Impact of Mycobacterium tuberculosis Infection on Human B Cell Compartment and Antibody Responses.

Tuberculosis (TB) remains one of the most important health challenges worldwide. Control of the TB epidemic has not yet been achieved because of the lack of an effective vaccine and rapid and sensitive diagnostic approaches, as well as the emergence of drug-resistant forms of M. tuberculosis. Cellular immunity has a pivotal role against M. tuberculosis infection, but the role of humoral immunity is still controversial. We analyzed the frequency, absolute counts, and phenotypic and functional subsets of B lymphocytes in the peripheral blood of patients with active TB and subjects with latent infection compared to healthy donors. Moreover, we analyzed serum levels of total Ig and their IgA, IgM, and IgG isotypes and the titers of preexisting antibodies against a pool of common viral pathogens. FlowCT and unsupervised clusterization analysis show that patients with active TB and LTBI subjects have modest non-significant reduction in the numbers of circulating B lymphocytes as compared to healthy donors. Moreover, LTBI subjects had high percentages of atypical B cell population and lower percentages of naive and switched memory B cells. These findings were supported by gene expression and GSEA analysis. Moreover, there were no differences between active TB patients, LTBI subjects and HD, either in serum levels of total Ig isotypes or in preexisting IgG antibody titers, to ten different antigens from eight common pathogenic viruses, clearly demonstrating that either active or latent M. tuberculosis infection preserves the antibody production capacity of long-lived plasma cells. Thus, our results agree with previous studies reporting unaltered B cell frequencies in the blood of active TB patients and LTBI individuals as compared to healthy controls.

Functional characterization of a novel 3D model of the epithelial-mesenchymal trophic unit.

BACKGROUND/AIM: Epithelial-mesenchymal communication plays a key role in tissue homeostasis and abnormal signaling contributes to chronic airways disease such as COPD. Most in vitro models are limited in complexity and poorly represent this epithelial-mesenchymal trophic unit. We postulated that cellular outgrowth from bronchial tissue would enable development of a mucosal structure that recapitulates better in vivo tissue architecture. MATERIALS AND METHODS: Bronchial tissue was embedded in Matrigel and outgrowth cultures monitored using time-lapse microscopy, electrical resistance, light and electron microscopy. Cultures were challenged repetitively with cigarette smoke extract (CSE). RESULTS: The outgrowths formed as a multicellular sheet with motile cilia becoming evident as the Matrigel was remodeled to provide an air interface; cultures were viable for more than one year. Immunofluorescence and electron microscopy (EM) identified an upper layer of mucociliary epithelium and a lower layer of highly organized extracellular matrix (ECM) interspersed with fibroblastic cells separated by a basement membrane. EM analysis of the mucosal construct after repetitive exposure to CSE revealed epithelial damage, loss of cilia, and ECM remodeling, as occurs in vivo. CONCLUSIONS: We have developed a robust bronchial mucosal model. The structural changes observed following CSE exposure suggest the model should have utility for drug discovery and preclinical testing, especially those targeting airway remodeling.

Alcoholic Liver Disease: A Mouse Model Reveals Protection by Lactobacillus fermentum.

OBJECTIVES: Alcoholism is one of the most devastating diseases with high incidence, but knowledge of its pathology and treatment is still plagued with gaps mostly because of the inherent limitations of research with patients. We developed an animal model for studying liver histopathology, Hsp (heat-shock protein)-chaperones involvement, and response to treatment. METHODS: The system was standardized using mice to which ethanol was orally administered alone or in combination with Lactobacillus fermentum following a precise schedule over time and applying, at predetermined intervals, a battery of techniques (histology, immunohistochemistry, western blotting, real-time PCR, immunoprecipitation, 3-nitrotyrosine labeling) to assess liver pathology (e.g., steatosis, fibrosis), and Hsp60 and iNOS (inducible form of nitric oxide synthase) gene expression and protein levels, and post-translational modifications. RESULTS: Typical ethanol-induced liver pathology occurred and the effect of the probiotic could be reliably monitored. Steatosis score, iNOS levels, and nitrated proteins (e.g., Hsp60) decreased after probiotic intake. CONCLUSIONS: We describe a mouse model useful for studying liver disease induced by chronic ethanol intake and for testing pertinent therapeutic agents, e.g., probiotics. We tested L. fermentum, which reduced considerably ethanol-induced tissue damage and deleterious post-translational modifications of the chaperone Hsp60. The model is available to test other agents and probiotics with therapeutic potential in alcoholic liver disease.

