Timing Is Everything When Using IL-7 To Boost Antiviral Immunity

Much research effort is being invested in identifying new ways to boost antiviral immune responses in individuals with chronic viral infections (such as those infected with HIV and hepatitis C virus) and to boost the efficacy of vaccines designed to target these viruses.

The use of the soluble factor IL-7, which is known to be important in the generation and maintenance of memory CD8+ T cells, has proven attractive. However, new data, generated in mice by M. Suresh and colleagues at the University of Wisconsin--Madison, have indicated that the timing of IL-7 treatment is important in determining how effective it is at enhancing antiviral immunity.

In the study, IL-7 was shown to enhance the number and function of memory CD8+ T cells only if it was administered during the contraction phase of the immune response mounted after mice were infected with either lymphocytic choriomeningitis virus or vaccinia virus, or were administered a DNA vaccine.

Importantly, CD8+ T cells from IL-7--treated mice exhibited improved viral control. These data have clinical implications for the use of IL-7 as an immunotherapeutic agent both to bolster vaccine-induced CD8+ T cell memory and to boost the immune response of individuals with a chronic viral infection.

The article "Effects of IL-7 on memory CD8+ T cell homeostasis are influenced by the timing of therapy in mice" was published in the Journal of Clinical Investigation February 1, 2008.