Gao-Hong Zhang

Human immunodeficiency virus-1 genotypic drug resistance among volunteer blood donors in Yunnan, China.

BACKGROUND: Drug resistance profiles of human immunodeficiency virus‐1 (HIV‐1) in treatment‐naïve infections have been reported in developed countries. However, little is known in developing countries, including China, especially in treatment‐naïve volunteer blood donors.

The Influence of Age and Sex on the Cell Counts of Peripheral Blood Leukocyte Subpopulations in Chinese Rhesus Macaques

Non-human primates such as Chinese rhesus macaques are the favorable models for preclinical study of potential therapeutic drugs, vaccines and mechanisms of human diseases. Little is known about the normal levels of leukocyte subpopulations of Chinese rhesus macaques. To obtain these data, 100 blood samples from Chinese rhesus macaques were collected. The normal range of major leukocyte subpopulations, such as T lymphocytes, B lymphocytes, monocytes, myeloid dendritic cells (mDCs) and plasmacytoid dendritic cells (pDCs), were quantitatively analyzed by flow cytometry through BD trucount tubes. The influence of age and sex on the cell counts of leukocyte subpopulations was analyzed. The counts of CD3+T cells, CD3+CD4+T cells, CD3+CD8+T cells and B cells decreased with age, but those of monocytes, mDCs and pDCs had no significant correlation with age. Significant differences existed in the cell counts of most leukocyte subpopulations between the male and female groups except pDCs. Furthermore the values of the females were higher than those of the males. The study provided basic information about the leukocyte subpopulations of Chinese rhesus macaques, and it may be valuable for immunobiological study of Chinese rhesus macaques.

Dendritic cell subsets dynamics and cytokine production in SIVmac239-infected Chinese rhesus macaques

BackgroundSeveral studies have demonstrated that SIV infection progresses more slowly to experimental AIDS in Chinese rhesus macaques (Ch Rhs) than in Indian rhesus macaques (Ind Rhs). Here we investigated the dynamic and functional changes in dendritic cell (DC) subsets in SIVmac239-infected Ch Rhs.ResultsThe numbers of both mDC and pDC strongly fluctuated but were not significantly changed during the acute and chronic phases of infection. However, the concentration of both poly (I:C)-induced IL-12 and HSV-1-induced IFN-α significantly increased in the acute phase of infection but returned to normal levels at the chronic phase of infection. The peak of IFN-α emerged earlier than that of IL-12, and it had a significantly positive correlation with IL-12, which indicated that IFN-α may initiate the immune activation. We also found that only the concentration of IFN-α was positively correlated with CD4+ T-cell counts, but it was negatively correlated with viral load.ConclusionHigh levels of IFN-α in the early stage of infection may contribute to effective control of virus replication, and normal levels of IFN-α during chronic infection may help Ch Rhs resist the disease progression. The change in DC subsets dynamics and cytokine production may help further our understanding of why Ch Rhs are able to live longer without progressing to an AIDS-like illness.

Molecular characterization, balancing selection, and genomic organization of the tree shrew (Tupaia belangeri) MHC class I gene.

The major histocompatibility complex (MHC) class I genes play a pivotal role in the adaptive immune response among vertebrates. Accordingly, in numerous mammals the genomic structure and molecular characterization of MHC class I genes have been thoroughly investigated. To date, however, little is known about these genes in tree shrews, despite the increasingly popularity of its usage as an animal model. To address this deficiency, we analyzed the structure and characteristic of the tree shrew MHC class I genes (Tube-MHC I) and performed a comparative gene analysis of the tree shrew and other mammal species. We found that the full-length cDNA sequence of the tree shrew MHC class I is 1074bp in length. The deduced peptide is composed of 357 amino acids containing a leader peptide, an α1 and α2 domain, an α3 domain, a transmembrane domain and a cytoplasmic domain. Among these peptides, the cysteines, CD8(+) interaction and N-glycosylation sites are all well conserved. Furthermore, the genomic sequence of the tree shrew MHC class I gene was identified to be 3180bp in length, containing 8 exons and 7 introns. In 21 MHC class I sequences, we conducted an extensive study of nucleotide substitutions. The results indicated that in the peptide binding region (PBR) the rate of non-synonymous substitutions (dN) to synonymous substitutions (dS) was greater than 1, suggesting balancing selection at the PBR. These findings provide valuable contributions in furthering our understanding of the structure, molecular polymorphism, and function of the MHC class I genes in tree shrews, further improving their utility as an animal model in biomedical research.