Medium-term culture of primary oral squamous cell carcinoma in a three- dimensional model: effects on cell survival following topical 5-fluororacile delivery by drug-loaded matrix tablets.

Since the activity of several conventional anticancer drugs is restricted by resistance mechanisms and dose-limiting side-effects, the design of formulations for local application on malignant lesions seems to be an efficient and promising drug delivery approach. In this study, the effect of locally applied 5-FU on cell death was evaluated both in a SCC4/HEK001 model and in a newly proposed 3D outgrowth model of oral squamous cell carcinoma (OSCC). Initially, the optimal drug dose was established by delivery of solutions containing different amounts of 5-FU. The solution containing 1% (w/v) of 5-FU resulted effective in inducing cell death with complete eradication of cell colonies. Buccal tablets were designed to deliver 5-FU locoregionally to the cancer lesions of the oral cavity. Tablets were prepared using a drug loaded matrix of acrylic/methacrylic acid copolymer containing 1% (w/w) of 5-FU and applied on 3D outgrowths. The drug release from tablets appeared to be sufficient to induce cell death as confirmed by transmission electron microscopy and enzymatic assay (TUNEL). After 120 h of treatment, when about 90% of the drug had been discharged from the tablets into the culture environment, 5-FU caused loss of cell-cell communications and apoptotic cell death. After 192 h, a complete disaggregation of the 3D oral outgrowths and the death of all the cells was observed. Buccal matrix tablets could be considered a promising new approach to the locoregional treatment of OSCC. Risks of systemic toxicity are avoided since very low drug doses are delivered.

Medium-term culture of normal human oral mucosa: a novel three-dimensional model to study the effectiveness of drugs administration.

Tissue-engineered oral mucosal equivalents have been developed for in vitro studies for a few years now. However, the usefulness of currently available models is still limited by many factors, mainly the lack of a physiological extracellular matrix (ECM) and the use of cell populations that do not reflect the properly differentiated cytotypes of the mucosa of the oral cavity. For this reason, we have developed a novel three-dimensional culture model reflecting the normal architecture of the human oral mucosa, with the main aim of creating a better in vitro model where to test cellular responses to drugs administration. This novel 3D cell culture model (3D outgrowth) was set up using an artificial extracellular matrix (Matrigel™ ), allowing the interactions required for proper differentiation of the various citotypes which form the mucosal layer. Biopsies of human oral mucosa, in fragments of about 0.5 mm3, were placed onto 6.5mm Transwells, covered with Matrigel™ and grown in a specific culture medium. A gradual formation of an architectural structure similar to that of the in vivo oral mucosa was observed. Transmission electron and confocal microscopy were employed to characterize the newly developed model: the cell components (keratinocytes and fibroblasts) differentiated properly within the outgrowth and reconstituted, in vitro, the physiological structure of the human oral mucosa, including a stratified non-keratinized squamous layer composed of four different layers, a proper basal membrane and a lamina propria where fibroblasts produce ECM. Moreover, keratinocytes expressed CK5, CK13, CK19 and E-cadherin, whereas fibroblasts expressed collagen type I and IV, laminin and fibronectin. 3D outgrowths could be considered a valid alternative to animal models, and provide useful information for researchers interested in studying the responses of the human oral mucosa to locally delivered drugs or other exogenous treatments.

Hsp60 is actively secreted by human tumor cells.

