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Background and objective: No clear-cut markers for predicting positive sperm retrieval (+SR) at microdissection testicular sperm extraction (mTESE) have been identified thus far. Our aim was to conduct a systematic review and meta-analysis to evaluate the ability of follicle-stimulating hormone (FSH), inhibin B (InhB), and anti-Müllerian hormone (AMH) to predict +SR in men with nonobstructive azoospermia (NOA) undergoing mTESE. Methods: We performed a search in the PubMed, EMBASE, Web of Science, and Scopus databases according to the Preferred Reporting Items for Systematic Review and Meta-analysis statement. Thirty-four publications were selected for inclusion in the analysis. Key findings and limitations: Overall, the mean +SR rate was 45%. Pooled standardized mean difference (SMD) values revealed significant hormonal differences between the +SR and −SR groups, with lower FSH (SMD −0.30), higher InhB (SMD 0.54), and lower AMH (SMD −0.56) levels in the +SR group. Pooled odds ratios (Ors) revealed no significant prediction of +SR by either FSH (OR 1.03, 95% confidence interval [CI] 1.00–1.06) or InhB (OR 1.01, 95% CI 1.00–1.02), despite variations in baseline levels and study heterogeneity. Conversely, AMH had significant predictive value (OR 0.82, 95% CI 0.73–0.92), with lower baseline levels in the +SR group. InhB and FSH levels were higher in the +SR group, while InhB exhibited the opposite trend. Conclusions and clinical implications: Despite study heterogeneity, our meta-analysis findings support the ability of AMH to predict +SR for men with NOA undergoing mTESE. Patient summary: We conducted a review and analysis of results from previous studies. Our findings show that for men with an infertility condition called nonobstructive azoospermia, blood levels of anti-Müllerian hormone can predict successful extraction of sperm using a microsurgical technique. Levels of two other hormones did not predict successful sperm extraction.

Background: Non-muscle invasive bladder cancer (NMIBC) patients are affected by a high risk of recurrence. The topography of collagen fibers represents a hallmark of the neoplastic extracellular microenvironment. Objective: Assess the topographic change associated with different stages of bladder cancer (from neoplastic lesions to bona fide tumor) and whether those changes favour the development of NMIBC. Design, Setting, and Participants: Seventy-one clinical samples of urothelial carcinoma at different stages were used. Topographic changes preceding tumor onset and progression were evaluated in the rat bladder cancer model induced by nitrosamine (BBN), a bladder-specific carcinogen. The preclinical model of actinic cystitis was also used in combination with BBN. Validated hematoxylin-eosin sections were used to assess the topography of collagen fibrils associated with pre-tumoral steps, NMIBC, and MIBC. Findings: Linearization of collagen fibers was higher in Cis and Ta vs. dysplastic urothelium, further increased in T1 and greatest in T2 tumors. In the BBN preclinical model, an increase in the linearization of collagen fibers was established since the beginning of inflammation, such as the onset of atypia of a non-univocal nature and dysplasia, and further increased in the presence of the tumor. Linearization of collagen fibers in the model of actinic cystitis was associated with earlier onset of BBN-induced tumor. Conclusions: The topographic modification of the extracellular microenvironment occurs during the inflammatory processes preceding and favoring the onset of bladder cancer. The topographic reconfiguration of the stroma could represent a marker for identifying and treating the non-neoplastic tissue susceptible to tumor recurrence.

Abstract Bladder mechanical properties are critical for organ function and tissue homeostasis. Therefore, alterations of tissue mechanics are linked to disease onset and progression. This study aims to characterize the tissue elasticity of the murine bladder wall considering its different anatomical components, both in healthy conditions and in actinic cystitis, a state characterized by tissue fibrosis. Here, we exploit Brillouin microscopy, an emerging technique in the mechanobiology field that allows mapping tissue mechanics at the microscale, in non-contact mode and free of labeling. We show that Brillouin imaging of bladder tissues is able to recognize the different anatomical components of the bladder wall, confirmed by histopathological analysis, showing different tissue mechanical properties of the physiological bladder, as well as a significant alteration in the presence of tissue fibrosis. Our results point out the potential use of Brillouin imaging on clinically relevant samples as a complementary technique to histopathological analysis, deciphering complex mechanical alteration of each tissue layer of an organ that strongly relies on mechanical properties to perform its function.

