Identification in HIV-1
In HIV immunity, factors that potentially distinguish between protective and ineffective anti-HIV-1 immune responses and control disease progression relate to epitope-MHC binding as well as stability and affinity. Researchers at ProImmune recently supported a study carried out by Samantha Westrop and her colleagues at Imperial College to examine the details of HIV-1 CD8+ T-cell epitope recognition. This study used rapid peptide synthesis, Reveal binding and affinity assays, and ProVE Pentamer synthesis in conjunction with flow cytometry, as well as ELISpot analyses to discover new T-cell epitopes for HIV-1.
The rate of HIV-1 disease progression is also influenced by the genetic profile of an individual. For example, individuals with HLA-B35 and HLA-B8 profiles have been associated with an increased rate of disease progression in HIV-1+ infections. To discover possible reasons for this rapid disease progression, ProImmune’s methods were used to investigate the HIV-1 Gag peptide-specific CD8+ T-cell immune response mounted by HLA-B35+ individuals. Initially, forty-four 9-mer HIV-1 Gag peptides were synthesized as a PEPscreen® Custom Peptide Library, and were assessed for binding to B*35:01 using the Reveal MHC-peptide binding assay.
The results implicated 12 peptides as potential epitopes (Figure 1), and these were further analyzed with the Reveal rate assay to determine their rates of dissociation from the MHC complex. Two of the 9-mer peptides, YPLTSLRSL (peptide 1) and HPVHAGPIA (peptide 8) were found to form a stable complex with B*35:01, indicating that these may be potential novel epitopes.