Increased number of CD25 FoxP3 regulatory T cells in oral squamous cell carcinomas detected by chromogenic immunohistochemical double staining.
BACKGROUND
The role of tumor-infiltrating regulatory T cells (Treg) compromising antitumor effects of immune cells in oral squamous cell carcinoma (OSCC) is largely unknown.


OBJECTIVE
The presence of CD25(+) FoxP3(+) Treg as well as of CD3(+) FoxP3(+) and of CD8(+) FoxP3(+) tumor-infiltrating lymphocytes (TIL) was verified in OSCC and compared with non-cancerous lymphoepithelial tissue.


METHODS
Three double stainings (CD3/FoxP3, CD8/FoxP3 and CD25/FoxP3) were performed on tissue sections of 15 OSCC and compared with 15 human tonsils.


RESULTS
OSCC biopsy samples provide evidence for a strong infiltration of TIL, in particular, naturally occurring CD25(+) FoxP3(+) Treg. Whereas a comparison of OSCC and control tissue did not show significant changes in the number of CD3(+) FoxP3(+) TIL and of CD8(+) FoxP3(+) TIL, a significantly higher frequency of CD25(+) FoxP3(+) TIL (Treg) could be observed in OSCC (P < 0.001, two-sided t-test). Given the small number of specimens, a significant correlation with tumor stage could not be verified.


CONCLUSIONS
Chromogenic double staining of CD4/FoxP3 is a promising tool for the detection of Treg in paraffin-embedded tissue of OSCC.
Schwarz
Stephan
S
Department of Pathology, University of Erlangen, Erlangen, Germany.
Butz
Martin
M
Morsczeck
Christian
C
Reichert
Torsten E
TE
Driemel
Oliver
O
D001706:Biopsy; D017252:CD3 Complex / Q000032:analysis; D015704:CD4 Antigens / Q000032:analysis; D018791:CD4 Lymphocyte Count; D018414:CD8-Positive T-Lymphocytes / Q000473:pathology; D002294:Carcinoma, Squamous Cell / Q000276:immunology* / Q000473:pathology; D002863:Chromogenic Compounds; D004396:Coloring Agents; D005260:Female; D051858:Forkhead Transcription Factors / Q000032:analysis*; D006801:Humans; D007150:Immunohistochemistry; D053645:Interleukin-2 Receptor alpha Subunit / Q000032:analysis*; D016246:Lymphocytes, Tumor-Infiltrating / Q000473:pathology; D008297:Male; D009062:Mouth Neoplasms / Q000276:immunology* / Q000473:pathology; D009367:Neoplasm Staging; D014066:Palatine Tonsil / Q000276:immunology / Q000473:pathology; D016176:T-Lymphocyte Subsets / Q000473:pathology; D050378:T-Lymphocytes, Regulatory / Q000473:pathology*
D017252:CD3 Complex; D015704:CD4 Antigens; D002863:Chromogenic Compounds; D004396:Coloring Agents; C418974:FOXP3 protein, human; D051858:Forkhead Transcription Factors; D053645:Interleukin-2 Receptor alpha Subunit