Abstract Background Early detection and removal of bladder cancer in patients is crucial to prevent tumor recurrence and progression. Because current imaging techniques may fail to detect small lesions of in situ carcinomas, patients with bladder cancer often relapse after initial diagnosis, thereby requiring frequent follow-up and treatments. Results In an attempt to obtain a sensitive and high-resolution imaging modality for bladder cancer, we have developed a photoacoustic imaging approach based on the use of PEGylated gold nanorods (GNRs) as a contrast agent, functionalized with the peptide cyclic [CphgisoDGRG] (Iso4), a selective ligand of α5β1 integrin expressed by bladder cancer cells. This product (called GNRs@PEG-Iso4) was produced by a simple two-step procedure based on GNRs activation with lipoic acid-polyethyleneglycol(PEG-5KDa)-maleimide and functionalization with peptide Iso4. Biochemical and biological studies showed that GNRs@PEG-Iso4 can efficiently recognize purified integrin α5β1 and α5β1-positive bladder cancer cells. GNRs@PEG-Iso4 was stable and did not aggregate in urine or in 5% sodium chloride, or after freeze/thaw cycles or prolonged exposure to 55 °C, and, even more importantly, do not settle after instillation into the bladder. Intravesical instillation of GNRs@PEG-Iso4 into mice bearing orthotopic MB49-Luc bladder tumors, followed by photoacoustic imaging, efficiently detected small cancer lesions. The binding to tumor lesions was competed by a neutralizing anti-α5β1 integrin antibody; furthermore, no binding was observed to healthy bladders (α5β1-negative), pointing to a specific targeting mechanism. Conclusion GNRs@PEG-Iso4 represents a simple and robust contrast agent for photoacoustic imaging and diagnosis of small bladder cancer lesions. Graphical Abstract

Purpose: Overall, male factor infertility (MFI) accounts for up to 50% of etiologies of couple’s infertility, with almost 30% of MFI cases being idiopathic in nature. Idiopathic MFI does not support a tailored treatment work-up in clinical practice. To investigate rates of and characteristics of men presenting for idiopathic versus unexplained primary infertility as compared with same-ethnicity, age-comparable fertile men. Materials and Methods: Demographic, clinical and laboratory data from 3,098 primary infertile men consecutively evaluated were analyzed and compared with those of 103 fertile controls. Idiopathic male infertility (IMI) was defined for abnormality at semen analysis with no previous history of diseases affecting fertility and normal findings on physical examination and genetic and laboratory testing. Unexplained male infertility (UMI) was defined as infertility of unknown origin with completely normal findings at semen analysis. Descriptive statistics and logistic regression models tested the association between clinical variables and idiopathic infertility status. Results: Overall, 570 (18.5%) and 154 (5.0%) patients depicted criteria suggestive for either IMI or UMI, respectively. Groups were similar in terms of age, BMI, CCI, recreational habits, hormonal milieu, and sperm DNA fragmentation indexes. Conversely, testicular volume was lower in IMI (p

