Infectious diseases

Infectious diseases

In principle, a number of chronic infectious diseases, including several types of hepatitis and herpesvirus infections, may be suitable targets for gene therapy approaches. However, only HIV infection has received much attention to date. Current efforts focus on two general areas: postexposure vaccination in an attempt to boost the host immune response to the infection and attempts to express genes in target cells that render them unable to be infected or of supporting HIV replication. Although a handful of trials are ongoing at present, they are in very early stages, and no results have been published.

In vaccination trials, modified HIV genes are introduced directly into infected individuals following ex vivo treatment of target CD4 or precursor cells, typically with retroviral vectors that express genes encoding antiviral products. Several such products are being tested: mutant proteins that inhibit virus replication; antisense RNA that blocks translation of HIV gene products or causes destruction of the HIV genome; ribozymes that attack HIV RNA at specific unique sites; "decoy" RNAs that efficiently compete for binding of viral proteins; and singlechain antibodies that prevent key HIV enzymes from functioning. Although these approaches block HIV replication in cell culture systems, serious obstacles to their practical application remain. Most importantly, it is not yet known what cell types to target, much less how they will be isolated, treated, and returned to the patient. Furthermore, it is unknown whether resistant mutants-the major obstacle to successful drug therapy-will also present a serious problem. Nevertheless, the pursuit of gene therapy remains an active area of acquired immunodeficiency syndrome research, and one that also promises to provide important insights into HIV pathogenesis.

Genetic strategies to inhibit HIV

Gene therapy alternative to HAART for HIV

Proving HIV-1 immunity: new tools offer new opportunities

In Orview to: new insights into liver biology and disease therapy

An advance in liver-specific gene delivery

More materials available can be found through our navigation system in CMBI.