Coupling of a Major Allergen to the Surface of Immune Cells for Use in Prophylactic Cell Therapy for the Prevention of IgE-Mediated Allergy

Up to a third of the world's population suffers from allergies, yet the effectiveness of available preventative measures remains, at large, poor. Consequently, the development of successful prophylactic strategies for the induction of tolerance against allergens is crucial. In proof-of-concept studies, our laboratory has previously shown that the transfer of autologous hematopoietic stem cells (HSC) or autologous B cells expressing a major grass pollen allergen, Phl p 5, induces robust tolerance in mice. However, eventual clinical translation would require safe allergen expression without the need for retroviral transduction. Therefore, we aimed to chemically couple Phl p 5 to the surface of leukocytes and tested their ability to induce tolerance. Phl p 5 was coupled by two separate techniques, either by 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC) or by linkage via a lipophilic anchor, 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-poly(ethylene glycol)-maleimide (DSPE-PEG-Mal). The effectiveness was assessed in fresh and cultured Phl p 5-coupled cells by flow cytometry, image cytometry, and immunofluorescence microscopy. Chemical coupling of Phl p 5 using EDC was robust but was followed by rapid apoptosis. DSPE-PEG-Mal-mediated linkage was also strong, but antigen levels declined due to antigen internalization. Cells coupled with Phl p 5 by either method were transferred into autologous mice. While administration of EDC-coupled splenocytes together with short course immunosuppression initially reduced Phl p 5-specific antibody levels to a moderate degree, both methods did not induce sustained tolerance towards Phl p 5 upon several subcutaneous immunizations with the allergen. Overall, our results demonstrate the successful chemical linkage of an allergen to leukocytes using two separate techniques, eliminating the risks of genetic modifications. More durable surface expression still needs to be achieved for use in prophylactic cell therapy protocols.

Adoptive transfer of allergen-expressing B cells prevents IgE-mediated allergy

Introduction

Prophylactic strategies to prevent the development of allergies by establishing tolerance remain an unmet medical need. We previously reported that the transfer of autologous hematopoietic stem cells (HSC) expressing the major timothy grass pollen allergen, Phl p 5, on their cell surface induced allergen-specific tolerance in mice. In this study, we investigated the ability of allergen-expressing immune cells (dendritic cells, CD4+ T cells, CD8+ T cells, and CD19+ B cells) to induce allergen-specific tolerance in naive mice and identified CD19+ B cells as promising candidates for allergen-specific cell therapy.

Methods

For this purpose, CD19+ B cells were isolated from Phl p 5-transgenic BALB/c mice and transferred to naive BALB/c mice, pre-treated with a short course of rapamycin and an anti-CD40L antibody. Subsequently, the mice were subcutaneously sensitized three times at 4-week intervals to Phl p 5 and Bet v 1 as an unrelated control allergen. Allergen-expressing cells were followed in the blood to monitor molecular chimerism, and sera were analyzed for Phl p 5- and Bet v 1-specific IgE and IgG1 levels by RBL assay and ELISA, respectively. In vivo allergen-induced lung inflammation was measured by whole-body plethysmography, and mast cell degranulation was determined by skin testing.

Results

The transfer of purified Phl p 5-expressing CD19+ B cells to naive BALB/c mice induced B cell chimerism for up to three months and prevented the development of Phl p 5-specific IgE and IgG1 antibody responses for a follow-up period of 26 weeks. Since Bet v 1 but not Phl p 5-specific antibodies were detected, the induction of tolerance was specific for Phl p 5. Whole-body plethysmography revealed preserved lung function in CD19+ B cell-treated mice in contrast to sensitized mice, and there was no Phl p 5-induced mast cell degranulation in treated mice.

Discussion

Thus, we demonstrated that the transfer of Phl p 5-expressing CD19+ B cells induces allergen-specific tolerance in a mouse model of grass pollen allergy. This approach could be further translated into a prophylactic regimen for the prevention of IgE-mediated allergy in humans.

Lipedema: The Use of Cultured Adipocytes for Identification of Diagnostic Markers

BACKGROUND

Lipedema, diagnosed most often in women, is a progressive disease characterized by the disproportionate and symmetrical distribution of adipose tissue, primarily in the extremities. Although numerous results from in vitro and in vivo studies have been published, many questions regarding the pathology and genetic background of lipedema remain unanswered.

