Given its population of CCR5-expressing, immunologically activated CD4 +T cells, the gastrointestinal (GI) mucosa is uniquely susceptible to human immunodeficiency virus (HIV)-1 infection. Recent studies have shown that, as in macaques infected with simian immunodeficiency virus (SIV), intestinal CD4 +T cells are selectively and rapidly depleted in the intestine of HIV-infected patients. Depletion of intestinal CD4 +T cells occurred at all stages of infection regardless of highly active antiretroviral therapy (HAART). Here we discuss the important implications of the recent findings for our understanding of HIV pathogenesis, treatment, and vaccine design. The major significance is that it supports a simple hypothesis to explain the pathogenesis of HIV infection, that most HIV replication occurs in the intestine and that disease progression may correlate with turnover of specific cell subsets in mucosal tissues.

AIM: To explore the correlation between development of CD4~+CD25~+ regulatory T cells (CD4~+CD25~+ Tr) and thymus CD4~-CD25~+ cells. METHODS: The ratios of CD4~+CD25~+ regulatory T cells to CD4~+ T cells in thymus, spleen, lymph node and peripheral blood of mice from birth to mature and also the ratios of CD4~-CD25~+cells to CD4~-T cells in thymus were measured by flow cytometry. Purified CD4~+CD25~+ T cells and CD4~+CD25~- T cells were labeled with CFDA-SE, and then stimulated with various kinds of stimulators. RESULTS: The percentages of CD4~+CD25~+ Tr in mouse spleen, lymph nodes and peripheral blood increased gradually, but not in thymus, from day one to week 10 of the age with rapid rising from day one to week 1. The percentages of CD4~-CD25~+ cells in mouse thymus were quite high on day one after birth, and decreased rapidly from day one to week 1. Both CD4~+CD25~+ Tr and CD4~+CD25~- T cells showed no proliferation in response to ConA, while CD4~+CD25~+ Tr showed a transient enlargement of cell size. Both CD4~+CD25~+ Tr and CD4~+CD25~- T cells underwent proliferation in response to PDB plus ionomycin. CD4~+CD25~- T cells, but not CD4~+CD25~+ Tr, showed a proliferative response to the stimulation of coated anti-CD3 plus soluble anti-CD28 antibody, however, CD4~+CD25~+ Tr showed significant proliferation and CD4~+CD25~- T cells showed a stronger response in addition of high dose of IL-2. CONCLUSION: The thymus CD4~-CD25~+ cells are probably the precursor of CD4~+CD25~+ Tr during cell development.

Objective:To study the effect of isoflavone and genistein on activation of T lymphocytes in order to develope new immuno intervention reagent.Methods:Fluorescence conjugated monoclonal antibodies and flow cytometer were used to detect the expression rate of CD69 by activated T cells in vitro in response to Phytohemagglutinin(PHA) and Phorbol 12,13 dibutyrate(PDB),with some samples pre incubated with 10,50 or 100 ?mol/L of genistein,after 2 h and 6 h of incubation in whole blood culture system.Results:After 2 h of culture,the inhibitory effect in PHA group was stronger than PDB group(P

AIM:To study the effects of progesterone(P4) on the maturation and immunologic function of dendritic cells(DCs) from human peripheral blood.METHODS:Cultured DCs were treated with P4 at doses of 10-7 mol/L and 10-6 mol/L.The morphologic changes were observed under the scanning electronic microscope.The immunophenotypes of DCs in control and treated groups were analyzed by flow cytometry.IL-10 and IL-12 production in culture supernatant was examined by ELISA assay.The capability of the stimulatory activity of the DCs on allogeneic T cells in mixed reaction was tested by incorporation of [3H]-TdR.RESULTS:Compared with control group,cultured DCs in the presence of P4 displayed less dendritic pseudopod,expressed low levels of MHC-II,CD40,CD80 and CD86,and exhibited weakly activity in stimulating the proliferation of allogeneic T cells.Increase in IL-10 production and decrease in IL-12 production were observed.CONCLUSION:P4 exerts negative effect on the maturation and immunologic function in dendritic cells from human peripheral blood.

AIM:To study the roles of bone marrow-derived dendritic cells from donor mouse treated with 17?-estradiol(E2)in immune tolerance induction in skin allograft.METHODS:Bone marrow-derived dendritic cells from C57 mouse as donor were cultured respectively treated with E2(E2 group).BALB/c mouse as recipient received respectively one injection of dendritic cells of E2 group,mature dendritic cell group and immature dendritic cell group intravenously.Skin transplantation was performed in the absence of immunosupression after 7 d.Mice that received PBS were served as control.The time of skin survival was observed after transplantation.Flow cytometry was used to analyze the percentage of CD4+CD25+ T cells in peripheral blood respectively before and after transplantation.RESULTS:Compared with immature dendritic cells and control group,the time of skin survival in E2 group was significantly longer(P

