Serial passage of clade C SHIV-XJ02170 in Chinese origin Rhesus macaques / 中华微生物学和免疫学杂志

Objective To analyze the virologic and immunologic properties during SHIV-XJ02170passage in vivo and construct the clade C SHIV/Chinese origin Rhesus macaques AIDS model . Methods SHIV-XJ02170 cell-free virus tranfected in 293T was adapted by serial passage in nine Chinese-origin Rhesus macaques. CD4/CD8 ratio was detected by flow cytometry to analyze the changes in viral pathogenicity. Real-time RT-PCR and IFN-γsecreting ELISPOT methods were used to analyze changes in characteristics of virology and immunology. Results During in vivo passage, CD4/CD8 ratio did not deeply decline. However,the peak and setpoint viral load in the line 3 show a continuous upward trend. The strong humoral and cellular immune responses were induced after SHIV-XJ02170 infection. Meanwhile, there was significant positive correlation between the viral load and binding antibody titer. Conclusion There were no pathogenic viral strains, and upward trend in virulence of SHIV-XJ02170 was found during in vivo passaging. SHIVXJ02170/Chinese origin Rhesus macaques model will play an important role in effect evaluation of candidate AIDS vaccines in China.

Sequence variation in the env region of SHIV-XJ02170 during in vivo passaging / 中华微生物学和免疫学杂志

Objective To identify the variation in the Env region of SHIV-XJ02170 during passaging in Chinese origin Rhesus Macaques.Methods Fragments of the SHIV-XJ02170 gp160 and gp120 gene were amplified by PCR and RT-PCR separately from the blood samples of SHIV-XJ02170 infected animals at the peak viral load time point.Purified RT-PCR product was ligated into T easy vector and transformed into JM109 competent cells,18 clones were selected by PCR method and sequenced by ABI 3730DNA sequencers.The gene distances(divergence,diversity)were calculated using DISTANCE.Results In all,the SHTV-XJ02170 gp120 gene evolved forward along the virus passaging.It could be found that viral divergence from the founder strain serially enhanced during in vivo passaging,but in the early phase of each passage,SHIV-XJ02170 gp120 gene evolved toward ancestral state upon transmission to a new host.All of the SHIV-XJ02170 strains had V3 loop central motif(GPGQ)and were predicted to be using CCR5 on the basis of the critical amino acids within V3 loop.Conclusion There was significant increase in the genetic distance during serial passaging,and SHIV-XJ02170 gp120 gene evolved forward along passaging.This could partly explain why the virus infectivity was enhanced during in vivo passaging.

Sequence Variation in the Gp120 region of SHIV-CN97001 during in vivo Passage / 中国病毒学·英文版

SHIV-CN97001 played an important role in assessing the immune effect and strategy of the AIDS vaccine which included genes of the predominant prevalent HIV-1 strain in China. In this study, SHIV-CN97001 was in vivo passaged serially to construct pathogenic SHIV-CN97001/rhesus macaques model. To identify variation in the gp120 region of SHIV-CN97001 during passage, the fragments of gp120 gene were amplified by RT-PCR from the plasma of SHIV-CN97001 infected animals at the peak viral load time point and the gene distances (divergence, diversity) were calculated using DISTANCE. The analysis revealed that the genetic distances of SHIV-CN97001 in the third passage animals were the highest during in vivo passage. It had a relationship between viral divergence from the founder strain and viral replication ability. The nucleic acid sequence of the V3 region was highly conservative. All of the SHIV-CN97001 strains had V3 loop central motif (GPGQ) and were predicted to be using CCR5 co-receptor on the basis of the critical amino acids within V3 loop. These results show that there was no significant increase in the genetic distance during serial passage, and SHIV-CN97001 gp120 gene evolved toward ancestral states upon transmission to a new host. This could partly explain why there was no pathogenic viral strain obtained during in vivo passage.