27 research outputs found

    A Detailed Analysis of the Murine TAP Transporter Substrate Specificity

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    The transporter associated with antigen processing (TAP) supplies cytosolic peptides into the endoplasmic reticulum for binding to major histocompatibility complex (MHC) class I molecules. Its specificity therefore influences the repertoire of peptides presented by MHC molecules. Compared to human TAP, murine TAP's binding specificity has not been characterized as well, even though murine systems are widely used for basic studies of antigen processing and presentation.We performed a detailed experimental analysis of murine TAP binding specificity by measuring the binding affinities of 323 peptides. Based on this experimental data, a computational model of murine TAP specificity was constructed. The model was compared to previously generated data on human and murine TAP specificities. In addition, the murine TAP specificities for known epitopes and random peptides were predicted and compared to assess the impact of murine TAP selectivity on epitope selection.Comparisons to a previously constructed model of human TAP specificity confirms the well-established differences for peptide substrates with positively charged C-termini. In addition these comparisons show that several residues at the N-terminus of peptides which strongly influence binding to human TAP showed little effect on binding to murine TAP, and that the overall influence of the aminoterminal residues on peptide affinity for murine TAP is much lower than for the human transporter. Murine TAP also partly prefers different hydrophobic amino acids than human TAP in the carboxyterminal position. These species-dependent differences in specificity determined in vitro are shown to correlate with the epitope repertoire recognized in vivo. The quantitative model of binding specificity of murine TAP developed herein should be useful for interpreting epitope mapping and immunogenicity data obtained in humanized mouse models

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

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    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

    Versi all’acquaforte: ‘I Poeti Illustrati’ di Franco Riva

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    Omics in urology: An overview on concepts, current status and future perspectives

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    Recent technological advances in molecular biology have led to great progress in the knowledge of structure and function of cells and their main constituents. In this setting, 'omics' is standing out in order to significantly improve the understanding of etiopathogenetic mechanisms of disease and contribute to the development of new biochemical diagnostics and therapeutic tools. 'Omics' indicates the scientific branches investigating every aspect of cell's biology, including structures, functions and dynamics pathways. The main 'omics' are genomics, epigenomics, proteomics, transcriptomics, metabolomics and radiomics. Their diffusion, success and proliferation, addressed to many research fields, has led to many important acquisitions, even in Urology. Aim of this narrative review is to define the state of art of 'omics' application in Urology, describing the most recent and relevant findings, in both oncological and non-oncological diseases, focusing the attention on urinary tract infectious, interstitial cystitis, urolithiasis, prostate cancer, bladder cancer and renal cell carcinoma. In Urology the majority of 'omics' applications regard the pathogenesis and diagnosis of the investigated diseases. In future, its role should be implemented in order to develop specific predictors and tailored treatments

    Robotic revision of vesicourethral stricture after robot-assisted radical prostatectomy

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    Vesicourethral anastomotic stenosis is an uncom- mon complication following radical prostatectomy (RP). The incidence is 1–26% and after surgery most strictures occur within the first 6 months and are rare after 24 months. In 2007, the CAPSURE study, on 3310 men, found an incidence of vesico- urethral anastomotic stenosis in 8.4% of patients following RP. Nathan et al. reported an incidence rate between 22 and 26% in salvage RARP (robot- assisted radical prostatectomy) post radiotherapy or brachytherapy. The exact pathophysiology needs to be better defined. There are different factors in- volved: patient-related factors such as body mass index (BMI) and age; and technical factors such as number of surgical procedures performed by the surgeon, absence of mucosal eversion, poor vesico- urethral mucosal apposition, urinary extravasation, increased blood loss, ischemia of the bladder neck/ membranous urethra, or excessive narrowing of the urethral anastomosis at the time of the procedure. The first-line treatment of vesicourethral anasto- motic stenosis includes endoscopic dilation, inter- nal urethrotomy, and transurethral resection of the strictured fragment. Further treatment options are bladder neck reconstruction or urinary diversion. We present a case of robotic revision of urethro- vescical stricture in a 62-year-old man treated with robot-assisted radical prostatectomy for acinar adenocarcinoma of prostate International Society of Urological Pathology (ISUP) 2, pT2c R1. Oncological follow-up was negative. The last pros- tate-specific antigen (PSA) level was 0.03 ng/mL. The postoperative course was complicated by steno- sis of vesicourethral anastomosis. The patient underwent transurethral resection (TUR) of the stenotic vesicourethral anastomosis, followed by urethrotomy for stenosis 2 cm before anastomosis. During the urethrocystography, no micturition occurred, so it was necessary to posi- tion an epicystostomy. A standard transperitoneal robotic approach was planned to correct the vesicourethral anastomotic stenosis. After removing the suprapubic catheter, the first step was the dissection of the bladder from the walls of the pelvis, anteriorly and laterally, try- ing to identify the levator ani muscle and the cor- rect anatomy, which was very difficult due to fibro- sis and adhesions. We opened the cystotomy site close to the bladder neck to highlight the anatomy of the bladder neck and the bladder more clearly regarding the position of the urethral orifice. Then the next step was to reach the site of the blad- der neck and of the stenotic anastomosis location with white light from the cystoscope inserted from the urethra. The robot's light was reduced to see the light from the cystoscope: the diameter of the urethra was very nar- row even after these first incisions. The dissection of the stenotic fibrotic part of the anastomosis was not excessively close to the bladder trigone to avoid injury. The bladder neck was separated from the urethra to dissect this fibrotic tissue and then make the anas- tomosis on healthy, well-vascularized tissue, paying attention to the rectal wall posteriorly. The scar tissue was excised. We then inserted a 20 Fr silicone catheter on a wire. We developed a posterior plane between the bladder neck and the rectum in the pouch of Douglas, rejoin- ing the lateral and the anterior planes of the dissection started at the beginning of the surgery. We obtained an isolated bladder neck from the urethral stump gaining healthy tissue to redo the vesicourethral anastomosis. Performing the vesicourethral re-anastomosis is similar to the standard surgery, but the posterior reconstruction should lower the tension in the new anastomosis. When the stricture is too close to the ureteral ostia, postoperative edema could obliterate them. To avoid this, the placement of Bracci ure- teral catheters is needed and the ureteral orifices should be checked during surgery. The operative time was 150 minutes. The hospital stay was 3 days. The urethral catheter was kept indwelling for 12 days. At the removal of the urinary catheter, micturition resumed. Five months after surgery, urethrocystography demonstrated regular bladder walls, better bladder lumen expansion, and complete bladder emptying after micturition, with bladder neck within radio- logical limits

