Epicutaneous immunotherapy protects cashew-sensitized mice from anaphylaxis

Background

The prevalence of tree nut allergy has increased worldwide, and cashew has become one of the most common food allergens. More critically, cashew allergy is frequently associated with severe anaphylaxis. Despite the high medical need, no approved treatment is available and strict avoidance and preparedness for prompt treatment of allergic reactions are considered dual standard of care. In the meantime, Phase III study results suggest investigational epicutaneous immunotherapy (EPIT) may be a relevant and safe treatment for peanut allergy and may improve the quality of life for many peanut allergic children.

Objective

We aimed to evaluate the capacity of EPIT to provide protection against cashew-induced anaphylaxis in a relevant mouse model.

Methods

The efficacy of EPIT was evaluated by applying patches containing cashew allergens to cashew-sensitized mice. As negative control, sham mice received patches containing excipient. Following treatment, mice were challenged orally to cashew and anaphylactic symptoms, as well as plasmatic levels of mast-cell proteases (mMCP)-1/7, were quantified.

Results

Of 16 weeks of EPIT significantly protects against anaphylaxis by promoting a faster recovery of challenged mice. This protection was characterized by a significant reduction of temperature drop and clinical symptoms, 60 minutes after challenge. This was associated with a decrease in mast-cell reactivity as attested by the reduction of mMCP-1/7 in plasma, suggesting that EPIT specifically decrease IgE-mediated anaphylaxis.

Conclusion

We demonstrate that EPIT markedly reduced IgE-mediated allergic reactions in a mouse model of cashew allergy, which suggests that EPIT may be a relevant approach to treating cashew allergy.

     

Dose-intensive therapy for extensive-stage small cell lung cancer and extrapulmonary small cell carcinoma: long-term outcome.

Treatment for extensive-stage small cell lung cancer (ES SCLC) or extrapulmonary small cell carcinoma (EPSC) is typically palliative. We set out to determine progression-free survival (PFS) and overall long-term survival of ES SCLC and EPSC patients, physiologically aged < or = 60 years, responding to first-line chemotherapy followed by high-dose combination alkylating agents with hematologic stem cell support. Patients in first-line chemotherapy response underwent stem cell collection (marrow, peripheral blood progenitor cells, or both) followed by high-dose therapy with 1 of 2 regimens: CBP (cyclophosphamide, cisplatin, and carmustine) or ICE (ifosfamide, carboplatin, and etoposide) with or without etanidazole. Involved-field radiotherapy was given to selected patients with oligometastatic disease distributed in sites allowing for reasonable radiation ports, and prophylactic cranial radiotherapy was given upon recovery to patients in complete response (CR) or near-CR. A total of 36 patients were treated. Of 29 patients with ES SCLC, 6 (21%) had achieved CR, 18 near-CR, and 5 partial response prior to high-dose therapy. Of 7 patients with EPSC, 3 (43%) had achieved CR, 3 had achieved near-CR, and 1 had progression of disease prior to high-dose therapy. Thirteen ES SCLC patients received high-dose CBP. Of the remaining 23 patients with SCLC or EPSC, 17 were treated with ICE and 6 with ICE plus etanidazole, a hypoxic cell sensitizer. Treatment-related mortality was 11% (4 of 36 patients). For all patients, the median event-free survival (EFS) was 5 months. The 2- and 5-year survivals after intensification were 12% (95% confidence interval [CI], 5%-31%) and 9% (95% CI, 3%-27%), respectively. Of the 30 patients in or near CR prior to high-dose therapy, 5 remain continuously progression-free (2 ES SCLC, 3 EPSC) for a median of 55 months (range, 1-96 months) after high-dose therapy. By multivariate analysis, factors associated with more favorable EFS were the use of a more aggressive induction regimen (ICE), and the EPSC histology. These factors were also associated with more favorable overall survival. Other factors associated with more favorable overall survival were the use of short induction therapy (< or = 4 cycles) and younger age (<50 years). Except for high-dose ICE with etanidazole, the use of high-dose systemic therapy in ES SCLC and EPSC was associated with low treatment-related morbidity and mortality over the past 5 years. Late complications were infrequent, and most patients returned to full-time work and activity, barring disease recurrence. Nonetheless, few patients with ES SCLC have progression-free long-term survival. We conclude that high-dose therapy is not indicated as an approach for ES SCLC, except as part of an investigative trial. Conversely, 3 of the 7 patients with EPSC remain relapse-free (range, 1-96 months), warranting further phase II evaluation of this approach in this population.     

