The EBV latent membrane protein 1 (LMP1) is expressed
in most of the EBV-associated malignancies including
nasopharyngeal carcinoma (NPC), Hodgkin's Lymphoma,
and immunosuppression-associated lymphoma.
have been identified by distinguishing amino acids. We
have identified seven sequence variants of LMP1 that can
be distinguished using a heteroduplex tracking assay and
have determined that most healthy individuals are
infected with multiple strains of EBV. Striking differences
were found between NPC and matching blood samples
with one specific variant, China 1, prevalent in NPC samples
and multiple other variants of LMP1 prevalent in the
blood samples. The possible selection against some
strains appearing in the tumor was highly significant with
a p < 0.0001. Many of the LMP1 variants had changes in
predicted HLA epitopes of various restrictions. The potential
negative selection of the immune system on strains
detected in the blood would be reflected in the striking
predominance of the China 1 strain in the tumors. In lymphoma
samples, changes were also frequently detected in
known HLA-restricted epitopes of EBNA3A, 3B, or 3C, in
addition to LMP1. Variation in potential immune recognition
could contribute to the development of EBV-associated
diseases in distinct populations and individuals
