Animals ; Asthma ; etiology ; Fatty Acids, Essential ; physiology ; Humans ; Hypersensitivity ; genetics ; Immunity ; Intestinal Diseases ; etiology ; Lymphocyte Activation ; T-Lymphocytes ; immunology

Previously, we demonstrated that the p190 Rho guanine nucleotide exchange factor (p190RhoGEF) was induced following CD40 stimulation of B cells. In this study, we examined whether p190RhoGEF and a downstream effector molecule RhoA are required for B cell differentiation. Expression of p190RhoGEF positively correlated with the expression of surface markers and transcriptional regulators that are characteristic of mature B cells with plasma cell (PC) phenotypes. Moreover, either the overexpression of p190RhoGEF or the expression of a constitutively active RhoA drove cellular differentiation toward PC phenotypes. B cell maturation was abrogated in cells that overexpressed p190RhoGEF and a dominant-negative form of RhoA simultaneously. CD40-mediated maturation events were also abrogated in cells that overexpressed either dominant-negative p190RhoGEF or RhoA. Together, these data provide evidence that p190RhoGEF signaling through RhoA in CD40-activated B cells drives the induction of the PC differentiation.
Animals ; B-Lymphocytes/*cytology/*metabolism ; Cell Differentiation/genetics/*physiology ; Cell Line ; Cells, Cultured ; Female ; Guanine Nucleotide Exchange Factors/genetics/*metabolism ; Humans ; Lymphocyte Activation/genetics/*physiology ; Mice ; Mice, Inbred BALB C ; Plasma Cells/*cytology/*metabolism ; rhoA GTP-Binding Protein/genetics/metabolism

AIMTo provide further evidence for the synthesis of catecholamines (CAs) in lymphocytes and to investigate the effect of the endogenous CAs synthesized by lymphocytes on function of the lymphocytes themselves and the receptor mechanisms involved in the effect.

METHODSRT-PCR was performed to detect the expression of TH mRNA in the lymphocytes from the mesenteric lymph nodes of rats. Different concentrations of pargyline, an inhibitor of monoamine oxydase, and antagonists of alpha1-, alpha2-, beta1-, and beta2-adrenergic receptor (AR) were added to the lymphocyte cultures, and then proliferative response of the lymphocytes to mitogen concanavalin A (Con A) were measured via methyl-thiazole-tetrazolium (MTT) assay.

RESULTSThe lymphocytes could express TH mRNA, and the expression of TH mRNA was significantly higher in the Con A-activated lymphocytes than in the resting ones. The treatment of pargyline of 10(-6) and 10(-5) mol/L (not 10(-7) mol/L) notably attenuated Con A-induced lymphocyte proliferation. Beta2-AR antagonist ICI118551 (10(-7) and 10(-6) mol/L) completely blocked, but alpha1-AR antagonist corynanthine and alpha2-AR antagonist yohimbine (10(-7) and 10(-6) mol/L) partly blocked the suppressive effect of pargyline on the Con A-induced lymphocyte proliferation. Nevertheless, atenolol, an antagonist of beta1-AR, had no blocking effect on pargyline inhibition of lymphocyte proliferation.

CONCLUSIONLymphocytes have the ability to synthesize CAs and the ability is enhanced in the activated lymphocytes. The endogenous CAs synthesized by lymphocytes can inhibit T cell proliferation and the inhibition of T cells by the CAs is mediated predominantly by beta2-AR on the lymphocytes.

Animals ; Catecholamines ; biosynthesis ; physiology ; Cell Proliferation ; drug effects ; Concanavalin A ; pharmacology ; Female ; Lymphocyte Activation ; Lymphocytes ; metabolism ; Male ; Neuroimmunomodulation ; physiology ; RNA, Messenger ; genetics ; metabolism ; Rats ; Rats, Sprague-Dawley ; Receptors, Adrenergic, beta ; physiology ; T-Lymphocytes ; cytology ; immunology ; Tyrosine 3-Monooxygenase ; genetics ; metabolism

BACKGROUNDDespite extensive research, the mechanism of immature dendritic cells (DCs) induced immune hyporesponsiveness remains incompletely understood.

