TY - JOUR
T1 - Binding and uptake of trichophyton rubrum mannan by human epidermal keratinocytes
T2 - A time-course study
AU - Grando, S. A.
AU - Herron, M. J.
AU - Dahl, M. V.
AU - Nelson, R. D.
PY - 1992
Y1 - 1992
N2 - Trichophyton rubrum infects skin. This fungus or its products might affect the function of epidermal cells. We previously reported that T. rubrum mannan (TRM) exhibits a suppressive effect on proliferation of human lymphocytes. The goal of the present study was to investigate the possibility of direct interaction of TRM with cultured normal human epidermal keratinocytes (EK). Mannan, a cell wall glycoprotein, was extracted from T. rubrum by precipitation with cetyltrimethylammonium bromide and conjugated with fluorescein isothiocyanate (FITC-TRM). After incubation of EK with 50 μg/ml FITC-TRM for 30 min, the surface of EK showed bright fluorescent staining. EK cultures pretreated with non-labelled TRM remained unstained. The fate of TRM bound to EK surface was determined in a time-course study. After pulse exposure to FITC-TRM, EK cultures were washed and incubated for various time periods. The EK moved surface mannan to the one area of cell membrane, so that at 4-6 h, the homogeneous staining of the entire cell surface was replaced by staining in a 'cap' pattern. By 12 h, FITC-TRM was taken up into the cell, brought to the nuclear area and concentrated in the EK nucleoli. During the next 3 days nucleolar and cytoplasmic staining of the cells was observed. The intensity of fluorescence gradually diminished. On the 4th day, the sharp staining of organelles disappeared; instead, a large number of small fluorescent granules were seen intra- and extracellularly. By the 6th day after exposure, no EK staining remained. Thus, EK specifically bound, internalized and apparently catabolized TRM. These findings indicate that EK take up mannan and suggest that this could influence their function. Excreted catabolites could have biological effects on other cells.
AB - Trichophyton rubrum infects skin. This fungus or its products might affect the function of epidermal cells. We previously reported that T. rubrum mannan (TRM) exhibits a suppressive effect on proliferation of human lymphocytes. The goal of the present study was to investigate the possibility of direct interaction of TRM with cultured normal human epidermal keratinocytes (EK). Mannan, a cell wall glycoprotein, was extracted from T. rubrum by precipitation with cetyltrimethylammonium bromide and conjugated with fluorescein isothiocyanate (FITC-TRM). After incubation of EK with 50 μg/ml FITC-TRM for 30 min, the surface of EK showed bright fluorescent staining. EK cultures pretreated with non-labelled TRM remained unstained. The fate of TRM bound to EK surface was determined in a time-course study. After pulse exposure to FITC-TRM, EK cultures were washed and incubated for various time periods. The EK moved surface mannan to the one area of cell membrane, so that at 4-6 h, the homogeneous staining of the entire cell surface was replaced by staining in a 'cap' pattern. By 12 h, FITC-TRM was taken up into the cell, brought to the nuclear area and concentrated in the EK nucleoli. During the next 3 days nucleolar and cytoplasmic staining of the cells was observed. The intensity of fluorescence gradually diminished. On the 4th day, the sharp staining of organelles disappeared; instead, a large number of small fluorescent granules were seen intra- and extracellularly. By the 6th day after exposure, no EK staining remained. Thus, EK specifically bound, internalized and apparently catabolized TRM. These findings indicate that EK take up mannan and suggest that this could influence their function. Excreted catabolites could have biological effects on other cells.
KW - Endocytosis
KW - Fluorescence
KW - Fungal cell wall glycoprotein
UR - http://www.scopus.com/inward/record.url?scp=0026686217&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0026686217&partnerID=8YFLogxK
M3 - Article
C2 - 1357884
AN - SCOPUS:0026686217
SN - 0001-5555
VL - 72
SP - 273
EP - 276
JO - Acta Dermato-Venereologica
JF - Acta Dermato-Venereologica
IS - 4
ER -