Current HIV Research - Volume 1, Issue 2, 2003

Human immunodeficiency virus type 1 (HIV-1) can infect quiescent cells, however, viral production is restricted to actively proliferating cells. Recent evidence has indicated that HIV-1 viral proteins, Vpr and Tat, perturb the cell cycle to optimize HIV-1 replication. Vpr arrests the cell cycle at G2 by inactivating the cyclin B / cdk1 complex. Tat regulates the cell cycle by altering factors involved in proliferation and differentiation (i.e. th Read More

One of the major obstacles to effective prolonged CD8 T cell control over HIV and other latent infections may be the intrinsic, genetically programmed barrier to unlimited proliferation that is characteristic of all normal human somatic cells. Replicative senescence, characterized extensively in cell culture for a variety of cell types, comprises both irreversible cell cycle arrest and striking changes in function. CD8 T Read More

Upon binding to the CD4 receptor the HIV envelope protein undergoes conformational changes that culminate in the fusion of the viral and cellular membranes. A few hours later, a sophisticated set of processes is initiated to ensure the down-modulation of the viral receptor. Three viral proteins participate in this process: Nef, Env, and Vpu, suggesting that this function is critical for virus replication. The mechanisms of action of th Read More

Human allelic variants influence the susceptibility to HIV-1 infection and/or the subsequent rates of disease progression towards AIDS that average ten years, although they vary greatly among infected subjects. In this respect, studies involving multiply exposed persons who remain uninfected, long-term nonprogressors (who remain asymptomatic for fifteen years or more) or, in contrast, rapid progressors (who develop AIDS wi Read More

Treatment of human immunodeficiency virus (HIV)-1 infection with potent antiretroviral medications has provided considerable clinical benefit. However because of the limitations of current therapy, innovative approaches are needed to better control HIV-1 infection. Several studies have suggested that robust CD4+ T helper and CD8+ T cell responses may contribute to the immunologic control of HIV-1 infection in certain Read More

HIV-1 coreceptor usage is believed to play a critical role in pathogenesis. To initiate infection, HIV-1 interacts with two cell surface receptors, CD4 is the primary receptor and the β-chemokine receptors CCR5 and CXCR4 usually serve as secondary receptors. HIV-1 strains transmitted in vivo generally use CCR5. Viruses that use CCR5 (R5 viruses) appear to be associated with relatively stable infection. Years after chronic infect Read More

The failure to develop vaccines to protect against important infectious diseases such as human immunodeficiency virus type I (HIV-1) or Hepatitis C virus (HCV) has increased the interest in new vaccine strategies. One of these methods is immunization with an attenuated recombinant viral vector expressing a foreign antigen, which could protect individuals from later exposure to the respective pathogen. A new method to r Read More

Foremost amongst human pathogens, the human immunodeficiency virus (HIV) exhibits a great genetic variability. The resultant fluidity of HIV enzymatic proteins allows them to remain functional whilst simultaneously evading immune surrveillance and antiretroviral therapy. This very variability, however, has been turned to powerful advantage in the study of the movement and evolution of HIV strains within and betwe Read More

In recent years, CD4 and CD8 T cell responses to HIV and SIV infection have been increasingly measured with the use of single-cell assays such as ELISPOT, MHC-peptide oligomers, and cytokine flow cytometry. The results of these assays have been compared to those obtained with traditional bulk assays such as lymphoproliferation (by 3H-thymidine incorporation) and cytotoxicity (by 51Cr release). Such comparisons have led t Read More