1.Targeted innovative design of Bt Cry toxin insecticidal mimics.
Chongxin XU ; Yuan LIU ; Xiao ZHANG ; Xianjin LIU
Chinese Journal of Biotechnology 2023;39(2):446-458
Bt Cry toxin is the mostly studied and widely used biological insect resistance protein, which plays a leading role in the green control of agricultural pests worldwide. However, with the wide application of its preparations and transgenic insecticidal crops, the resistance to target pests and potential ecological risks induced by the drive are increasingly prominent and attracting much attention. The researchers seek to explore new insecticidal protein materials that can simulate the insecticidal function of Bt Cry toxin. This will help to escort the sustainable and healthy production of crops, and relieve the pressure of target pests' resistance to Bt Cry toxin to a certain extent. In recent years, the author's team has proposed that Ab2β anti-idiotype antibody has the property of mimicking antigen structure and function based on the "Immune network theory" of antibody. With the help of phage display antibody library and specific antibody high-throughput screening and identification technology, Bt Cry toxin antibody was designed as the coating target antigen, and a series of Ab2β anti-idiotype antibodies (namely Bt Cry toxin insecticidal mimics) were screened from the phage antibody library. Among them, the lethality of Bt Cry toxin insecticidal mimics with the strongest activity was close to 80% of the corresponding original Bt Cry toxin, showing great promise for the targeted design of Bt Cry toxin insecticidal mimics. This paper systematically summarized the theoretical basis, technical conditions, research status, and discussed the development trend of relevant technologies and how to promote the application of existing achievements, aiming to facilitate the research and development of green insect-resistant materials.
Insecticides/metabolism*
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Bacillus thuringiensis
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Endotoxins/pharmacology*
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Bacillus thuringiensis Toxins/metabolism*
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Hemolysin Proteins/pharmacology*
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Bacterial Proteins/chemistry*
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Plants, Genetically Modified/genetics*
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Pest Control, Biological
2.ISA 61 VG adjuvant enhances protective immune response of Listeria monocytogenes inactivated vaccine.
Tengfei ZHU ; Fanzeng MENG ; Hao YAO ; Yuting WANG ; Xin'an JIAO ; Yuelan YIN
Chinese Journal of Biotechnology 2020;36(7):1378-1385
Listeria monocytogenes (Lm) is zoonotic pathogen that can cause listeriosis, and vaccine is one of the effective methods to prevent this pathogen infection. In this study, we developed a novel vaccine that is a mixture of inactivated bacteria and Montanide™ ISA 61 VG, a mineral oil adjuvant, and evaluated the safety and immune response characteristics of this vaccine. The mice immunized with the ISA 61 VG adjuvant had high safety, and it could induce significantly higher titer of anti-listeriolysin O (LLO) antibody and higher value of IgG2a/IgG1 ratio compared with the group without the adjuvant. In particular, it could provide 100% immune protection against lethal doses of Lm challenge in mice. In summary, ISA 61VG adjuvant significantly enhanced the ability of inactivated listeria vaccine to induce humoral and cellular immune responses, thereby enhanced the protective immune response in the host, and it is a potential vaccine candidate for the prevention of Lm infection in humans and animals.
Adjuvants, Immunologic
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pharmacology
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Animals
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Hemolysin Proteins
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immunology
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pharmacology
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Immunity, Cellular
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drug effects
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Listeria monocytogenes
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immunology
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Listeriosis
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prevention & control
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Mice
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Mice, Inbred BALB C
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Vaccines, Inactivated
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immunology
3.Study on pharmacology of ultra-fine particles compound Rehmannia.
Li-li SONG ; Gang-jun DU ; Bing-yi FAN ; Da-lu ZHANG
China Journal of Chinese Materia Medica 2002;27(6):436-439
OBJECTIVETo observe pharmacological difference between ultra-fine particles of six ingredient Rehmannia pill and traditional six ingredient Rehmannia pill.
METHODPharmacokinetic index was measured by death rate, and pharmacology actions were compared by anti-fatigue, hypoglycemic, clearance rate of charcoal particle, hypoxia resistance and serum hemolysin concentration experiment.
