A novel vaccine with beta₂-microglobulin linked to a viral epitope stimulates a CTL response and provides immunity to the virus

Access full-text files




Piper, John Daniel

Journal Title

Journal ISSN

Volume Title



Designing a vaccine that can elicit a strong cytotoxic T-lymphocytes (CTL) response will be an important component of vaccines against many viruses, but in particular against HIV. CTL stimulation occurs through the recognition of epitopes presented in the context of the class-I major histocompatibility complex (MHC-I). As a way to achieve this, the physical coupling of a viral epitope to the N-terminus of β2-microglobulin (β2m) via a flexible linker has been explored. With the stimulation of CTLs against the Sendai virus as a model, both the effect of linker size on the vaccine and the ability of the β2m-viral epitope fusion vaccine to trigger a primary immune response, as either a recombinant protein expressed in E. coli or as part of a mammalian expression vector are presented in this work. Here we show that as a DNA vaccine, β2mlinked to the immunodominant Sendai NP(324-332) epitope, administered intramuscularly (IM) with or without a plasmid encoding for the cytokine IL-12, can cause the proliferation of viral specific splenocytes. However, when the vaccine was administered IM or subcutaneously as recombinant protein, no response was observed. We also show that a construct with a 21 amino acid (AA) linker stimulates more viral specific splenocytes than constructs with either a 10 AA or a 15 AA linker. Further, DNA vaccine dosages of 100 µg and 200 µg generate more viral specific splenocytes than dosages of 400 µg or 800 µg. We suggest that the reason for this might be high-localized concentrations of β2m. Finally, we show that in response to a sub-lethal challenge with the Sendai virus, mice primed with both the β2m-Sendai epitope DNA vaccine and the IL-12 plasmid can trigger the early arrival of viral specific CD8+ memory cells in the lungs.