Major role for genes in AIDS progression

Variations in two key genes help determine how swiftly an individual infected with HIV progresses to AIDS, according to a new study. The finding challenges quarter-century-old wisdom that what chiefly drives the advance to AIDS is "viral load," the amount of HIV in the blood, whose relentless rise bludgeons the immune system, according to a study in the British journal Nature Immunology. Instead, the authors argue, the situation is more complex. An individual's genetic profile can greatly affect replication of the human immunodeficiency virus (HIV) as well as the body's response to the intruder.

Benign to lethal

The interaction between the virus and the immune system switches "an otherwise benign infection to a lethal one," they said. The genes in question are called CCR5 and CCL3L1, although other genes, still not fully explored, may also play a part. CCR5 controls a key receptor, or docking point, on the surface of the CD4 immune cell onto which HIV latches. CCL3L1, meanwhile, controls an immune system signalling molecule called a chemokine that prevents the virus attaching itself to the CCR5 receptor. Previous work has already established that certain genetic variants in CCR5 appear to give a shield against viral entry. 

Disease progression

The viral load at the early stages of infection accounted for only nine percent of the difference in speed at which HIV-infected people progressed to AIDS. Just as important was the sort of combination of the two genes. "The genetic variations contribute nearly as much to the extent of inter-individual variability in AIDS progression rates as does HIV-1 viral load.

The CCR5-CCL3L1 profile also has an effect on the immune responses among healthy people, which suggest that this combination might play a role in how the body responds to other infectious diseases, the paper suggests. Similar research in the field of genetic variation and HIV has looked at differences among three genes that control signalling molecules called human leucocyte antigens (HLA), which tag an intruder for destruction by the immune system.

HIV Virus

To start putting together a story for the script and story board I am researching the life cycle of HIV and breaking it down into key processes it goes through to create a simple structure I can follow. Looking through a couple of websites a came across this PDF that breaks the cycle down into 6 stages. Its has been extremely useful to me to get my head around the whole process to form a logical structure. Taking this into account, following the sci-fi mission log idea, I could structure it as mission phases around these key processes.  

 

Stages: 

 

1. Binding and Fusion
    
2. Reverse Transcription
    
3. Integration
    
4. Transcription
    
5. Assembly
    
6. Budding/ Virus Release
    
    
   
   
   
   
   
    

How the HIV virus attack?

The HIV virus was first discovered in 1981  when homosexual men first had symptoms of a disease that were quite different from other viral infections. Full blown symptoms of the disease which are now indicative of AIDS were first described along with an unusual type of lung infection, weird skin tumors and upon laboratory testing of their blood samples, have revealed a significant decrease in CD4 cells which are useful in fighting infections. The HIV virus was soon seen in many countries in Europe and in Africa and by the year 1983 researchers have described the make-up of the virus that causes AIDS plus the actual definition of AIDS which is the “development of a low CD4 count  or any one of a long list of complications of HIV infection”