Cytokine expression in the delayed-type hypersensitivity response of Peromyscus yucatanicus infected by Leishmania (Leishmania) mexicana that healed spontaneously / Expressão de citocinas na resposta de hipersensibilidade de tipo retardado de Peromyscus yucatanicus infectado por Leishmania (Leishmania) mexicana que curou espontaneamente

Peromyscus yucatanicus tem sido empregado como modelo para estudar a leishmaniose tegumentar causada por Leishmania (Leishmania) mexicana. No entanto, não há informações sobre a cura espontânea e a resposta imune associada nesses roedores. O objetivo deste trabalho foi analisar a expressão de citocinas na resposta de hipersensibilidade do tipo retardado de Peromyscus yucatanicus infectado por Leishmania (Leishmania) mexicana que cicatrizou espontaneamente. Peromyscus yucatanicus (n = 40) foram inoculados com 2.5 × 106 parasitas na cauda e a evolução foi registrada semanalmente até o aparecimento das lesões ativas (Grupo I: não cicatrizadas) e até a cicatrização espontânea (Grupo II: cicatrizadas). Um grupo controle foi injetado com meio RPMI-1640. A resposta de hipersensibilidade do tipo retardado (DTH) e as expressões de citocinas (IFN-γ, IL-10, TNF) foram determinadas. A cura espontânea foi observada em 65% (13/20) dos P. yucatanicus do Grupo II. O grupo curado desenvolveu uma forte reação DTH que foi significativamente maior do que o grupo controle. Às 24 h, o IFN-γ foi altamente expresso na reação DTH de ambos os camundongos não curados e curados. IL-10 foi maior em camundongos curados em comparação com o grupo controle, enquanto a expressão de TNF foi maior em camundongos não curados. Em 48 h, INF-γ foi altamente expresso em camundongos não curados. A cicatrização espontânea de lesões cutâneas em P. yucatanicus foi associada à expressão de citocinas imunorreguladoras (IL-10) e efetoras (IFN-γ) na resposta DTH.

Cross-Linking Cellular Prion Protein Induces Neuronal Type 2-Like Hypersensitivity

BackgroundPrevious reports identified proteins associated with ‘apoptosis’ following cross-linking PrPC with motif-specific anti-PrP antibodies in vivo and in vitro. The molecular mechanisms underlying this IgG-mediated neurotoxicity and the role of the activated proteins in the apoptotic pathways leading to neuronal death has not been properly defined. Previous reports implicated a number of proteins, including apolipoprotein E, cytoplasmic phospholipase A2, prostaglandin and calpain with anti-PrP antibody-mediated ‘apoptosis’, however, these proteins are also known to play an important role in allergy. In this study, we investigated whether cross-linking PrPC with anti-PrP antibodies stimulates a neuronal allergenic response.MethodsInitially, we predicted the allergenicity of the epitope sequences associated with ‘neurotoxic’ anti-PrP antibodies using allergenicity prediction servers. We then investigated whether anti-PrP antibody treatment of mouse primary neurons (MPN), neuroblastoma cells (N2a) and microglia (N11) cell lines lead to a neuronal allergenic response.ResultsIn-Silico studies showed that both tail- and globular-epitopes were allergenic. Specifically, binding regions that contain epitopes for previously reported ‘neurotoxic’ antibodies such as ICSM18 (146-159), ICSM35 (91-110), POM 1 (138-147) and POM 3 (95-100) lead to activation of allergenic related proteins. Following direct application of anti-PrPC antibodies on N2a cells, we identified 4 neuronal allergenic-related proteins when compared with untreated cells. Furthermore, we identified 8 neuronal allergenic-related proteins following treatment of N11 cells with anti-PrPC antibodies prior to co-culture with N2a cells when compared with untreated cells. Antibody treatment of MPN or MPN co-cultured with antibody-treated N11 led to identifying 10 and 7 allergenic-related proteins when compared with untreated cells. However, comparison with 3F4 antibody treatment revealed 5 and 4 allergenic-related proteins respectively. Of importance, we showed that the allergenic effects triggered by the anti-PrP antibodies were more potent when antibody-treated microglia were co-cultured with the neuroblastoma cell line. Finally, co-culture of N2a or MPN with N11-treated with anti-PrP antibodies resulted in significant accumulation of NO and IL6 but not TNF-α in the cell culture media supernatant.ConclusionsThis study showed for the first time that anti-PrP antibody binding to PrPC triggers a neuronal hypersensitivity response and highlights the important role of microglia in triggering an IgG-mediated neuronal hypersensitivity response. Moreover, this study provides an important impetus for including allergenic assessment of therapeutic antibodies for neurodegenerative disorders to derive safe and targeted biotherapeutics.

