BACKGROUNDVascular endothelial growth factor (VEGF) in the thymus was mainly produced by the thymic epithelial cells (TECs), the predominant component of the thymic microenvironment. The progression of TECs and the roles of VEGF in the neonatal thymus during sepsis have not been reported. This study aimed to explore the alterations of TECs and VEGF level in the neonatal thymus involution and to explore the possible mechanisms at the cellular level.

METHODSBy establishing a model of clinical sepsis, the changes of TECs were measured by hematoxylin-eosin staining, confocal microscopy, and flow cytometry. Moreover, the levels of VEGF in serum and thymus were assessed based on enzyme-linked immunosorbent assay and Western blotting.

RESULTSThe number of thymocytes and TECs was significantly decreased 24 h after lipopolysaccharide (LPS) challenge, (2.40 ± 0.46)×10 7 vs. (3.93 ± 0.66)×10 7 and (1.16 ± 0.14)×10 5 vs. (2.20 ± 0.19)×10 5 , P < 0.05, respectively. Cortical TECs and medullary TECs in the LPS-treated mice were decreased 1.5-fold and 3.9-fold, P < 0.05, respectively, lower than those in the controls. The number of thymic epithelial progenitors was also decreased. VEGF expression in TECs was down-regulated in a time-dependent manner.

CONCLUSIONVEGF in thymic cells subsets might contribute to the development of TECs in neonatal sepsis.

Animals ; Animals, Newborn ; Cells, Cultured ; Epithelial Cells ; cytology ; drug effects ; metabolism ; Lipopolysaccharides ; toxicity ; Mice ; Thymus Gland ; cytology ; drug effects ; metabolism ; Vascular Endothelial Growth Factor A ; metabolism

Thymopentin (TP5) and bursopentin (BP5) are both immunopotentiators. To explore whether the TP5-BP5 fusion peptide (TBP5) has adjuvant activity or not, we cloned the TBP5 gene and confirmed that the TBP5 gene in a recombinant prokaryotic expression plasmid was successfully expressed in Escherichia coli BL21. TBP5 significantly promoted the proliferation of thymic and splenic lymphocytes of mice. The potential adjuvant activity of the TBP5 was examined in mice by coinjecting TBP5 and H9N2 avian influenza virus (AIV) inactivated vaccine. HI antibody titers, HA antibodies and cytokines levels (IL-4 and IFN-γ) were determined. We found that TBP5 markedly elevated serum HI titers and HA antibody levels, induced the secretion of both IL-4 and IFN-γ cytokines. Furthermore, virus challenge experiments confirmed that TBP5 contributed to inhibition replication of the virus [H9N2 AIV (A/chicken/Jiangsu/NJ07/05)] from mouse lungs. Altogether, these findings suggest that TBP5 may be an effective adjuvant for avian vaccine and that this study provides a reference for further research on new vaccine adjuvants.
Adjuvants, Immunologic ; pharmacology ; Animals ; Antibodies, Viral ; blood ; Cell Proliferation ; drug effects ; Influenza A Virus, H9N2 Subtype ; drug effects ; physiology ; Influenza Vaccines ; immunology ; Interferon-gamma ; immunology ; Interleukin-4 ; immunology ; Lymphocytes ; drug effects ; Mice ; Oligopeptides ; immunology ; Orthomyxoviridae Infections ; drug therapy ; Recombinant Fusion Proteins ; immunology ; Spleen ; cytology ; Thymopentin ; immunology ; Thymus Gland ; cytology ; Vaccines, Inactivated ; immunology ; Virus Replication

OBJECTIVETo investigate the effects of intragastric administration of human interferon-α (hIFN-α)-transformed Bifidobacterium on immune functions of mice.