IntroductionHuman immunodeficiency virus type 1 (HIV) transmission mostly occurs through the genital and intestinal mucosae. Although HIV-1 transmission has been extensively investigated, gaps remain in understanding the initial steps of HIV entry through the colonic mucosa. We previously showed that HIV can selectively trigger mononuclear phagocytes (MNP) to migrate within colonic epithelial cells to sample virions. Mucosal exposure to human seminal plasma (HSP), rich in pro- and anti-inflammatory cytokines, chemokines and growth factors, may as well induce alterations of the colonic mucosa and recruit immune cells, hence, affecting pathogen sampling and transmission.MethodsHere, we studied the role of HSP on the paracellular intestinal permeability by analyzing the distribution of two proteins known to play a key role in controlling the intestinal barrier integrity, namely the tight junctions-associated junctional adhesion molecule (JAM-A) and the adherents junction associated protein E-cadherin (E-CAD), by immunofluorescence and confocal microscopy. Also, we evaluated if HSP promotes the recruitment of MNP cells, specifically, the CD11c and CD64 positive MNPs, to the apical side of the human colonic mucosa. At this scope, HSP of HIV-infected and uninfected individuals with known fertility status was tested for cytokines, chemokines and growth factors concentration and used in an ex vivo polarized colonic tissue culture system to mimic as closely as possible the physiological process.ResultsHSP showed statistically significant differences in cytokines and chemokines concentrations between the three groups of donors, i.e. HIV infected, or uninfected fertile or randomly identified. Nevertheless, we showed that in the ex vivo tissue culture HSP in general, neither affected the morphological structure of the colonic mucosa nor modulated the paracellular intestinal permeability. Interestingly, CD11c+ MNP cells migrated to the apical surface of the colonic epithelium regardless, if incubated with HIV-infected or -uninfected HSPs, while CD64+ MNP cells, did not change their distribution within the colonic mucosa.DiscussionIn conclusion, even if HSP did not perturb the integrity of the human colonic mucosa, it affected the migration of a specific subset of MNPs that express CD11c towards the apical side of the colonic mucosa, which in turn may be involved in pathogen sampling.

ObjectivesTo investigate which infertile men with semen parameters above WHO reference limits at first semen analysis deserve a second semen test.Materials and methodsData from 1358 consecutive infertile men were analysed. Patients underwent two consecutive semen analyses at the same laboratory. Descriptive statistics and logistic regression models tested the association between clinical variables and semen parameters. A new predicting model was identified through logistic regression analysis exploring potential predictors of semen parameters below WHO reference limits after a previously normal one. Diagnostic accuracy of the new model was compared with AUA/ASRM and EAU guidelines. Decision curve analyses (DCA) tested their clinical benefit.ResultsOf 1358, 212 (15.6%) infertile men had semen parameters above WHO reference limits at first analysis. Of 212, 87 (41.0%) had a second semen analysis with results above WHO reference limits. Men with sperm parameters below reference limits at second analysis had higher FSH values, but lower testicular volume (TV) (all pConclusionsApproximately 60% of infertile men with a first semen analysis above WHO limits have a second analysis with results below limits. The newly identified risk model might be useful to select infertile men with initial semen results above WHO limits who deserve a second semen analysis.

Detection and removal of bladder cancer lesions at an early stage is crucial for preventing tumor relapse and progression. This study aimed to develop a new technological platform for the visualization of small and flat urothelial lesions of high-grade bladder carcinoma in situ (CIS).We found that the integrin α5β1, overexpressed in bladder cancer cell lines, murine orthotopic bladder cancer and human bladder CIS, can be exploited as a receptor for targeted delivery of GNRs functionalized with the cyclic CphgisoDGRG peptide (Iso4). The GNRs@Chit-Iso4 was stable in urine and selectively recognized α5β1 positive neoplastic urothelium, while low frequency ultrasound-assisted shaking of intravesically instilled GNRs@Chit-Iso4 allowed the distribution of nanoparticles across the entire volume of the bladder. Photoacoustic imaging of GNRs@Chit-Iso4 bound to tumor cells allowed for the detection of neoplastic lesions smaller than 0.5 mm that were undetectable by ultrasound imaging and bioluminescence.

Molecular mechanisms associated with human germ cell aplasia in infertile men remain undefined. Here the authors perform single-cell transcriptome profiling to highlight differentially expressed genes and pathways in each somatic cell type in testes of men with idiopathic germ cell aplasia.

Mechanisms underlying severe male infertility are still largely elusive. However, recently, a single-cell transcription study by our group identified several differentially expressed coding genes in all the somatic cell types in testes of patients with idiopathic germ cell aplasia (iGCA). Here, we leverage this work by extending the analysis also to the non-coding portion of the genome. As a result, we found that 43 LncRNAs were differentially expressed in the somatic cells of these patients. Interestingly, a significant portion of the overexpressed LncRNAs was found to be a target of TAF9B, a transcription factor known to be involved in germ cell survival. Moreover, several overexpressed LncRNAs were also found to be activated in a mouse model of Sertoli cells treated with bisphenol A, a widespread environmental contaminant, long suspected to impair male fertility. Finally, a literature search for MEG3, a maternally imprinted LncRNA overexpressed as well in our patients, found it to be involved, among other things, in obesity and inflammation, known comorbidities of iGCA, ultimately suggesting that our findings deepen the understanding of the molecular insights coupled not only to the pathogenesis, but also to the clinical course of this class of patients.

