A Janus role for MerTK in the outcome of septic shock

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Uncompensated polychromatic analysis of mitochondrial membrane potential using JC-1 and multilaser excitation

The lipophilic cation JC-1 (5,5',6,6'-tetrachloro-1,1',3,3'-etraethylbenzimidazolyl carbocyanine iodide) has been used for more than 20 years as a specific dye for measuring mitochondrial membrane potential (δψm). In this unit, we revise our original protocol (that made use of a single 488 nm laser for the detection of monomers and aggregates, and where compensation was an important step) to use dual-laser excitation. Moreover, thanks to recently developed multilaser instruments and novel probes for surface and intracellular markers, JC-1 can be utilized by polychromatic flow cytometry to simultaneously detect, without any compensation between fluorescences, δψm along with other biological parameters, such as apoptosis and the production of reactive oxygen species

Injury-induced immunosuppression: we are finally on the right track?

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Emerging role of Lon protease as a master regulator of mitochondrial functions

Lon protease is a nuclear-encoded, mitochondrial ATP-dependent protease highly conserved throughout the evolution, crucial for the maintenance of mitochondrial homeostasis. Lon acts as a chaperone of misfolded proteins, and is necessary for maintaining mitochondrial DNA. The impairment of these functions has a deep impact on mitochondrial functionality and morphology. An altered expression of Lon leads to a profound reprogramming of cell metabolism, with a switch from respiration to glycolysis, which is often observed in cancer cells. Mutations of Lon, which likely impair its chaperone properties, are at the basis of a genetic inherited disease named of the cerebral, ocular, dental, auricular, skeletal (CODAS) syndrome. This article is part of a Special Issue entitled 'EBEC 2016: 19th European Bioenergetics Conference, Riva del Garda, Italy, July 2-6, 2016', edited by Prof. Paolo Bernardi

Reliable and Accurate CD4+ T Cell Count and Percent by the Portable Flow Cytometer CyFlow MiniPOC and \u201cCD4 Easy Count Kit-Dry\u201d, as Revealed by the Comparison with the Gold Standard Dual Platform Technology

An accurate and affordable CD4+ T cells count is an essential tool in the fight against HIV/AIDS. Flow cytometry (FCM) is the "gold standard" for counting such cells, but this technique is expensive and requires sophisticated equipment, temperature-sensitive monoclonal antibodies (mAbs) and trained personnel. The lack of access to technical support and quality assurance programs thus limits the use of FCM in resource-constrained countries. We have tested the accuracy, the precision and the carry-over contamination of Partec CyFlow MiniPOC, a portable and economically affordable flow cytometer designed for CD4+ count and percentage, used along with the "CD4% Count Kit-Dry"

Anti-TNF-α drugs differently affect the TNFa-sTNFR system and monocyte subsets in patients with psoriasis

TNF-a has a central role in the development and maintenance of psoriatic plaques, and its serum levels correlate with disease activity. Anti-TNF-a drugs are, however, ineffective in a relevant percentage of patients for reasons that are currently unknown. To understand whether the response to anti-TNF-a drugs is influenced by the production of anti-drug antibodies or by the modulation of the TNFa-TNFa receptor system, and to identify changes in monocyte phenotype and activity, we analysed 119 psoriatic patients who either responded or did not respond to different anti-TNF-a therapies (adalimumab, etanercept or infliximab), and measured plasma levels of TNF-a, TNF-a soluble receptors, drug and anti-drug antibodies. Moreover, we analyzed the production of TNF-a and TNF-α soluble receptors by peripheral blood mononuclear cells (PBMCs), and characterized different monocyte populations. We found that: i) the drug levels varied between responders and non-responders; ii) anti-infliximab antibodies were present in 15% of infliximab-treated patients, while anti-etanercept or anti-adalimumab antibodies were never detected; iii) plasma TNF-a levels were higher in patients treated with etanercept compared to patients treated with adalimumab or infliximab; iv) PBMCs from patients responding to adalimumab and etanercept produced more TNF-a and sTNFRII in vitro than patients responding to infliximab; v) PBMCs from patients not responding to infliximab produce higher levels of TNF-a and sTNFRII than patients responding to infliximab; vi) anti- TNF-a drugs significantly altered monocyte subsets. A complex remodelling of the TNFa-TNFa receptor system thus takes place in patients treated with anti-TNF-α drugs, that involves either the production of anti-drug antibodies or the modulation of monocyte phenotype or inflammatory activity