    Is antibiotic prophylaxis still mandatory for transperineal prostate biopsy? Results of a comparative study

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    Introduction and objectives: This study aimed to assess the incidence of urinary tract infections (UTIs) after transperineal prostate biopsy (TP-PB) comparing patients who underwent antibiotic prophylaxis (AP) with patients who had no prophylaxis. Materials and methods: This prospective, double-center trial was conducted between August and December 2020. Patient&nbsp;candidates to PB were included with 1:1 allocation to case (Group A-no AP) and control group (Group B-standard AP). All TP-PBs were performed in an outpatient setting&nbsp;under local anesthesia. Data collected 2&nbsp;weeks after the procedure included incidence of UTIs or bacteriuria, evaluated with a urine culture (UC), main symptoms, and complications related to TP-PBs. Results: A total of 200 patients were included (100 patients in each group). The mean age was 66.2&nbsp;±&nbsp;7.7 in Group A and 67.4&nbsp;±&nbsp;8&nbsp;years in Group B (P&nbsp;=&nbsp;0.134). Mean prostate volume was 65.5&nbsp;±&nbsp;26.7 vs. 51&nbsp;±&nbsp;24.6&nbsp;cc (P &lt;&nbsp;0.001), number of biopsy cores was 17.8&nbsp;±&nbsp;2.4 vs. 14.9&nbsp;±&nbsp;0.8 (P &lt;&nbsp;0.001), and PSA value was 15.9&nbsp;±&nbsp;28.1 vs. 13.3&nbsp;±&nbsp;22.3&nbsp;ng/ml (P =&nbsp;0.017). Overall PCa detection rate was 55% vs. 59% (P =&nbsp;0.567). Postoperative UTI occurred in one patient in Group A vs. zero in Group B. Asymptomatic bacteriuria was present in 3 vs. 5 patients (P =&nbsp;0.470) and was not treated with antibiotics. Postoperative hematuria was observed in 13 patients vs. 29 (P &lt;&nbsp;0.05), and acute urinary retention was observed in one patient in each group. Conclusions: The incidence of bacteriuria and UTIs in TP-PBs is not related to AP. Therefore, AP could be discontinued in TP-PB candidates without the risk of increasing UTI-related complications

    Effects of Physical Activity at High Altitude on Hormonal Profiles in Foreign Trekkers and Indigenous Nepalese Porters

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    : Altitude exposure affects hormonal homeostasis, but the adaptation of different populations is still not finely defined. This study aims to compare the mid-term effects of combining physical activity and altitude hypoxia on hormonal profiles in foreign trekkers coming from Italy versus indigenous Nepalese porters during a Himalayan trek. Participants (6 Italians and 6 Nepalese) completed a 300&nbsp;km distance in 19&nbsp;days of an accumulated altitude difference of 16,000&nbsp;m, with an average daily walk of 6&nbsp;h. The effect of high altitude on hormonal pathways was assessed by collecting blood samples the day before the expedition and the day after its completion. Foreign trekkers had an additional follow-up sample collected after 10&nbsp;days. The findings revealed a different adaptation of thyroidal and gonadal axes to mid-term strenuous physical activity combined with high-altitude hypobaric hypoxia. The thyroid function shifted to the protective mechanism of low free triiodothyronine (FT3), whereas the gonadal axis was suppressed. The Italian trekkers and Nepalese porters had lower total testosterone and 17-β-estradiol levels after the expedition. At the follow-up, the Italians had increased testosterone values. Prolactin secretion decreased in the Italians but increased in the Nepalese. We conclude that exposure to high-altitude affects the hormonal axes. The effect seems notably pronounced for the hypothalamus-pituitary gonadal axis, suppressed after high-altitude exposure
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