Role of IL-15 and IL-21 in viral immunity: applications for vaccines and therapies

Abstract

Most people suffer from at least one viral infection in their life, some more virulent and aggressive than others. The aggressiveness and progression of viral diseases depends on the type of virus and quality of antiviral response generated during innate immunity and maintained during adaptive immunity. Two recently discovered cytokines (IL-15 and IL-21) appear to be key regulators in this process. IL-15 induces an antiviral state during innate immunity through the regulation of IFN-α/β production and natural killer cell proliferation. During the memory phase, antigen-specific CD8⁺ T cells are highly dependent on IL-15 signaling. IL-21 induces natural killer cell maturation and IFN-γ production and acts to enhance the proliferation of memory CD8⁺ T cells, its effects being more pronounced when combined with IL-15. We describe the mechanisms and potential uses of these cytokines in the design of antiviral vaccines and therapies.

Keywords::

• adjuvant
• cytokine
• memory CD8⁺ T cell
• vaccine
• virus

Financial & competing interests disclosure

The authors have no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.

No writing assistance was utilized in the production of this manuscript.