Th1 and Th17 pro-inflammatory profile characterizes iNKT cells in virologically suppressed HIV+ patients with low CD4/CD8 ratio

INTRODUCTION:: Scanty data exist on the phenotype and functionality of invariant natural killer T (iNKT) cells in HIV+ patients (pts). METHODS:: By flow cytometry, we studied iNKT cells from 54 HIV+ pts who started combined antiretroviral therapy (cART) and had undetectable viral load for >1 year. Twenty-five maintained a CD4/CD8 ratio <0.4, while 29 reached a ratio >1.1; 32 age- and sex-matched subjects were healthy controls (CTR). RESULTS:: Pts with low ratio had lower percentage of CD4+ iNKT cells compared to pts with high ratio, and higher CD8+ iNKT cell percentage; double negative (DN) iNKT cells were lower in HIV+ pts compared to CTR. Pts with low ratio had higher percentage of CD4+ and DN iNKT cells expressing CD38 and HLA-DR compared to pts with high ratio. CD4+ iNKT cells expressing PD-1 were higher in pts with CD4/CD8 ratio <0.4, while DN iNKT cells expressing PD-1 were lower compared to pts with ratio >1.1. Pts with low ratio had higher CD4+ iNKT cells producing IL-17, CD8+ iNKT cells producing IFN-γ, TNF-α or IFN-γ plus TNF-α, and DN iNKT cells producing IL-17 or IL-17 plus IFN-γ compared to CTR. Activated CD4+ (or CD8+) T cells correlated with activated CD4+ (or CD8+) iNKT cells, as well as the percentages of CD4+ (or CD8+) T cells expressing PD-1 was correlated to that of CD4+ (or CD8+) iNKT cells expressing PD-1. CONCLUSIONS:: Low CD4/CD8 ratio despite effective cART is associated with altered iNKT cell subsets, enhanced activation and prominent Th1/Th17 pro-inflammatory profile

Chemical genetics analysis of an aniline mustard anticancer agent reveals complex I of the electron transport chain as a target

Supplementary information is available at the Journal of Biological Chemistry website.The antitumor agent 11β (CAS 865070-37-7), consisting of a DNA-damaging aniline mustard linked to an androgen receptor (AR) ligand, is known to form covalent DNA adducts and to induce apoptosis potently in AR-positive prostate cancer cells in vitro; it also strongly prevents growth of LNCaP xenografts in mice. The present study describes the unexpectedly strong activity of 11β against the AR-negative HeLa cells, both in cell culture and tumor xenografts, and uncovers a new mechanism of action that likely explains this activity. Cellular fractionation experiments indicated that mitochondria are the major intracellular sink for 11β; flow cytometry studies showed that 11β exposure rapidly induced oxidative stress, mitochondria being an important source of reactive oxygen species (ROS). Additionally, 11β inhibited oxygen consumption both in intact HeLa cells and in isolated mitochondria. Specifically, 11β blocked uncoupled oxygen consumption when mitochondria were incubated with complex I substrates, but it had no effect on oxygen consumption driven by substrates acting downstream of complex I in the mitochondrial electron transport chain. Moreover, 11β enhanced ROS generation in isolated mitochondria, suggesting that complex I inhibition is responsible for ROS production. At the cellular level, the presence of antioxidants (N-acetylcysteine or vitamin E) significantly reduced the toxicity of 11β, implicating ROS production as an important contributor to cytotoxicity. Collectively, our findings establish complex I inhibition and ROS generation as a new mechanism of action for 11β, which supplements conventional DNA adduct formation to promote cancer cell death.National Institutes of Health (U.S.) (Grant R01 CA077743)United States. Dept. of Defense (Prostate Cancer Research Program Award DAMD17-98-1-8520

Geriatric-HIV medicine: A science in its infancy

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