Toll-like Receptor 4 Deficiency Aggravates Airway Hyperresponsiveness and Inflammation by Impairing Neutrophil Apoptosis in a Toluene Diisocyanate-Induced Murine Asthma Model

Purpose@#Accumulating evidence has suggested that toll-like receptor 4 (TLR4) is critically involved in the pathogenesis of asthma. The aim of this study was to investigate the role of TLR4 in toluene diisocyanate (TDI)-induced allergic airway inflammation. @*Methods@#TLR4−/− and wild-type (WT) C57BL/10J mice were sensitized and challenged with TDI to generate a TDI-induced asthma model. B-cell lymphoma 2 (Bcl-2) inhibitors, ABT-199 (4 mg/kg) and ABT-737 (4 mg/kg), were intranasally given to TDI-exposed TLR4−/− mice after each challenge. @*Results@#TDI exposure led to increased airway hyperresponsiveness (AHR), granulocyte flux, bronchial epithelial shedding and extensive submucosal collagen deposition, which were unexpectedly aggravated by TLR4 deficiency. Following TDI challenge, TLR4−/− mice exhibited down-regulated interleukin-17A and increased colony-stimulating factor 3 in bronchoalveolar lavage fluid (BALF), while WT mice did not. In addition, TLR4 deficiency robustly suppressed the expression of NOD-like receptor family pyrin domain containing 3 and NLR family CARD domain containing 4, decreased caspase-1 activity in TDI-exposed mice, but had no effect on the level of high mobility group box 1 in BALF. Flow cytometry revealed that TDI hampered both neutrophil and eosinophil apoptosis, of which neutrophil apoptosis was further inhibited in TDI-exposed TLR4−/− mice, with marked up-regulation of Bcl-2. Moreover, inhibition of Bcl-2 with either ABT-199 or ABT-737 significantly alleviated neutrophil recruitment by promoting apoptosis. @*Conclusions@#These data indicated that TLR4 deficiency promoted neutrophil infiltration by impairing its apoptosis via up-regulation of Bcl-2, thereby resulting in deteriorated AHR and airway inflammation, which suggests that TLR4 could be a negative regulator of TDI-induced neutrophilic inflammation.

Toll-like Receptor 4 Deficiency Aggravates Airway Hyperresponsiveness and Inflammation by Impairing Neutrophil Apoptosis in a Toluene Diisocyanate-Induced Murine Asthma Model

Purpose@#Accumulating evidence has suggested that toll-like receptor 4 (TLR4) is critically involved in the pathogenesis of asthma. The aim of this study was to investigate the role of TLR4 in toluene diisocyanate (TDI)-induced allergic airway inflammation. @*Methods@#TLR4−/− and wild-type (WT) C57BL/10J mice were sensitized and challenged with TDI to generate a TDI-induced asthma model. B-cell lymphoma 2 (Bcl-2) inhibitors, ABT-199 (4 mg/kg) and ABT-737 (4 mg/kg), were intranasally given to TDI-exposed TLR4−/− mice after each challenge. @*Results@#TDI exposure led to increased airway hyperresponsiveness (AHR), granulocyte flux, bronchial epithelial shedding and extensive submucosal collagen deposition, which were unexpectedly aggravated by TLR4 deficiency. Following TDI challenge, TLR4−/− mice exhibited down-regulated interleukin-17A and increased colony-stimulating factor 3 in bronchoalveolar lavage fluid (BALF), while WT mice did not. In addition, TLR4 deficiency robustly suppressed the expression of NOD-like receptor family pyrin domain containing 3 and NLR family CARD domain containing 4, decreased caspase-1 activity in TDI-exposed mice, but had no effect on the level of high mobility group box 1 in BALF. Flow cytometry revealed that TDI hampered both neutrophil and eosinophil apoptosis, of which neutrophil apoptosis was further inhibited in TDI-exposed TLR4−/− mice, with marked up-regulation of Bcl-2. Moreover, inhibition of Bcl-2 with either ABT-199 or ABT-737 significantly alleviated neutrophil recruitment by promoting apoptosis. @*Conclusions@#These data indicated that TLR4 deficiency promoted neutrophil infiltration by impairing its apoptosis via up-regulation of Bcl-2, thereby resulting in deteriorated AHR and airway inflammation, which suggests that TLR4 could be a negative regulator of TDI-induced neutrophilic inflammation.