In this Review, Laura Martinez-Vidal et al. summarize current knowledge of factors affecting extracellular matrix (ECM) remodeling in the context of pathological mechanical changes to tissue properties. They focus on the importance of research on tissue stiffness to the development of diagnostic tools and therapies to treat urological disease.

Testicular volume (TV) is considered a good clinical marker of hormonal and spermatogenic function. Accurate reference values for TV measures in infertile and fertile men are lacking. We aimed to assess references values for TV in white-European infertile men and fertile controls. We analyzed clinical and laboratory data from 1940 (95.0%) infertile men and 102 (5.0%) fertile controls. Groups were matched by age using propensity score weighting. TV was assessed using a Prader orchidometer (PO). Circulating hormones and semen parameters were investigated in every male. Descriptive statistics, Spearman's correlation, and logistic regression models tested potential associations between PO-estimated TV values and clinical variables. Receiver operating characteristic (ROC) curves were used to find TV value cutoffs for oligoasthenoteratozoospermia (OAT) and nonobstructive azoospermia (NOA) status in infertile men. The median testicular volume was smaller in infertile than that of fertile men (15.0 ml vs 22.5 ml; P < 0.001). TV positively correlated with total testosterone, sperm concentration, and progressive sperm motility (all P ≤ 0.001) in infertile men. At multivariable logistic regression analysis, infertile status (P < 0.001) and the presence of left varicocele (P < 0.001) were associated with TV < 15 ml. Testicular volume thresholds of 15 ml and 12 ml had a good predictive ability for detecting OAT and NOA status, respectively. In conclusion, infertile men have smaller testicular volume than fertile controls. TV positively correlated with total testosterone, sperm concentration, and progressive motility in infertile men, which was not the case in the age-matched fertile counterparts.

Substances of abuse (SoA), as well as smoking and alcohol consumption, are well known for their impact on male fertility status, erectile function, and ejaculation. We assessed SoA consumption habits in a cohort of men seeking medical attention for uro-andrological purposes. Data from 7447 men seeking medical attention for the first time for uro-andrological purposes were analyzed. A complete medical and sexual history was collected for each patient. Smoking, alcohol, and SoA consumption were investigated. Descriptive statistics was used to describe the whole cohort. The primary motivations for their evaluation were lower urinary tract symptoms (LUTS), erectile dysfunction (ED), and infertility in 1912 (25.7%), 2944 (39.5%), and 2591 (34.8%) men, respectively. Previous use of SoA was reported by 378 (5.1%) men, and 190 (2.6%) individuals were current users. Patients seeking medical attention for infertility were more frequently current SoA users (107; 4.1%) than men with ED (66; 2.2%) and LUTS (17; 0.9%) (both P < 0.001). Current users of SoA were younger than those with past or no SoA history (P < 0.001). Current SoA users were more frequently smokers (P < 0.001) and alcohol consumers (P < 0.001) than those with a previous history or those who had never tried SoA. In conclusion, approximately 3% of men seeking medical attention for uro-andrological purposes were current SoA consumers. Infertile men reported a higher use of SoA than those with ED or LUTS. Current SoA users were younger and more frequently concomitant smokers and alcohol consumers compared to those who did or had never used SoA.

