Showing papers by "Andrea Cossarizza published in 2017"

Guidelines for the use of flow cytometry and cell sorting in immunological studies

Abstract: The marriage between immunology and cytometry is one of the most stable and productive in the recent history of science. A rapid search in PubMed shows that, as of July 2017, using “flow cytometry immunology” as a search term yields more than 68 000 articles, the first of which, interestingly, is not about lymphocytes. It might be stated that, after a short engagement, the exchange of the wedding rings between immunology and cytometry officially occurred when the idea to link fluorochromes to monoclonal antibodies came about. After this, recognizing different types of cells became relatively easy and feasible not only by using a simple fluorescence microscope, but also by a complex and sometimes esoteric instrument, the flow cytometer that is able to count hundreds of cells in a single second, and can provide repetitive results in a tireless manner. Given this, the possibility to analyse immune phenotypes in a variety of clinical conditions has changed the use of the flow cytometer, which was incidentally invented in the late 1960s to measure cellular DNA by using intercalating dyes, such as ethidium bromide. The epidemics of HIV/AIDS in the 1980s then gave a dramatic impulse to the technology of counting specific cells, since it became clear that the quantification of the number of peripheral blood CD4+ T cells was crucial to follow the course of the infection, and eventually for monitoring the therapy. As a consequence, the development of flow cytometers that had to be easy-to-use in all clinical laboratories helped to widely disseminate this technology. Nowadays, it is rare to find an immunological paper or read a conference abstract in which the authors did not use flow cytometry as the main tool to dissect the immune system and identify its fine and complex functions. Of note, recent developments have created the sophisticated technology of mass cytometry, which is able to simultaneously identify dozens of molecules at the single cell level and allows us to better understand the complexity and beauty of the immune system.

Basic science and pathogenesis of ageing with HIV: potential mechanisms and biomarkers.

Abstract: The increased prevalence of age-related comorbidities and mortality is worrisome in ageing HIV-infected patients. Here, we aim to analyse the different ageing mechanisms with regard to HIV infection. Ageing results from the time-dependent accumulation of random cellular damage. Epigenetic modifications and mitochondrial DNA haplogroups modulate ageing. In antiretroviral treatment-controlled patients, epigenetic clock appears to be advanced, and some haplogroups are associated with HIV infection severity. Telomere shortening is enhanced in HIV-infected patients because of HIV and some nucleoside analogue reverse transcriptase inhibitors. Mitochondria-related oxidative stress and mitochondrial DNA mutations are increased during ageing and also by some nucleoside analogue reverse transcriptase inhibitors. Overall, increased inflammation or 'inflammageing' is a major driver of ageing and could result from cell senescence with secreted proinflammatory mediators, altered gut microbiota, and coinfections. In HIV-infected patients, the level of inflammation and innate immunity activation is enhanced and related to most comorbidities and to mortality. This status could result, in addition to age, from the virus itself or viral protein released from reservoirs, from HIV-enhanced gut permeability and dysbiosis, from antiretroviral treatment, from frequent cytomegalovirus and hepatitis C virus coinfections, and also from personal and environmental factors, as central fat accumulation or smoking. Adaptive immune activation and immunosenescence are associated with comorbidities and mortality in the general population but are less predictive in HIV-infected patients. Biomarkers to evaluate ageing in HIV-infected patients are required. Numerous systemic or cellular inflammatory, immune activation, oxidative stress, or senescence markers can be tested in serum or peripheral blood mononuclear cells. The novel European Study to Establish Biomarkers of Human Ageing MARK-AGE algorithm, evaluating the biological age, is currently assessed in HIV-infected patients and reveals an advanced biological age. Some enhanced inflammatory or innate immune activation markers are interesting but still not validated for the patient's follow-up. To be able to assess patients' biological age is an important objective to improve their healthspan.

Activation of Fas/FasL pathway and the role of c-FLIP in primary culture of human cholangiocarcinoma cells.

Abstract: Intrahepatic cholangiocarcinoma (iCCA) represents a heterogeneous group of malignancies emerging from the biliary tree, often in the context of chronic bile ducts inflammation. The immunological features of iCCA cells and their capability to control the lymphocytes response have not yet been investigated. The aims of the present study were to evaluate the interaction between iCCA cells and human peripheral blood mononuclear cells (PBMCs) and the role of Fas/FasL in modulating T-cells and NK-cells response after direct co-culture. iCCA cells express high levels of Fas and FasL that increase after co-culture with PBMCs inducing apoptosis in CD4+, CD8+ T-cells and in CD56+ NK-cells. In vitro, c-FLIP is expressed in iCCA cells and the co-culture with PBMCs induces an increase of c-FLIP in both iCCA cells and biliary tree stem cells. This c-FLIP increase does not trigger the caspase cascade, thus hindering apoptotis of iCCA cells which, instead, underwent proliferation. The increased expression of Fas, FasL and c-FLIP is confirmed in situ, in human CCA and in primary sclerosing cholangitis. In conclusion our data indicated that iCCA cells have immune-modulatory properties by which they induce apoptosis of T and NK cells, via Fas/FasL pathway, and escape inflammatory response by up-regulating c-FLIP system.