METHODSThe E.coli-Bifidobacterium shuttle expression vector containing hIFN-α gene was constructed and transformed into Bifidobacterium. The hIFN-α-transformed Bifidobacterium suspension (1010 /ml) was prepared after induction with 0.2% L-arabinose for hIFN-α expression and administered intragastrically in male Balb/C mice at the dose of 0.1 ml every other day for 2 weeks, with the mice receiving empty vector-transformed Bifidobacteria as the negative control and those having an equal volume of saline as the blank control. The percentages of mononuclear cell subsets in the thymus, spleen and blood were detected in the mice by flow cytometry, and the serum levels of IL-4, IL-12, IFN-γ and TNF-α were assayed using mouse cytokine FlowCytomix Kit.

RESULTSThe percentages of CD3⁺CD8⁺ and CD4⁺CD8⁺ cells in the thymus, CD3⁺CD4⁺, CD3⁺CD8⁺ and CD4⁺CD8⁺ cells in the spleen, and CD3⁺CD8⁺ cells in the blood all increased significantly in IFN group as compared with those in the negative and blank control groups (P<0.01 or 0.05). The serum level of IFN-γ also increased significantly (P<0.05) while IL-4 level remained unchanged in IFN group compared with those in the two groups.

CONCLUSIONIntragastric administration of hIFN-α-transformed Bifidobacterium promotes lymphocyte proliferation and maturation and increases the serum levels of Th1 cytokines in mice.

Animals ; Bifidobacterium ; Cell Proliferation ; Genetic Vectors ; Humans ; Interferon-alpha ; pharmacology ; Interferon-gamma ; blood ; Interleukin-12 ; blood ; Interleukin-4 ; blood ; Lymphocyte Activation ; drug effects ; Male ; Mice ; Mice, Inbred BALB C ; Recombinant Proteins ; pharmacology ; Spleen ; cytology ; Th1 Cells ; cytology ; Thymus Gland ; cytology ; Tumor Necrosis Factor-alpha ; blood

This study was purposed to investigate the effects of high-dose dexamethasone on structure and function of thymic epithelial cells (TEC). Male C57BL/6 mice aged 6 to 8 weeks were used as experimental animals. The mice were injected intraperitoneally with dexamethasone (20 mg/kg), and the other mice treated with saline were used as controls. Thymus was harvested at day 5 after treatment. The histological changes of the treated thymus were monitored by HE staining and in situ immunofluorescence staining. The ratio of each subset in the thymus were analyzed by using flow cytometry, and quantitative PCR was applied to detect the expression levels of IL-22 and Foxn1, which represent the regenerative function of thymus. The results showed that compared with control mice, the structure of TEC in mice treated with high-dose dexamethasone was damaged and the thymic cell number was declined dramatically (P < 0.05); the ratios of thymus cell subsets were changed, the number of double positive (DP) thymus cells among these subsets declined sharply (P < 0.05); the expression levels of Foxn1 and IL-22 increased by 34 and 8 folds respectively. It is concluded that the use of high-dose dexamethasone can lead to damage of the structure and function of TEC, and induce up-regulation of the expression of genes related to thymus repair.
Animals ; Dexamethasone ; administration & dosage ; adverse effects ; Epithelial Cells ; cytology ; drug effects ; Forkhead Transcription Factors ; metabolism ; Interleukins ; metabolism ; Male ; Mice ; Mice, Inbred C57BL ; Thymus Gland ; cytology ; drug effects

Blood deficiency model of mice was copied by subcutaneous injection with 200, 100 and 100 mg x kg(-1) (0.01 mL x g(-1)) acetyl phenylhydrazine (APH) at the frist, fourth, and seventh days. Mice in each group were perfused with different extracted parts of Angelica sinensis (drug dosage was 2.4 g x kg(-1)) at the tenth day, once a day for 10 days. Then compare the influence of different extracted parts of Angelica sinensis to RBC, Hb, PLT and thymus, spleen and weight changes of blood deficiency mice. The peak areas of each common peak from HPLC fingerprint were associated with the date of replenishing blood pharmacodynamics efficacy by using gray relation statistic, which was used to research the chromatogram-pharmacodynamics relationship. The results showed that the part of DSC has the better effect in replenishing blood. The contribution degree of the DSC to replenishing blood of each component were determined by correlation size, and ferulic acid made the largest contribution, but contribution of other components should not be ignored. In this paper, we research the relationship of the HPLC fingerprint and spectrum activity relationship, determine the material basis of the DSC for replenishing blood, and provide effective way to represent the spectral correlation effect.
Angelica sinensis ; chemistry ; Animals ; Chromatography, High Pressure Liquid ; Drugs, Chinese Herbal ; analysis ; pharmacokinetics ; Erythrocytes ; cytology ; drug effects ; Female ; Hematologic Diseases ; drug therapy ; Humans ; Male ; Mice ; Spleen ; drug effects ; Thymus Gland ; drug effects