BACKGROUND: Hsp60, a Group I mitochondrial chaperonin, is classically considered an intracellular chaperone with residence in the mitochondria; nonetheless, in the last few years it has been found extracellularly as well as in the cell membrane. Important questions remain pertaining to extracellular Hsp60 such as how generalized is its occurrence outside cells, what are its extracellular functions and the translocation mechanisms that transport the chaperone outside of the cell. These questions are particularly relevant for cancer biology since it is believed that extracellular chaperones, like Hsp70, may play an active role in tumor growth and dissemination. METHODOLOGY/PRINCIPAL FINDINGS: Since cancer cells may undergo necrosis and apoptosis, it could be possible that extracellular Hsps are chiefly the result of cell destruction but not the product of an active, physiological process. In this work, we studied three tumor cells lines and found that they all release Hsp60 into the culture media by an active mechanism independently of cell death. Biochemical analyses of one of the cell lines revealed that Hsp60 secretion was significantly reduced, by inhibitors of exosomes and lipid rafts. CONCLUSIONS/SIGNIFICANCE: Our data suggest that Hsp60 release is the result of an active secretion mechanism and, since extracellular release of the chaperone was demonstrated in all tumor cell lines investigated, our observations most likely reflect a general physiological phenomenon, occurring in many tumors.

OPLA scaffold, collagen I, and horse serum induce an higher degree of myogenic differentiation of adult rat cardiac stem cells.

In the last few years, a major goal of cardiac research has been to drive stem cell differentiation to replace damaged myocardium. Several research groups have attempted to differentiate potential cardiac stem cells (CSCs) using bi- or three-dimensional systems supplemented with growth factors or molecules acting as differentiating substances. We hypothesize that these systems failed to induce a complete differentiation because they lacked an architectural space. In the present study, we isolated a pool of small proliferating and fibroblast-like cells from adult rat myocardium. The phenotype of these cells was assessed and the characterized cells were cultured in a collagen I/OPLA scaffold with horse serum to obtain fine myocardial differentiation. C-Kit(POS)/Sca-1(POS) CSCs fully differentiated in vitro when an environment more similar to the CSC niche was created. These experiments demonstrated an important model for the study of the biology of CSCs and the biochemical pathways that lead to myocardial differentiation. The results pave the way for a new surgical approach.

Prostasome-like vesicles stimulate acrosome reaction of pig spermatozoa.

BACKGROUND: The presence of small membranous particles characterizes the male genital fluids of different mammalian species. The influence of semen vesicles, denominated prostasomes, on sperm functional properties has been well documented in humans, but their biological activity is scarcely known in other species. The present work investigated prostasome-like vesicles in pig semen for their ability to interact with spermatozoa and to affect acrosome reaction. METHODS: Prostasome-like vesicles have been isolated from pig seminal plasma by high-speed centrifugation and Sephadex G-200 gel chromatography. Morphology of purified vesicles has been checked by scanning electron microscopy while their protein pattern has been investigated by SDS-PAGE. Then prostasome- like vesicles have been incubated with pig spermatozoa and their ability to interact with sperm has been tested by the aminopeptidase assay. In addition, the efficiency of vesicles to influence the acrosome reaction has been investigated by assessing the sperm acrosomal status by the PI/FITC-PNA (propidium iodide/fluorescein isothiocyanate-labeled peanut agglutinin) stainings. RESULTS: Purified vesicles revealed a complex protein pattern with the occurrence of bands in the high, medium and low molecular weight range. However, the two major bands were observed at approximately 90 kDa and approximately 60 kDa. A vesicle-mediated transfer of aminopeptidase to sperm cells has been also detected. Furthermore, a significant increase of acrosome reaction extent has been revealed in spermatozoa incubated with prostasome-like vesicles in comparison to control sperm. CONCLUSION: This is the first report demonstrating that pig prostasome-like vesicles are able, in vitro, to interact with spermatozoa and to stimulate the acrosome reaction. These findings lead to hypothesize a transfer of molecules from vesicles to sperm membrane, thus sensitizing male gametes to undergo the acrosome reaction.

The synovial joints of the human foot.