Background The thermally-induced urine flow can generate cooling that may alter the treatment outcome during hyperthermic treatments of bladder cancer. This paper investigates the effects of natural convection inside the bladder and at skin surface during gold nanorods (GNR) - assisted photothermal therapy (PTT) of bladder cancer in mice. Methods 3D models of mouse bladder at orientations corresponding to the mouse positioned on its back, its side and its abdomen were examined. Numerical simulations were carried out for GNR volume fractions of 0.001, 0.005 and 0.01% and laser power of 0.2 and 0.3 W. Results The obtained results showed that cooling due to natural convection inside the bladder and above the skin depends on the mouse orientation. For a mouse positioned on its back, on its side or on its abdomen, the maximum temperature achieved inside the tumour at 0.001% GNR volume fraction and 0.2 W laser power was 55.2°C, 50.0°C and 52.2°C, respectively compared to 56.8°C when natural convection was not considered. The average thermal gradients when natural convection was considered were also lower, suggesting a more homogenous temperature distribution. Conclusions Natural convection inside the bladder can be beneficial but also detrimental to GNR-assisted PTT depending on the level of heating. At low levels of heating due to low GNR volume fraction and/or laser power, flow inside the bladder may dissipate heat from the targeted tissue; making the treatment ineffective. At high levels of heating due to high GNR volume fraction and/or laser power, cooling may prevent excessive thermal damage to surrounding tissues.

ObjectiveUp to 40% of infertile men remain without a recognized cause (i.e., idiopathic infertility). We aimed to identify, categorize, and report the supposed causes of male infertility in a cohort of white-European men presenting for primary couple’s infertility, by using a thorough and extensive baseline diagnostic work-up.Material and MethodsCross-sectional study of 1,174 primary infertile men who underwent a thorough diagnostic work-up including: detailed medical history, physical examination, hormonal assessment, genetic testing, semen analyses; semen and urine cultures; testis color Duplex US. Men without any identified causal factor were considered as idiopathic. Six different etiological categories were established, and their prevalence was estimated. Logistic regression models estimated the risk of missing causal identification.ResultsA possible causal factor was identified in 928 (81%) men. Hypogonadism was the most frequent identified cause (37%), followed by varicocele (27%). Genetic abnormalities were found in 5% of patients. A causal factor was more easily identifiable for the more severe infertility cases, and azoospermic men were those less likely to be defined as idiopathic (OR and 95% CIs: 0.09; 0.04-0.20). Relative proportion of identified causes remained constant during the 10-year study period (p>0.43).ConclusionsDue to a more comprehensive and extensive diagnostic work-up, at least one underlying cause of male infertility factor in 4 out of 5 infertile men can be identified. Men with a less severe phenotype remain a clinical challenge in terms of establishing a possible etiologic factor. Further studies are needed to assess which subset of infertile men deserves a more extensive work-up.

Aim: Since its discovery Prostate Specific Antigen (PSA), also referred to as kallikrein-3 (KLK3), has been used as standard circulating biomarker for prostate cancer (PCa). However, its specificity remains not adequate and its mechanism of action still elusive. Therefore, deciphering PSA role throughout PCa-pathobiology would be relevant in improving both cancer diagnosis and outcome prediction. We investigated the possible role played by PSA on/in the tumor microenvironment and over the first steps of cancer invasion. Methods: Fresh PCa-specimens and cell lines were used for ex-vivo/in-vitro invasion assays and assessment of prostate tissue-PSA (tPSA), type 1 collagen (COL1A1) and ß1-integrin expression. Tissue Cancer Genome Atlas (TCGA) and Decipher® datasets were considered to estimate tPSA clinical relevance. Results: A more precise, inverse, correspondence between tPSA and clinical/pathological parameters was found than for circulating PSA. KLK3 combined with Gleason grade and pathologic stage, better predicted cancer-related mortality. Consistently, we demonstrated that PSA inhibits prostate extracellular-matrix (ECM) invasion by PCa cells. As for the mechanism of action, we provided novel information that PSA is able to cleave COL1A1, a main component of the ECM. Finally, ß1-integrin, a crucial COL1A1 transducing-receptor involved in tumor adhesion/invasion, resulted to be downregulated in PCa specimens with higher levels of tPSA. Conclusions: By interfering with type 1 collagen and its downstream targets, PSA may hamper adhesion and path of the cancer cells through ECM and their migration ability, thus explaining the inverse correlation highlighted between prostate tPSA levels and clinically significant disease.

