Effect of Chinese Herbal Extract HNA-1 on the Thymic Output Function in Simian Immunodeficiency Virus Chronically Infected Chinese Rhesus Macaques / 中国中西医结合杂志

<p><b>OBJECTIVE</b>To observe the effect of Chinese herbal extract HuNan A-1 (HNA-1) on the thymic output function in Simian immunodeficiency virus (SIV) chronically infected rhesus macaques.</p><p><b>METHODS</b>Eight Chinese rhesus macaques had been infected by SIVmac239 for 16 to 21 months, and then they were randomly divided into the treatment group and the control group, 4 in each group. Monkeys in the treatment group were administered with HNA-1 by gastrogavage, once daily for 2 successive months, while those in the control group were administered with equal volume of normal saline by gastrogavage, once daily for 2 successive months. The general condition and body weight of monkeys were observed. Plasma viral loads were detected using real-time fluorescent quantitative PCR assay. CD4 percentages and counts, as well as naive CD subsets were detected using flow cytometry. T-cell receptor excision circles (TREC) were detected using real-time fluorescent quantitative PCR assay. The thymus tissue was pathologically observed using routine HE staining. The correlation between lesions of the thymus tissue, CD4 counts, naive CD counts, and TREC were analyzed.</p><p><b>RESULTS</b>There was no statistical difference in body weight, viral loads, absolute CD ratios between the two groups after treatment (P > 0.05). The altered TREC multiple showed an obvious decreasing tendency in the control group, while it showed an increasing tendency in the treatment group (P < 0.05). In both groups, destroyed structures of the thymus tissue could be seen, filled with pink unstructured material. Increased connective tissues, lowered connective cell density, and confused arrangement could also be seen in the two groups, with no obvious difference. TREC contents were positively correlated with naive CD4 counts after removing extremum (r = 0.926, P = 0.001). Naive CD4 counts were positively correlated with CD4 counts (r = 0.961, P = 0.005).</p><p><b>CONCLUSIONS</b>TREC content determination, as a marker of newly thymic emigrants, could be taken as a testing method for evaluating the thymic output function. Besides, HNA-1 treatment increased the thymic output significantly in SIV chronically infected monkeys. Correlation existed among TREC contents, naive CD4 counts, and pathologies of thymus tissues, especially in late infection stage.</p>

Study on Cellular Immune Responses of DNA Vaccine, rAd5 and rMVA Expressing SIV Gag/Env Gene Combined Immunization in Mice / 病毒学报

Therapeutic HIV vaccine was considered as a hopeful curative method for AIDS patients. However, there is still no suitable HIV animal model for vaccine study since the difference in the immune system between human and animals. To evaluate the therapeutic effect of combined immunization strategy with multiple vector vaccines in macaque models. Plasmid DNA, recombinant Ad5 and MVA vaccines which expressing SIV gag and env genes were constructed. Sequential and repeated immune strategy were applied to immunize mice with these three vaccines. Cellular immune responses in mice immunized with these three vaccines were measured by ELISPOT test in vitro and CTL assay in vivo. The results were analyzed and compared with different antigen combination, order of vaccines and intervals to choose a suitable immunization strategy for macaque immunization in future. It indicated that strong SIV-Gag/Env-specific cellular immune responses were induced by these three vector vaccines. It laid a foundation for evaluating the therapeutic effect of combined immunization strategy with multiple vector vaccines in SIV infected macaque models.

