2006年 · 第119卷第19期

A cquired immunodeficiency syndrome (AIDS)was first recognized in the United States in the Summer of 1981,1,2 when the US Centers for Disease Control and Prevention (CDC) reported the unexplained occurrence of Pneumocystis carinii pneumonia (PCP) in 5 cases and Kaposi's sarcoma in 26 cases of previouly healthy homosexual men in Los Angeles and New York. Within months, the disease became recognized in male and female intravenous drug users (IDU) and soon after in recipients of blood or IDV transfusions and in hemophiliacs.3

Acquired immunodeficiency syndrome (AIDS),caused by the human immunodeficiency virus (HIV), has become a major public health issue in China. It not only posesses formidable challenges for the health of the Chinese people, but has also influenced China's economic development and social stability。

Abstract：Background The correlation between HIV-1 Nef-specific CD8 T-cell responses and markers of HIV-1 disease progression still remains unclear. This study analysed and compared the role of HIV-1 Nef-specific CD8 T-cell responses in patients with different disease status.Methods Two groups of patients with HIV-1 subtype B infection were selected according to CD4 count and clinical manifestations: long-term nonprogresssors (LTNPs, n = 20) and advanced progressors (Aps, CD4 count ＜500 cells/μ1, n = 34). Nef-specific CD8 T-cell responses were studied by interferon- γ ELISpot assay against 3 pools of HIV-Nef peptides.Results Nef-specific CD8 T-cell responses did not correlate with viral load or CD4 count in all patients and no significant differences were found in the magnitude of Nef-specific CD8 T-cell responses between groups LTNPs and Aps (670 SFC/106 peripheral blood mononuclear cells vs 1107 SFC/106 peripheral blood mononuclear cells,P = 0.255). Further comparisons showed that there were also no significant correlations observed in group LTNPs,but Nef-specific CD8 T cells correlated negatively with viral load (r = -0.397, P = 0.020) and positively with CD4 count (r = 0.364, P = 0.034) in group Aps.Conclusion These data suggest that different correlation patterns between Nef-specific CD8 T-cell responses and disease progression exist in LTNPs and Aps. Although a negative association was observed with concurrent plasma HIV RNA in Aps, Nef-specific CD8 T-cell responses might fail to play a protective role in different stages of HIV- 1 infection。

Abstract：Background Studies of highly exposed persistently seronegative (HEPS) individuals may provide valuable information on mechanisms of protection and on vaccine design. Cellular immune responses play a critical role in containing human immunodeficiency virus. However, the cellular immune responses in HEPS individuals have not been thoroughly assessed at the entire viral genome level.Methods Ten HEPS Chinese with a history of frequent penetrative vaginal intercourse (mean frequency, at least once a week), with some unprotected sexual contact occurring in the weeks or days immediately before enrollment, 25 HIV-1 seropositive individuals, 10 HIV-1-seronegative healthy individuals with low-risk sexual behavior and no history suggestive of exposure to HIV-1 infection were enrolled. HIV-1-specific T cell responses were comprehensively analyzed by an interferon- γ Elispot assay against 770 overlapping peptides spanning all HIV-1 proteins.Results HIV-1-specific T-cell responses of interferon- γ secretion were identified in 3 (30%) out of 10 HEPS individuals; the specific cytotoxic T lymphocytes were targeted at Pol (2/10), Env (2/10), and Tat (1/10).HIV-1-specific T-cell responses of interferon- γ secretion were identified in 20 (80%) out of 25 seropositive intravenous drug users (IDUs), revealing that all HIV-1 proteins and protein subunits could serve as targets for HIV-1-specific CD8+ T cell responses with 85% recognizing Gag, 80% recognizing Nef, 75% recognizing Pol,60% recognizing Env, 55% recognizing Vpu, 45% recognizing Vpr, 20% recognizing Vif, 20% recognizing Tat and 15% recognizing Rev in these seropositive individuals. None of the seronegative healthy individuals gave the positive T-cell responses.Conclusions About 30% of HEPS Chinese mounted HIV-1 specific T cell immune responses. Cell-mediated immunity against HIV-1 may be developed through non-productive infections。