Shedding of ADAM10 substrates, like TNFa or CD30, can affect both anti-tumor immune response and antibody-drug-conjugate (ADC)-based immunotherapy. We have published two new ADAM10 inhibitors, LT4 and MN8 able to prevent such shedding in Hodgkin lymphoma (HL). Since tumor tissue architecture deeply influences the outcome of anti-cancer treatments, we set up a new threedimensional (3D) culture systems to verify whether ADAM10 inhibitors can contribute to, or enhance, the anti-lymphoma effects of the ADC brentuximab-vedotin (BtxVed). In order to recapitulate some aspects of lymphoma structure and architecture, we assembled two 3D culture models: mixed spheroids made of HL lymph node (LN) mesenchymal stromal cells (MSC) and Reed Sternberg/Hodgkin lymphoma cells (HL cells) or collagen scaffolds repopulated with LN-MSC and HL cells. In these 3D systems we found that: i) the ADAM10 inhibitors LT4 and MN8 reduce ATP content or glucose consumption, related to cell proliferation, increasing lactate dehydrogenase release as a cell damage hallmark; ii) these events are paralleled by mixed spheroids size reduction and inhibition of CD30 and TNFa shedding; iii) the effects observed can be reproduced in repopulated HL LN-derived matrix or collagen scaffolds; iv) ADAM10 inhibitors enhance the anti-lymphoma effect of the anti-CD30 ADC BtxVed both in conventional cultures and in repopulated scaffolds. Thus, we provide evidence for a direct and combined antilymphoma effect of ADAM10 inhibitors with BtxVed, leading to the improvement of ADC effects; this is documented in 3D models recapitulating features of the LN microenvironment, that can be proposed as a reliable tool for anti-lymphoma drug testing.

Summary: Lymph nodes (LNs) are secondary lymphoid tissues that play a critical role in filtering the lymph and promoting adaptive immune responses. Surgical resection of LNs, radiation therapy, or infections may damage lymphatic vasculature and compromise immune functions. Here, we describe the generation of functional synthetic lympho-organoids (LOs) using LN stromal progenitors and decellularized extracellular matrix-based scaffolds, two basic constituents of secondary lymphoid tissues. We show that upon transplantation at the site of resected LNs, LOs become integrated into the endogenous lymphatic vasculature and efficiently restore lymphatic drainage and perfusion. Upon immunization, LOs support the activation of antigen-specific immune responses, thus acquiring properties of native lymphoid tissues. These findings provide a proof-of-concept strategy for the development of functional lympho-organoids suitable for restoring lymphatic and immune cell functions. : In this article, Lenti and colleagues show the generation of functional lympho-organoids using basic constituents of the lymph node. Their findings indicate that transplantation of lympho-organoids may represent a therapeutic approach to restore lymphatic and immune cell functions in lymphedema and other diseases in which lymph nodes have been removed or are dysfunctional. Keywords: lymphoid tissue development, stromal cell biology, tissue engineering, preclinical mouse models, tissue regeneration, lymphatic system, lympho-organoids

AimTo assess the prevalence of isolated teratozoospermia (iTZS) in a cohort of infertile and fertile men; explore the relationship between iTZS, inflammatory parameters and sperm DNA fragmentation index (SDF) in the same cohort.Materials and methods1824 infertile men and 103 fertile controls. Semen analysis, the neutrophil-to-lymphocyte ratio (NLR) and serum hormones were investigated. DFI was tested in infertile men only. According to 2010 WHO semen analysis, patients were categorized in 3 sub-groups of isolated sperm defects: isolated oligozoospermia (iOZS), isolated asthenozoospermia (iAZS) and iTZS. Descriptive statistics and linear regression models tested the association between clinical variables and inflammatory markers.ResultsAmong infertile men, iAZS, iTZS, and iOZS were found in 13.9%, 11.9% and 4.1% participants, respectively. iTZS was found in 37 (35.9%) fertile men. Infertile men with iTZS had higher NLR values than those with iOZS, iAZS and men with normal semen parameters (all pConclusionsiTZS was found in 11.9% of infertile men but it was even more prevalent in fertile controls. Infertile men with iTZS had higher NLR than fertile controls and increased SDF values than infertile participant with iAZS, iOZS, or normal semen parameters. No differences in hormonal characteristics were found between infertile and fertile men with iTZS.