Protein and Antibody Engineering: Suppressing Degranulation of the Mast Cells and Type I Hypersensitivity Reaction

With an increase in atopic cases and owing to a significant role of mast cells in type I hypersensitivity, a therapeutic need to inhibit degranulation of mast cells has risen. Mast cells are notorious for IgE-mediated allergic response. Advancements have allowed researchers to improve clinical outcomes of already available therapies. Engineered peptides and antibodies can be easily manipulated to attain desired characteristics as per the biological environment. A number of these molecules are designed to target mast cells in order to regulate the release of histamine and other mediators, thereby controlling type I hypersensitivity response. The aim of this review paper is to highlight some of the significant molecules designed for the purpose.

168 Nursery diets formulated with deoxynivalenol-contaminated corn reduced growth performance but did not modulate the cutaneous hypersensitivity response to ovalbumin or candida albicans

A total of 144 newly weaned pigs (21 days of age) were used to determine the effect of deoxynivalenol (DON)-contaminated corn, with or without NutraMix™ supplementation, on growth performance and indices of immune system functionality during the nursery period. Pigs were randomly allocated to 24 pens of six pigs and assigned to 1 of 4 dietary treatments according to a 2X2 factorial design (n=6); treatments were fed for the 43±1-day nursery period in three phases (phases I, II, and III fed for 8, 14, and 21±1 days, respectively). The factors were clean or DON-contaminated corn and with (2 g/kg in complete diet) or without NutraMix™ supplementation. The DON diets were formulated to ensure a step-up in DON concentration for each phase (3, 4, and 5 ppm in phases I, II, and III, respectively; analyzed concentrations were 3, 3 and 4 ppm). Individual pig body weights and per pen feed intake were recorded weekly. Two pigs per pen were vaccinated against ovalbumin and candida albicans to measure humoral and cell-mediated immune responses by the cutaneous hypersensitivity response test. The ADG (600 vs 693±28 g) and ADFI (979 vs 1110±51 g) in phase III and final BW (25.2 vs 27.1±0.9 kg) were reduced for pigs fed contaminated corn (P< 0.005, P=0.088, and P< 0.05, respectively). NutraMix™ supplementation tended (P=0.086) to improve ADFI (181 vs 142±14 g) in the first week after weaning. All pigs responded to both ovalbumin and candida albicans during the cutaneous hypersensitivity response (P< 0.05), but DON nor NutraMix™ influenced the response. The DON-contaminated diets had the greatest impact on pig growth performance during phase III and when DON concentration was 4 ppm, with no modulation of the cutaneous hypersensitivity response. NutraMix™ supplementation during the early weaning period may be a means to stimulate nursery pig feed intake.

In vitro and In Vivo Immunomodulatory Activity of Physalis angulata Concentrated Ethanolic Extract

The need for new immunomodulatory drugs is due to the side effects associated with the prolonged use of the currently used immunomodulatory drugs. In this context, the present work aimed to investigate the immunomodulatory effect of an ethanolic concentrated extract from Physalis angulata. The cytotoxicity of samples was determined using peritoneal macrophages though the Alamar Blue assay. The immunomodulatory activity of the ethanolic extract from P. angulata on activated macrophages was determined by measurement of nitrite and cytokine production. The immunosuppressive effects of the ethanolic extract from P. angulata was evaluated on lymphocyte proliferation and cytokine production. The effects of the extract on cell cycle progression and cell death on lymphocytes were evaluated by flow cytometry. Lastly, the ethanolic extract from P. angulata was tested in vivo in toxicological tests and in models of peritonitis and delayed-type hypersensitivity response. The ethanolic extract from P. angulata decreased nitrite, interleukin-6, interleukin-12, and TNF-α production by activated macrophages without affecting the cell viability. In addition, the ethanolic extract from P. angulata inhibited lymphoproliferation and the secretion of interleukin-2, interleukin-6, and IFN-γ, and increased interleukin-4 secretion by activated splenocytes. Flow cytometry analysis in lymphocyte cultures showed that treatment with the ethanolic extract from P. angulata induces cell cycle arrest in the G1 phase followed by cell death by apoptosis. Moreover, mice treated with the extract from P. angulata at 100 or 200 mg/kg did not show signs of toxicity or alterations in serum components. Finally, the ethanolic extract from P. angulata significantly reduced neutrophil migration and reduced paw edema in bovine serum albumin-induced the delayed-type hypersensitivity response model. Our results demonstrate the potential of the ethanolic extract of P. angulata as an alternative for the treatment of immune-inflammatory diseases.