Abstract：Background One of the major characteristics of the human immunodeficiency virus type 1 (HIV-1) is its unusually high degree of genetic variability, which involves in genetic diagnosis, subtyping, vaccine design, and epidemiology. HIV-1 CRF01_AE is a main prevalent HIV-1 recombinant strain in China. In this study, three full-length CRF01_AE genomes from Fujian Province, China were cloned, sequenced, and analyzed; and the further genetic diversity defining and epidemiologic analysis were carried out.Methods Proviral DNA was extracted from non-cultured peripheral blood mononuclear cells, the near full-length HIV-1 genome was amplified and the PCR products were cloned into Pcr-XL-TOPO vector and sequenced. 5'-long terminal repeat (LTR) and 3'-LTRs were amplified by additional independent PCR and cloned into Pmd18t vector. Gene-based phylogenic tree was constructed and genetic distances were calculated by MEGA 3.1. Simplot was used for Bootscan analysis.Results The phylogeny and genetic distance analysis of the three near full-length sequences confirmed that these three samples clustered with CRF01_AE isolates, more close to Thailand CRF01_AE strain CM240, and were distantly related to African CRF01_AE strain 90CF402. Analysis of their genomic organization revealed the presence of nine potential open reading frames. There were no major deletions, rearrangements, or insertions in the three sequences, but an in-frame stop codon was found in tat gene of Fj051. LTRs of the three sequences contained a few nucleotides mutation. We did not find new mosaic recombinant in the three sequences. The V3 motif was GPGQ in all the three sequences, and there were only few amino acids differences in all three V3 loop sequences.Conclusion This report reveals the background of the three full-length CRF01_AE genomes, the most dominantly circulating HIV-1 strain in Fujian Province, China. The work is essential for the design and development of an effective AIDS vaccine for the region。

Abstract：Background The mechanism of chronic immune activation and impairment of HIV-specific immune responses during chronic infection is not fully understood. However, it is known that high immune activation leads to more rapid progression to AIDS. We hypothesize that CD4+ T cell-mediated viral antigen presentation contributes to this pathologic immune activation in HIV-infected individuals.Methods HIV-specific T cells, responding to noninfectious HIV-1 virions as antigen, were measured by flow cytometric assays. These experimental conditions reflect the in vivo condition where noninfectious HIV-1 represents more than 99% of the antigens.Results CD4+ T cells purified from HIV-infected individuals were capable of cross presenting exogenous noninfectious HIV-1 virions to HIV-1-specific CD8+ T cells. Cross presentation required the entry of HIV-1 to CD4+ T cells and antigen translocation from endoplasmic reticulum to the Golgi complex. Blocking CD4+mediated activation of HIV-specific CD8+ T cells and redirecting the viral antigens to antigen presenting cells improved HIV-specific T cell responses.Conclusions One possible cause of chronic immune activation and impairment of HIV-1 specific T cell responses is represented by HIV-1 harboring CD4+ T cells cross presenting HIV-1 antigen to activate CD8+ T cells. This new mechanism provides the first evidence that cross presentation of noninfectious HIV-1. Virions play a role in the immunopathogenesis of HIV-1 infection。

Abstract：Background Islet transplantation represents an ideal therapeutic approach for treatment of type 1 diabetes but islet function and regeneration may be influenced by necrosis or apoptosis induced by oxidative stress and other insults. Heme oxygenase-1 (HO-1) is the rate-limiting enzyme in the catabolism of heme into biliverdin,releasing free iron and carbon monoxide. It has also been reported to be an antioxidant enzyme which can improve the function of grafted islets by cytoprotection via free radical scavenging and apoptosis prevention. In the present study, we investigated whether transduction of HO-1 genes into human islets with an adenovirus vector has cytoprotective action on islets cultured in vitro and discuss this method of gene therapy for clinical islet transplantation.Methods Cadaveric pancreatic islets were isolated and purified in vitro. Transduction efficiency of islets was determined by infecting islets with adenovirus vector containing the enhanced green fluorescent protein gene (Ad-EGFP) at multiplicities of infection (MOI) of 2, 5, 10, or 20. Newly isolated islets were divided into three groups: EGFP group, islets transduced with Ad-EGFP using MOI=20; HO-1 group, transduced with adenovirus vectors containing the human HO-1 gene using MOI=20; and control group, mock transduced islets. Insulin release after glucose stimulation of the cell lines was determined by a radioimmunoassay kit and the stimulation index was calculated. Flow cytometry was used to detect apoptotic cells in the HO-1 group and in the control group after induction by recombinant human tumor necrosis factor-α (rTNFα) and cycloheximide (CHX) for 48 hours.Results Adenovirus vectors have a high efficiency of gene transduction into adult islet cells. Transduction of islets with the Ad-EGFP was most successful at MOI 20, at which MOI fluorescence was very intense on day 7 after transduction and EGFP was expressed in cultured islet cells for more than four weeks in vitro. The insulin release in the control group was (182.36± 58.96) Miu/L after stimulation by high glucose media (16.7 mmol/L),while insulin release from the HO-1 group and the EGFP group were (270.09 ± 89.37) Miu/L and (175.95 ± 75.05) Miu/L respectively. Compared to the control group and the EGFP group, insulin release in the HO-1 group increased significantly (P＜0.05). After treatment with rTNFα and CHX the apoptotic ratio of islet cells was (63.09 ±10.86)% in the HO-1 group, significantly lower than (90.86 ± 11.25)% in the control group (P＜0.05).Conclusions Transduction of human islets with Ad-HO-1 can protect against TNF-α and CHX mediated cytotoxicity. The HO-1 gene also appears to facilitate insulin release from human islets. Transduction of donor islets with the adenovirus vector containing an HO-1 gene might have potential value in clinical islet transplantation。