The human foot is considered an organ with an assortment of tissues with different morphological characteristics and well defined limits, but effectively has a simple functionality when static that becomes extremely complex when in movement. Its complex structure, comprised of an elastic and resistant skin covering a bone framework, joints, muscles, tendons, veins and nerves, can be compared to an efficient mechanical assembly. After a long and extraordinary evolutive journey, the human foot has undergone numerous changes to perfect its function; it has lost most of its grabbing function whilst gaining new characteristics that have ultimately allowed the modern man to stand upright. The complex articular structure of the human foot consists of thirty four synovial joints, of which eighteen have curved surfaces and sixteen plane surfaces. Following the criteria set by the systematic, radiological and clinical anatomy, the Authors contribute further to the current knowledge on the ankle, tarsal (anatomic subtalar, transverse tarsal, cuneonavicular, intercuneiform and cuneocuboid), tarsometatarsal, intermetatarsal, metatarsophalangeal and interphalangeal joints and dorsal, plantar and interosseous ligaments of the human foot. The articular lines of the transverse tarsal (Chopart) and tarsometatarsal (Lisfranc) joints are particularly interesting and not only from a surgical point of view; through a straightforward identification of few reference points, it is possible to find the medial and lateral extremities of the Chopart's and Lisfranc's lines, the former pinpoints the boundary between the hindfoot and midfoot and the latter between the midfoot and forefoot.

Three-dimensional geometrical models of the liver.

In this work we used a virtual approach to study the human liver by three-dimensional geometrical models. We built the models through computer aided geometric modelling techniques starting from pictures taken during both real dissections and diagnostic medical imaging. The results show in a complete modular synthesis and with a schematic iconology the structural organization of this organ in a logic sequence of layers and topographic and spatial relationship among its components. This approach represents an amazing support to clinical anatomy for teaching and research.

Senescence-associated HSP60 expression in normal human skin fibroblasts.

Normal mammalian fibroblasts cultured in vitro undergo a limited number of divisions before entering a senescent phase in which they can be maintained for long periods but cannot be induced to divide. Senescent cells become unresponsive to growth-promoting signals and exhibit senescent cell morphology with flattened and enlarged cell shape. Several chaperones have a direct effect on cellular senescence. HSP60 has been largely studied in our laboratories and it has been associated with uncontrolled cell proliferation in tumor cells. Since senescence is firmly regulated during cell cycle progression, we wanted to investigate HSP60 protein level during cellular senescence. Our data show that HSP60 increases during the initial stage of senescence and that it is localized in cellular compartments, resembling mitochondria. An increase in HSP60 protein amount is associated with a cell cycle slow-down and it may have a role in cell cycle progression.

Pericardium of the frog, Rana esculenta, is morphologically designed as a lymphatic space.

The importance of the pericardium and the pericardial fluid (PF) in the control of cardiac function has emerged over the past few years. Despite the acknowledgment that amphibians are exposed to both dehydration and excessive water accumulation, nothing is known about their pericardial structure and the morphological basis of the PF formation. We have studied the parietal pericardium (PP) morphology in Rana esculenta by electron microscopy. SEM images of the inner surface, which lines the pericardial cavity, revealed the presence of large vesicles and many small circular openings. TEM observations showed that the PP is made up of an inner mesothelial lining, often constituted by two layers of very flat cells lying on a basal membrane and of regularly oriented collagen bundles. The PP outer surface is lined by a layer of flat cells, without a basal membrane. The mesothelial cells had overlapping boundaries with complex intercellular connections and a rich pool of caveolae opened in the direction of both the pericardial cavity and intercellular spaces. These cells indicate an intense intracellular and/or intercellular transfer of fluids and substances. The intraperitoneal injection of the idromineral hormone, Val(5)-ANG II, induced PP modifications, particularly evident at the level of the structures involved in the transmesothelial traffic. These lymphatic-like traits suggest that the frog PP represents a large lymphatic sac, subject to paracrine-endocrine remodeling, which can actively adjust the PF, influencing the composition and volume of the myocardial interstitial fluid.

Three-dimensional geometrical models of the inguinal region. Towards a new stereology.

In this work we studied the inguinal-abdominal region and the inguinal canal using three-dimensional geometrical models. We built the models through computer aided geometric modeling techniques on the basis of observations during real dissections, operations and diagnostic medical imaging. The obtained models show in a complete modular synthesis and with a schematic iconology the structural organization of the anatomical districts in a logic sequence of layers and topographic and spatial relationships among its components. The models represent an amazing support to anatomy and clinical anatomy for teaching and research purposes on organogenesis, surgery and diagnosis.