Separation of human lymphocytes from citrated blood by density gradient (NycoPrep) centrifugation: monocyte depletion depending upon activation of membrane potassium channels

Enhancing CAR-T Cell Therapy with Functional Nucleic Acids

Chimeric antigen receptor (CAR) T cell therapy is a relatively new form of immunotherapy that has had success in treating patients with hematologic malignancies, leading to three recent United States Food and Drug Administration approvals. However, several challenges hinder the widespread use of CAR-T therapy. Here, we review the application of functional nucleic acids such as aptamers and ribozymes as novel tools to improve a variety of steps in CAR-T cell therapy development. We critically examine key studies that highlight the benefits of functional nucleic acids at different stages of cell-based therapy and discuss the feasibility of their practical clinical application. Finally, we offer insights into potential opportunities where chemists can significantly contribute to the innovative incorporation of functional nucleic acids to overcome challenges associated with this cutting-edge immunotherapy.

Guidelines for the use of flow cytometry and cell sorting in immunological studies (second edition)

These guidelines are a consensus work of a considerable number of members of the immunology and flow cytometry community. They provide the theory and key practical aspects of flow cytometry enabling immunologists to avoid the common errors that often undermine immunological data. Notably, there are comprehensive sections of all major immune cell types with helpful Tables detailing phenotypes in murine and human cells. The latest flow cytometry techniques and applications are also described, featuring examples of the data that can be generated and, importantly, how the data can be analysed. Furthermore, there are sections detailing tips, tricks and pitfalls to avoid, all written and peer-reviewed by leading experts in the field, making this an essential research companion.

Cellular immune response in MDR-TB patients to different protein expression of MDR and susceptible Mycobacterium tuberculosis: Rv0147, a novel MDR-TB biomarker

Tuberculosis (TB) is a crucial public health problem with prevalence of multidrug resistant (MDR) rising. An accurate TB biomarker is urgently needed to monitor the response to treatment in patients with MDR tuberculosis. To analyze interaction between selected MDR-TB purified protein and immune cells, dendritic cells from MDR-TB patients and healthy subjects were stimulated by 55KDa protein fractions (Rv0147). The purified proteins identified by proteomic techniques (two-dimensional gel electrophoresis, mass spectrometry) and peptide sequences are known to bind a MHC class I alleles which are extracted from the Immune Epitope Database and Analysis Resource database ( www.iedb.org ). T cells were isolated from PBMC by negative selection and cells were cultured in RPMI-1640 at 37 °C and 5% CO₂. Cell culture was assayed for cytokine IL-10 and INF-γ by ELISA. We found that INF-γ production was significantly (335 ± 35.5 pg/ml, P ˂ 0.05) upregulated after protein candidate (Rv0147) stimulation by dendritic cells from MDR-TB patients, whereas IL-10 production was greatly reduced compared with production in healthy subjects (212 ± 9.94 pg/ml, P ˂ 0.05). In fact, the purified protein, Rv0147, stimulated dendritic cells from MDR-TB patients, failed to produce IL-10 and directly stimulates INF-γ production by T cells. These results suggest that the purified protein, Rv0147, may stimulate Th1 type protective cytokine response in MDR-TB patients but not in normal subjects. The production of INF-γ but not IL-10 in the presence of purified protein, Rv0147, may be shifted to Th1 responses in MDR-TB patients and supports its potential as protein vaccine candidates against TB.

Targeted CYP2E1 quantification and its correlation to currently acceptable clinical biochemical indices

BACKGROUND

The Cytochrome P450 enzymes are commonly known for their major role in metabolism. Besides its metabolic role, CYP2E1 gene expression has been associated with the onset of diabetic nephropathy. CYP2E1 protein elevation has also been reported to be responsible for the production of reactive oxygen species. The aims of this study were (i) to optimize and validate a targeted proteomic approach for quantitating CYP2E1 and validating it as a suitable clinical test, (ii) to investigate the concurrency between ESI-LCMS-MS quantitated circulating CYP2E1 and gold standard indices in the context of outpatient point-of-care clinical settings involving various groups of diabetic patients and (iii) to investigate the concurrency profile of circulating CYP2E1 protein, CYP2E1 gene expression and reactive oxygen species (ROS). This is a cross sectional study involving three groups of subjects (n = 166): control, pre-diabetes, and diabetes. We optimized a targeted proteomic approach for absolute quantification of CYP2E1. "YPEIEEK" and "GTVVVPTLYDNQEFPDPEK" were the representative peptides of CYP2E1 for our analytical method. Deuterated forms of "YPEIEEK" and "GTVVVPTLYDNQEFPDPEK" were used as internal standards. Lymphocytes were isolated from whole blood, microsomes were prepared, followed by in-solution digestion for production of tryptic peptides. Amounts of "YPEIEEK" and "GTVVVPTLYDNQEFPDPEK" from patients' samples were calculated from a calibration curve.