Abstract：Background Experimental 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.Methods EAM 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 × 106/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 IκB, the inhibitor of NF-κB pathway, was determined by Western blot. Results BMDCs 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. IκB protein was up-regulated significantly in the IL-10 gene modified iDC group.Conclusions IL-10 gene modified iDC induced antigen-specific tolerance in EAM. The underlying mechanisms may be related to costimulatory molecules down-regulation and NF-κB pathway inhibition。

Abstract：Background Generally, total surgical removal of craniopharyngioma results in satisfactory outcome with a low recurrence rate, however, the location of the tumor and its adherence to the hypothalamic structures can make the operation difficult. The goal of the present study was to assess the outcome of craniopharyngiomas in 284patients treated surgically.Methods A total of 284 patients (151 men and 133 women) with craniopharyngioma were treated surgically by our neurosurgeons from January 1996 to March 2006. Among them, 226 (79.6%) patients were adults (15 years of age or older; mean, 35.8 ± 10.6), 58 (20.4%) were children (14 years of age or younger; mean, 9.1 ±3.8).The diameter of the tumors were 2.0-9.0 cm (mean, 36.54 ± 11.4). The tumors were classified into the superior (23 patients) and inferior ventricular (261) types according to the location of the tumor relative to the third ventricular floor. For the patients with craniopharyngioma of inferior ventricular type, pterional approach was used in 191 (67.3%) patients, subfrontal approach in 17 (6.0%), and translamina terminalis through frontobasal interhernispheric approach in 53 (18.7%). For those with the tumors of superior ventricular type, transcallosal approach into the anterior third ventricle was done in 10 (3.5%) patients, and the lamina terminalis approach in 13 (4.6%). Of the 284 patients, 204 (71.8%) were followed up for 0.5 to 8 years (mean, 2.1 ±1.8), including 162 patients received total tumor removal, and 37 underwent subtotal or partial removal.Results Total, subtotal and partial removal of the tumors were achieved in 237 (83.5%), 34 (12.0%) and 13(4.5%) patients, respectively. The pituitary stalk was preserved in 176 (62.0%) patients, severed in 52 (18.3%),and unidentified in 56 (19.7%). Twelve (4.2%) patients died within one month after the surgery. During the follow-up, 23 (14.1%) patients experienced tumor recurrence 1.0-3.5 years (mean, 1.8±1.6) after total tumor removal, and 24 (64.9%) had recurrent tumor 0.25 - 1.5 years (mean, 0.5 ± 0.4) after subtotal or partial resection.Normal activities of daily living were regained in 63 (80%) patients, independence in 29 (14.2%), and daily life with assistance in 9 (4.4%). Four (2.0%) patients died 0.9-3 years (mean, 1.6±1.4) after discharge from hospital, 3 of them died of hypothalamic deficiency.Conclusions We can protect the hypothalamic structures and its perforating arteries by choosing surgical approaches according to the location of craniopharygioma relative to the third ventricular floor. The mortality, morbidity, and recurrence rate in patients received total resection are lower than those of patients underwent subtotal or partial resections. In addition, preservation of the pituitary stalk is critical when total tumor resection is feasible。

Transplantation of mesenchymal stem cells (MSCs) for myocardial reconstruction has shown promise in both animal models and human phase 1 clinical studies.1,2 Vascular endothelial growth factor (VEGF) is a strong therapeutic agent for treating ischaemia by inducing angiogenesis.3 The feasibility of ex vivo MSCs mediated gene transfer is documented.…… Foundation Item：This work was supported in part by grants from the National Nature Science Foundation of China (No. 30471923 and No.30570667) and Shaanxi Provincial Science Grant (No. 2004C2-03)。

Asthma and chronic obstructive airway disease (COAD) are chronic inflammatory disorders of the airways which are usually associated with widespread airway obstruction that is often relieved by treatment. β2-adrenoreceptor agonists and corticosteriods are the mainstay of the management of this disease. The preferred route of administration of these agents is by inhalation。