Preliminary experimental study on mechanism of intestinal mucosal damage induced by IgG immune complex in mice / 中国免疫学杂志

Objective:To study the cellular pathology and molecular mechanisms of intestinal mucosal damage induced by IgG immune complex in mice.And to explore the pathogenic mechanism and molecular diagnosis evidence of ulcerative colitis induced by food intolerance in clinical practice.Methods: Six weeks old BALB/c female mice were used to build animal model.All the mice were divided into four groups:the control group(group A),the rabbit intestinal mucosal protein immunized group(group B),the DSS induced group(group C),the rabbit intestinal mucosal protein immunized combined with DSS induced group(group D).After successful establishment of animal model,serum and colon tissues were collected to be performed relevant tests.Results: IgG level in serum and colonic mucosa of group B mice increased.And inflammatory cell infiltration and a small amount of mast cell activation were observed in intestinal mucosa;group C mice showed the typical acute ulcerative colitis:a large number of inflammatory cells infiltration,inflammatory factor levels increased in mucosa and mucosa lamina propria,and mucosal epithelial cells′ tight junction weakened;group D mice manifested both high level of IgG in serum and colonic mucosa and also typical acute ulcerative colitis.Besides,significant mast cell activation was observed in the intestinal mucosa.Conclusion: We infer from the experimental results that IgG immune complexes can induce the damage of intestinal epithelium by mediating activation of mast cells.And during the process,the level of inflammatory cytokines increased in intestinal mucosa and the expression of tight junction protein in epithelial cell decreased.These factors contribute to the promotion of intestinal mucosa damage induced by immune complexes.

Cell-in-Cell Death Is Not Restricted by Caspase-3 Deficiency in MCF-7 Cells / 한국유방암학회지

PURPOSE: Cell-in-cell structures are created by one living cell entering another homotypic or heterotypic living cell, which usually leads to the death of the internalized cell, specifically through caspase-dependent cell death (emperitosis) or lysosome-dependent cell death (entosis). Although entosis has attracted great attention, its occurrence is controversial, because one cell line used in its study (MCF-7) is deficient in caspase-3. METHODS: We investigated this issue using MCF-7 and A431 cell lines, which often display cell-in-cell invasion, and have different levels of caspase-3 expression. Cell-in-cell death morphology, microstructures, and signaling pathways were compared in the two cell lines. RESULTS: Our results confirmed that MCF-7 cells are caspase-3 deficient with a partial deletion in the CASP-3 gene. These cells underwent cell death that lacked typical apoptotic properties after staurosporine treatment, whereas caspase-3-sufficient A431 cells displayed typical apoptosis. The presence of caspase-3 was related neither to the lysosome-dependent nor to the caspase-dependent cell-in-cell death pathway. However, the existence of caspase-3 was associated with a switch from lysosome-dependent cell-in-cell death to the apoptotic cell-in-cell death pathway during entosis. Moreover, cellular hypoxia, mitochondrial swelling, release of cytochrome C, and autophagy were observed in internalized cells during entosis. CONCLUSION: The occurrence of caspase-independent entosis is not a cell-specific process. In addition, entosis actually represents a cellular self-repair system, functioning through autophagy, to degrade damaged mitochondria resulting from cellular hypoxia in cell-in-cell structures. However, sustained autophagy-associated signal activation, without reduction in cellular hypoxia, eventually leads to lysosome-dependent intracellular cell death.