Model index observations in SIVmac251-infected rhesus macaques / 病毒学报

In this study, five rhesus macaques were inoculated intravenously with SIVmac251 to establish a model of simian autoimmune deficiency syndrome (SAIDS). Peripheral blood samples were collected at different time points to monitor changes in the total T cell number and T lymphocyte subset. Plasma viral loads, cytokine expression levels and anti-SIV antibody levels were also assayed to acquire certain basic indexes to evaluate disease progression in the rhesus macaque SAIDS model. During the acute stage of infection, plasma viral loads reached a peak at week 1 post-inoculation and lasted for approximately 3 to 44 weeks. The CD3+ CD4+ T lymphocyte count in peripheral blood also transitorily decreased. During the same period, the level of interferon-gamma show an increasing trend, whereas IL-12 levels decreased; IL-2, IL-4, IL-10 and TNF-alpha were maintained at normal levels or could not be detected. During the asymptomatic and ARC phases, plasma viral loads persisted above 10(4) RNA copies/mL and either increased or declined during the later stages of disease; CD3+ CD4+ counts showed a steadily declining trend and the ratio of CD4 to CD8 decreased during late-stage disease. Moreover, antibodies against viral proteins were detected in the plasma and showed a significant increasing trend, while there were no apparently changes in the levels of IFN-gamma, IL-12, IL-2, IL-4, IL-10 and TNF-alpha. In conclusion, the characteristics of the SIV animal models in our study are similar to those of patients with AIDS. Therefore, the rhesus macaque SIVmac251 infection models can be applied for further studies into AIDS.

Experimental observation of SIVmac239 Chinese rhesus monkey model at sub-acute phase of AIDS / 中国中药杂志

<p><b>OBJECTIVE</b>To observe T lymphocyte subsets and indicators of changes in viral load in sub-acute period in Chinese rhesus monkey model of AIDS SIVmac239. To explore Virology related index variation in sub-acute period of the Chinese rhesus monkey model of AIDS.</p><p><b>METHOD</b>To replicate Chinese rhesus monkey model of AIDS, healthy Chinese rhesus monkey was inoculated with SIVmac239 viral strain. To observe changes in T lymphocyte subsets indexes and viral load after infection with the simian immunodeficiency virus (SIV) in sub-acute period on an animal model. The clinical symptoms of the animal model was recorded simultaneously.</p><p><b>RESULT</b>During the 10 weeks after SIV acute infection, body weight and BMI index were relatively stable, the difference was not significant at all time points. Twelve monkeys were tested SIV positive by real-time PCR after three days of infection. On the 7th day after infection, 15 monkeys were tested SIV positive. Viral load increased rapidly, but reached a peak on the 10th-14th day after infection, then showed a level of volatility decline. T lymphocyte subsets showed significant changes, among them, CD3% and CD3 counts fluctuated upward trend and reached to the highest level in two weeks after infection; of CD4% and CD4 count changes were not synchronized, CD4% declined trend while the CD4 count was an increasing trend after the infection; of CD8% and CD8 counts fluctuate upward trend, and reached to a highest level in two weeks after infection ;the ratio of CD4/CD8 and the counts of CD4CD28 T cells decreased significantly in two weeks after infection; the former followed by a slow decline, the latter followed by a rapid rise. Three mouths after the infection 3 monkeys showed significant clinical symptoms. One of the rhesus monkeys had symptoms of diarrhea and two of them had reduced food intake.</p><p><b>CONCLUSION</b>This experiments established standardization of Chinese Rhesus monkeys used in the research of AIDS and provide a detailed contents in the changes of sub-acute phase.</p>

Is an HIV vaccine possible?

The road to the discovery of a vaccine for HIV has been arduous and will continue to be difficult over the ensuing twenty years. Most vaccines are developed by inducing neutralizing antibodies against the target pathogen or by using attenuated strains of the particular pathogen to engender a variety of protective immune responses. Unfortunately, simple methods of generating anti-HIV antibodies have already failed in a phase III clinical trial. While attenuated SIV variants work well against homologous challenges in non-human primates, the potential for reversion to a more pathogenic virus and recombination with challenge viruses will preclude the use of attenuated HIV in the field. It has been exceedingly frustrating to vaccinate for HIV-specific neutralizing antibodies given the enormous diversity of the Envelope (Env) glycoprotein and its well-developed glycan shield. However, there are several antibodies that will neutralize many different strains of HIV and inducing these types of antibodies in vaccinees remains the goal of a vigorous effort to develop a vaccine for HIV based on neutralizing antibodies. Given the difficulty in generating broadly reactive neutralizing antibodies, the HIV vaccine field has turned its attention to inducing T cell responses against the virus using a variety of vectors. Unfortunately, the results from Merck's phase IIb STEP trial proved to be disappointing. Vaccinees received Adenovirus type 5 (Ad5) expressing Gag, Pol, and Nef of HIV. This vaccine regimen failed to either prevent infection or reduce the level of HIV replication after challenge. These results mirrored those in non-human primate testing of Ad5 using rigorous SIV challenge models. This review will focus on recent developments in HIV vaccine development. We will deal largely with attempts to develop a T cell-based vaccine using the non-human primate SIV challenge model.