This study was purposed to investigate the effect of G-CSF on the proliferation, differentiation, and cell cycle distribution of thymocytes in sublethally irradiated mice. Female BALB/c mice were exposed to 6.0 Gy γ-ray irradiation and then randomly divided into control and G-CSF treatment group. In the treatment group rhG-CSF 100 µg/(kg·d) was given subcutaneously for 14 continuous days and to make sure the first injection was given within 1 hour after irradiation. Cell cycle distribution and apoptosis of thymocytes were detected within 72 hours after irradiation. Subpopulations of CD4(-)CD8(-) cells and sequential changes in the distribution of CD4(+)CD8(+), CD8(+)CD4(-), CD8(-)CD4(+) cells were detected by a three-color flow cytometry during a four-weeks period after irradiation. The results showed that in G-CSF treatment group marked increase of cells in G(0)/G(1) phase (G-CSF vs control: 82.0 ± 5.0% vs 75.9 ± 2.8%) (p < 0.05) and a decrease of cells in S phase (G-CSF vs control: 10.2 ± 4.8% vs 15.7 ± 2.3%) (p < 0.05)could be observed as early as 6 hours after irradiation, but G-CSF seems have no evident effects on the cells in G(2)/M phase. G-CSF could also protect thymocytes against apoptosis. 6 and 12 hours after irradiation the apoptosis rates of thymic cells in G-CSF treatment group were 11.5 ± 2.4% and 15.5 ± 3.3% respectively, while in the control group the apoptosis rates were 16.5 ± 2.2% and 22.6 ± 0.7% respectively. Comparison between the two group demonstrated significant difference (p < 0.05). CD4(-)CD8(-) double negative thymocytes (DN)can be defined as DN1-4 according to their maturation. G-CSF treatment resulted in a significant increase in DN1 thymocytes and promoted their proliferation and differentiation to a more mature DN3 and DN4 stage. G-CSF could enhance the recovery of CD4(+)CD8(+) thymocytes and mitigate their relapse during reconstitution. The percentage of CD4(+)CD8(+) thymocytes in the G-CSF treatment group 28 days after irradiation was significantly higher than that of the control group (71.0 ± 6.3% vs 25.5 ± 6.3%) (p < 0.05). It is concluded that G-CSF has a positive effects on the thymic cell cycle distribution, proliferation and differentiation, which may contribute to the reconstitution of central immune system after acute irradiation.
Animals ; Apoptosis ; drug effects ; Cell Cycle ; drug effects ; Cell Differentiation ; drug effects ; Cells, Cultured ; Female ; Flow Cytometry ; Granulocyte Colony-Stimulating Factor ; pharmacology ; therapeutic use ; Lymphocyte Count ; Mice ; Mice, Inbred BALB C ; Radiation Injuries, Experimental ; therapy ; Thymus Gland ; cytology

OBJECTIVETo explore the characteristic of hypoxia-induced immune injury, its mechanisms and the intervention measure.

METHODSThe change of immune organ index, T lymphocyte subsets of peripheral blood and immune organ in mice during hypoxia were detected. Lymphocyte apoptosis of immune organ, pathology of lung and kidney in mice were observed. Then by way of prophylaxis we studied the effect of Chinese Traditional Medicine on hypoxia-induced immune injury in mice.