Phenotype and Function of Monocyte-Derived Dendritic Cells from Chinese Rhesus Macaques

Dendritic cells (DCs) play a pivotal role in linking the innate immunity and acquired immunity in responses to pathogen. Non-human primates such as Chinese Rhesus Macaque (CRM) are the favorable models for preclinical study of potential therapeutic drugs, vaccines and mechanisms of human diseases. However, the phenotypical characterization of monocyte-derived dendritic cells (MDDCs) from CRM has not been elucidated. Monocytes from CRM were cultured with GM-CSF and IL-4 in RPMI-1640. Six days later, these cells were differentiated with typical dendritical morphology. CD11c and DC-SIGN were highly expressed. The immature MDDCs expressed the low levels of CD25, CD80, CD83, moderate CD40, CD86, and high MHC. After stimulation, the mature MDDCs increased expression of mature molecules CD25 and CD83, co-stimulatory molecules such as CD80, CD86 and CD40, and kept a high level of MHC. The capacity of endocytosis decreased with maturation. The mature MDDCs have strong ability of inducing allogeneic T cell proliferation and producing IL-12. In conclusion, we have characterized the phenotype and ultimate function of MDDCs from CRM for the first time.

The β2-Microglobulin–Free Heterodimerization of Rhesus Monkey MHC Class I A with Its Normally Spliced Variant Reduces the Ubiquitin-Dependent Degradation of MHC Class I A

The MHC class I (MHC I) molecules play a pivotal role in the regulation of immune responses by presenting antigenic peptides to CTLs and by regulating cytolytic activities of NK cells. In this article, we show that MHC I A in rhesus macaques can be alternatively spliced, generating a novel MHC I A isoform (termed “MHC I A-sv1”) devoid of α3 domain. Despite the absence of β2-microglobulin (β2m), the MHC I A-sv1 proteins reached the cell surface of K562-transfected cells as endoglycosidase H-sensitive glycoproteins that could form disulfide-bonded homodimers. Cycloheximide-based protein chase experiments showed that the MHC I A-sv1 proteins were more stable than the full-length MHC I A in transiently or stably transfected cell lines. Of particular interest, our studies demonstrated that MHC I A-sv1 could form β2m-free heterodimers with its full-length protein in mammalian cells. The formation of heterodimers was accompanied by a reduction in full-length MHC I A ubiquitination and consequent stabilization of the protein. Taken together, these results demonstrated that MHC I A-sv1 and MHC I A can form a novel heterodimeric complex as a result of the displacement of β2m and illustrated the relevance of regulated MHC I A protein degradation in the β2m-free heterodimerization-dependent control, which may have some implications for the MHC I A splice variant in the fine tuning of classical MHC I A/TCR and MHC I A/killer cell Ig-like receptor interactions.

Replication potentials of HIV-1/HSIV in PBMCs from northern pig-tailed macaque ( Macaca leonina )

The northern pig-tailed macaque (Macaca leonina) has been identified as an independent species of Old World monkey, and we previously found that PBMCs from M. leonina were susceptible to human immunodeficiency virus type 1 (HIV-1), which may be due to the absence of a TRIM5 protein restricting HIV-1 replication. Here we investigated the infection potentials of six laboratory adapted HIV-1 strains and three primary HIV-1 isolates in PBMCs from M. leonina. The results indicate that these strains are characterized by various but low replication levels, and among which, HIV-1NL4-3 shows the highest replication ability. Based on the abundant evidence of species-specific interactions between restriction factors APOBEC3 and HIV/SIV-derived Vif protein, we subsequently examined the replication potentials of vif-substituted HIV-1 (HSIV) in M. leonina PBMCs. Notably, HSIV-vifmac and stHIV-1SV chimeras, two HIV-1NL4-3-derived viruses encoding the viral infectivity factor (Vif) protein from SIVmac239, replicated robustly in cells from M. leonina, which suggests that HSIV could effectively antagonize the antiviral activity of APOBEC3 proteins expressed in cells of M. leonina. Therefore, our data demonstrate that M. leonina has the potential to be developed into a promising animal model for human AIDS.

Inhibitory effects of chloroquine on the activation of plasmacytoid dendritic cells in SIVmac239-infected Chinese rhesus macaques.

