The Intergenic Recombinant HLA-B*46:01 Has a Distinctive Peptidome that Includes KIR2DL3 Ligands.
2017; 19 (7): 1394-1405
HLA-B(?)46:01 was formed by an intergenic mini-conversion, between HLA-B(?)15:01 and HLA-C(?)01:02, in Southeast Asia during the last 50,000 years, and it has since become the most common HLA-B allele in the region. A functional effect of the mini-conversion was introduction of the C1 epitope into HLA-B(?)46:01, making it an exceptional HLA-B allotype that is recognized by the C1-specific natural killer (NK) cell receptor KIR2DL3. High-resolution mass spectrometry showed that HLA-B(?)46:01 has a low-diversity peptidome that is distinct from those of its parents. A minority (21%) of HLA-B(?)46:01 peptides, with common C-terminal characteristics, form ligands for KIR2DL3. The HLA-B(?)46:01 peptidome is predicted to be enriched for peptide antigens derived from Mycobacterium leprae. Overall, the results indicate that the distinctive peptidome and functions of HLA-B(?)46:01 provide carriers with resistance to leprosy, which drove its rapid rise in frequency in Southeast Asia.
View details for DOI 10.1016/j.celrep.2017.04.059
View details for PubMedID 28514659
Acute systemic DNA damage in youth does not impair immune defense with aging
2016; 15 (4): 686-693
Aging-related decline in immunity is believed to be the main driver behind decreased vaccine efficacy and reduced resistance to infections in older adults. Unrepaired DNA damage is known to precipitate cellular senescence, which was hypothesized to be the underlying cause of certain age-related phenotypes. Consistent with this, some hallmarks of immune aging were more prevalent in individuals exposed to whole-body irradiation (WBI), which leaves no anatomical repository of undamaged hematopoietic cells. To decisively test whether and to what extent WBI in youth will leave a mark on the immune system as it ages, we exposed young male C57BL/6 mice to sublethal WBI (0.5-4 Gy), mimicking human survivor exposure during nuclear catastrophe. We followed lymphocyte homeostasis thorough the lifespan, response to vaccination, and ability to resist lethal viral challenge in the old age. None of the irradiated groups showed significant differences compared with mock-irradiated (0 Gy) animals for the parameters measured. Even the mice that received the highest dose of sublethal WBI in youth (4 Gy) exhibited equilibrated lymphocyte homeostasis, robust T- and B-cell responses to live attenuated West Nile virus (WNV) vaccine and full survival following vaccination upon lethal WNV challenge. Therefore, a single dose of nonlethal WBI in youth, resulting in widespread DNA damage and repopulation stress in hematopoietic cells, leaves no significant trace of increased immune aging in a lethal vaccine challenge model.
View details for DOI 10.1111/acel.12478
View details for Web of Science ID 000383718400009
View details for PubMedID 27072188
View details for PubMedCentralID PMC4933672