RESULTS(1) Exposure to hypoxia at 8 000 m simulated altitude for 8 h resulted in marked decrease in CD4+ CD8+ thymocytes and marked increase in CD4+ CD8-, CD4- CD8+ thymocytes (P < 0.01). After 3 days of hypoxia, the mice had a much lower percentage of CD4+ T-cell (P < 0.05). The ratio of CD4+/CD8+ decreased significantly and aforesaid changes of thymocyte were further enlarged. Also mice had a pronounced increase in rates of late apoptosis or necrosis of spleen lymphocyte and thymocyte (P < 0.05). After 6 days of hypoxia, index of spleen was significantly increased (P < 0.05), index of thymus was significantly decreased (P < 0.05) and CD3+, CD4+, CD8+ lymphocyte percentage of spleen were significantly decreased (P < 0.01). Also late apoptosis or necrosis lymphocytes of spleen and thymus were further increased (P < 0.01), viable cell rates of spleen lymphocyte and thymocytes were markedly decreased (P < 0.01), early apoptosis rates of spleen lymphocyte were markedly increased (P < 0.01). There was no significant change in the percentage of CD8+ lymphocyte in peripheral blood during the whole hypoxia period. (2) New Compound Codonopsis Pilosula (NCCP), Xiang Qi Polysaccharide (XQP) and NCCP + XQP could significantly increase the number of peripheral blood CD3+, CD4+ and spleen CD4+, but had no significant influence on the number of spleen CD8+. XQP and XQP+ NCCP could significantly decrease the number of CD4+ CD8+ (P < 0.01), increase that of CD4+ CD8- (P < 0.01), and had no significant influence on CD4- CD8+ in thymus. However, NCCP didn't influence the component of thymocytes.

CONCLUSIONAfter hypoxia at 8 000 m simulated altitude decrease of lymphocyte of periphery in mice may be related with increase of apoptosis and necrosis of lymphocyte, and with increase of distribution of lymphocyte to lung in early period of exposure. NCCP and XQP have hopeful prospect in intervention study of hypoxia-induced immune injury.

Altitude ; Animals ; Apoptosis ; drug effects ; CD4-Positive T-Lymphocytes ; CD8-Positive T-Lymphocytes ; Drugs, Chinese Herbal ; pharmacology ; Flow Cytometry ; Hypoxia ; immunology ; pathology ; prevention & control ; Lung ; cytology ; Lymphocyte Count ; Male ; Medicine, Chinese Traditional ; Mice ; Mice, Inbred BALB C ; Spleen ; cytology ; T-Lymphocyte Subsets ; cytology ; drug effects ; Thymus Gland ; cytology

OBJECTIVETo study effects of polysaccharide of Radix Ranunculi Ternati (PRT) on immunological function and anti-oxidation activity of mouse.

METHODCell proliferations of splenocyte, thymocyte and peritoneal macrophage were measured by MTT colorimetry. The phagocytic function of peritoneal macrophage was measured by neutral red colorimetric method. The disoxidation power of PRT was measured by Prussian blue method. The clearing effect of PRT on hydroxyl radical was measured by salicylic acid capture method. The clearing effect of PRT on superoxide anion free radical was measured by pyrogallol auto oxidation method.

RESULTPRT among 25-400 mg x L(-1) could enhance thymocytes and spleen lymphocyte proliferation and macrophage phagocytosis. PRT(200 mg x L(-1)) has the strongest macrophage proliferation. PRT in different concentration has shown some disoxidation effects. PRT in 8 g x L(-1) has nearly the same ability of clearing x OH by Vit C with the same concentration. The clearance rate of PRT on O2*- is 95.39%.

CONCLUSIONPRT can enhance the cell proliferation capability of thymocytes, spleen lymphocytes and peritoneal macrophages. PRT can enhance macrophage phagocytosis in a dose-response relationship. PRT has saome disoxidation power and strong ability of clearing x OH and O2*-.