METHODS

In this study, adipose tissue-derived stromal/stem cells were isolated from lipoaspirates derived from nonobese and obese donors with or without lipedema. Growth and morphology, metabolic activity, differentiation potential, and gene expression were evaluated using quantification of lipid accumulation, metabolic activity assay, live-cell imaging, reverse transcription polymerase chain reaction, quantitative polymerase chain reaction, and immunocytochemical staining.

RESULTS

The adipogenic potential of lipedema and nonlipedema adipose tissue-derived stromal/stem cells did not rise in parallel with the donors' body mass index and did not differ significantly between groups. However, in vitro differentiated adipocytes from nonobese lipedema donors showed significant upregulation of adipogenic gene expression compared with nonobese controls. All other genes tested were expressed equally in lipedema and nonlipedema adipocytes. The adiponectin/leptin ratio was significantly reduced in adipocytes from obese lipedema donors compared with their nonobese lipedema counterparts. Increased stress fiber-integrated smooth muscle actin was visible in lipedema adipocytes compared with nonlipedema controls and appeared enhanced in adipocytes from obese lipedema donors.

CONCLUSIONS

Not only lipedema per se but also body mass index of donors affect adipogenic gene expression substantially in vitro. The significantly reduced adiponectin/leptin ratio and the increased occurrence of myofibroblast-like cells in obese lipedema adipocyte cultures underscores the importance of attention to the co-occurrence of lipedema and obesity. These are important findings toward accurate diagnosis of lipedema.

CLINICAL RELEVANCE STATEMENT

Our study highlights not only the difficulty in lipedema diagnostics but also the tremendous need for further studies on lipedema tissue. Although lipedema might seem to be an underestimated field in plastic and reconstructive surgery, the power it holds to provide better treatment to future patients can not be promoted enough.

Epidermal Growth Factor Receptor T790M Mutation Testing in Non-Small Cell Lung Cancer: An International Collaborative Study to Assess Molecular EGFR T790M Testing in Liquid Biopsy

BACKGROUND

The detection of the EGFR T790M (T790M) mutation in non-small cell lung cancer (NSCLC) patients who progressed under treatment with first- or second-generation EGFR-tyrosine kinase inhibitors (TKIs) is important to offer a subsequent therapy with a third-generation EGFR-TKI. Liquid biopsy is a powerful tool to determine the T790M mutation status. Several liquid biopsy platforms with varying degrees of accuracy are available to test for T790M mutations, and sensitivities may differ among these methods.

METHODS

As no standard exists for the testing of T790M mutation in liquid biopsy, we performed a collaborative study to describe and compare the sensitivity of different in-house liquid biopsy platforms for the detection of the T790M mutation, EGFR exon 19 deletion (del19) and EGFR L858R mutation (L858R) across multiple participating laboratories in seven Central and Eastern European countries.

RESULTS

Of the 25 invited laboratories across Central and Eastern Europe, 21 centers participated and received 10 plasma samples spiked with cell-line DNA containing the T790M, del19, or L858R mutation in different concentrations. In-house PCR-based and NGS-based methods were used accordingly, and results were reported as in routine clinical practice. Two laboratories, which used the AmoyDx^® EGFR 29 Mutations Detection Kit (AmoyDx) with Cobas^® cfDNA Sample Preparation Kit and QX200 Droplet Digital PCR (ddPCR) with the QIAamp Circulating Nucleic Acid Kit identified all ten samples correctly. Cobas^® EGFR Mutation Test v2 (Cobas), the NGS methods, and the Idylla^TM detection method used in this study performed within the known sensitivity range of each detection method.

CONCLUSIONS

If a negative result was obtained from methods with lower sensitivity (e.g., Cobas), repeated liquid biopsy testing and/or tissue biopsy analysis should be performed whenever possible, to identify T790M-positive patients to allow them to receive the optimal second-line treatment with a third-generation EGFR TKI.

