Toxoplasma gondii: an AIDS enhancing cofactor.
Disseminated toxoplasmosis, one of the most severe acquired immune deficiency syndrome (AIDS)-associated infections in humans, is believed to develop from a latent infection after the cellular immune system is suppressed by human immunodeficiency virus type 1 (HIV-1). However, Toxoplasma gondii may serve as a cofactor in enhancing the immunodeficiency induced by HIV-1. This hypothesis is supported by the facts that: 1) co-infection with other pathogens in humans infected with HIV-1 may enhance the progression of the disease to AIDS; and 2) concomitant infection with T. gondii enhances feline immunodeficiency virus-induced immune dysfunction and is likely to cause a more rapid disease onset than an infection with HIV alone. It is possible that T. gondii infection induces tumor necrosis factor (TNF) production. TNF then stimulates the induction of T-cell proteins that bind to the long terminal repeat of HIV-1. This binding at the repeat site then leads to increased HIV-1 activation which causes the dysfunction of CD4 cells and a resulting immunodeficiency that allows even greater amounts of T. gondii replication.
Lin
D S
DS
Department of Veterinary Medicine, National Taiwan University, Taipei, Republic of China.
Bowman
D D
DD
D017088:AIDS-Related Opportunistic Infections / Q000150:complications* / Q000276:immunology; D000818:Animals; D002415:Cats; D016181:Feline Acquired Immunodeficiency Syndrome / Q000150:complications / Q000276:immunology; D015497:HIV-1; D006801:Humans; D016089:Immunodeficiency Virus, Feline; D014123:Toxoplasmosis / Q000150:complications* / Q000276:immunology; D014124:Toxoplasmosis, Animal / Q000150:complications / Q000276:immunology