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Updated: Jul 22, 2026
A Restriction Enzyme Based Cloning Method to Assess the In vitro Replication Capacity of HIV-1 Subtype C Gag-MJ4 Chimeric Viruses
Published on: August 31, 2014
Molecularly cloned SHIV-1157ipd3N4: a highly replication- competent, mucosally transmissible R5 simian-human
R J Song1, A-L Chenine, R A Rasmussen
1Dana-Farber Cancer Institute, Boston, Massachusetts 02115, USA.
Abstract:
Human immunodeficiency virus type 1 (HIV-1) clade C causes >50% of all HIV infections worldwide, and an estimated 90% of all transmissions occur mucosally with R5 strains. A pathogenic R5 simian-human immunodeficiency virus (SHIV) encoding HIV clade C env is highly desirable to evaluate candidate AIDS vaccines in nonhuman primates. To this end, we generated SHIV-1157i, a molecular clone from a Zambian infant isolate that carries HIV clade C env. SHIV-1157i was adapted by serial passage in five monkeys, three of which developed peripheral CD4(+) T-cell depletion. After the first inoculated monkey developed AIDS at week 137 postinoculation, transfer of its infected blood to a naïve animal induced memory T-cell depletion and thrombocytopenia within 3 months in the recipient. In parallel, genomic DNA from the blood donor was amplified to generate the late proviral clone SHIV-1157ipd3. To increase the replicative capacity of SHIV-1157ipd3, an extra NF-kappaB binding site was engineered into its 3' long terminal repeat, giving rise to SHIV-1157ipd3N4. This virus was exclusively R5 tropic and replicated more potently in rhesus peripheral blood mononuclear cells than SHIV-1157ipd3 in the presence of tumor necrosis factor alpha. Rhesus macaques of Indian and Chinese origin were next inoculated intrarectally with SHIV-1157ipd3N4; this virus replicated vigorously in both sets of monkeys. We conclude that SHIV-1157ipd3N4 is a highly replication-competent, mucosally transmissible R5 SHIV that represents a valuable tool to test candidate AIDS vaccines targeting HIV-1 clade C Env.
Insights
Researchers developed SHIV-1157ipd3N4, a new simian-human immunodeficiency virus (SHIV) model. This R5-tropic virus effectively replicates and transmits mucosally, making it a valuable tool for testing AIDS vaccines against HIV-1 clade C.
Area of Science:
- Virology
- Immunology
- Vaccinology
Background:
- Human immunodeficiency virus type 1 (HIV-1) clade C accounts for over 50% of global infections.
- Mucosal transmission, primarily via R5 strains, drives the majority of HIV-1 spread.
- A pathogenic R5 simian-human immunodeficiency virus (SHIV) encoding HIV clade C env is crucial for AIDS vaccine evaluation in nonhuman primates.
Purpose of the Study:
- To generate a highly replication-competent, mucosally transmissible R5 SHIV for testing AIDS vaccines targeting HIV-1 clade C Env.
- To develop a nonhuman primate model that accurately mimics key aspects of HIV-1 infection and transmission.
Main Methods:
- Generated SHIV-1157i, a molecular clone with HIV clade C env, from a Zambian infant isolate.
- Adapted SHIV-1157i through serial passage in monkeys, leading to CD4(+) T-cell depletion and AIDS development.
- Generated a late proviral clone, SHIV-1157ipd3, and engineered SHIV-1157ipd3N4 with enhanced replication capacity via an NF-kappaB binding site.
- Inoculated Rhesus macaques intrarectally with SHIV-1157ipd3N4 to assess infectivity and transmissibility.
Main Results:
- Serial passage of SHIV-1157i resulted in CD4(+) T-cell depletion and AIDS in inoculated monkeys.
- Transfer of infected blood induced memory T-cell depletion and thrombocytopenia in recipient animals.
- SHIV-1157ipd3N4 demonstrated exclusive R5 tropism and potent replication in Rhesus peripheral blood mononuclear cells.
- SHIV-1157ipd3N4 replicated vigorously in Rhesus macaques of both Indian and Chinese origin following intrarectal inoculation.
Conclusions:
- SHIV-1157ipd3N4 is a highly replication-competent, mucosally transmissible R5 SHIV.
- This novel SHIV model is a valuable tool for evaluating candidate AIDS vaccines targeting HIV-1 clade C Env.
- The developed SHIV provides a robust platform for preclinical AIDS vaccine research.
