RE: New Moditope research10 Apr 2022 09:13
Having demonstrated that immunized transgenic mice expressing human HLA types show homocitrulline-specific immune responses, we next determined whether healthy human donors exhibit a repertoire for homocitrullinated peptides. For this we concentrated on the Vim116-135Hcit peptide.
PBMCs were isolated from 17 healthy donors and assessed for proliferative responses to homocitrullinated peptides. Donor details including HLA-types are shown in Table 2. Flow cytometry staining was used to assess CFSE proliferation in the CD4+ or CD8+ cell populations. Proliferation was assessed at day 10 post-stimulation as this timepoint showed clear peptide-induced proliferative responses. An example staining profile is shown in Figure 3A and additional example CFSE profiles for day 7 and day 10 are shown in Supplementary Figure 2. CFSE proliferation to the positive control PHA was seen in both the CD4 and CD8 populations, however, Vim116-135Hcit proliferation was predominantly seen in the CD4 population. Collated data from healthy donors is shown in Figure 3B whilst CD4 proliferative responses in individual healthy donors are shown in Figure 3Ci. In PBMCs from healthy donors, 15/17 showed CD4 T-cell proliferation in response to Vim116-135Hcit peptide. Across all donors, Vim116Hcit induced a significant increase in CD4 proliferation compared to media only (p<0.0001) (Figure 3Cii).