RESULTDose-effection was significant and pharmacology actions were more than traditional six ingredient Rehmannia pill in six ingredient Rehmannia pill.
CONCLUSIONUltra-fine particles of six ingredient Rehmannia pill are better than traditional six ingredient Rehmannia pill in bioavailability and pharmacology actions, and the weight of pill is reduced while efficacy is enhenced by ultra-fine particles.
Animals ; Biological Availability ; Drugs, Chinese Herbal ; pharmacokinetics ; pharmacology ; Fatigue ; drug therapy ; Hemolysin Proteins ; blood ; Hypoglycemic Agents ; pharmacology ; Male ; Metabolic Clearance Rate ; Mice ; Plants, Medicinal ; chemistry ; Powders ; Rehmannia ; chemistry
4.Advances in receptor-mediated resistance mechanisms of Lepidopteran insects to Bacillus thuringiensis toxin.
Leilei LIU ; Peiwen XU ; Kaiyu LIU ; Wei WEI ; Zhongshen CHANG ; Dahui CHENG
Chinese Journal of Biotechnology 2022;38(5):1809-1823
Bacillus thuringiensis is widely used as an insecticide which is safe and environmentally friendly to humans and animals. One of the important insecticidal mechanisms is the binding of Bt toxins to specific toxin receptors in insect midgut and forming a toxin perforation which eventually leads to insect death. The resistance of target pests to Bt toxins is an important factor hampering the long-term effective cultivation of Bt crops and the continuous use of Bt toxins. This review summarizes the mechanism of insect resistance to Bt toxins from the perspective of important Bt toxin receptors in midgut cells of Lepidopteran insects, which may facilitate the in-depth study of Bt resistance mechanism and pest control.
Animals
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Bacillus thuringiensis/genetics*
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Bacillus thuringiensis Toxins
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Bacterial Proteins/metabolism*
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Endotoxins/metabolism*
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Hemolysin Proteins/metabolism*
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Insecta/metabolism*
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Insecticide Resistance/genetics*
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Insecticides/pharmacology*
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Pest Control, Biological
5.Cloning and superexpression of cry1Ac gene from 20kb DNA associated with Bacillus thuringiensis Cry1A Crystal Protein.
Hong-Yuan HU ; Li-Qiu XIA ; Hong-Juan SHI ; Yun-Jun SUN ; Bi-Da GAO ; Xue-Zhi DING
Chinese Journal of Biotechnology 2004;20(5):656-661
The CrylA Crystal Protein from Bacillus thuringiensis is associated with DNA, but the role and sequences of these DNA molecules are unknown. CrylA bipyramidal crystals from B. thuringiensis strain 4.0718 was selectively dissolved and associated DNA was extracted from protoxin. The DNA was digested with Nde I to obtain 3 to 5 kb fragments and then the fragments were subcloned into pMD18-T vector, screening of recombinants were done by PCR-RFLP and sequencing. The ORF of cry1Ac gene was amplified by primers designed and then subcloned. The 3.5 kb BamH I and Sal I fragments of pMDX35 was inserted into the pET30a vector, giving 8.9 kb recombinant plasmid, pETX35. ETX35 strain were obtained by transformed pETX35 into B121 (DE3). A 141 kD fusion protein was superexpressed as inclusion bodies. Quantitative protein analysis indicated that the amount of 141 kD protein was above the level of 51.36% of total cellular protein. Plasmid pHTX42 constructed from shuttle vector pHT304 was transformed B. thuringiensis acrystalliferous strain XBU001 with electroporation to obtain the recombinant HTX42. The recombinant protein was found with a molecular mass of 130 kD on sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). Scanning analysis indicated that the expressed protein accounted up to 79.28% of total cellular proteins and accumulated in the cells mounted up to 64.13% of cellular dry weight. Under Atomic Force Microscopy (AFM), typical bipyramidal crystals from HTX42 strain were found with a size of 1.2 microm x 2.0 microm. Bioassay showed that these inclusion bodies of ETX35 strain and crystals from HTX42 strain were highly toxic against the larvae of Plutella xylostella. On such a base, constructing insecticidal recombinant and analyzing the source, structure, and function of the 20 kb DNA can be further achieved.