Optimum timing of antithymocyte globulin in relation to adoptive regulatory T cell therapy

Reducing the recipient's T cell repertoire is considered to increase the efficacy of regulatory T cell (Treg) therapy. This necessitates timing the administration of antithymocyte globulin (ATG) early enough before adoptive cell therapy (ACT) so that residual serum ATG does not deplete the transferred Tregs. The optimum time point in this regard has not been defined. Herein, we report the effects of residual serum ATG on the viability of an in vitro expanded Treg cell product used in a clinical trial of ACT in kidney transplant recipients (NCT03867617). Patients received ATG monotherapy (either 6 or 3 mg/kg body weight) without concomitant immunosuppression 2 to 3 weeks before transplantation and Treg transfer. An anti-ATG immunoglobulin G (IgG) immune response was elicited in all patients within 14 days. In turn, the elimination of total and Treg-specific ATG was accelerated substantially over control patients receiving the same dose of ATG with concomitant immunosuppression. However, ATG serum concentrations of <1 μg/mL, which had previously been reported as subtherapeutic threshold, triggered apoptosis of Tregs in vitro. Therefore, ATG levels need to decline to lower levels than those previously thought for efficacious Treg transfer. In 5 of 6 patients, such low levels of serum ATG considered safe for Treg transfer were reached within 2 weeks after ATG administration.

The OncoMasTR test predicts distant recurrence in estrogen receptor-positive, HER2-negative early-stage breast cancer: A validation study in ABCSG Trial 8

PURPOSE

To validate the clinical performance of the OncoMasTR Risk Score in the biomarker cohort of ABCSG Trial 8.

EXPERIMENTAL DESIGN

We evaluated the OncoMasTR test in 1200 formalin-fixed, paraffin-embedded surgical specimens from postmenopausal women with estrogen receptor (ER)-positive, human epidermal growth factor receptor 2 (HER2)-negative primary breast cancer with 0-3 involved lymph nodes in the prospective, randomized ABCSG Trial 8. Time to distant recurrence (DR) was analyzed by Cox models.

RESULTS

The OncoMasTR Risk Score categorized 850 of 1087 (78.2%) evaluable patients as "low risk". At 10 years, the DR rate for patients in the low-risk group was 5.8% versus 21.1% for patients in the high-risk group (P<0.0001, absolute risk reduction 15.3%). The OncoMasTR Risk Score was highly prognostic for prediction of DR in years 0-10 in all patients (hazard ratio (HR) 1.91, 95% confidence interval (CI) 1.62 to 2.26, P<0.0001; C-index 0.73), in node-negative patients (HR 1.79, 95% CI 1.43 to 2.24, P<0.0001; C-index 0.72), and in patients with 1-3 involved lymph nodes (HR 1.93, 95% CI 1.44 to 2.58, P<0.0001; C-index 0.71). The OncoMasTR Risk Score provided significant additional prognostic information beyond clinical parameters, Ki67, Nottingham Prognostic Index, and Clinical Treatment Score.

CONCLUSIONS

OncoMasTR Risk Score is highly prognostic for DR in postmenopausal women with ER-positive, HER2-negative primary breast cancer with 0-3 involved lymph nodes. In combination with prior validation studies, this fully independent validation in ABCSG Trial 8 provides level 1B evidence for the prognostic capability of the OncoMasTR Risk Score.

IL-27 regulates HIF-1α-mediated VEGFA response in macrophages of diabetic retinopathy patients and healthy individuals

Human macrophages produce vascular endothelial growth factor A (VEGFA) for angiogenesis in diabetic retinopathy (DR). The regulatory function of IL-27 on human macrophages is not well understood. In particular, the effect of IL-27 on VEGFA response in human macrophages has not been investigated. We find that IL-27 suppresses VEGFA mRNA expression as well as protein secretion by human macrophages. The synergistic action of purinergic signaling and activation of hypoxia-inducible factor 1 alpha (HIF-1α) induces VEGFA production in a positive feedback loop. IL-27 signaling in human macrophages disrupts this positive feedback loop thus suppresses VEGFA production. Blockade of IL-27 signaling with a JAK2 antagonist reverses this downregulatory effect on HIF-1α and partially blocks the inhibitory effect on VEGFA production. Lastly, DR patient macrophages have a higher propensity to produce VEGFA and this is amplified by an in vitro challenge with the pro-inflammatory cytokine IL-1β. IL-27 suppresses VEGFA production by DR patient macrophages even in the presence of IL-1β challenge indicating a potential therapeutic use of IL-27 in the clinic.