Objective To investigate the association between the C609T polymorphism of NAD (P)H:quinoneoxidoreductase (NQO1) gene and post operative cognitive dysfunction (POCD).Methods 90 ASA Ⅰ-Ⅱ patients of 59 to 78 years old, undergoing elective hip replacement with epidural anesthesia were enrolled.All patients were given a battery of 5 neuropsychological tests before operation and seven days after operation.Patients were divided into POCD group and control group according to test results (45 patients in each group).The single nucleotide polymorphism C609T of NQO1 gene was detected using real-time PCR by Taqman probes and subjected to odd ratio assessment.Results 5 samples in control group couldn' t be used in the real-time PCR analysis due to quality control.The frequency of C/C genotype in POCD control was lower than that of control group ( 30.0% vs 11.1% ) with statistical significance ( OR = 0.292,95 % CI 0.092 ～ 0.92 1, P ＜ 0.05 ).The C/T +T/T genotype frequency was significantly higher in group POCD than in the control group(88.8% vs 70% ).Patients presented with C/T + T/T genotype showed an evidently increased risk of POCD ( OR =3.42,95% CI 1.08 ～ 10.82,P ＜ 0.05 ).The frequency of C allele of NQO1 gene in group control was 56.2%, as compared with 40% in group POCD with significance ( OR = 0.519,95% CI 0.282 ～ 0.955, P ＜ 0.05 ).The frequency of T allele of NQOI gene in control group was 43.7% ,as compared with 60.0% in POCD group( OR = 1.93,95% CI 1.047 ～3.552,P＜O.05).Conclusion The NQO1 gene single nucleotide polymorphism C609T is evidently associated with the increased risk of POCD.

AIM:To study the changes of mitochondria during apoptosis in Jurkat cells induced by arsenic oxide(As2O3).METHODS:By treated with 4?10-6 mol/L As2O3,apoptosis and necrosis of Jurkat cells were assessed by annexin V-FITC/PI double staining flowcytometry.Mitochondrial mass and its membrane potential(△?m)was measured by NAO/PI and DiOC6(3)/PI staining,respectively.Free radical formation was detected by DCFDA staining.RESULTS:After 48 h of As2O3 treatment,the rates of early apoptotic Jurkat cells in As2O3 and control groups were(18.98?1.40)% and(5.17?0.80)%,respectively(P

0.05), the percentage of MDC and PDC and the ratio of MDC/PDC at the second (MDC, 0.11%?0.09%; PDC, 0.06%?0.05%; MDC/PDC, 0.76?0.80), third trimester (MDC, 0.12%?0.08%; PDC, 0.07%?0.06%; MDC/PDC, 0.78?0.82) were significantly lower (P

AIM: To study mitochondrial mass and structural protein changes in dexamethasone (DEX)-mediated mouse thymocyte apoptosis process. METHODS: DEX-induced mouse thymocyte apoptosis model was established. Annexin V-FITC/PI double staining was used to identify apoptotic and necrotic cells by flowcytometry, JC-1 staining was adopted to test mitochondrial membrane potential (△?_m), and cellular structural protein changes were studied with CFDA-SE staining. RESULTS: By 1?10~(-6) mol/L DEX stimulation, the apoptotic rate was 51.25%?5.51% and had significantly difference from control group (12.03%?2.00%); the necrotic rate in DEX group was 30.25%?3.67% and also had significantly difference from control group (10.11%?1.11%, P

AIM: To explore the characteristics of T cell activation and regulatory T cells derived from murine Peyer's patches through comparative studies on Peyer's patches, mesenteric lymph nodes and inguinal lymph nodes. METHODS: Signal cell suspendsions were prepared from murine mesenteric lymph nodes (MLNs), the Peyer's patches (PPs) and inguinal lymph nodes (ILNs), respectively. The percentage of cell subpopulations such as CD3+ T cells, CD3+CD4+ helper T cells and regulatory T cells (Treg, CD4+CD25+) were analyzed. Lymphocytes were activated by polyclonal stimulators such as concanavalin (Con A), phorbol 12, 13-dibutyrate (PDB) only, and PDB plus ionomycin (Ion). The expression of CD69 (the early marker of CD3+ T cell activation) was measured by FACS. RESULTS: A lower ratio of CD3+ T cells was seen in PPs than those in MLNs and ILNs. The ratios of CD3+ CD4+ T cells to CD3+ T cells in PPs, MLNs and ILNs were almost the same. A higher rate of Treg was seen in CD4+ T cells from the PPs as compared with those from MLNs and ILNs. A higher percentage of activated CD3+ T cells derived from the PPs cultured without polyclonal stimulators were detected as compared to MLNs and ILNs, while lower responsiveness of CD3+ T cells from the PPs stimulated by Con A was seen as compared with those from MLNs and ILNs. CONCLUSIONS: The lower rate of CD3+ T cells as well as higher rate of Treg in PPs was due to its desensitization. The higher rate of basic activated state in CD3+ T cells from the PPs indicated that the T cells were activated by enteric antigens in physiological conditions. The lower responsiveness of activation to some polyclonal stimulators probably reveals that the T cells are in a state of anergy. All the characteristics mentioned above contribute to prevent pathological inflammations and maintain tolerance to enteric antigens such as food proteins and commensal bacteria but simultaneously retain proper immune responses to pathogenic microbes.