High numbers of DC-SIGN+ dendritic cells in lesional skin of cutaneous T-cell lymphoma.
BACKGROUND
The role of dendritic cells (DCs) in disease progression of primary cutaneous T-cell lymphoma (CTCL) is not well understood. With their unique ability to induce primary immune responses as well as immunotolerance, DCs play a critical role in mediation of anti-tumor immune responses. Tumor-infiltrating DCs have been determined to represent important prognostic factors in a variety of human tumors.


OBJECTIVE
To date, only circulating DC populations have been investigated in CTCL. Therefore we analyzed the expression and tissue distribution of different DC subset markers in lesional and nonlesional skin of patients with CTCL.


METHODS
Twelve patients with mycosis fungoides or Sézary syndrome were included in the study. Tissue samples were obtained from lesional and nonlesional skin as a control. Immunohistochemistry was performed with different DC subset and regulatory T-cell markers and assessed using a digital image analysis system. Tissue distribution of DCs in relation to the tumor was analyzed by double immunofluorescence.


RESULTS
We found a significant infiltration of CTCL lesions by immature CD209/DC-SIGN+ DCs with close contact to tumor cells. Matured and activated DCs were only rarely detected in lesions of CTCL.


CONCLUSIONS
The sample size was small.


CONCLUSIONS
The preponderance of immature CD209/DC-DIGN+ DCs in contact with regulatory T cells in lesions of CTCL points to an important role of this subset in the host's immune reaction to the malignant T cells. Since these immature DCs are known to induce immunotolerance, they might play a role in the mediation of immune escape of the proliferating clone.
Schlapbach
Christoph
C
Department of Dermatology, University of Bern, Bern, Switzerland.
Ochsenbein
André
A
Kaelin
Ursula
U
Hassan
Akmal S
AS
Hunger
Robert E
RE
Yawalkar
Nikhil
N
D000328:Adult; D000368:Aged; D015703:Antigens, CD / Q000032:analysis; D015815:Cell Adhesion Molecules / Q000378:metabolism*; D003713:Dendritic Cells / Q000145:classification / Q000276:immunology* / Q000378:metabolism / Q000473:pathology; D005260:Female; D005455:Fluorescent Antibody Technique; D051858:Forkhead Transcription Factors / Q000378:metabolism; D006801:Humans; D007150:Immunohistochemistry; D037181:Lectins, C-Type / Q000378:metabolism*; D016410:Lymphoma, T-Cell, Cutaneous / Q000276:immunology* / Q000473:pathology; D008297:Male; D008875:Middle Aged; D009182:Mycosis Fungoides / Q000276:immunology / Q000473:pathology; D011956:Receptors, Cell Surface / Q000378:metabolism*; D012751:Sezary Syndrome / Q000276:immunology / Q000473:pathology; D012867:Skin / Q000276:immunology* / Q000473:pathology; D012878:Skin Neoplasms / Q000276:immunology* / Q000473:pathology; D050378:T-Lymphocytes, Regulatory / Q000276:immunology; D000099215:DC-Specific ICAM-3 Grabbing Nonintegrin
D015703:Antigens, CD; D015815:Cell Adhesion Molecules; D051858:Forkhead Transcription Factors; D037181:Lectins, C-Type; D011956:Receptors, Cell Surface; D000099215:DC-Specific ICAM-3 Grabbing Nonintegrin; C418974:FOXP3 protein, human