In silico prediction for physicochemical properties and structure of major pollen allergen Lig v 1 in Ligustrum vulgare / 中国免疫学杂志

Objective:To analyse the physicochemical properties and structure of major privet pollen allergen Lig v 1 using bioinformatics software and provide a reference for choosing suitable recombinant expression system for Lig v 1 and modifying the allergen Lig v 1 experimentally.Methods:The physicochemical properties were analysed by ProtParam,the signal peptide by SignalP 4.1 Server,the transmembrane helix by TMHMM Server v.2.0,the secondary structure by GOR4,MHCⅡepitopes by NetMHCⅡ2.2 Server,B-cell epitopes by ProteanTM 5.01 and the phylogenetic tree by MEGA 6.Results: Privet major pollen allergen Lig v 1 was stable in Escherichia coli and it doesn′t possess any signal peptide and transmembrane helix.Most secondary structures of Lig v 1 were random coils.Potential region of MHCⅡepitope of Lig v 1 was 30-44.Potential B-cell epitopes possess discontinuous and continuous a mino acid sequences.Lig v 1 and its counterparts from Fraxinus excelsior and Olea europaea were clustered into one group.Conclusion:Escherichia coli is the suitable expression system for recombinant Lig v 1.In silico prediction of the epitopes of Lig v 1 provides a reference for modifying the allergen Lig v 1 experimentally.

Expression and purification of Litopenaeus vannamei allergen protein Lit v1.2 / 中国免疫学杂志

Objective:To obtain purified recombinant Litopenaeus vannamei allergen protein Lit v 1.2.Methods: The target gene of Lit v 1.2 was inserted into clone vector pGEM-T and then ligated to the expression vector pET 44a.The pET44a-Liv 1.2 was transformed into Rosetta and screened by ampicillin resistance .The recombinant protein was expressed by IPTG induction .The protein was purified by 6-His tag affinity chromatography and the purification was analyzed by SDS-PAGE gel electrophoresis .Results:The ex-pression plasmid pET44a-Lit v 1.2 was constructed.SDS-PAGE showed that expressed Lit v 1.2 was efficient and soluble in E.coli Rosetta.The protein molecular weight was consistent with the theoretical value .The highly purified target protein was obtained.Conclusion:In this study ,we successfully gained highly purified recombinant allergen protein Lit v 1.2 which was expressed in prokaryotic system and purified by affinity chromatography column .The purified Lit v 1.2 protein will facilitate us to further study its role in immunological responses .

Prediction of antigenic epitopes on HA, NA amino acid sequences of novel influenza A (H7N9) virus and analysis association between susceptibility and HLA-Ⅱalleles / 中国免疫学杂志

Objective:To compare the amino acid sequences difference of HA,NA novel influenza virus A/H7N9 isolates, decipher possible B cell epitopes and T cell epitopes of HA,NA protein,and analyze the association between susceptibility and HLA polymorphisms.Methods:The amino acid sequences of novel influenza A ( H7N9) virus were downloaded from Genbank.Phylogenetic trees were constructed based on the amino acid sequences of HA and NA by using software Clustal X and MEGA 4.0.B cell and T cell epitopes were respectively predicted with Protean software and NetMHCⅡ2.2 Server online server.Results:The homology of HA and NA proteins of H7N9 virus was high.10 B cell epitopes and 15 T cell epitopes were randomly distributed throughout HA sequence and 12 B cell epitopes and 9 T cell epitopes were randomly distributed throughout NA sequence.HLA-DRB1*0701 allele which was commonly observed in Northern Chinese population have a high binding affinity for 9-mer peptides of HA and NA proteins.Conclusion:The prediction of B and T cell epitopes of HA and NA proteins with multiple methods benefits the research and development of vaccine against human infection with avian influenza A H7N9 virus.HLA-DRB1*0701 allele may contribute to susceptibility to novel influenza A (H7N9) virus.H7N9 influenza virus is more easily spread in Urumqi,Harbin,Shandong Province,Liaoning Province,Beijing, Shijiazhuang and Tianjin of China.

Application status of odds ratio for medical animal experiments / 中国药理学通报

Aim To study the application status of odds ratio for medical animal experiments.Methods Odds ratio and seven kinds of animal models were used as retrieval strategy to search medical animal experiment related papers in several Chinese and English databases.Papers relating to each kind of animal model and using odds ratio in abstract and text were counted. Data from different databases were compared. Calculation of odds ratio was exemplified and the significance of different odds ratio values was illustrated in this paper.Results Few medical animal experiments cited odds ratio as statistics.Conclusions The importance of odds ratio has not been fully recognized in Chinese references.