Given the increasing prevalence of cancer, it is vital to systematically collect data in order to monitor disease trends and quality of cancer care. For this purpose, clinical cancer registries have been developed in some countries. These registers are intended to be used as a basis for quality assurance and quality improvement, but they also constitute a rich resource of real world data for research. The aim of this mini-review was to describe the structure and the organization of the National Prostate Cancer Register (NPCR) with some examples on how data in NPCR have affected prostate cancer care in Sweden.

Cell-associated receptor for urokinase plasminogen activator (uPAR) is released as both full-length soluble uPAR (suPAR) and cleaved (c-suPAR) form that maintain ability to bind to integrins and other receptors, thus triggering and modulating cell signaling responses. Concerning HIV-1 infection, plasma levels of suPAR have been correlated with the severity of disease, levels of immune activation and ineffective immune recovery also in individuals receiving combination anti-retroviral therapy (cART). However, it is unknown whether and which suPAR forms might contribute to HIV-1 induced pathogenesis and to the related state of immune activation. In this regard, lymphoid organs represent an import site of chronic immune activation and virus persistence even in individuals receiving cART. Lymphoid organs of HIV-1(+) individuals showed an enhanced number of follicular dendritic cells, macrophages and endothelial cells expressing the cell-associated uPAR in comparison to those of uninfected individuals. In order to investigate the potential role of suPAR forms in HIV-1 infection of secondary lymphoid organs, tonsil histocultures were established from HIV-1 seronegative individuals and infected ex vivo with CCR5- and CXCR4-dependent HIV-1 strains. The levels of suPAR and c-suPAR were significantly increased in HIV-infected tonsil histocultures supernatants in comparison to autologous uninfected histocultures. Supernatants from infected and uninfected cultures before and after immunodepletion of suPAR forms were incubated with the chronically infected promonocytic U1 cell line characterized by a state of proviral latency in unstimulated conditions. In the contest of HIV-conditioned supernatants we established that c-suPAR, but not suPAR, inhibited chemotaxis and induced virus expression in U1 cells. In conclusion, lymphoid organs are an important site of production and release of both suPAR and c-suPAR, this latter form being endowed with the capacity of inhibiting chemotaxis and inducing HIV-1 expression.

HIV replication in mononuclear phagocytes is a multi-step process regulated by viral and cellular proteins with the peculiar feature of virion budding and accumulation in intra-cytoplasmic vesicles. Interaction of urokinase-type plasminogen activator (uPA) with its cell surface receptor (uPAR) has been shown to favor virion accumulation in such sub-cellular compartment in primary monocyte-derived macrophages and chronically infected promonocytic U1 cells differentiated into macrophage-like cells by stimulation with phorbol myristate acetate (PMA). By adopting this latter model system, we have here investigated which intracellular signaling pathways were triggered by uPA/uPAR interaction leading the redirection of virion accumulation in intra-cytoplasmic vesicles.uPA induced activation of RhoA, PKCδ and PKCε in PMA-differentiated U1 cells. In the same conditions, RhoA, PKCδ and PKCε modulated uPA-induced cell adhesion and polarization, whereas only RhoA and PKCε were also responsible for the redirection of virions in intracellular vesicles. Distribution of G and F actin revealed that uPA reorganized the cytoskeleton in both adherent and polarized cells. The role of G and F actin isoforms was unveiled by the use of cytochalasin D, a cell-permeable fungal toxin that prevents F actin polymerization. Receptor-independent cytoskeleton remodeling by Cytochalasin D resulted in cell adhesion, polarization and intracellular accumulation of HIV virions similar to the effects gained with uPA.These findings illustrate the potential contribution of the uPA/uPAR system in the generation and/or maintenance of intra-cytoplasmic vesicles that actively accumulate virions, thus sustaining the presence of HIV reservoirs of macrophage origin. In addition, our observations also provide evidences that pathways controlling cytoskeleton remodeling and activation of PKCε bear relevance for the design of new antiviral strategies aimed at interfering with the partitioning of virion budding between intra-cytoplasmic vesicles and plasma membrane in infected human macrophages.