Animals
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Bacillus thuringiensis
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genetics
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Bacterial Proteins
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biosynthesis
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genetics
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pharmacology
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Cloning, Molecular
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Endotoxins
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biosynthesis
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genetics
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pharmacology
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Hemolysin Proteins
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biosynthesis
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genetics
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pharmacology
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Microscopy, Atomic Force
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Moths
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Plasmids
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Recombinant Proteins
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biosynthesis
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pharmacology
6.Modeling relationship between sequence characteristics of insecticidal crystal proteins and their inhibitory against Plutella xylostella.
Yi LIN ; Fuying CAI ; Guangya ZHANG
Chinese Journal of Biotechnology 2008;24(8):1395-1400
The knowledge of the relationship between sequence characteristics of insecticidal crystal proteins (ICP) and their inhibitory against Plutella xylostella provided helpful information for the rational design of ICP with desirable activity against Plutella xylostella. The four key loops of ICP with determined activities against Plutella xylostella were selected to study the quantitative relationship between sequence characteristics and insecticidal activity. The first principle components' score vectors for 20 amino acids were assigned to converting amino acids into data. The six key sites X3, X9, X12, X13, X14 and X19 were predicted by stepwise regression method. The amino acids L/ X3, S/ X9, S/ X12, T/ X13, A/ X14 and G/ X19 found by partial least squares regression and second order polynomial models were predicted to increase the activity of ICP against Plutella xylostella.
Amino Acid Sequence
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Animals
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Bacterial Proteins
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genetics
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pharmacology
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Endotoxins
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genetics
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pharmacology
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Hemolysin Proteins
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genetics
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pharmacology
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Insecticides
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metabolism
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pharmacology
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Models, Biological
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Molecular Sequence Data
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Moths
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genetics
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metabolism
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Pest Control, Biological
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Sequence Analysis, Protein
7.Homology modeling of mosquitocidal Cry30Ca2 of Bacillus thuringiensis and its molecular docking with N-acetylgalactosamine.
Xin Min ZHAO ; Pan Deng ZHOU ; Li Qui XIA
Biomedical and Environmental Sciences 2012;25(5):590-596
OBJECTIVETo investigate the theoretical model of the three-dimensional structure of mosquitocidal Cry30Ca2 and its molecular docking with N-acetylgalactosamine.
METHODSThe theoretical model of Cry30Ca2 was predicted by homology modeling on the structure of the Cry4Ba. Docking studies were performed to investigate the interaction of Cry30Ca2 with N-acetylgalactosamine on the putative receptor.
RESULTSCry30Ca2 toxin is a rather compact molecule composed of three distinct domains and has approximate overall dimensions of 95 by 75 by 60Å. Domain II is a helix bundle, Domain II consists of three antiparallel β-sheets, Domain III is composed of two β-sheets that adopt a β-sandwich fold. Residue 321Ile in loop1, residues 342Gln 343Thr and 345Gln in loop2, residue 393Tyr in loop3 of Cry30Ca2 are responsible for the interactions with GalNAc via 7 hydrogen bonds, 6 of them were related to the oxygen atoms of hydroxyls of the ligand, and one to the nitrogen of the ligand.
CONCLUSIONThe 3D structure of Cry30Ca2 resembles the previously reported Cry toxin structures but shows still some distinctions. Several residues in the loops of the apex of domain II are responsible for the interactions with N-acetylgalactosamine.
Acetylgalactosamine ; chemistry ; Amino Acid Sequence ; Animals ; Bacterial Proteins ; chemistry ; pharmacology ; Catalytic Domain ; Culicidae ; drug effects ; Endotoxins ; chemistry ; pharmacology ; Hemolysin Proteins ; chemistry ; pharmacology ; Insecticides ; chemistry ; pharmacology ; Models, Molecular ; Molecular Sequence Data ; Protein Conformation
8.Bacillus thuringiensis helper protein P20 affects the formation of Cry1Ab.
