Expression of histocompatibility leukocyte antigen (HLA) class I molecules on the cell surface depends on the heterodimer of the transporter associated with antigen processing 1 and 2 (TAP1 and TAP2), which transport peptides cleaved by proteasome to the class I molecules. Defects in the TAP2 protein have been reported in two families with HLA class I deficiency, the so-called bare lymphocyte syndrome (BLS) type I. We have, to our knowledge, identified for the first time a splice site mutation in the TAP1 gene of another BLS patient. In addition, class I heavy chains (HCs) did not form the normal complex with tapasin in the endoplasmic reticulum (ER) of the cells of our patient.
Hiroshi Furukawa, Shigeo Murata, Toshio Yabe, Naoki Shimbara, Naoto Keicho, Kouichi Kashiwase, Kaoru Watanabe, Yoshihide Ishikawa, Tatsuya Akaza, Kenji Tadokoro, Shigeto Tohma, Tetsufumi Inoue, Katsushi Tokunaga, Kazuhiko Yamamoto, Keiji Tanaka, Takeo Juji