The Hierarchy of Proinflammatory Cytokines in Ocular Inflammation

PURPOSE

The concept of tissue-dependent cytokine hierarchy has been demonstrated in a number of diseases, but it has not been investigated in ophthalmic diseases. Here, we evaluated the functional hierarchy of interleukin-1β (IL-1β), IL-6, IL-17A, and tumor necrosis factor (TNF) in the induction of ocular inflammation.

MATERIALS AND METHODS

We delivered adeno-associated virus (AAV) vectors expressing IL-1β, IL-6, IL-17A, or TNF intravitreally in naïve C57/BL6 mice and compared and contrasted the inflammatory effects in the eye 5 weeks after AAV-mediated gene transfer. We also used an in vitro human system to test the effect of cytokines on barrier function.

RESULTS

We found that IL-1β had the highest ability to initiate ocular inflammation. The continuous overexpression of IL-1β resulted in a significant upregulation of additional proinflammatory mediators in the eye. Using scanning laser ophthalmoscope and optical coherence tomography imaging techniques, we showed that a low dose of AAVIL-1β was sufficient and was as pathogenic as a high dose of TNF in inducing vascular leakage, retinal degeneration, and cellular infiltration. Furthermore, only a marginal increase in IL-1β was enough to cause cellular infiltration, thus confirming the highly pathogenic nature of IL-1β in the eye. Contrary to our expectation, IL-6 or IL-17A had minimal or no effect in the eye. To examine the clinical relevance of our findings, we used an impedance assay to show that IL-1β alone or TNF alone was able to cause primary human retinal endothelial cell barrier dysfunction in vitro. Again, IL-6 alone or IL-17A alone had no effect on barrier function; however, in the presence of IL-1β or TNF, IL-17A but not IL-6 may provide additive proinflammatory effects.

CONCLUSIONS

Our studies demonstrate the existence of a functional hierarchy of proinflammatory cytokines in the eye, and we show that IL-1β is the most pathogenic when it is continuously expressed in the eye.

Phosphorylation of BK channels modulates the sensitivity to hydrogen sulfide (H2S)

Introduction: Gases, such as nitric oxide (NO), carbon monoxide (CO), or hydrogen sulfide (H₂S), termed gasotransmitters, play an increasingly important role in understanding of how electrical signaling of cells is modulated. H₂S is well-known to act on various ion channels and receptors. In a previous study we reported that H₂S increased calcium-activated potassium (BK) channel activity.

Aims: The goal of the present study is to investigate the modulatory effect of BK channel phosphorylation on the action of H₂S on the channel as well as to recalculate and determine the H₂S concentrations in aqueous sodium hydrogen sulfide (NaHS) solutions.

Methods: Single channel recordings of GH3, GH4, and GH4 STREX cells were used to analyze channel open probability, amplitude, and open dwell times. H₂S was measured with an anion selective electrode.

Results: The concentration of H₂S produced from NaHS was recalculated taking pH, temperature salinity of the perfusate, and evaporation of H₂S into account. The results indicate that from a concentration of 300 μM NaHS, only 11–13%, i.e., 34–41 μM is effective as H₂S in solution. GH3, GH4, and GH4 STREX cells respond differently to phosphorylation. BK channel open probability (Po) of all cells lines used was increased by H₂S in ATP-containing solutions. PKA prevented the action of H₂S on channel Po in GH4 and GH4 STREX, but not in GH3 cells. H₂S, high significantly increased Po of all PKG pretreated cells. In the presence of PKC, which lowers channel activity, H₂S increased channel Po of GH4 and GH4 STREX, but not those of GH3 cells. H₂S increased open dwell times of GH3 cells in the absence of ATP significantly. A significant increase of dwell times with H₂S was also observed in the presence of okadaic acid.

Conclusions: Our results suggest that phosphorylation by PKG primes the channels for H₂S activation and indicate that channel phosphorylation plays an important role in the response to H₂S.

