Human dendritic cell lysosome-associated membrane protein expressed in lung type II pneumocytes

Kenji Akasaki, Nobuki Nakamura, Naoko Tsukui, Sadaki Yokota, Shin Ichi Murata, Ryohei Katoh, Akihiro Michihara, Hiroshi Tsuji, Ernesto T.A. Marques, J. Thomas August

Research output: Contribution to journalArticle

Abstract

Human dendritic cell LAMP (hDC-LAMP) is a unique member of the lysosome-associated membrane protein (LAMP) family with a tissue distribution initially described as restricted to major histocompatibility class II (MHC II) compartments of activated DC before the translocation of MHC II to the cell surface [Immunity 9 (1998) 325]. In this report, we show that hDC-LAMP is also expressed by lung type II pneumocytes, another cell type with constitutive expression of MHC II. A recombinant hDC-LAMP protein and a monospecific anti-hDC-LAMP polyclonal antibody were prepared. The antibody reacted specifically with hDC-LAMP sequences of hDC-LAMP protein expressed in transfected cells and with a 54kDa protein of normal human lung tissue with properties corresponding to those of transgene expressed hDC-LAMP. Immunohistochemical analysis of hDC-LAMP in human lung showed its presence in alveolar type II epithelial cells (type II pneumocytes) as well as in cells in the interfollicular area of bronchus-associated lymph nodes, where interdigitating DCs are concentrated, and with lesser staining of alveolar macrophages. The native protein contained approximately 16% carbohydrates, most of which are sialyl N-linked oligosaccharides, with an acidic isoelectric point (pI 4.8). The restricted localization of this protein to lung type II pneumocytes and DCs is in contrast to hLAMP-1, which was present in many cell types of the lung and lymph node. Type II pneumocytes are known to express MHC II and the abundant expression of hDC-LAMP in these cells as well as in DCs suggests its possible relationship to specific MHC II related function(s) of DC and type II pneumocytes.

Original languageEnglish (US)
Pages (from-to)147-157
Number of pages11
JournalArchives of Biochemistry and Biophysics
Volume425
Issue number2
DOIs
StatePublished - May 15 2004

    Fingerprint

ASJC Scopus subject areas

  • Biophysics
  • Biochemistry
  • Molecular Biology

Cite this

Akasaki, K., Nakamura, N., Tsukui, N., Yokota, S., Murata, S. I., Katoh, R., Michihara, A., Tsuji, H., Marques, E. T. A., & August, J. T. (2004). Human dendritic cell lysosome-associated membrane protein expressed in lung type II pneumocytes. Archives of Biochemistry and Biophysics, 425(2), 147-157. https://doi.org/10.1016/j.abb.2004.02.042