Methodological research on the application of AFLP in complicated samples / 中国基层医药

Objective To explore the application probability of AFLP method (Amplified Fragment Length Polymorphism) for the genetic study of complicated samples and to make clear the analytical approach on polymorphic fragments.Methods An AFLP fragement sequence,resolved between murines with high and low metastatic hepatocarcinoma,was retrieved from a reference paper and was annotated on NCBI database by different BLAST programs. Results The retrieved information varied along with the different BLAST programs, nevertheless BLASTX program provided more comprehensive information and showed that the differentiated fragment exhibited high homology with terminase large subunits from Burkholderia phage Bups phil and Mycobacterium tuberculosis H37Ra. However, there is no detailed information for the latter,key words search returned the relationship between terminase and the formation and metastasis of tumors and provided the further research clues. Conclusions Whole genome screening in parallel of AFLP markers between genetically differentiated paired materials would readily produce informatic fragments. Further analysis of the sequenced fragments by informatic methods would facilitate the subsequent research.

Allergenicity evaluation and three dimensional structure analysis of pollen panallergen Profilin from Amaranthus spinosus L / 中华微生物学和免疫学杂志

Objective To clone and characterize Profilin encoding genes in Amaranthus spinosus and to analyze the contribution of different amino acids in isoallergens to allergen antigenicity and tertiary structure. Methods The primers were designed according to the core sequences which were obtained by bioinformatic analysis of the known Profilin amino acid sequences, followed by gene cloning from the Ama- ranthus spinosus cDNA pool and subsequent confirmation by double-digestion, colony PCR and DNA sequen- cing. Antigenicity evaluation and tertiary structural modeling of the encoded protein were accomplished by online software MULTIPRED and SWISS-MODEL, respectively. Results Two panallergenic genes, named as PRF7 and PRF23, were acquired from Amaranthus spinosus. Sequence and structure analysis demonstra- ted that there was some discrepancy in tertiary structures of the encoded proteins, besides distinct difference in their amino acid sequences. PRF7 exhibited high homology with panallergen Profilins Q64LH0, with the identities 98%, whereas the homology of PRF23 and Q9XF42 (apple allergen) was 81%. Q64LH0 and PRF23 were modeled as 3nulA (Q42449) and lg5uB (Q9LE18), respectively. PRF23 exhibited distinct0 three dimensional structural difference in certain fragments compared with Q64LH0 and other Profilins. Though the average values of antigenicity displayed no difference between Q64LH0 and PRF23 on whole se- quences, the antigenicity of PRF23 on certain fragments was obviously lower than that of Q64LHO because of the alteration of some amino acids with different characters, implying the cause of lower incidence of hay fe- ver in South China than in North China. Conclusion Based on sequence analysis, antigenicity evaluation and tertiary structural modeling for Q64LH0 and PRF23, we obtained lots of useful information about the contribution of different amino acids to antigenicity and protein structures, thus would facilitate allergen ge- netic improvement by amino acid replacement.

Antigenic Localization of Specific Allergen in the Body of Dermatophagoides pteronyssinus by Immunohistochemistry / 中国寄生虫学与寄生虫病杂志

Objective To study the localization of specific allergen of Dermatophagoides pteronyssinus. \ Methods\ Through optical microscope,the specific allergens of D.pteronyssinus were observed in paraffin sections using D.pteronyssinus\|specific IgE antibodies from the patient sera. \ Results and Conclusion \ The digestive system was found occupying large parts of body cavity of D.pteronyssinus by HE staining, while the specific allergens of D.pteronyssinus were mostly occurred in the midgut tissue, gut contents, cuticle and reproductive system in the immunostained sections. The results also showed that many parts of D. pteronyssinus were recognized by the specific IgE antibodies obtained from allergic individuals to D.pteronyssinus, which provided a theoretic base for further study of isolation and purification of the specific allergen.