RESULTS

"YPEIEEK" is a unique and reliable representative peptide for CYP2E1 quantification. "GTVVVPTLYDNQEFPDPEK" showed poor reproducibility and sensitivity. Incremental amounts of CYP2E1 protein in the peripheral circulation clearly showed concurrency with CYP2E1 gene expression and ROS levels in our study population. Elevations of CYP2E1 were observed even when gold standard clinical indicator for glycemic control (HbA1c) was within normal reference limits. Quantitated amounts of CYP2E1 protein in the pre-diabetes and diabetes groups showed significant difference relative to control group (p < 0.001). No significant differences were observed between the medians of pre-diabetes and diabetes groups (p = 0.870).

CONCLUSIONS

CYP2E1 protein in peripheral blood can be reliably quantitated by the validated targeted proteomic approach method. Quantifiable amounts of CYP2E1 preceded abnormal HbA1C levels which indicates quantitation of CYP2E1 could be useful as an additional tool for early indication of diabetic risks and it complications.

Smokeless tobacco consumption impedes metabolic, cellular, apoptotic and systemic stress pattern: A study on Government employees in Kolkata, India

Smokeless tobacco (SLT) remains a threat amongst a large population across the globe and particularly in India. The oral use of tobacco has been implicated to cause physiological stress leading to extreme toxicological challenge. The study included 47 SLT-users and 44 non-users providing a spectrum of pathophysiological, clinico-biochemical, antioxidant parameters, cell cycle progression study of PBMC and morphological changes of red blood cells (RBC). The expressions of p53, p21, Bax, Bcl-2, IL-6, TNF- α, Cox-2, iNOS were analyzed from thirteen representative SLT-users and twelve non-users. Difference in CRP, random glucose, serum cholesterol, TG, HLDL-C, LDL-C, VLDL-C, neutrophil count, monocyte count, ESR, SOD (PBMC) and TBARS (RBC membrane) were found to be statistically significant (p < 0.05) between the studied groups. The current study confers crucial insight into SLT mediated effects on systemic toxicity and stress. This has challenged the metabolic condition leading to a rise in the inflammatory status, increased apoptosis and RBC membrane damage. The above findings were substantiated with metabolic, clinical and biochemical parameters. This is possibly the first ever in-depth report and remains an invaluable document on the fatal effects of SLT.

Noninvasive management of the diabetic foot with critical limb ischemia: current options and future perspectives

Foot ulcers are a major complication in patients with diabetes mellitus and involve dramatic restrictions to quality of life and also lead to enormous socio-economical loss due to the high amputation rate. The poor and slow wound healing is often aggravated by the frequent comorbidity of foot ulcers with peripheral arterial disease, making the treatment of this condition even more complicated. While the local treatment of foot ulcers is mainly based on mechanical relief and prevention or treatment of infection, improving perfusion of the impaired tissue remains the major challenge in peripheral arterial disease. While focal arterial stenosis is the domain of interventional angioplasty or vascular surgery, patients with critical limb ischemia and lacking options for revascularization have a much worse prognosis, because current treatment options avoiding amputation are scarce. However, based on recent research efforts, there is rising hope for promising and more-effective therapeutic approaches for these patients. Here, we discuss the current improvements of established therapies aimed at an improvement of limb perfusion, as well as the development of novel cutting-edge therapies based on stem-cell technology. The experiences of a 'high-volume center' for treatment of diabetic foot syndrome with a current major amputation rate of 4% are discussed.

