ABSTRACT
The acquired immunode—ciency syndrome (AIDS) is a global epidemic caused by one of two related retroviruses of the lentivirus family, human immunode—ciency virus (HIV) types 1 and 2. Most cases of AIDS worldwide are due to HIV-1 infection, but cases due to HIV-2 infection are more prevalent in certain areas of Africa. According to reports from the United Nations Program on HIV/AIDS (UNAIDS), in 2008, approximately 33.4 million people were living with HIV-AIDS, although the global percentage of people living with HIV has leveled off since 2000. Sub-Saharan
CONTENTS
Introduction ....................................................................................................................................269 Desirable Features of an Ideal Animal Model for HIV-AIDS ...................................................... 270 Equine Infectious Anemia Virus (EIAV) Infection in Horses as a Model .................................... 271 Bovine Immunode—ciency Virus (BIV) Infection in Cattle as a Model ....................................... 271 Caprine Arthritis-Encephalitis Virus (CAEV) and Maedi-Visna Virus (MVV) Infections in Sheep as Models ........................................................................................................................ 272 Feline Immunode—ciency Virus (FIV) Infection in Cats as a Model ............................................ 272 HIV Infection in Small Animal Models ........................................................................................ 273
Transgenic Mice and Rats ......................................................................................................... 273 SCID-hu Mice ........................................................................................................................... 274 RAG-hu Mice ............................................................................................................................ 275 Humanized BLT Mice............................................................................................................... 275
HIV, SIV, and SHIV Infections in Nonhuman Primate Models ................................................... 276 Chimpanzees (Pan troglodytes) ................................................................................................ 276 Baboons (Papio cynocephalus) ................................................................................................. 277 Monkeys .................................................................................................................................... 277
Comparisons between the Primate Immunode—ciency Viruses and HIV in Terms of Infections in Respective Host Species ............................................................................. 278 Nonhuman Primate Models for Studies Related to HIV-Associated Pathology .................. 279 Nonhuman Primate Models for HIV Vaccine Development ............................................... 281
Conclusions ....................................................................................................................................285 Acknowledgments ..........................................................................................................................286 References ......................................................................................................................................286
Africa is still the region most affected by HIV, accounting for 71% of all HIV cases in 2008. However, increases in new infection rates are now occurring in countries in other regions, such as India, China, Indonesia, and Russia (UNAIDS). Important strides have been made in the treatment of HIV infection with highly active antiretroviral therapy (HAART). However, this therapy is expensive and, therefore, is accessible mainly to people in developed countries. Drug-related toxicity and the development of drug-resistant strains of HIV are the main problems associated with HAART that hinder progress to curtail this epidemic.
