Our lab recently identified a cross-reactive antibody response between human T-lymphotropic virus type-1- p24-(gag) (HTLV-1-p24-(gag)) and peroxiredoxin-1 (PrX- 1) as potentially contributing to the pathogenesis of HTLV-1 associated neurological disease via molecular mimicry. These targets proteins were glycosylated, yet the glycan side chains immunoreactive with the immunoglobulins were unknown. Using a combination of lectin isolation and serial enzymatic deglycosylation of glycoproteins, we determined that the immunoreactive epitopes contained branched oligomannose side chains. These data suggest that posttranslational glycosylation specifically related to oligomannose immunoreactivity to both the infecting and host antigens may contribute to molecular mimicry and be important in the pathogenesis of HTLV-1 associated neurological disease. © Springer Science+Business Media, LLC 2012.