response and four partial responses) and 5.2% in patients with TNBC. A trend toward a higher ORR was seen in patients with PD-L1+ versus PD-L1- tumor-associated immune cells in the overall population (16.7% vs. 1.6%) and in the TNBC subgroup (22.2% vs. 2.6%). CONCLUSION: Avelumab showed an acceptable safety profile and clinical activity in a subset of patients with MBC. PD-L1 expression in tumor-associated immune cells may be associated with a higher probability of clinical response to avelumab in MBC

31st Annual Meeting and Associated Programs of the Society for Immunotherapy of Cancer (SITC 2016) : part two

Background The immunological escape of tumors represents one of the main ob- stacles to the treatment of malignancies. The blockade of PD-1 or CTLA-4 receptors represented a milestone in the history of immunotherapy. However, immune checkpoint inhibitors seem to be effective in specific cohorts of patients. It has been proposed that their efficacy relies on the presence of an immunological response. Thus, we hypothesized that disruption of the PD-L1/PD-1 axis would synergize with our oncolytic vaccine platform PeptiCRAd. Methods We used murine B16OVA in vivo tumor models and flow cytometry analysis to investigate the immunological background. Results First, we found that high-burden B16OVA tumors were refractory to combination immunotherapy. However, with a more aggressive schedule, tumors with a lower burden were more susceptible to the combination of PeptiCRAd and PD-L1 blockade. The therapy signifi- cantly increased the median survival of mice (Fig. 7). Interestingly, the reduced growth of contralaterally injected B16F10 cells sug- gested the presence of a long lasting immunological memory also against non-targeted antigens. Concerning the functional state of tumor infiltrating lymphocytes (TILs), we found that all the immune therapies would enhance the percentage of activated (PD-1pos TIM- 3neg) T lymphocytes and reduce the amount of exhausted (PD-1pos TIM-3pos) cells compared to placebo. As expected, we found that PeptiCRAd monotherapy could increase the number of antigen spe- cific CD8+ T cells compared to other treatments. However, only the combination with PD-L1 blockade could significantly increase the ra- tio between activated and exhausted pentamer positive cells (p= 0.0058), suggesting that by disrupting the PD-1/PD-L1 axis we could decrease the amount of dysfunctional antigen specific T cells. We ob- served that the anatomical location deeply influenced the state of CD4+ and CD8+ T lymphocytes. In fact, TIM-3 expression was in- creased by 2 fold on TILs compared to splenic and lymphoid T cells. In the CD8+ compartment, the expression of PD-1 on the surface seemed to be restricted to the tumor micro-environment, while CD4 + T cells had a high expression of PD-1 also in lymphoid organs. Interestingly, we found that the levels of PD-1 were significantly higher on CD8+ T cells than on CD4+ T cells into the tumor micro- environment (p < 0.0001). Conclusions In conclusion, we demonstrated that the efficacy of immune check- point inhibitors might be strongly enhanced by their combination with cancer vaccines. PeptiCRAd was able to increase the number of antigen-specific T cells and PD-L1 blockade prevented their exhaus- tion, resulting in long-lasting immunological memory and increased median survival

Chirurgia del distacco regmatogeno di retina: cerchiaggio con benderella in silicone con chiusura in filo assorbibile.

Il cerchiaggio è una delle tecniche elettive nella chirurgia del distacco regmatogeno di retina, i materiali che possono essere utilizzati si differenziano per la lunghezza dell' indentazione e per essere o no assorbibili. la conseguenza è un' effetto dell' indentazione permanente o temporaneo. lo scopo del presente lavoro è stato quello di valutare la validità dell' utilizzo di una benderella di silicone la cui chiusura è stata effettuata con filo assorbibile Vicryl 6/0. Sono stati osservati 8 occhi operati di distacco di retina secondo questa tecnica valutando le modificazioni della refrazione e della lunghezza assiale. I risultati ottenuti dimostrano che 60 giorni dopo l' intervento la refrazione e la lunghezza assiale degli occhi operati presentano cambiamenti, rispetto ai valori preoperatori, minori in confronto agli interventi in cui la chiusura del cerchiaggio viene effettuata con filo non riassorbibile.Encircling scleral buckling of the eye has usually a permanent effect of indentation.The purpose of this study is to examine the validity of an encircling silicon band closed temporarily with an absorbable thread (Vicryl 6/0) in retinal detachment surgery. A total of 8 eyes were observed, wich had undergone retinal rhegmatogenous detachment using this technique, with the purpose of estimating the changes in refraction and axial length. The results obtained show that 60 days after surgery, refraction and axial length of the eyes changes, as compared to preoperative values, and they are less if compared to surgery in wich closing of the sclera buckling is carried out with not adsorbable threa