METHODSRecipient DCs from C3H mouse bone marrow cells were incubated with donor antigen from splenic lymphocytes of C57BL/6 mouse; these DCs were transfected with CD80/86 specific siRNA using lentiviral vectors. Flow cytometry was used to evaluate expression of CD80/86 on the antigen-pulsed recipient DCs. Immune regulatory activity was examined by mixed lymphocyte reaction, in which irradiated DCs were cultured with C3H spleen T cells. After the reaction, interleukin (IL)-2, IL-4, IL-10, and interferon (INF)-γ levels of mixed lymphocyte reaction culture supernatant were measured by enzyme-linked immunosorbent assay. The apoptotic T lymphocytes were identified by Annexin V and CD3 staining.

RESULTSThere was a significant inhibition of CD80/86 expression in DCs transfected with CD80/86 lentiviral vectors compared with the control groups (P < 0.05), indicating the specificity of RNA interference. Enzyme-linked immunosorbent assay results showed a significant reduction of INF-γ, IL-2 and IL-10 in the CD80/86 lentivirus transfected group compared to the control groups (P < 0.05). There was no significant difference in IL-4 levels between the groups (P > 0.05). We also showed that CD80/86 low DCs loaded with alloantigen (1) stimulated low T cell proliferative responses via the indirect recognition pathway and (2) enhanced apoptotic activity (P < 0.05) in co-cultured T cells.

CONCLUSIONSLentiviral vector transfection can effectively and specifically knock down target genes in DCs. The CD80/86 low DCs may show tolerogenic activity via induction of T-cell apoptosis, thereby modulating the activity of recipient-derived DCs. The use of this approach may potentially be clinically applicable.

Animals ; Apoptosis ; B7-1 Antigen ; genetics ; physiology ; B7-2 Antigen ; genetics ; physiology ; Dendritic Cells ; immunology ; Lentivirus ; genetics ; Lymphocyte Activation ; Mice ; Mice, Inbred C3H ; Mice, Inbred C57BL ; RNA Interference ; T-Lymphocytes ; cytology ; immunology

BACKGROUNDExperimental autoimmune myocarditis (EAM) in rats is a T-cell-mediated disorder. The initiation and maintenance of autoimmune responses in EAM depend on the maturation state of dendritic cells. IL-10 is a pleiotrophic immunomodulatory cytokine that functions at different levels of the immune response, so it has emerged as a promising therapeutic factor for the treatment of autoimmune/inflammatory diseases. This study was designed to test the hypothesis that IL-10 gene modified bone marrow-derived immature dendritic cells (iDCs) ameliorate EAM and to explore the underlying mechanisms.

METHODSEAM was induced using the methods of cardiac myosin immunization on day 0 and day 7. Immature and mature bone marrow-derived dendritic cells (BMDCs) were generated without or with the stimulation by lipopolysaccharide (LPS) and the phenotype was analyzed by flow cytometry. Some of the iDCs were transfected by pcDNA3-IL-10 plasmid. 2 x 10(6)/per rat mature DC (mDC), immature DC (iDC), pcDNA3 transfected iDC, pcDNA3-IL-10 transfected iDC or phosphate buffered saline (PBS) were injected intravenously for treatment 5 days after the first immunization. On day 21, HE staining was performed to detect the myocardial inflammation and T lymphocyte proliferation assay was used to determine the effects of IL-10 gene transfected iDC on autoreactive T cell proliferation. Expression of IkappaB, the inhibitor of NF-kappaB pathway, was determined by Western blot.

RESULTSBMDCs generated in a medium supplemented with granulocyte-macrophage-colony-stimulating factor (GM-CSF) were relatively immature, as determined by flow cytometry. However, stimulation with LPS induced these cells to become mature (m) DCs with higher levels of surface major histocompatibility complex (MHC)-II and costimulatory molecules. Intravenous administration of iDCs, especially pcDNA3-IL-10 transfected iDC, ameliorated the histopathological severity of the myosin induced-EAM, and the effect was lost after the DCs underwent maturation induced by in vitro exposure to LPS. IL-10 gene modified iDC inhibited the antigen specific T cell responses towards cardiac myosin. IkappaB protein was up-regulated significantly in the IL-10 gene modified iDC group.

