Early markers for protective mechanisms during rush venom immunotherapy

BACKGROUND

Allergen-specific venom immunotherapy (VIT) represents the only rational-based option to treat allergic sensitizations against bee and wasp venom. So far, there is not much knowledge about early induction of protective and tolerogenic pathways during VIT.

OBJECTIVES

To identify the earliest markers for protective mechanisms against allergic reactions in the peripheral blood during the build-up phase of VIT.

METHODS

PBMC and monocytes were isolated, and serum samples were taken before and during a five day build-up phase from 65 hymenoptera venom allergic patients. Expression level of tolerogenic markers was analyzed on mRNA and protein level. Serum levels of different soluble tolerogenic factors were measured.

RESULTS

We observed significantly enhanced tryptophan degradation, elevated ILT4 expression of monocytes as well as IL-10 production of CD3(+) T cells only a few hours after the first injection on day 1, followed by increased IL-10 serum levels, monocyte apoptosis and elevated intracellular cAMP levels of monocytes on day 3 combined with a higher ILT3 protein expression and IL-10 secretion of monocytes on day 5.

CONCLUSION

From these data, we conclude that tryptophan depletion, ILT3/4-mediated inhibition, higher IL-10 production as well as intracellular cAMP might contribute to early induction of protective mechanisms against allergic reactions during the build-up phase of VIT.

Static and Dynamic Electrocardiographic Patterns Preceding Torsades de Pointes in the Acquired and Congenital Long QT Syndrome

The arrhythmogenic mechanisms involved in the triggering of the polymorphic ventricular tachycardia called torsades de pointes (TdPs) remains to be elucidated. In this work, we investigated the static and dynamic profiles of the repolarization interval from the surface electrocardiogram recorded in healthy individuals and in cardiac patients with TdPs. We implemented this analysis just prior to the arrhythmia onset and we computed the delta values based on baseline periods (1 hour prior to event). We measured QT/QTc prolongation, QT variability, ventricular ectopic beats (VPBs) frequency, T-wave amplitude, T-peak to T-end interval, and T-wave complexcity. The analysis of these parameters in reference to baseline revealed 1) an increased QTc variability, 2) the presence of VPCs, and 3) the profound changes in T-loop morphology in patients developing TdPs.

Monoclonal antibody treatment to prolong the secondary cardiac allograft survival in alloantigen-primed mice

We have previously shown that costimulation blockade using a combination of monoclonal antibodies (mAbs) - CTLA4Ig, antibodies to CD154, LFA-1, and OX40L - can induce tolerance of cardiac allografts in mice with adoptively transferred CD4(+) memory T cells [1]. However, the effect of costimulatory blockade in secondary allograft rejection has not been studied. B6 mice that rejected BALB/c skin grafts for more than 4 weeks (defined as alloantigen-primed mice) were used as recipients. The recipient mice were treated with the mAbs to CD154, LFA-1, OX40L, and CD122 on days 0, 2, 4, and 6 after the secondary transplantation of BALB/c heart. The mean survival time (MST) of secondary cardiac allografts in rats treated with antibodies to CD154 and LFA-1 (2-antibodies approach) and those treated with antibodies to CD154, LFA-1, OX40L, and CD122 (4-antibodies approach) was greater than that of the controls (MST = 6.7 days, 22.2 days, and 3.2 days, respectively). The 4-antibodies approach prevented lymphocytic infiltration in the grafts, inhibited memory T-cells proliferation in the spleen, increased IL-10 secretion in the serum, and enhanced the expression of CD4(+) Foxp3(+) regulatory T cells (Tregs) in spleen. Expression levels of alloreactive antibodies were high in the recipient mice of experimental and control groups. Inhibiting the memory T cells by costimulation blockade extended allograft survival in secondary transplant models but could not induce tolerance of graft. Alloreactive antibodies may participate in alloresponse and play an important role in secondary cardiac allograft rejection.

Epigenetic modification of vomeronasal (V2r) precursor neurons by histone deacetylation

Vomeronasal neurons undergo continuous neurogenesis throughout development and adult life. These neurons originate as stem cells in the apical zone of the lumen of the vomeronasal organ (VNO) and are described as nestin-expressing glia-like progenitor cells (Murdoch and Roskams, 2008). They then migrate horizontally along the basal zone where they differentiate into functional VNO neurons (Kaba et al., 1988). We harvested progenitor cells from the adult VNO and, after 3-6 months of invitro culture, these VNO neurons remained in a stable undifferentiated state expressing nestin, beta-tubulin III and vomeronasal type 2 (V2r), but not vomeronasal type 1 (V1r) receptors. Application of histone-deacetylase inhibitors induced development of a neural phenotype that expressed V2r receptors, a down-regulation of nestin expression and no change in any specific genetic markers associated with glial cells. Treatment with valproic acid induced extensive changes in gene expression in the axon guidance pathway. The adult VNO is known to functionally adapt throughout life as a consequence of changes in both a mouse's physiological status and its social environment. These pluripotent cultured neurons may provide valuable insights into how changes in both physiology and environment, exert epigenetic effects on vomeronasal neurons as they undergo continuous neurogenesis and development throughout the life of a mouse.