Hypothalamic and basal ganglia projections to the posterior thalamus: possible role in modulation of migraine headache and photophobia

Migraine attacks are typically described as unilateral, throbbing pain that is usually accompanied by nausea, vomiting, and exaggerated sensitivities to light, noise and smell. The headache phase of a migraine attack is mediated by activation of the trigeminovascular pathway; a nociceptive pathway that originates in the meninges and carries pain signals through meningeal nociceptors to the spinal trigeminal nucleus and from there to the cortex through relay neurons in the thalamus. Recent studies in our lab have identified a population of trigeminovascular neurons in the posterior (Po) and lateral posterior (LP) thalamic nuclei that may be involved in the perception of whole-body allodynia (abnormal skin sensitivity) and photophobia (abnormal sensitivity to light) during migraine. The purpose of the current study was to identify sub-cortical areas that are in position to directly regulate the activity of these thalamic trigeminovascular neurons. Such process begins with anatomical mapping of neuronal projections to the posterior thalamus of the rat by performing discrete injections of the retrograde tracer Fluorogold into the Po/LP region. Such injections yielded retrogradely labeled neurons in the nucleus of the diagonal band of Broca, the dopaminergic cells group A11/A13, the ventromedial and ventral tuberomammillary nuclei of the hypothalamus. We also found that some of these neurons contain acetylcholine, dopamine, cholecystokinin and histamine, respectively. Accordingly, we speculate that these forebrain/hypothalamic projections to Po and LP may play a role in those migraine attacks triggered by disrupted sleep, skipping meals and emotional reactions.

Potassium channel blockers quinidine and caesium halt cell proliferation in C6 glioma cells via a polyamine-dependent mechanism

Potassium channels are ubiquitous in cells and serve essential functions in physiology and pathophysiology. Potassium channel blockers have been shown to block tumour growth by arresting cells at the G(0)/G(1) checkpoint of the cell cycle. We investigated the effect of quinidine and caesium (Cs(+)) on cell proliferation, LDH (lactate dehydrogenase) release, free internal calcium, membrane potential, polyamine concentration, ODC (ornithine decarboxylase) activity and polyamine uptake in C6 glioma cells. The EC(50) for reducing cell proliferation was 112 microM for quinidine, whereas Cs(+) was less effective with an EC(50) of 4.75 mM. KCl or sucrose did not affect proliferation. LDH release was augmented by quinidine. Quinidine caused a transient increase in free internal calcium but decreased calcium after a 48 h incubation period. Further 300 microM quinidine depolarized the cell membrane in a similar range as did 30 mM KCl. Quinidine decreased cellular putrescine beyond detection levels while spermidine and spermine remained unaffected. ODC activity was reduced. Addition of putrescine could not override the antiproliferative effect owing to a reduced activity of the polyamine transporter. Our study indicates that the antiproliferative effect of quinidine is not due to a simple membrane depolarization but is caused by a block of ODC activity.

Antiproliferative properties of Padma Lax and its components ginger and elecampane

BACKGROUND

Padma Lax (PL) is a multi-component herbal laxative, derived from traditional Tibetan medicine. It has been used in the treatment of constipation dominant irritable bowel syndrome. Beyond its purgative and bowel-regulating properties we found it to exhibit antiproliferative properties.

MATERIALS AND METHODS

C6 tumor cells were incubated with either an ethanolic or aqueous extract of PL. Cell proliferation, cell cycle, percentage of apoptotic cells, caspase-3/-7 activity as well as mitochondrial membrane potential were determined.

RESULTS

Ethanolic extracts of PL inhibited cell proliferation in a dose- and time-dependent manner (half max concentration: 384.4 mug/ml after 48 h of incubation). Aqueous extracts were less effective. Ginger and elecampane were the active components of PL in respect to its antiproliferative action and were found to act synergistically. Supplementing the culture medium with polyamines could not override the cytostatic action of PL. Incubation of C6 cells with PL in the presence of catalase proved that the PL effect was specific and not due to oxidative stress. PL had no effects on the cell cycle at a low dose but arrested cells in G1 at high concentrations. Reduction of cell numbers was found to be due to apoptosis. The caspase- 3/-7 pathway was not involved in the PL-induced cell death. However, mitochondrial membrane potential was lost during the course of incubation with PL indicating a mitochondrial- but not caspase-mediated induction of apoptosis.