CONCLUSIONSIL-10 gene modified iDC induced antigen-specific tolerance in EAM. The underlying mechanisms may be related to costimulatory molecules down-regulation and NF-kappaB pathway inhibition.

Animals ; Autoimmune Diseases ; immunology ; Dendritic Cells ; physiology ; Immune Tolerance ; Interleukin-10 ; genetics ; Lymphocyte Activation ; Male ; Myocarditis ; immunology ; Myosins ; immunology ; NF-kappa B ; physiology ; Rats ; Rats, Inbred Lew ; Signal Transduction ; Transfection

OBJECTIVETo investigate the effect of retinoic acid on the differentiation and maturation of B cells from lymph node of children, and relational changes of the expression levels of retinoic acid receptor genes.

METHODSTwenty-four patients with digestive tract malformation underwent surgical operation in the surgical ward of our hospital. They were divided into 3 groups according to age: < 1 yr, 1 - 3 yr, -5 yr, 8 cases in each age group. The lymph nodes in the margin of excised tissues were obtained. The cells separated from lymph nodes were cultured in vitro. The cells were divided into 5 groups: Retinoic acid (RA), RA plus Ro41-5253, RA receptor antagonist (RA+Ro), lipopolysaccharide (LPS), lipopolysaccharide plus RA (LPS+RA) and control, and were subjected to the corresponding treatments. After 24 h and 48 h of cell culture, the surface markers on the B cells were detected by flow cytometer to observe the maturation and activation of B cells. The expression levels of retinoic acid receptor genes were quantitatively analyzed by RT- fluorescent quantitative PCR.

RESULTSAfter culture, in < 1 yr group, the number of the mature B cells (IgM(+)IgD(+)CD25(-)) in the RA group was significantly higher than that in the control (24 h: 23% +/- 5% vs. 17% +/- 3%; 48 h: 28% +/- 6% vs. 22% +/- 4%) (P < 0.05), and that in the RA + RO group was not significantly different from that in the control (24 h: 16% +/- 4%; 48 h: 20% +/- 9%) (P > 0.05). The number of activated B cells (IgM(+)CD25(+)) in the LPS + RA group was obviously higher than that in the LPS group (24 h: 82% +/- 10% vs. 76% +/- 8%; 48 h: 83% +/- 8% vs. 78% +/- 10%)(P < 0.05). The level of RARalpha gene expression of B cells (lg copies/50 ng RNA) in the RA group was significantly higher than that in the control (24 h: 7.03 +/- 1.36 vs. 5.79 +/- 2.05; 48 h: 7.91 +/- 1.60 vs. 6.21 +/- 1.88) (P < 0.05), and that in the LPS + RA group was significantly higher than that in the LPS group (24 h: 7.29 +/- 1.53 vs. 5.98 +/- 1.48; 48 h: 7.83 +/- 1.66 vs. 5.79 +/- 2.36)(P < 0.05). In 1 - 3 yr group the changes of maturation and activation of B cells in the lymph nodes were the same as the < 1 yr group. In -5 yr group, such changes were not significant.

CONCLUSIONRA can promote the development of B cell from lymph node in vitro culture in
B-Lymphocytes ; drug effects ; physiology ; Cells, Cultured ; Child, Preschool ; Female ; Humans ; Infant ; Lymph Nodes ; drug effects ; Lymphocyte Activation ; drug effects ; Male ; Receptors, Retinoic Acid ; genetics ; Retinoic Acid Receptor alpha ; Tretinoin ; pharmacology