Construction and characterization of a new simian/human immunodeficiency viruses clone carrying an env gene derived from a CRF07_BC strain / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>The CRF07_BC recombinant strain has been one of the most predominantly circulated HIV-1 strains in China, it is therefore necessary and urgent to develop a relevant animal model to evaluate candidate vaccines targeting HIV-1 CRF07_BC. A highly replication-competent simian/human immunodeficiency viruses (SHIV) construct containing the Chinese CRF07_BC HIV-1 env gene with the ability to infect Chinese rhesus monkeys would serve as an important tool in the development of HIV vaccines. The aim of this study was to examine whether SHIV XJDC6431 with the env fragment from a Chinese HIV-1 isolate virus could infect the human and monkey peripheral blood mononuclear cell (PBMC), establish infection in Chinese rhesus macaque.</p><p><b>METHODS</b>A SHIV strain was constructed by replacing the rev/env genes of SHIV KB9 with the corresponding fragment derived from the HIV-1 CRF07_BC strain. The infectious activity of the SHIV clones was determined in vitro in PBMCs from both non-human primate animals and humans. Finally, one Chinese rhesus macaques (Macaca mulatta) was infected with one SHIV via intravenous infusion.</p><p><b>RESULTS</b>One SHIV clone designated as SHIV XJDC6431, was generated that could infect macaque and human PBMC. The virus produced from this clone also efficiently infected the CCR5-expressing GHOST cell lines, indicating that it uses CCR5 as its coreceptor. Finally, the virus was intravenously inoculated into one Chinese rhesus macaque. Eventually, the animal became infected as shown by the occurrence of viremia within 3 of infection. The viral load reached 105 copies of viral RNA per ml of plasma during the acute phase of infection and lasted for 10 weeks post infection.</p><p><b>CONCLUSIONS</b>We conclude that SHIV XJDC6431 is an R5-tropic chimeric virus, which can establish infection not only in vitro but also in vivo in the Chinese rhesus macaque. Although the animal inoculated with SHIV XJDC6431 became infected without developing a pathologic phenotype, the virus efficiently replicated with a persistent level of viral load in the plasma. This suggested that the SHIV could be used as a tool to test candidate AIDS vaccines targeting the Chinese HIV-1 CRF_07BC recombinant strain.</p>

Purification, crystallographic analysis of rhesus MHC-I Mamu-A*02 complexed with simian immunodeficiency virus nonapeptide / 生物工程学报

Rhesus macaque (Macaca mulatta) is the best model to study of human immunodeficiency virus (HIV) infection and to develop acquired immunodeficiency syndrome (AIDS) vaccine. The crystal structure of its major histocompatibility antigen complex (MHC) is helpful to understand the mechanism of HIV immune evasion. In this study, we cloned the light chain (beta2m) of MHC class I allele of rhesus macaques, Mamu-A*02, and inserted it into pET21a(+) vector. We transfected the recombinant plasmid pET21a(+)-Mamu-beta2m and pET21a(+)-Mamu-alpha into BL21(DE3). Mamu-A*02 and beta2m were expressed in the form of inclusion bodies in BL21 (DE3). We co-refolded the inclusion bodies of Mamu-alpha and Mamu-beta2m with SIV nonapeptide YY9 and obtained the correct refolded protein complex. Then we purified the protein complex by the gel filtration and anion-exchange column. With hanging-drop method, we screened and optimized for the protein crystal. We managed to collect a X-ray diffraction with the resolution to 2.8 angstroms in the condition of 0.1 mol/L BIS-TRIS (pH5.5), 2.0 mol/L(NH4)2SO4. This crystal belong to perpendicular space group P2(1)2(1)2(1), with unit-cell parameters a = 128.99 angstroms, b = 129.01 angstroms, c = 129.03 angstroms. This data is available for the structure determination.