The Treg/Th17 imbalance in patients with idiopathic dilated cardiomyopathy

To assess whether Treg/Th17 balance was broken in patients with idiopathic dilated cardiomyopathy (DCM). We studied 25 patients who were diagnosed as idiopathic DCM (18 men and seven women, mean age 35.6 +/- 5.2) and 25 normal persons (18 men and seven women, mean age 33.8 +/- 4.9). Then, we detected Treg/Th17 functions on different levels including cell frequencies, related cytokine secretion and key transcription factors in patients with idiopathic DCM and controls. The results demonstrated that patients with idiopathic DCM revealed significant increase in peripheral Th17 number, Th17-related cytokines (IL-17, IL-6, IL-23) and transcription factor (RORgammat) levels and obvious decrease in Treg number, Treg-related cytokines (TGF-beta1 and IL-10) and transcription factor (Foxp3) levels when compared to normal persons. Results indicated that Treg/Th17 functional imbalance existed in patients with idiopathic DCM, suggesting a potential role for Treg/Th17 imbalance in the development of idiopathic DCM.

Defects of synaptic vesicle turnover at excitatory and inhibitory synapses in Niemann-Pick C1-deficient neurons

Niemann-Pick disease type C (NPC) is a progressive neurodegenerative disorder characterized by accumulation of free cholesterol in late endosomes/lysosomes. The pathological basis for the disease is poorly understood. In the present study, electrophysiological and fluorescent dye studies were applied to examine neuron-specific functions of Niemann-Pick disease type C1 (NPC1) and to determine whether excitatory and inhibitory synapses are differentially impaired by NPC1 deficiency. Densities of spines and postsynaptic receptor clusters were not affected by NPC1 deficiency over the period examined. However, drastic defects on exocytosis were found both in glutamatergic and GABAergic synapses. The defects were caused in part by a delay in the time required for replacement of excytosed vesicles with new fusion-competent ones. Moreover, we found that the delay of synaptic vesicle turnover was longer in inhibitory synapses (>3 s) than in excitatory synapses (<0.2 s). These defects may be early indicators, and could provide a potential explanation for key features of the disease, such as dystonia and seizures.

CCR5 blockade in combination with rapamycin prolongs cardiac allograft survival in mice

Both chemokine receptor 5 (CCR5) blockade and rapamycin (rapa) are effective in modulating transplant immunity and led to prolonged allograft survival, yet a great many grafts were ultimately lost to acute rejection. In this study we examined the inhibition of CCR5 in combination with the treatment with rapa in cardiac transplantation. Fully major histocompatibility complex-mismatched murine cardiac allograft models were randomized to five groups. They were administered with anti-CCR5 antibody or control antibody and rapa or phosphate-buffered saline (PBS), respectively. An additional group was treated with anti-CCR5 antibody, rapa and anti-CD25 antibody. Allograft rejection was investigated by flow cytometric analyses and enzyme-linked immunospot assay. Allografts treated with anti-CCR5 antibody plus rapa showed significantly prolonged survival (83 +/- 3 days, P < 0.001) compared with control antibody plus PBS-treated allografts (6 +/- 1 days). Treatment with anti-CCR5 monoclonal antibody (mAb) plus rapa inhibited significantly the progression of chronic rejction. Further analysis of donor hearts in the anti-CCR5 antibody plus rapa-treated group demonstrated increased infiltration of CD4(+)CD25(+)forkhead box P3(+) regulatory T cells, and depletion of CD25(+) cells resulted in acute rejection of allografts in 18 +/- 1 day. CCR5 blockade in combination with rapa is effective in preventing acute and chronic rejection in a robust murine model. This effect is mediated by CD25(+) T cell recruitment and control of T lymphocyte proliferation.

Antitumor activity of patient-derived renal cell carcinoma cells fused with allogeneic dendritic cells: In vitro results and clinical responses

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Background: Renal cell carcinoma (RCC) has been shown to be highly susceptible to immune-based treatment strategies. Methods: In the present study, patient-derived tumor cells were fused with allogeneic dendritic cells (DC) to elicit antitumor activity against RCC. DC from HLA-A2+ healthy donors were fused with primary RCC cells from 10 patients. Phenotype of fusion cells was characterized by flow cytometer and confocal microscopy. In vitro, T-cell proliferation, IFN-γ secretion, and cytotocic T lymphocytes (CTL) activity elicited by allogeneic DC/RCC fusion cells were assessed. Clinically, 10 patients were vaccinated with allogeneic DC/RCC fusion vaccine. The adverse effects and toxicity were observed. The clinical response was evaluated by CT scans. Results: After fusion, the created hybrids expressed both tumor-associated antigen and DC-derived molecules and could stimulate the proliferation and IFN-γ secretion of T-cells as well as elicit strong CTL activity against RCC cells in vitro. In vivo, neither serious adverse effects nor signs of autoimmune disease were observed after vaccination therapy. Percentage of T lymphocyte subsets in peripheral blood of patients was increased significantly. One of 10 patients exhibited a partial response with regression of lung metastases. Six patients showed stable disease with stabilization of previously progressive disease (follow-up 1.5 year). Conclusions: The data suggest that allogeneic DC/RCC fusion vaccine is safe and can elicit immunological responses in patients with RCC.

