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

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

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 effect of transfusion of necrotic cells on regulatory T (Treg) and Th17 cell balance in septic mice.

METHODSThirty-four C57BL/6 mice were randomized into PBS group (n=5), sham-operated group (n=5), sepsis group (n=12), and necrotic cell transfusion group (n=12) and subjected to intraperitoneal PBS injection, sham operation by separating the cecum only, cecal ligation and puncture (CLP), and injection of 2 × 10⁷ necrotic cells 5 days before CLP, respectively. All the mice were sacrificed 2 weeks after CLP for analyzing the proportion of CD4⁺Foxp3⁺Treg cells and CD4⁺IL17A⁺Th17 cells in the peripheral blood, spleen and thymus by flow cytometry.

RESULTSThe percentage of Th17 cells and Treg/Th17 ratio in the spleen was significantly higher in CLP group than in the sham-operated group and PBS group (P<0.01). The percentage of Treg cells in the thymus was significantly lower in CLP group than in the sham-operated group (P<0.01). Pre-infusion of necrotic cells redressed the abnormality of Treg and Th17 cell percentages and Treg/Th17 imbalance in mice following CLP (P<0.05).

CONCLUSIONPre-infusion of necrotic cells can reverse Treg/Th17 imbalance in septic mice.

Animals ; Cecum ; Flow Cytometry ; Interleukin-17 ; Ligation ; Mice ; Mice, Inbred C57BL ; Necrosis ; Sepsis ; therapy ; Spleen ; T-Lymphocytes, Regulatory ; cytology ; Th17 Cells ; cytology ; Thymus Gland

OBJECTIVETo study the effect of spleen lymphocytes on the splenomegaly by hepatocellular carcinoma-bearing mouse model.

METHODSCell counts, cell cycle distribution, the percentage of lymphocytes subsets and the levels of IL-2 were measured, and two-dimensional gel electrophoresis (2-DE) was used to investigate the relationship between spleen lymphocytes and splenomegaly in hepatocellular carcinoma-bearing mice.

RESULTSCompared with the normal group, the thymus was obviously atrophied and the spleen was significantly enlarged in the tumor-bearing group. Correlation study showed that the number of whole spleen cells was positively correlated with the splenic index. The cell diameter and cell-cycle phase distribution of splenocytes in the tumor-bearing group showed no significant difference compared to the normal group. The percentage of CD3+ T lymphocytes and CD8+ T lymphocytes in spleen and peripheral blood of tumor-bearing mice were substantially higher than that in the normal mice. Meanwhile, the IL-2 level was also higher in the tumor-bearing group than in the normal group. Furthermore, two dysregulated protein, β-actin and S100-A9 were identified in spleen lymphocytes from H22-bearing mice, which were closely related to cellular motility.

CONCLUSIONIt is suggested that dysregulated β-actin and S100-A9 can result in recirculating T lymphocytes trapped in the spleen, which may explain the underlying cause of splenomegaly in H22-bearing mice.

Animals ; Carcinoma, Hepatocellular ; complications ; Cell Cycle ; Female ; Liver Neoplasms ; complications ; Lymphocytes ; physiology ; Mice ; Mice, Inbred ICR ; Neoplasms, Experimental ; therapy ; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization ; Spleen ; cytology ; pathology ; Splenomegaly ; etiology ; therapy ; Thymus Gland

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

Thymic epithelial cells (TECs) are one of the most important components in thymic microenvironment supporting thymocyte development and maturation. TECs, composed of cortical and medullary TECs, are derived from a common bipotent progenitor, mediating thymocyte positive and negative selections. Multiple levels of signals including intracellular signaling networks and cell-cell interaction are required for TEC development and differentiation. Transcription factors Foxn1 and autoimmune regulator (Aire) are powerful regulators promoting TEC development and differentiation. Crosstalks with thymocytes and other stromal cells for extrinsic signals like RANKL, CD40L, lymphotoxin, fibroblast growth factor (FGF) and Wnt are also definitely required to establish a functional thymic microenvironment. In this review, we will summarize our current understanding about TEC development and differentiation, and its underlying multiple signal pathways.
Cell Communication ; genetics ; Cell Differentiation ; Epithelial Cells ; cytology ; metabolism ; Forkhead Transcription Factors ; genetics ; metabolism ; Humans ; Signal Transduction ; genetics ; Thymocytes ; cytology ; metabolism ; Thymus Gland ; cytology ; growth & development ; Transcription Factors ; genetics ; metabolism

