Aquaporin expression in human lymphocytes and dendritic cells.
Aquaporins (AQPs) are molecular water channels, and 10 related AQPs have been identified in mammals. So far, the study of mammalian AQP expression has been limited mainly to mice and rat lung, kidney, brain, and gastrointestinal tract. Although AQP3 and AQP7 have been shown to be involved in volume-regulating mechanisms in dendritic cells, the exact patterns of AQP expression in the human immune system are not well understood. Using reverse transcriptase-polymerase chain reaction (RT-PCR) analysis of peripheral blood from healthy donors, we demonstrated the expression of AQP1, AQP3, and AQP5 in activated B and T lymphocytes and the expression of AQP3 and AQP5 in immature dendritic cells. None of the tested AQPs was expressed in inactivated B or T lymphocytes. In situ hybridization studies using human tonsils showed that AQP1, AQP3, and AQP5 were expressed almost exclusively in the germinal centers. Further in situ hybridization showed that expression of AQP1, AQP3, and AQP5 were detected in tumor-infiltrating lymphocytes surrounding bronchogenic carcinoma of the lung and that expression of AQP3 and AQP5 was detected in dendritic cells. These findings provide new insights into the expression patterns of AQPs in the human immune system. While the exact role of AQPs in the human immune system remains to be determined, we propose that AQP expression patterns may be used as a marker to study lymphocyte activation and proliferation.
Department of Otolaryngology-Head and Neck Surgery, The Johns Hopkins Medical Institution, Baltimore, Maryland 21205, USA. cmoon5@jhmi.edu
Chulso
C
Moon
Raphael
R
Rousseau
Jean-Charles
JC
Soria
Mohammad Obaidul
MO
Hoque
Juna
J
Lee
Se Jin
SJ
Jang
Barry
B
Trink
David
D
Sidransky
Li
L
Mao
D020346:Aquaporins / Q000096:biosynthesis* / Q000235:genetics / Q000276:immunology; D002283:Carcinoma, Bronchogenic / Q000276:immunology / Q000378:metabolism; D017931:DNA Primers / Q000235:genetics; D003713:Dendritic Cells / Q000166:cytology / Q000276:immunology / Q000378:metabolism*; D006801:Humans; D017403:In Situ Hybridization; D008175:Lung Neoplasms / Q000276:immunology / Q000378:metabolism; D008214:Lymphocytes / Q000276:immunology / Q000378:metabolism*; D014066:Palatine Tonsil / Q000276:immunology / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction
D020346:Aquaporins; D017931:DNA Primers