It is currently widely accepted that immune activation in HIV-infected individuals leads to a severe loss of CD4+ T cells and the progression to AIDS. However, the underlying mechanism of this immune activation remains unclear. Experimental data suggest that the activation of plasmacytoid dendritic cells (pDCs) by plasma viremia may play a critical role in HIV-induced immune activation. In this study, we found that the level of immune activation was higher in the late phase of SIVmac239 infection compared with chronic infection, which suggests that immune activation might be related to disease progression in SIVmac239-infected non-human primate models. Our work also showed that chloroquine could effectively inhibit the activation of pDCs in vitro and in vivo. However, chloroquine treatment of SIVmac239-infected macaques had no significant influence on the Cellular composition of peripheral blood in these animals.

The Recombinant Maize Ribosome-Inactivating Protein Transiently Reduces Viral Load in SHIV89.6 Infected Chinese Rhesus Macaques

Ribosome inactivating proteins (RIPs) inhibit protein synthesis by depurinating the large ribosomal RNA and some are found to possess anti-human immunodeficiency virus (HIV) activity. Maize ribosome inactivating protein (RIP) has an internal inactivation loop which is proteolytically removed for full catalytic activity. Here, we showed that the recombinant active maize RIP protected chimeric simian-human immunodeficiency virus (SHIV) 89.6-infected macaque peripheral blood mononuclear cells from lysis ex vivo and transiently reduced plasma viral load in SHIV89.6-infected rhesus macaque model. No evidence of immune dysregulation and other obvious side-effects was found in the treated macaques. Our work demonstrates the potential development of maize RIP as an anti-HIV agent without impeding systemic immune functions.

Measurement and analysis of hematology and blood chemistry parameters in northern pig-tailed macaques ( Macaca leonina )

nnnnnn 平顶猴是重要的非人灵长类实验动物，广泛应用于艾滋病等重大疾病的动物模型研究。平顶猴分为明打威猴、巽他平顶猴和北平顶猴三个种。我国及周边东南亚国家分布的平顶猴为北平顶猴。该文测定和分析了青幼年 (2～4 a) 和成年 (5～10 a) 北平顶猴的血液学和血液生化指标参考值。结果表明个体性别、年龄和体重等对该指标均有影响。雌性个体的红细胞数、血红蛋白和碱性磷酸酶均低于雄性个体。青幼年个体的白细胞数、淋巴细胞数、单核细胞数、血小板分布宽度、碱性磷酸酶、天冬氨酸转氨酶和胆固醇均高于成年猴，而肌酐和甘油三酯则低于成年猴。个体体重与青年猴的平均血红蛋白含量和肌酐正相关，与成年猴的平均血红蛋白含量、粒细胞百分比、血红蛋白和肌酐正相关，而与成年猴的淋巴细胞数、淋巴细胞百分比、红细胞分布宽度变异系数、天冬氨酸转氨酶和胆固醇负相关。该研究提供的北平顶猴血液学和血液生化指标参考值范围，对其基础研究、疾病诊断和模型建立等具有重要意义。The pig-tailed macaque is an important non-human primate experimental animal model that has been widely used in the research of AIDS and other diseases. Pig-tailed macaques include Mentawai macaques (Macaca pagensis), Sunda pig-tailed macaques (M. nemestrina) and northern pig-tailed macaques (M. leonina). Northern pig-tailed macaques inhabit China and surrounding Southeast Asia countries. To our knowledge, no reports have been published regarding the hematology and blood chemistry parameters of northern pig-tailed macaques, which are important for the objective evaluation of experimental results. We measured and analyzed 18 hematology parameters and 13 blood chemistry parameters in juvenile (aged 2-4 years) and adult (aged 5-10 years) northern pig-tailed macaques. We found that red blood cells, hemoglobin and alkaline phosphatase values were lower in female macaques than male macaques in both juvenile and adult groups. White blood cells, lymphocyte, monocytes, platelet distribution width, cholesterol, aspartate aminotransferase and alkaline phosphatase values were higher in juvenile macaques than adult macaques, while creatinine and triglycerides values were lower in juvenile macaques. Mean corpuscular hemoglobin and creatinine values were positively correlated with weight in juvenile groups. In adult groups, mean corpuscular hemoglobin, percentage of granulocyte, hemoglobin and creatinine were also positively correlated with weight, and lymphocyte, percentage of lymphocyte, red cell distribution width, aspartate aminotransferase and cholesterol values were negatively correlated with weight. The results suggest that age, gender and weight of northern pig-tailed macaques affected their hematology and blood chemistry parameters. This hematological and blood chemistry study has great significance in biomedical research and animal models using northern pig-tailed macaque as an experimental animal.