No significant financial relationships to disclose.

Efficacy and safety of ginsenoside-Rd for acute ischaemic stroke: a randomized, double-blind, placebo-controlled, phase II multicenter trial

BACKGROUND AND PURPOSE

Ginsenoside-Rd is a selective competitive Ca2+ receptor antagonist. A phase II randomized, double-blind, placebo-controlled, multicenter study was conducted to examine the efficacy and safety of ginsenoside-Rd in patients with acute ischaemic stroke.

METHODS

A total of 199 patients were randomized equally to receive a 14-day infusion of placebo (group B), ginsenoside-Rd 10 mg (group A) or ginsenoside-Rd 20 mg (group C). Primary end-points were National Institutes of Health Stroke Scale (NIHSS) scores at 15 days. Secondary end-points were NIHSS scores and the Barthel Index at 8 days, the Barthel Index and the modified Rankin scale at 15 days and 90 days. The safety end-points included serious and non-serious adverse events, laboratory values and vital signs. Analysis was by intention to treat.

RESULTS

For the primary study outcome, there is significant difference amongst the three groups at 15 days in NIHSS scores (P = 0.0003). Comparing group A with B and group B with C, the difference in the mean for NIHSS was significant in statistics (P = 0.0004, P = 0.0009 respectively). This is no significant difference between group A and C (P = 0.9640). For the secondary study outcome, ginsenoside-Rd did not improve neurological functioning. Incidence of serious and non-serious adverse events was similar amongst the three groups.

CONCLUSIONS

Ginsenoside-Rd may be of some benefit in acute ischaemic stroke.

Cloning, mapping and mutation analysis of human geneGJB5 encoding gap junction protein beta-5

By homologous EST searching and nested PCR a new human geneGJB5 encoding gap junction protein beta-5 was identified.GJB5 was genetically mapped to human chromosome 1p33-p35 by FISH. RT-PCR revealed that it was expressed in skin, placenta and fetal skin. DNA sequencing ofGJB5 was carried out in 142 patients with sensorineural hearing impairment and probands of 36 families with genetic diseases, including erythrokeratodermia (5 families), Charcot-Marie-Tooth disease (13), ptosis (4), and retinitis pigmentosa and deafness (14). Two missense mutations (686A-->G, H229R; 25C-->T, L9F) were detected in two sensorineural hearing impairment families. A heterologous deletion of 18 bp within intron was found in 3 families with heredity hearing impairment, and in one of the 3 families, a missense mutation (R265P) was identified also. But the deletion and missense mutation seemed not segregating with hearing impairment in the family. No abnormal mRNA or mRNA expression was detected in deletion carriers by RT-PCR analysis in skin tissue. Mutation analysis in 199 unaffected individuals revealed that two of them were carriers with the same 18 bp deletion.

GABA-mediated inhibition correlates with orientation selectivity in primary visual cortex of cat

Orientation selectivity is an important emergent property of neurons in the primary visual cortex, and inhibition is thought to play an important role in establishing this selectivity. But the relationship between strength of inhibition and orientation selectivity is unclear. To investigate this relationship, we electrophoretically applied the inhibitory transmitter GABA and the GABA(A) antagonist bicuculline on the same individual area 17 neurons in anesthetized cats. Neurons were classified as weakly orientation-selective, moderately orientation-selective, or strongly orientation-selective, according to the values of an orientation bias index. Orientation bias, half-width of the tuning curve at half-height and an orientation-specificity index (orthogonal to optimal ratio) were compared with or without GABA and bicuculline administration. GABA improved orientation selectivity with the greatest effects on weakly orientation-selective cells, smaller effects on moderately orientation-selective cells, and minimal effects on strongly orientation-selective cells; bicuculline diminished orientation selectivity the most on moderately and strongly orientation-selective cells, with minimal effects on weakly orientation-selective cells. We also found that orientation selectivity correlated with the level of neurons' spontaneous activity. These results suggest that the degree of orientation selectivity of an area 17 neuron correlates with its endogenous inhibition strength, and that GABAergic inhibition can bi-directionally regulate orientation selectivity. This correlation indicates that GABA-mediated inhibition plays an important role in establishing sharp orientation selectivity of individual neurons.