The hope for an HIV vaccine based on induction of CD8+ T lymphocytes: a review

The only long-term and cost-effective solution to the human immunodeficiency virus (HIV) epidemic in the developing world is a vaccine that prevents individuals from becoming infected or, once infected, from passing the virus on to others. There is currently little hope for an AIDS vaccine. Conventional attempts to induce protective antibody and CD8+ lymphocyte responses against HIV and simian immunodeficiency virus (SIV) have failed. The enormous diversity of the virus has only recently been appreciated by vaccinologists, and our assays to determine CD8+ lymphocyte antiviral efficacy are inadequate. The central hypothesis of a CTL-based vaccine is that particularly effective CD8+ lymphocytes directed against at least five epitopes that are derived from regions under functional and structural constraints will control replication of pathogenic SIV. This would be somewhat analogous to control of virus replication by triple drug therapy or neutralizing antibodies.

Comparison of intravenous and intrarectal SIVmac239 infections in rhesus monkeys of Chinese origin / 中国医学科学院学报

<p><b>OBJECTIVE</b>To investigate the biological and clinical features of Chinese rhesus monkeys after intravenous (IV) and intrarectal (IR) challenge with SIVmac239 in rhesus monkeys of Chinese origin, and compare the differences between the routes of infection.</p><p><b>METHODS</b>Rhesus monkeys of Chinese origin were inoculated with SIVmac239 either by IV (n = 19) or IR (n = 6) routes. Simian immunodeficiency virus (SIV)-specific antibody titer, CD4 + T cell counting, plasma SIV load, lymph node pathology, and clinical manifestations were compared between these two groups 232 or 168 days after challenging.</p><p><b>RESULTS</b>All SIVmac239-inoculated animals became seropositive for SIV-specific antibodies. SIV-specific IgM was detected in IV groups as from day 10 but was not detected in IR for all the time points. Although SIV-specific IgG was detected as from day 30 in both groups, the IgG titers were ten-fold higher in IV group than in IR group after day 168. CD4 + T-cell counting decreased progressively in IV group but remained stable in IR group over time. Plasma SIV RNA loads peaked in all animals between day 10 and day 14 (10(7) copies/ml), then declined to "setpoint" (10(3) - 10(6) copies/ml) about 2 months later. Most inoculated animals manifested lymphadenopathy. Two animals in IV group and one in IR group died of simian AIDS between day 150 and day 210, as evidenced by the autopsies showing the depletion of lymph tissues, Pneumocystis carinii pneumonia and other opportunity infections. Conclusion IV or IR inoculation of SIVmac239 in Chinese rhesus monkeys will result in chronic SIV infection with a similar clinical feature of natural HIV infection, which provides an excellent experimental animal model for AIDS.</p>

Establishment of a real-time RT-PCR to detect plasma viral load of simian/human immunodeficiency virus CN97001 during its in vivo passage in rhesus monkeys / 中华实验和临床病毒学杂志

<p><b>OBJECTIVE</b>To establish a real-time RT-PCR based plasma virus quantification method and monitor the plasma viral load of SHIV-CN97001 during its in vivo passages in rhesus macaques.</p><p><b>METHODS</b>Viral RNA standards were prepared by in vitro transcription and one-tube real-time RT-PCR were established and optimized using TaqMan EZ RT-PCR CORE REAGENTS and TaqMan probes and primers directed to the 91 bases within the conserved gag region of SHIV. Plasma viral RNA of 126 plasma samples from rhesus macaques of different viral passages was quantified.</p><p><b>RESULTS</b>The PCR system was optimized by using serial dilution of standards, and the viral RNA load was detected. The lowest limit of the standard curve reached 2x10(-2) copies/ml. The correlation (r>0.99) and the repetition (CV=4.14 percent) also met the requirement. It was revealed that the viral RNA load of third passage was the highest. Generally, the viral load peaks (10(5)-10(6) copies/ml) appeared at the fourteenth day after the infection or inoculation.</p><p><b>CONCLUSION</b>The method of one-tube real-time RT-PCR was established successfully, which may provide a sensitive way to qualify SHIV viral load. This will contribute to the establishment and application of SHIV/rhesus macaque models. It was also found that the replicative ability of SHIV-CN97001 was enhanced during the first 2 in vivo passages.</p>

