Departamento de Farmacobiología, Centro de Investigación y de Estudios Avanzados del IPN, Sede Sur, Calzada de los Tenorios No 235, Col Granjas Coapa, Tlalpan, Mexico, DF, México.
Inflamm Res. 2011 Jan;60(1):19-27. doi: 10.1007/s00011-010-0230-4. Epub 2010 Jul 13.
Effects of immunoglobulin E (IgE)-dependent sensitization on the response to bacterial lipopolysaccharide (LPS) were analyzed in mast cells.
Murine bone marrow-derived mast cells (BMMCs) were sensitized or not with IgE before stimulation with LPS. TLR4 and co-receptors expression was analyzed by flow cytometry and RT-PCR, TNF-α production by ELISA, IKK and IκB activation by western blot or immunoprecipitation. NFκB nuclear translocation was determined by EMSA.
IgE-sensitized BMMCs secreted larger amounts of TNF-α than non-sensitized cells shortly after LPS challenge. No change in TLR4, CD14 or MD-2 expression was detected after the IgE-dependent sensitization process, whereas TLR4-dependent phosphorylation of IKK and IκB was augmented. IgE-dependent sensitization increased basal NFκB activity. Endotoxin tolerance was not affected by the IgE-dependent sensitization process.
IgE-induced sensitization primes mast cells for higher response to LPS through pre-activation of NFκB transcription factor. IgE-dependent sensitization does not modify events leading to endotoxin tolerance.
分析免疫球蛋白 E（IgE）依赖性致敏对肥大细胞对细菌脂多糖（LPS）反应的影响。
在 LPS 刺激前，用 IgE 对鼠骨髓来源的肥大细胞（BMMCs）进行致敏或非致敏处理。通过流式细胞术和 RT-PCR 分析 TLR4 和共受体表达，通过 ELISA 分析 TNF-α 产生，通过 Western blot 或免疫沉淀分析 IKK 和 IκB 激活，通过 EMSA 测定 NFκB 核易位。
与未致敏细胞相比，IgE 致敏的 BMMCs 在 LPS 刺激后短时间内分泌出更多的 TNF-α。在 IgE 依赖性致敏过程后，TLR4、CD14 或 MD-2 的表达没有变化，而 TLR4 依赖性 IKK 和 IκB 的磷酸化增强。IgE 依赖性致敏增加了基础 NFκB 活性。内毒素耐受不受 IgE 依赖性致敏过程的影响。
IgE 诱导的致敏通过 NFκB 转录因子的预先激活，使肥大细胞对 LPS 产生更高的反应。IgE 依赖性致敏不改变导致内毒素耐受的事件。
