The Role Of HIV Infection Of Astrocytes In The Development Of HIV Associated Dementia
Funder
National Health and Medical Research Council
Funding Amount
$144,250.00
Summary
Dementia is an extremely common problem in the late stages of Human Immunodeficiency Virus (HIV) infection. HIV-associated dementia is the most common cause of dementia in people under 40 years of age. Despite the development of very good drugs to attack the virus, HIV-associaed dementia continues to be a major clinical problem. We are looking at the reasons why some people infected with HIV become demented and others do not. We are also looking at how best to prevent the development of dementia ....Dementia is an extremely common problem in the late stages of Human Immunodeficiency Virus (HIV) infection. HIV-associated dementia is the most common cause of dementia in people under 40 years of age. Despite the development of very good drugs to attack the virus, HIV-associaed dementia continues to be a major clinical problem. We are looking at the reasons why some people infected with HIV become demented and others do not. We are also looking at how best to prevent the development of dementia. We believe that astrocytes (an important brain cell that supports neurons) play a very important role in the development of HIV-associated dementia. With an improved understanding of the steps leading to dementia we can better plan treatments to prevent the development of this devastating complication of HIV-AIDS.Read moreRead less
The Kynurenine Pathway Chemokines And MIC-1 In The Pathogenesis Of AIDS Dementia Complex.
Funder
National Health and Medical Research Council
Funding Amount
$241,980.00
Summary
This proposal will examine the mechanisms by which HIV and other brain disorders such as encephalitis damage the brain. Further understanding of the biochemical pathway involved will lead to the possibility of novel drug therapy for these disorders.
HIV infection of CD4+ lymphocytes leads to a high rate of reproduction of new virus. However, in the brain, HIV infection of the astrocytes does not yield high levels of new virus. HIV is genetically active in these astrocytes, producing high levels of the messenger molecules, the so-called mRNA, that code for the proteins required for a new virus particle. We have determined that these HIV mRNAs are specifically prevented from translating into protein. The mechanisms controlling protein transla ....HIV infection of CD4+ lymphocytes leads to a high rate of reproduction of new virus. However, in the brain, HIV infection of the astrocytes does not yield high levels of new virus. HIV is genetically active in these astrocytes, producing high levels of the messenger molecules, the so-called mRNA, that code for the proteins required for a new virus particle. We have determined that these HIV mRNAs are specifically prevented from translating into protein. The mechanisms controlling protein translation from RNA are relatively poorly understood compared with the other control points of cellular gene expression, such as the synthesis of mRNA. This project examines how astrocytes rapidly detect the presence of HIV mRNA and alter their translation machinery to halt the expression of HIV protein. This host defence mechanism involves two key components; the cellular component that identifies and responds to the viral mRNA, and the structural features of the HIV mRNA that enable the cell to detect its viral origin. We will study how translation of HIV proteins requires both HIV and cellular factors. We will determine the impact of both viral RNA elements and viral RNA binding proteins on the translation of viral and cellular proteins. The contribution of the type-1 interferons that are produced in response to viral infection will be studied for their role in augmenting the inhibition of HIV protein translation. Since HIV infected astrocytes significantly contribute to the onset of AIDS dementia, we will sees a strategy to lock HIV into a dormant state in the brain and thereby prevent the neurodegenerative disease associated with HIV. We will use the anti-viral mechanism blocking HIV protein translation in astrocytes to protect other cell populations, such as the CD4+ lymphocytes, from HIV infection. These studies will also give insights into the general mechanisms for translational control of gene expression in human cells.Read moreRead less