Autoantibodies and autoimmunity in simian immunodeficiency virus-infected monkeys / 中国医学科学院学报

<p><b>OBJECTIVE</b>To study the relationship between simian acquired immunodeficiency syndromn (SAIDS) and autoimmunity in simian immunodeficiency virus (SIV)-infected monkeys.</p><p><b>METHODS</b>Indirect immunofluorescence assays were performed to detect plasma or serum autoantibodies in SIV-infected monkeys. The heart, liver, spleen, lung, kidney, and lymph node of BALB/c mice, a strain of endothelial cell ECV304, and granulocytes were used as target antigens. These results were compared with HE stained slides of SIV-infected monkeys.</p><p><b>RESULTS</b>The levels of various autoantibodies, including anti-lymphocyte autoantibodies, anti-endothelial cell autoantibodies, and anti-granulocyte antibodies, increased after SIV infection in monkeys. Moreover, pathological examinations showed injuries in the lymphoid tissue and vascular pathological changes in cerebral cortex, submucosa of gastrointestinal tract, interstitial capillaries of myocardium, nephron of the kidney, and sinusoid cell of liver.</p><p><b>CONCLUSION</b>The increased autoantibodies and the pathological changes of tissues and organs confirm the existence of autoimmunity in SIV-infected monkeys.</p>

One-Stage Polymerase Chain Reaction for the Comprehensive Detection of Type D Retrovirus Provial DNA

To develop the polymerase chain reaction (PCR) for the detection of type D simian retrovirus (SRV) infection, an oligonucleotide primer pair was designed to hybridize to the sequences within euv gene of SRV subtype 1 (SRV-1). The 3'proximal env sequences annealing to the primers had been rather conserved among three different subtypes of SRV, SRV-1, SRV-2, and SRV-3 (Mason-Pfizer Monkey Virus: MPMV). The PCR using the primer pair targetingan an env region the successfully detected and amplified all three subtypes of SRV with excellent specificity after single round of reaction. The tests with peripheral blood mononuclear cells infected either with simian immunodeficiency virus or simian T-lymphotropic virus type 1, maior immunosuppressive viral agents together with SRV in simian, verified the specificity of the PCR by excluding any cross reactivity. Semiquantitative titration PCR, amplifying serially diluted plasmid DNA of each subtype, was performed to evaluate sensitivity limits of the reaction. Based on molecular weight of each cloned SRV genome, the PCR should be able to detect one SRV-infected cell per more than 5-7x104 uninfected cells after simple ethidium bromide staining of resulting products. The PCR must be very efficient screening sisters with its quickness, certainty, and sensitivity for SRV-infected animals used in human AIDS research model. Second round amplification of the reaction products from the first PCR, or Southern hybridization by radiolabeled probes shall render to compete its efficacy to ELISA which has been the most sensitive technique to screen SRV infection but with frequent ambiguity problem.

Breve historia del SIDA en los primates no humanos y su contribución al estudio del síndrome de inmunodeficiencia adquirida / Brief history of AIDS in non-human primates and its contribution to the study of acquired imunodeficiency syndrome

Infection of the rhesus monkey (Macaca mulatta) with retroviruses originating from African non human primates (SIV) induces in this species an acquired immunodeficiency syndrome (SAIDS) closely resembling AIDS in humans. Analogies between the SIV-rhesus system and AIDS in humans are described in this work, analyzing the close relationship existing between the HIV and SIV viruses, and the similarities between SIV disease in the rhesus and HIV disease in humans. A review of current advances in AIDS vaccine research, using the SIV-rhesus model, is also included