HIV-2 virus

An impressive example of the application of structure-based methods was the design of a inhibitor of the HIV protease by a group of scientists at DuPont Merck [Lam et al. 1994 This enzyme is crucial to the replication of the HIV virus, and inhibitors have bee shown to have therapeutic value as components of anti-AIDS treatment regimes. The star1 ing point for their work was a series of X-ray crystal structures of the enzyme with number of inhibitors boimd. Their objective was to discover potent, novel leads whid were orally available. Many of the previously reported inhibitors of this enzyme possessei substantial peptide character, and so were biologically unstable, poorly absorbed am rapidly metabolised. 

Bomsel M, David V. Mucosal gatekeepers selecting HIV viruses for early infection. Nat Med 2002 8(2) 114-116. 

Trophoblastin, therefore, has been named interferon-tau (IFN-x), and is classified as a type I interferon. There are at least three or four functional IFN-x genes in sheep and cattle. The molecule displays a molecular mass of 19 kDa and an isoelectric point of 5.5-5.7, in common with other type I interferons. Interestingly, the molecule can also promote inhibition of reverse transcriptase activity in cells infected with the HIV virus. 

Within a year of the isolation of HIV as the causative agent of AIDS, a test was developed that determines if an individual has been exposed to HIV. The procedure is to test whether an individual has antibodies to HIV virus proteins. The most common HIV antibody test is an ELISA test. 

Despite these theoretical concerns, a number of HIV vaccines are under development. Most of these vaccines have been developed by recombinant DNA techniques that have allowed a large-scale production of individual viral proteins. The predominant HIV proteins that make up these potential vaccines are env proteins (e.g., gp 120) and, to a lesser extent, gag proteins. In addition, inactivated whole HIV virus is being tested. 

Another potential class of antivirals is those that interfere with the ability of virus to enter cells. If the virus entry process is inhibited, then spread of infection within an individual might be inhibited. As discussed earlier, HIV virus particles initially attach to cells by way of the cellular receptor for CD4 protein, which is embedded in the surface of normal T lymphocytes and macrophages. Recently, recombinant DNA techniques have been used to make large amounts of a part of the pure CD4 protein. Test-tube experiments have shown that if this CD4 protein fragment is incubated with T lymphocytes or macrophages, it can saturate all the CD4 receptors and prevent subsequent infection with HIV. It is possible that this approach might be effective in people, as well. 

Patients suffering from cystic fibrosis often use various aerosolized drugs. To reduce the viscosity of the mucus in the airways, recombinant human deoxyribonuclease is used. This enzyme is the first recombinant protein that has been developed for specific delivery to the lungs via the airways. It has a local action on the mucus in the airways and its absorption is minimal. Another drug that decreases the viscosity of the mucus is acetylcysteine. Aerosolized antibiotics are a further group of therapeutics that is widely used by cystic fibrosis patients. Solutions of antibiotics like tobramycin or colistin are used in nebulizers to prevent exacerbation of the disease. Pentamidine has been used for the prophylaxis of Pneumocystis pneumonia in patients infected with HIV virus, while chronic rejection of lung transplants provided a reason to develop an aerosol formulation of cyclosporine A. 

HIV-1, RNase H enzyme, 46 307 HIV virus, inhibition by bis(cyclam) derivatives, 45 76... 

Human immunodeficiency virus (HIV)— Virus that causes AIDS (acquired immunodeficiency syndrome) by destroying a critical cell of the body s immune system. 

In many instances, the unaided immune response to such infections can be inadequate, leading to prolonged and/or serious illness. Examples include the malaria and tuberculosis agents, the HIV virus (which has infected at least 14 million people worldwide), leishmaniasis (caused by the protozoan Leishmania, from which 12 million people suffer) and schistosomiasis, (caused by the Schistoma mansoni helminth, which currently infects approximately 250 million people worldwide). 

A) Attach to the HIV virus, making it more susceptible to phagocytosis... 

B. IL-2 stimulates the immune system by binding to the IL-2 receptors on responsive immune cells, causing differentiation and proliferation of T helper and T cytotoxic cells. It has no direct effect on the HIV virus, complement, or basophils. 

Two major diseases, malaria and AIDS, are still out of control vaccines are not available, while the malaria parasite and the HIV virus, responsible for AIDS, have developed resistance to current dmgs. Variability of the agent, lack of commercial interest, and perhaps also unconfessed political plans at population growth control, have been an obstacle to active immunization against malaria. The hope for an HIV vaccine is now from the engagement of Merck Co (Conference 2001). 

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