Isolation of Rat Lung Mast Cells for Purposes of One-Week Cultivation Using Novel Percoll Variant Percoll PLUS

Prolonged cultivation of separated rat lung mast cells (LMC) in vitro is necessary to better investigate a possible role of LMC in different stages of tissue remodeling induced by hypoxia. Rat lung mast cells (LMC) were separated using a protocol including an improved proteolytic extraction and two subsequent density gradient separations on Ficoll-Paque PLUS and a new generation of Percoll, i.e. Percoll PLUS. Instead of usual isotonic stock Percoll solution, an alternative “asymptotically isotonic” stock solution was more successful in our density separation of LMC on Percoll PLUS. Separated cells were cultivated for six days in media including stem cell factor, interleukins IL-3 and IL-6, and one of two alternative mixtures of antibiotics. These cultivations were performed without any contamination and with only rare changes in cell size and morphology. Model co-cultivation of two allogenic fractions of LMC often caused considerable rapid changes in cell morphology and size. In contrast to these observations no or rare morphological changes were found after cultivation under hypoxic conditions. In conclusions, we modified separation on Percoll PLUS to be widely used, altered LMC separation with respect to purposes of long-lasting cultivation and observed some model morphological changes of LMC.

Treatment of peripheral arterial disease using stem and progenitor cell therapy

Peripheral arterial disease (PAD) is a highly prevalent atherosclerotic syndrome associated with significant morbidity and mortality. PAD is most commonly caused by atherosclerosis obliterans (ASO) and thromboangiitis obliterans (TAO), and can lead to claudication and critical limb ischemia (CLI), often resulting in a need for major amputation and subsequent death. Standard treatment for such severe cases of PAD is surgical or endovascular revascularization. However, up to 30% of patients are not candidates for such interventions, due to high operative risk or unfavorable vascular involvement. Therefore, new strategies are needed to offer these patients a viable therapeutic option. Bone-marrow derived stem and progenitor cells have been identified as a potential new therapeutic option to induce angiogenesis. These findings prompted clinical researchers to explore the feasibility of cell therapies in patients with peripheral and coronary artery disease in several small trials. Clinical benefits were reported from these trials including improvement of ankle-brachial index (ABI), transcutaneous partial pressure of oxygen (TcO(2)), reduction of pain, and decreased need for amputation. Nonetheless, large randomized, placebo-controlled, double-blind studies are necessary and currently ongoing to provide stronger safety and efficacy data on cell therapy. Current literature is supportive of intramuscular bone marrow cell administration as a relatively safe, feasible, and possibly effective therapy for patients with PAD who are not subjects for conventional revascularization.

Effect of hyperosmolality and cations on iodinated contrast medium-induced potassium release from human blood cells

PURPOSE

Potassium release from blood cells is a contrast medium-induced phenomenon. The purposes of the study were to (1) assess the effect of hyperosmolality and of adding sodium ions and calcium ions to a solution on potassium release from human blood cells and (2) reevaluate the possibility of hemolysis as a cause of potassium elevation.

MATERIALS AND METHODS

Fresh human blood was mixed with a test solution to examine the temporal changes in the whole blood potassium levels and to calculate the potassium release rate. Test solutions included 5%, 20%, and 50% glucose; 0.9% and 10% NaCl; and 50% glucose mixed with various amounts of sodium and calcium ions. We also measured serum glutamine oxaloacetic acid transaminase (GOT) and serum lactate dehydrogenase (LDH) to evaluate the possibility of hemolysis.

RESULTS

Hyperosmolality using glucose solutions promoted higher potassium release. The average +/- SD potassium release rates were 7.3 +/- 2.4 micromol/min with 5% glucose, 13.5 +/- 2.3 micromol/min with 20% glucose, and 128.4 +/- 44.9 micromol/min with 50% glucose. The solutions including sodium ions showed lower release rates. The addition of sodium and calcium ions into 50% glucose significantly lowered the potassium release rates. No significant elevation of GOT or LDH was observed, and the possibility of hemolysis was eliminated.

CONCLUSION

Hyperosmolar glucose solution promoted potassium release, but the presence of sodium ions in the hypertonic solution inhibited it. In addition, there is no possibility of hemolysis as a cause of potassium release.