The study was purposed to investigate the effect of alloreactive natural killer (alloNK) cells on immune reconstitution in murine haploidentical bone marrow transplantation (BMT). The murine model of haploidentical BMT was established by using (C57BL/6×BALB/c)BCF(1)(H-2(d/b)) mouse as the donor, and BALB/c (H-2(d)) mouse as the recipient. Recipient mice were divided into BMT group, non-allo-reactive NK (non-alloNK) cell group and alloNK cell group according to different transfusion. The effect of adding alloNK cells to transfusion was assessed by thymus pathology, the proportion of spleen NK cells, the spleen cell proliferation, the IFN-γ and IL-4 concentrations product at 24 and 48 h of recipient spleen cell culture supernatant at 2 months after BMT. The results showed that there were no obvious difference in thymus tissue among 3 groups under the optical microscope. The proportion of recipient spleen NK cells in non-alloNK group was significantly lower than that in BMT group (P < 0.05). There was no significant difference in proliferation of the recipient spleen cells among 3 groups at 2 months after BMT. The IFN-γ concentration product at 24 and 48 h of recipient spleen cell culture supernatant in alloNK group was significantly lower than that in other 2 groups at 2 months after BMT (P < 0.05). The IL-4 concentration in each group was not significantly different (P > 0.05). It is concluded that alloNK cells do not damage the thymus structure and may induce Th2 immune response in murine haploidentical BMT.
Animals ; Bone Marrow Transplantation ; Interferon-gamma ; immunology ; Interleukin-4 ; immunology ; Killer Cells, Natural ; immunology ; Mice ; Mice, Inbred BALB C ; Mice, Inbred C57BL ; Spleen ; cytology ; Thymus Gland ; pathology ; Transplantation, Homologous

OBJECTIVETo explore the mechanism of electroacupuncture of "Shuanggu Yitong" prescription on postponing aging.

METHODSForty 3-month SD rats, male only, 30 rats were made sub-acute aging model by D-galactose s.c. injection continuously for 42 d, and rest of the rats, 10, were divided into a normal control group. After the modeling, the sub-acute aging model rats were randomly into a Shuanggu Yitong group [electroacupuncture at "Guanyuan" (CV 4) and "Zusanli" (ST 36), hand needle at "Baihui" (GV 20)], an acupuncture control group [electroacupuncture at "Weizhong" (BL 40) and "Shuifen" (CV 9), hand needle at "Yintang" (GV 29)] and an aging model group, ten in each one. The treatment was given once in a day, six of which made a course. The rats in the normal control group and aging model group were not received any treatment. After the treatment for three weeks, the rats were put to death and their spleen index, thymus index and the T lymphocytes subgroups (CD8(+) T/T cell and CD8(+) CD28(-) T/CD8(+) T cell) were tested.

RESULTSThe spleen index (1.74 +/- 0.059) and thymus index (0.64 +/- 0.039) in the aging model group was obviously lower than those in the normal control group (1.93 +/- 0.061), (0.81 +/- 0.053) respectively (both P < 0.05); the CD8(+) CD28(-) T/CD8(+) T cell percentages (26.28 +/- 4.69)% and CD8(+) T/T cell percentages (43.33 +/- 2.84)% in the aging model group were both significantly higher than those (15.08 +/- 5.58)% (P < 0.01), (34.70 +/- 4.24)% (P < 0.01) in the normal control group. Compared with the aging model group, the spleen index (1.91 +/- 0.081) and thymus index (0.79 +/- 0.080) in the Shuanggu Yitong group were significantly higher (both P < 0.05), but obviously decreased with the percentage of CD8(+) CD28(-) T/CD8(+) T cell (18.07 +/- 1.73) (P < 0.01); the percentage of CD8(+) CD28(-) T/CD8(+) T cell (18.07 +/- 1.73)% in the acupuncture control group was also lower than the aging model group (P < 0.05), but more obvious reduce for the Shuanggu Yitong group (P < 0.05).

CONCLUSIONThe treatment of Shuanggu Yitong prescription could regulate the proportions of the T lymphocyte subset, and slow down the immunosenescence of subacute aging model rats induced by D-galactose.

Acupuncture Points ; Aging ; physiology ; Animals ; Electroacupuncture ; Flow Cytometry ; Humans ; Male ; Rats ; Rats, Sprague-Dawley ; Spleen ; cytology ; T-Lymphocyte Subsets ; cytology ; Thymus Gland ; cytology