Xenotransplantation, the transplantation of cells, tissues or organs between individuals of different species, would resolve the current shortage of organs, but rejection remains the major hurdle to successful xenotransplantation. In the present study, we analyzed mixed lymphocyte reactions (MLRs) and used 51Cr release assays in order to identify the proliferation and expansion of mouse CD8+ cytotoxic T lymphocyte cells against PK15, PK15/pIL-18 or PK15/mIL-18 cells. In addition, we identified T cell populations in mouse splenocytes and lymph node cells using two-color flow cytometry. It was found that the CD8+T cells of xenograft recipients proliferated extensively and that the survival rates of populations of PK15/mIL-18 or PK15/pIL-18 cells were higher than untransfected controls. Moreover, CD3+T cells were increased in mice injected with PK15 cells or PK15/pIL-18 cells but PK15/pIL-18 cell numbers were lower in lymph nodes than untransfected controls. CD8+T cells numbers were reduced in the lymph nodes of PK15/pIL-18 injected mice. These results suggest that porcine IL-18 regulates anti-pig cellular rejection in C57BL/6 mice.
Transplantation, Heterologous ; Transplantation ; Transgenes/immunology/physiology ; Transfection ; Tissue Distribution ; T-Lymphocytes/metabolism ; Swine ; RNA, Messenger/metabolism ; Phenotype ; Mice, Inbred C57BL ; Mice ; Lymphocyte Culture Test, Mixed ; Lymphocyte Activation ; Kidney/cytology/*immunology ; Interleukin-18/*genetics/metabolism/physiology ; Immunosuppression/*methods ; Graft Rejection/immunology/*prevention & control ; Genetic Vectors/chemical synthesis ; Female ; Epithelial Cells/*drug effects/*transplantation ; Cytokines/metabolism ; Cells, Cultured ; Animals

BACKGROUNDTriggering receptor expressed on myeloid cell-1 (TREM-1) may play a vital role in mammalian target of rapamycin (mTOR) modulation of CD8+ T-cell differentiation through the transcription factors T-box expressed in T-cells and eomesodermin during the immune response to invasive pulmonary aspergillosis (IPA). This study aimed to investigate whether the mTOR signaling pathway modulates the proliferation and differentiation of CD8+ T-cells during the immune response to IPA and the role TREM-1 plays in this process.

METHODSCyclophosphamide (CTX) was injected intraperitoneally, and Aspergillus fumigatus spore suspension was inoculated intranasally to establish the immunosuppressed IPA mouse model. After inoculation, rapamycin (2 mg.kg-1.d-1) or interleukin (IL)-12 (5 μg/kg every other day) was given for 7 days. The number of CD8+ effector memory T-cells (Tem), expression of interferon (IFN)-γ, mTOR, and ribosomal protein S6 kinase (S6K), and the levels of IL-6, IL-10, galactomannan (GM), and soluble TREM-1 (sTREM-1) were measured.

RESULTSViable A. fumigatus was cultured from the lung tissue of the inoculated mice. Histological examination indicated greater inflammation, hemorrhage, and lung tissue injury in both IPA and CTX + IPA mice groups. The expression of mTOR and S6K was significantly increased in the CTX + IPA + IL-12 group compared with the control, IPA (P = 0.01; P= 0.001), and CTX + IPA (P = 0.034; P= 0.032) groups, but significantly decreased in the CTX + IPA + RAPA group (P < 0.001). Compared with the CTX + IPA group, the proportion of Tem, expression of IFN-γ, and the level of sTREM-1 were significantly higher after IL-12 treatment (P = 0.024, P= 0.032, and P= 0.017, respectively), and the opposite results were observed when the mTOR pathway was blocked by rapamycin (P < 0.001). Compared with the CTX + IPA and CTX + IPA + RAPA groups, IL-12 treatment increased IL-6 and downregulated IL-10 as well as GM, which strengthened the immune response to the IPA infection.

CONCLUSIONSmTOR modulates CD8+ T-cell differentiation during the immune response to IPA. TREM-1 may play a vital role in signal transduction between mTOR and the downstream immune response.