Cellular Senescence, Immunosenescence and HIV.

Abstract: Aging is a complex biological process that leads to several physiological changes. Among these changes, the most striking are those involving the innate and adaptive parts of the immune system. Furthermore, these changes are associated with a low-grade inflammation called inflamm-aging, which is the result of several lifelong antigenic stimulations, including chronic viral infections such as cytomegalovirus. Immunosenescence, concomitantly with inflamm-aging, is considered as the leading cause of age-related diseases including cardiovascular, neurodegenerative and metabolic diseases, and cancer. HIV infection, once considered a unique deadly infectious disease, has now become a chronic disease with efficacious highly active antiretroviral therapy. This signifies that the treatment transforms HIV infection from a chronic infection to a chronic inflammatory disease. Most people with HIV infection become aged, and older adults have been contracting HIV infection. Thus, there is a great interest to study HIV infection in relation to immunosenescence and inflamm-aging to determine whether immunosenescence contributes to HIV infection, or if HIV is causing immunosenescence and, as such, represents a premature immunosenescence and accelerated aging. Although there are many similarities in the immune and inflammatory changes and the occurrence of age-related chronic diseases between normal aging and HIV infection, the interaction between these processes is not well understood, and consequently the concept that HIV infection is an accelerated aging model is questioned. Future studies are needed to effectively answer this question for the better care of HIV-infected elderly patients.

Mortality in Patients With Septic Shock by Multidrug Resistant Bacteria.

Abstract: Patients with septic shock by multidrug resistant (MDR) microorganism maybe considered a specific population of critical patients at very high risk of death in whom the effects of standard sepsis treatment has never been assessed. The objective of this retrospective analysis was to evaluate the risk factors for 30-day mortality and the impact of sepsis management in patients with septic shock caused by MDR bacteria. Patients with septic shock by MDR bacteria admitted to the mixed intensive care unit (ICU) of Modena University Hospital during a 6-year period were studied. The clinical and microbiological characteristics and sepsis treatments provided were analyzed and compared between survivors (S) and nonsurvivors (NS) at 30 days after septic shock appearance. Ninety-four patients were studied. All therapeutic interventions applied to patients during their ICU stay did not show statistical significance between S and NS groups, except for administration of immunoglobulin M (IgM) preparation which were provided more frequently in S group ( P

HIV-DNA content in different CD4+ T-cell subsets correlates with CD4+ cell : CD8+ cell ratio or length of efficient treatment.

Abstract: Objectives HIV establishes a latent infection at different degrees within naive (TN) or central (TCM) and effector memory (TEM) CD4 T cell. Studying patients in whom HIV production was suppressed by combined antiretroviral therapy, our main aim was to find which factors are related or can influence intracellular viral reservoir in different CD4 T-cell subsets. Methods We enrolled 32 HIV patients successfully treated for more than 2 years, with a CD4 T-cell count more than 500 cells/μl and plasma viremia undetectable from at least 1 year. Proviral HIV-DNA, the amount of cells expressing signal-joint T-cell receptor rearrangement excision circles and telomere length were quantified by droplet digital PCR in highly purified, sorted CD4 T-cell subsets; plasma IL-7 and IL-15 were measured by ELISA. Results HIV-DNA was significantly lower in TN cells compared with TCM or to TEM. Conversely, TN cells contained more signal-joint T-cell receptor rearrangement excision circles compared with TCM or to TEM; no appreciable changes were observed in telomere length. HIV-DNA content was significantly higher in TN and TCM cells, but not in TEM, from patients with shorter time of treatment, or in those with lower CD4 : CD8 ratio. Conclusion Length of treatment or recovery of CD4 : CD8 ratio significantly influences viral reservoir in both TN and TCM. Measuring HIV-DNA in purified lymphocyte populations allows a better monitoring of HIV reservoir and could be useful for designing future eradication strategies.

Geriatric-HIV medicine: A science in its infancy.

Abstract: In the last decades a dramatic increase in human lifespan has taken place. This is due to relevant ameliorations not only of living and behavioral conditions, including the prevention of diseases a...

Rare Cells: Focus on Detection and Clinical Relevance

Abstract: The study of rare-cell populations is assuming a growing importance to the advancement of medical diagnostics and therapeutics. In several clinical studies, counting rare cells can provide valuable information on the status of the patient; examples are the search for circulating tumor cells in peripheral blood, tumor stem cells, endothelial cells, hematopoietic progenitor cells and their subpopulations, antigen-specific T-cells, invariant natural killer T cells, and fetal cells in maternal circulation. The study of rare-cell populations is useful not only to understand disease mechanisms, but also to find novel targets. With multiparameter capabilities and a very high analysis rate, flow cytometry is at present the most potent technology to address rare-cell analysis. This chapter will describe the main issues of the pre-analytical phase, including the amount of blood to use, the use of pre-enriched populations, the number of markers to use, and the number of cells to acquire. Moreover, we will discuss the importance of excluding doublets and the use of a DUMP channel, along with the importance of using optimal methodologies in all phases, including collection of biological samples, adequate controls, and expert use of software and hardware.