Plasma viral RNA load is widely accepted as the most relevant parameter to assess the status and progression of Simian immunodeficiency virus （SIV） infections. To accurately measure RNA levels of the virus, a one-step fluorescent quantitative assay was established based on the SYBR green Real-time reverse transcription-polymerase chain reaction （RT-PCR）. The lower detection limit of the assay was 10 copies per reaction for the virus. This method was successfully applied to quantify SIVmac251 and SIVmac239 viruses produced in CEMx174 cells. Additionally, the performance of the SYBR green RT-PCR was assessed in a SIVmac251 infected rhesus macaque. The result demonstrated that the method could detect as little as 215 copies per milliliter of plasma and the dynamic pattern of viral load was highly consistent with previous results. With regard to convenience, sensitivity and accuracy our assay represents a realistic alternative to both branched-chain DNA （b-DNA） assays or real-time PCR assays based on TaqMan probes.
Jing LU Li QIN Guang-jie LIU Si-ting ZHAO Xiao-ping CHEN
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 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. CDllc 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.