Animals ; Antioxidants ; analysis ; pharmacology ; Cell Proliferation ; drug effects ; Cells, Cultured ; Macrophages, Peritoneal ; cytology ; drug effects ; immunology ; Male ; Mice ; Oxidation-Reduction ; drug effects ; Phagocytosis ; drug effects ; Polysaccharides ; immunology ; pharmacology ; Ranunculus ; chemistry ; Spleen ; cytology ; drug effects ; immunology ; Thymus Gland ; cytology ; drug effects ; immunology

BACKGROUNDTbx1 is the major candidate gene for DiGeorge syndrome (DGS). Similar to defects observed in DGS patients, the structures disrupted in Tbx1(-/-) animal models are derived from the neural crest cells during development. Although the morphological phenotypes of some Tbx1 knock-down animal models have been well described, analysis of the cardiac performance is limited. Therefore, myocardial performance was explored in Tbx1 morpholino injected zebrafish embryos.

METHODSTo elucidate these issues, Tbx1 specific morpholino was used to reduce the function of Tbx1 in zebrafish. The differentiation of the myocardial cells was observed using whole mount in situ hybridization. Heart rates were observed and recorded under the microscope from 24 to 72 hours post fertilization (hpf). The cardiac performance was analyzed by measuring ventricular shortening fraction and atrial shortening fraction.

RESULTSTbx1 morpholino injected embryos were characterized by defects in the pharyngeal arches, otic vesicle, aortic arches and thymus. In addition, Tbx1 knock down reduced the amount of pharyngeal neural crest cells in zebrafish. Abnormal cardiac morphology was visible in nearly 20% of the Tbx1 morpholino injected embryos. The hearts in these embryos did not loop or loop incompletely. Importantly, cardiac performance and heart rate were reduced in Tbx1 morpholino injected embryos.

CONCLUSIONSTbx1 might play an essential role in the development of pharyngeal neural crest cells in zebrafish. Cardiac performance is impaired by Tbx1 knock down in zebrafish.

Animals ; Branchial Region ; cytology ; drug effects ; Heart ; drug effects ; physiology ; Heart Rate ; drug effects ; In Situ Hybridization ; Myocardium ; cytology ; Neural Crest ; cytology ; drug effects ; Oligonucleotides, Antisense ; pharmacology ; T-Box Domain Proteins ; antagonists & inhibitors ; metabolism ; Thymus Gland ; cytology ; drug effects ; Zebrafish ; embryology ; metabolism ; Zebrafish Proteins ; antagonists & inhibitors ; metabolism

The objective of this study was to explore the immunomodulatory effects of betulinic acid (BA) extracted from the bark of white birch on mice. Female mice were orally administered BA for 14 days in doses of 0, 0.25, 0.5, and 1 mg/kg body weight. We found that BA significantly enhanced the thymus and spleen indices, and stimulated lymphocyte proliferation induced by Concanavalin A and lipopolysaccharide as shown by MTT assay. Flow cytometry revealed that BA increased the percentage of CD4+ cells in thymus as well as the percentage of CD19+ and the ratios of CD4+/CD8+ in spleen. BA increased the number of plaque-forming cell and macrophage phagocytic activity as indicated by a neutral red dye uptake assay, and the peritoneal macrophages levels of TNF-alpha were also increased. In contrast, serum levels of IgG and IgM and serum concentrations of IL-2 and IL-6 were significantly decreased in BA-treated mice compared to the control as assayed by haemagglutination tests and ELISA, respectively. Taken together, these results suggest that BA enhances mouse cellular immunity, humoral immunity, and activity of macrophages. Thus, BA is a potential immune stimulator and may strengthen the immune response of its host.
Adaptive Immunity/*drug effects ; Animals ; Betula/*chemistry ; Cell Proliferation/drug effects ; Cytokines/blood ; Female ; Immunity, Innate/*drug effects ; Immunologic Factors/*pharmacology ; Macrophages/drug effects ; Mice ; Phagocytosis/drug effects ; Random Allocation ; Spleen/cytology ; Thymus Gland/cytology ; Triterpenes/*pharmacology