In vitro studies of DNA damage and its repair in cells from NHL patients with different p53 mutant protein status, resistant (p53+) and sensitive (p53−) to cancer chemotherapy

INTRODUCTION

Resistance to an anthracycline-based regimen, such as CHOP, constitutes a problem for curing non-Hodgkin's lymphoma (NHL) patients. Chemoresistance in the clinic manifests itself as a lack of response to treatment or regrowth of a tumour after an initial response.

METHODS

In this study, lymphocytes from NHL patients were treated with hydrogen peroxide (H(2)O(2)), a free radical generating model agent, and ethyl methanesulfonate (EMS), a model alkylating agent, to induce DNA damage which was evaluated by SCGE. This study assessed whether or not there were any differences in the patterns of damage and repair between cells from patients with p53 mutant protein abnormalities, i.e. over-expression (p53(+)) not responding to the CHOP regimen and patients responding to the CHOP regimen without p53 protein abnormalities (p53(-)) by comparison with control individuals (wild-type). An NHL cell line model [Raji TK(+) (mex(+)) and TK(-) (mex(-))] with p53 over-expression was also investigated.

RESULTS

Results showed that frozen/thawed samples from healthy people were not suitable for use in repair studies, whilst fresh samples or samples incubated for 20 h at room temperature could be used. Tumour cells were more sensitive to damage than control cells. After treatment with H(2)O(2), cells from fresh or incubated blood showed a similar repair capacity. After treatment with EMS, there was a difference between repair in resistant and sensitive cells.

DISCUSSION

These results suggest that the repair process is a useful cellular biomarker for investigating chemoresistance. The lack of repair in p53(+) cells may correlate with a low level of MGMT, since there was no repair in the Raji TK(-) cells lacking this enzyme.

Homogeneous Assays Allow Direct "In Well" Cytokine Level Quantification

We have developed several homogeneous cytokine assays based on TR-FRET using europium cryptate- and cross-linked allophycocyanin-conjugated antibodies. Taking advantage of homogeneous assays, we have coincubated the cells with the antibody pair during the stimulation step. The results show that the presence of cells in wells at the time of reading does not alter the results. Furthermore, this experimental procedure avoids cumbersome transfer and storage steps streamlining sample analysis. Finally, it facilitates the follow-up of cytokine production.

Effect of radiologic contrast media on cell volume regulatory mechanisms in human red blood cells

RATIONALE AND OBJECTIVES

The authors performed this study to evaluate cell volume regulation in human red blood cells (RBCs) after incubation in solutions of three contrast media: iohexol (830 mOsm), ioxaglate (520 mOsm), and iodixanol (300 mOsm).

MATERIALS AND METHODS

Whole blood sampled from six healthy subjects was exposed to Ringer solutions containing 25% or 5% vol/vol iohexol (final osmolality, 440 or 340 mOsm, respectively), ioxaglate (final osmolality, 395 or 335 mOsm, respectively), iodixanol (final osmolality, 330 or 315 mOsm, respectively), or NaCl (control solutions with the same osmolality as that of the contrast media). In some experiments, control RBCs were subjected to a hyposmotic solution (100 mOsm). RBC volumes were obtained with a Coulter counter.

RESULTS

The RBCs showed normal regulatory cell shrinkage after hyposmotically induced swelling. All 25% vol/vol contrast material solutions and their control solutions induced RBC shrinkage (range, 6% +/- 1 [standard error] to 22% +/- 3). The same was true for cells exposed to 5% vol/vol contrast material (range, 4% +/- 1 to 7% +/- 1). The shrinkage phase was followed by cell swelling (10% +/- 2 to 20% +/- 2 for 25% contrast material and their control solutions and 8% +/- 1 to 15% +/- 2 for 5% contrast material and their control solutions). No contrast material-exposed RBCs increased their volumes to the level reached with their control solutions.

CONCLUSION

RBCs exposed to hyperosmotic iohexol, ioxaglate, or iodixanol solutions shrank and then swelled. The degree of shrinkage and subsequent swelling could not be explained simply with the osmolality of the test solutions. Physicochemical properties of the contrast media must be involved, putatively affecting electrolyte fluxes over the RBC membrane. Possible targets of these effects are the K+/Cl- symporter, K+ channels, and the Na+/K+/Cl- symporter.