Chirurgia del distacco regmatogeno di retina: cerchiaggio con benderella di silicone con chiusura con filo riassorbibile.

Il cerchiaggio è una delle tecniche elettive nella chirurgia del distacco regmatogeno di retina, I materiali che possono essere utilizzati si differenziano per la larghezza della indentazione e per essere o no assorbibili. La conseguenza è un effetto dell’ indentazione permanente o temporaneo. Lo scopo del presente lavoro è stato quello di valutare la validità dell’ utilizzo di una benderella di silicone la cui chiusura è stata effettuata con filo riassorbibile Vicryl 6/0. Sono stati osservati 8 occhi operati di distacco di retina secondo questa tecnica valutando le modificazioni della refrazione e della lunghezza assiale. I risultati ottenuti dimostrano che 60 giorni dopo l’ intervento la refrazione e la lunghezza assiale degli occhi operati presentano cambiamenti, rispetto ai valori preoperatori, minori in confronto agli interventi in cui la chiusura del cerchiaggio viene effettuata con filo non assorbibileEncircling scleral buckling of the eye is one of the elective surgical methods in retinal rhegmatogenous detachment; the elements available are characterized by the breadth of indentation and by whether or not they are absorbable. Consequently, they have a permanent or temporary effect of indentation. It is the purpose of this study to estimate the validity of a silicone band that has been closed with Vicryl 6/0 absorbable thread. A total of 8 eyes were observed, which had undergone retinal rhegmatogenous detachment using this technique, with the purpose of estimating the changes in refraction and axial length. The results obtained show that 60 days after surgery, refraction and axial length of the eyes changes, as compared to preoperative values, and they are less if compared to surgery in which closing of the scleral bucklingis carried out with not absorbable thread

Recurrent vitreous haemorrhage from sporadic retinal astrocytic hamartoma.

This paper describes the case of a 25-year-old white male presented in 2005 as an emergency with floaters and decreased visual acuity in the right eye who had recurrent vitreous hemorrhage. His past ocular history was positive for unexplained juxtapapillary retinal oedema and vitreous haemorrhage in 1996 with spontaneous resolution. Systemic and family history was negative. Fundus examination showed a circumscribed yellow white juxtapapillary retinal lesion along the superotemporal arcade with vitreous haemorrhage arising from the lesion. Our final diagnosis was sporadic retinal epipapillary astrocytic hamartoma with recurrent vitreous haemorrhage. Vitreous haemorrhage in retinal astrocytic hamartoma is unusual and has been reported previously only in the context of tuberous sclerosis. Our case suggests a vascular component exists in sporadic retinal astrocytic hamartoma. Retinal astrocytic hamartomas of tuberous sclerosis have been classified into three types by angiographic features: all three types block choroidal fluorescence to some extent and show late leakage on FA, but on ICG type 1 has subtle blockage of choroidal fluorescence, type 2 has total blockage (from calcification) and type 3 has total blockage only in the centre. Though our case is sporadic, it has features of type 1 on FA and type 2 on ICG, suggesting incomplete calcification. OCT features are also consistent with retinal astrocytic hamartoma. We believe that sporadic retinal astrocytic hamartoma should now be included in the differential diagnosis of recurrent vitreous haemorrhage – sporadic cases can exhibit vasculopathic features

Détection de Mycobacterium dans le microbiote pulmonaire de patients atteints de la mucoviscidose par métaprotéomique

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