Molecular cytogenetic characterization of nasopharyngeal carcinoma cell lines and xenografts by comparative genomic hybridization and spectral karyotyping

Nasopharyngeal carcinoma (NPC) cell lines and xenografts represent valuable models for functional and therapeutic studies on this common malignancy in Southeast Asia. The karyotypic information in most NPC cell lines and xenografts, however, remains largely unclear to date. We have characterized the chromosomal aberrations in six commonly used human NPC cell lines and xenografts using the molecular cytogenetic technique of comparative genomic hybridization (CGH). Genomic imbalances identified in cell lines were further correlated with structural abnormalities indicated from spectral karyotyping (SKY) analysis. CGH revealed consistent overrepresentations of 8q (six out of six cases) with a smallest overlapping region identified on 8q21.1q22. Other common gains included 7p (4/6 cases), 7q (4/6 cases), 12q (4/6), and 20q (4/6 cases), where minimal overlapping regions were suggested on 7p15p14, 7q11.2q21, and 12q22q24.1. Common losses were detected on 3p12p21 (4/6 cases) and 11q14qter (4/6 cases). Although SKY analysis on cell lines revealed predominantly unbalanced rearrangements, reciprocal translocations that involved chromosome 2 [i.e., t(1;2), t(2;3), and t(2;4)] were suggested. Furthermore, SKY examination illustrated additional breakpoints on a number of apparently balanced chromosomes. These breakpoints included 3p21, 3q26, 5q31, 6p21.1p25, 7p14p22, and 8q22. Our finding of regional gains and losses and breakpoints represents information that may contribute to NPC studies in vitro.     

Antigen presentation and tumor cytotoxicity by interferon-gamma-treated microglial cells

In this study microglial cells isolated from brain cell cultures of newborn mice were characterized and investigated for morphology, their responses to growth factors and their functional properties. The microglial cells were phagocytic, contained nonspecific esterase activity and expressed Fc (IgG1/2b) and type-3 complement receptors. Scanning electron microscopy revealed that in analogy to brain tissue two types of microglial cells are present in the cultures: the ameboid and the ramified type which both display similar appearance by transmission electron microscopy. Interleukin 3 and the granulocyte-macrophage colony-stimulating factor were potent growth factors for the cultured microglial cells. The cells were negative for class II antigens (Ia) of the major histocompatibility antigen complex. However, upon treatment with interferon-gamma (IFN-gamma) microglial cells became Ia+ and functioned as antigen-presenting cells when tested on ovalbumin-specific Ia-restricted helper T cells. Furthermore, microglial cells exposed to IFN-gamma and endotoxin developed tumor cell cytotoxicity and produced tumor necrosis factor alpha. Taken together, microglial cells share the characteristics of cells of the macrophage lineage.     