CONCLUSION

PL exhibits antiproliferative properties which may be beneficial to prevent constipation-related cancer. This study may also contribute to a future development of a new herbal-based antiproliferative treatment.

Parvalbumin-immunoreactive proteins in the nervous system of planarians

1. Using immunological methods, we have identified parvalbumin-like material in the triclade flatworms, Polycelis nigra, Polycelis auriculata, Crenobia alpina, Dugesia tahitiensis, and Dugesia polychroa. 2. Western immunoblot analysis of these five species revealed heat stable parvalbumin-immunoreactive proteins between 32 kD and 44 kD. 3. Proteins at 19 and 32 kD revealed intense labeling with 45Ca2+. 4. Double immunodiffusion of planarian supernatants showed complete fusion of precipitates, indicating immunological relatedness of the parvalbumin-like material among the species investigated. 5. Immunocytochemical studies exhibit parvalbumin-immunoreactive material exclusively in neurons supporting the notion of an early evolutionary appearance of these proteins in the nervous system.

Sarcoplasmic calcium-binding protein-immunoreactive material in the central nervous system of the snail, Helix pomatia

In Helix pomatia a 10 kDa sarcoplasmic calcium binding protein I (SCP I)-immunoreactive material was localized immunologically in neurons of the central nervous system, including the electrically silent serotonergic metacerebral giant neuron. Antisera against sarcoplasmic calcium binding protein II (SCP II) stained a 20 kDa protein in individual muscle cells of the epineurium. SCP- and parvalbumin (PV)-immunoreactive material were not co-localized.

Nick translation of DNA immobilized on nylon membranes

Nick translation of DNA bound to nylon membranes is described. Phage lambda DNA was digested with restriction endonuclease HindIII. The fragments were separated by agarose electrophoresis and electrophoretically transferred to Zeta-Probe nylon membranes. After being air-dried, the areas with DNA fragments attached were cut out and subjected to nick translation. The labeled fragments, removed from the membranes by a single wash step, can be used as specific hybridization probes. Currently used methods require time-consuming electroelution and often additional purification procedures if a specific DNA fragment, separated by gel electrophoresis, is to be labeled by nick translation. With the procedure described it is possible to label many DNA fragments in parallel in a time- and cost-saving manner.

The effect of gossypol acetic acid on the different stages of the spermatogenic cycle in the rat

The reversibility of the effect of gossypol on testicular histology and fertility was studied in rats. Adult males of proven fertility were treated orally with gossypol acetic acid (15 mg/kg) for 9 or 16 weeks (groups 1 and 2, respectively). Another groups of animals (group 3) was given gossypol (15 mg/kg) for 16 weeks and killed 6 weeks after the end of treatment. Control animals (group 4) were given the vehicle only by oral intubation. In the mating studies, although only 33% of the animals in group 1 were infertile, 100% infertility was observed following 16 weeks of gossypol treatment (group 2). All animals in group 3 regained their fertility 6 weeks after cessation of drug treatment. Damage was observed to 15.7% of the seminiferous tubules after 9 weeks of drug treatment, and to 78% after 16 weeks of treatment. Extensive vacuolization, increased numbers of lipid droplets, degeneration of germ cells, loosening of the epithelium, and a significant decrease in the number of pachytene spermatocytes (stages VII-X) and spermatids (steps 7-10 at stages VII-X) were observed after gossypol treatment. There was a decrease in the diameter of only stage VIII seminiferous tubules after 9 weeks of treatment, whereas a reduction was observed in the tubules of all stages after 16 weeks of gossypol treatment. In the recovery phase, the diameter of seminiferous tubules was similar to that of controls, except for tubules at stage VIII. No change in the area of the lumen of the seminiferous tubules and lipid bodies was observed after 9 weeks of drug treatment, but a marked reduction in the area of the lumen (stages II-X) and an increase in lipid bodies (all stages) was observed after 16 weeks of gossypol treatment. Six weeks after cessation of treatment, the area of the lumen and the number of lipid bodies were comparable to values in controls. A reduction in the area of the epithelium was restricted to just a few stages (VIII-XIV) in treated animals at 9 weeks, whereas after 16 weeks the area of the epithelium was decreased in all tubules. In the recovery phase, except for tubules at stage VIII, the area of the seminiferous epithelium was comparable to that in controls.