Mu-Jin TANG ; Mei-Jin YUAN ; Jian-Wu CHEN ; Yong-Xia SHI ; Shao-Ling ZENG ; Jian-Xiu YU ; Yi PANG
Chinese Journal of Biotechnology 2003;19(5):566-571
The Cry1Ab differs most significantly from the other related ICPs by its absence of a carboxyl terminus of 28 amino acids including four cysteines; consequently it is less stable. We report that the helper protein P20 plays a role in the expression and crystallization of Cry1Ab. Three Cry1Ab expression plasmids pT1B, pP1B, and pDP1B, were constructed based on the shuttle vector pHT3101. The vector pT1B does not contain the p20 gene, pP1B carries p20, and pDP1B contains p20 with cry1A(c) promoter. Transformants were obtained by electroporating the plasmids into Bacillus thuringiensis acrystalliferous mutant CryB. Western blot demonstrated that crylAb was expressed as a 130 kD protein in all the transformants, and some of the protein was partially degraded into a 60 kD peptide. Quantitative protein analysis indicated that the amount of the 130 kD protein varied in the transformants and was in the ratio of 1:1.4:1.5 for PT1B, pP1B and pDP1B respectively. For the 60 kD proteins, the ratio was 1:1.1:1.6. Microscopic examination revealed that the size of the typical pyramidal crystals in the three transformants was in the order of T1B < P1B < DP1B. Bioassay showed that T1B, P1B and DP1B were all toxic to the larvae of Helicoverpa armigera with similar LC50. This study suggested that P20 plays a role in the expression and crystallization of Cry1Ab.
Animals
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Bacillus thuringiensis
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genetics
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metabolism
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ultrastructure
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Bacterial Proteins
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genetics
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metabolism
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pharmacology
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Biological Assay
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methods
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Blotting, Western
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Electroporation
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Endotoxins
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genetics
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metabolism
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pharmacology
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Hemolysin Proteins
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genetics
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metabolism
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pharmacology
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Microscopy, Electron, Transmission
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Moths
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drug effects
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Promoter Regions, Genetic
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genetics
9.Suilysin remodels the cytoskeletons of human brain microvascular endothelial cells by activating RhoA and Rac1 GTPase.
Qingyu LV ; Huaijie HAO ; Lili BI ; Yuling ZHENG ; Xuyu ZHOU ; Yongqiang JIANG
Protein & Cell 2014;5(4):261-264
Brain
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Cholesterol
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chemistry
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Cytoskeleton
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drug effects
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Endothelial Cells
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cytology
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metabolism
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Hemolysin Proteins
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chemistry
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pharmacology
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Humans
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Phalloidine
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pharmacology
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Pseudopodia
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drug effects
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Stress Fibers
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drug effects
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rac1 GTP-Binding Protein
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metabolism
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rhoA GTP-Binding Protein
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metabolism
10.Effect of xue hanjing oral fluid on mice immunological function.
Da-lian QIN ; Shun-han XIAO ; Zhuo ZHANG ; Hua LI ; Liang LI ; Xin-wu HUANG
China Journal of Chinese Materia Medica 2003;28(8):769-771
OBJECTIVETo observe effect of Xue Hanjing oral fluid on mice immunological function.
METHODThe weight of thymus gland and spleen and the function of abdominal cavity macrophage were measured. Production of the hemolysin antibody, the immunoglobulin of blood serum and complement and the proliferation of T lymphocytes were observed respectively by means of microblood, immune-turbidimetry and MTT staining.
RESULTXue Hanjing oral fluid could enhance index of the thymus gland and spleen and the phago-percent of abdominal cavity macrophage, increase the immunoglobulin of blood serum(IgG and IgM), and accelerate production of the hemolysin antibody and the proliferation of T lymphocytes.
CONCLUSIONSXue Hanjing oral can reinforce immunological function in mice.
Adjuvants, Immunologic ; pharmacology ; Administration, Oral ; Animals ; Antibody Formation ; Cell Division ; drug effects ; Drugs, Chinese Herbal ; administration & dosage ; isolation & purification ; pharmacology ; Female ; Hemolysin Proteins ; immunology ; Immunoglobulin G ; blood ; Immunoglobulin M ; blood ; Macrophages, Peritoneal ; physiology ; Male ; Mice ; Organ Size ; drug effects ; Phagocytosis ; drug effects ; Plants, Medicinal ; chemistry ; Poaceae ; chemistry ; Random Allocation ; T-Lymphocytes ; cytology