Animals ; CD8-Positive T-Lymphocytes ; cytology ; metabolism ; Cell Differentiation ; genetics ; physiology ; Female ; Interferon-gamma ; metabolism ; Invasive Pulmonary Aspergillosis ; metabolism ; Lymphocyte Activation ; genetics ; physiology ; Mice ; Mice, Inbred BALB C ; Myeloid Cells ; cytology ; metabolism ; Ribosomal Protein S6 Kinases ; metabolism ; TOR Serine-Threonine Kinases ; genetics ; metabolism ; Tissue Culture Techniques

OBJECTIVETo investigate the difference in the CD4+T lymphocytes activation between long term non progressors (LTNP) and typical progressors (TP) of HIV-1 infected patients.

METHODSTwenty-four HIV-1 infected patients and 15 heathy control adults were tested and flow cytometry was used to detect the activation marker CD38 and CD4 count in blood samples taken from the patients and control. bDNA method was used to test the virus load in the plasma of patients.

RESULTSThe activation of CD4+T cells was positively correlated with virus load and negatively correlated with CD4 counts. Compared with normal controls, the activation of CD4+T cells was obviously increased in TP patients but not obviously changed in LTNP patients.

CONCLUSIONCompared with healthy controls, the activation of CD4+T cells in LTNP did not obviously increase. This maybe partially accounts for LTNP patients keeping a good state for a long time.

ADP-ribosyl Cyclase 1 ; analysis ; Adult ; CD4 Lymphocyte Count ; CD4-Positive T-Lymphocytes ; cytology ; immunology ; Female ; Flow Cytometry ; HIV Infections ; blood ; immunology ; virology ; HIV-1 ; genetics ; physiology ; Host-Pathogen Interactions ; Humans ; Lymphocyte Activation ; immunology ; Male ; Middle Aged ; RNA, Viral ; blood ; Time Factors ; Viral Load ; Young Adult

BACKGROUNDSurvivin is a rather specific gene in tumor tissue. We transfected dendritic cells (DCs) with recombinant adenovirus (Ad) containing survivin gene and granulocyte-macrophage colony-stimulating factor (GM-CSF) gene and tested the inducing effect of the transfected DCs on cytotoxic T lymphocytes (CTL) to kill leukemic cells.

METHODSAfter derived from the peripheral, DCs was assayed by mixed leukocyte reaction (MLR) tests. Lactate dehydrogenase (LDH) release test was used to evaluate cytotoxicity of CTL.

RESULTSExpression of survivin in transfected DCs was confirmed by Western blotting analysis. GM-CSF expression was confirmed by enzyme-linked immunosorbent assay (ELISA). In MLR assay, DCs coinfected with Ad-survivin and Ad-GM-CSF induced higher allogeneic lymphocyte reaction than control DCs at ratios of 1:5, 1:10, 1:50 and 1:100. DCs coinfected with Ad-survivin and Ad-GM-CSF had much higher activity of CTL to HL-60 cells than DCs infected with Ad-survivin only, Ad-GM-CSF only, or control DCs. Levels of interleukin-12 (IL-12) and interferon gamma (IFN-gamma) in lymphocyte supernatants containing DCs coinfected with Ad-survivin and Ad-GM-CSF were significantly higher than those in the control group.

CONCLUSIONDCs coinfected with Ad-survivin and Ad-GM-CSF induce much higher anti-leukemic response in vitro than those infected with either factor. Therefore, adenovirus vectors containing survivin and GM-CSF genes may be promising vaccine candidates for leukemia therapy.

Adenoviridae ; genetics ; Cytotoxicity, Immunologic ; Dendritic Cells ; physiology ; ultrastructure ; Genetic Therapy ; Granulocyte-Macrophage Colony-Stimulating Factor ; genetics ; HL-60 Cells ; Humans ; Inhibitor of Apoptosis Proteins ; Interferon-gamma ; biosynthesis ; Interleukin-12 ; biosynthesis ; Leukemia ; therapy ; Lymphocyte Activation ; Microtubule-Associated Proteins ; genetics ; Neoplasm Proteins ; genetics ; T-Lymphocytes, Cytotoxic ; immunology ; Transfection