Long-term evaluation of usefulness of skin and incremental challenge tests in patients with history of adverse reaction to local anesthetics

A variety of adverse reactions to local anesthetics has been described, some of which are thought to be allergic. Different protocols of prick and intradermal skin tests as well as subcutaneous challenge tests are used to select a local anesthetic which can safely be used. Their long-term effectiveness has not yet been assessed. Twenty-eight patients with a history of adverse reaction to local anesthetics were evaluated over a 3-year period. Loss of consciousness occurred in eight patients, skin reaction in nine, and vagal symptoms in eight. Various reactions were recorded in the remaining three patients. Rapid spontaneous recovery was the rule, suggesting that immediate allergic reaction and, in particular, anaphylactic reaction were unlikely. Investigation allowed the selection of a tolerated anesthetic in all cases. Reexposure occurred in 19 patients 16–50 months after evaluation and 6.8 ± 5.5 years after the first reaction. No patient presented a second reaction. In conclusion, adverse reactions to local anesthetics seem to be, in most cases, not allergic in nature. Evaluation protocols are effective in selecting an agent susceptible to tolerance, but are time consuming. However, they probably contribute to an important reassurance effect that is likely to increase tolerance to subsequent local anesthetic administration. Simplification of the protocols and better patient selection are proposed.     

Stable genes

Some genes such as those for histones and RNAs are conserved unchanged through much of evolution and have numerous tandem repeat copies in the genome. It is proposed that as yet undetected 'polystrand' enzymes use such multiple copies as a means of conserving their sequence by comparing the copies and eliminating errors.     

Mechanisms of peptide YY release induced by an intraduodenal meal in rats: neural regulation by proximal gut

 Peptide YY (PYY) release in anaesthetized rats was studied during the 2 h following the intraduodenal administration of a semi-liquid meal of 21 kJ. Surgical and pharmacological manipulations were performed in order to analyse the mechanisms of PYY release. Postprandial PYY release was suppressed or strongly decreased by caecocolonectomy, truncal vagotomy, tetrodotoxin, hexamethonium, sensory denervation by perivagal capsaicin, and by the NO-synthase inhibitor L-N-arginine methyl ester, while atropine, adrenergic blockers, antagonists of type-A or type-B cholecystokinin (CCK) receptors or bombesin receptors had no effect. Comparing the digestive transit of the semi-liquid meal with the amount of PYY contained in the small bowel wall showed that nutrients had not reached the area rich in cells containing PYY by 30 min, the time at which there was a large PYY release in plasma. By 120 min, the meal front had travelled 72% of the small intestine length, just beginning to reach the PYY-rich part of the ileum. We conclude that the main postprandial PYY release studied in this model comes from ileal and colonic L-cells indirectly stimulated through a neural mechanism originating in the proximal gut and involving sensory vagal fibres, nicotinic synapses and NO release, while CCK and bombesin do not seem to be physiologically involved. Received: 17 July 1996 / Received after revision: 11 October 1996 / Accepted: 18 October 1996     

The glioblastoma-derived T cell suppressor factor/transforming growth factor-beta 2 inhibits T cell growth without affecting the interaction of interleukin 2 with its receptor

Human glioblastoma cells secrete a peptide termed glioblastoma-derived T cell suppressor factor (G-TsF) which inhibits T cell activation. Recently, purification and cloning of G-TsF revealed that G-TsF is identical to transforming growth factor-beta 2. As shown here, G-TsF suppresses the growth of an ovalbumin-specific mouse T helper cell clone (OVA-7T) independently of the stimulus used being either (a) antigen in the presence of antigen-presenting cells, or (b) interleukin 2 (IL2) or (c) phorbol ester and calcium ionophore. Furthermore, in the presence of antibodies against IL2 receptors, G-TsF was able to suppress the residual proliferation still observed when OVA-7T were stimulated with phorbol ester/ionophore. G-TsF failed to inhibit the release of IL3 from OVA-7T activated with IL2. Taken together, the data provide evidence that G-TsF does not directly interfere with interactions of IL2 with its receptor but rather inhibits T cell activation by interfering with an as yet unidentified pathway used by both IL2 and phorbol ester/ionophore. When analyzing different monokines and lymphokines for its effect on G-TsF-induced suppression of T cell growth the only factor found to partially neutralize the effect of G-TsF was tumor necrosis factor-alpha.