Hisato Yoshida1,2, Hitomi Hoshino1, Yoshiaki Imamura3, Hitoshi Yoshimura2, Kazuo Sano2, Motohiro Kobayashi1. 1. Department of Tumor Pathology, Faculty of Medical Sciences, University of Fukui, Eiheiji, Japan. 2. Department of Dentistry and Oral Surgery, Faculty of Medical Sciences, University of Fukui, Eiheiji, Japan. 3. Division of Surgical Pathology, University of Fukui Hospital, Eiheiji, Japan.
Abstract
BACKGROUND: Tumor-infiltrating lymphocytes (TILs) reportedly play a pivotal role in antitumor immunity against oral squamous cell carcinoma (OSCC); however, mechanisms governing TIL recruitment to OSCC tissues remain to be clarified. This study was undertaken to assess a potential association between TILs and high endothelial venule (HEV)-like vessels that express sialyl 6-sulfo Lewis X (LeX). METHODS: OSCC tissue sections (n=41) were subjected to immunohistochemistry for sialyl 6-sulfo LeX and CD34 to allow quantitation of HEV-like vessels. Triple immunohistochemistry for sialyl 6-sulfo LeX and either CD3 and CD20 or CD4 and CD8 was conducted to determine which lymphocyte subset is more closely associated with HEV-like vessels. RESULTS: HEV-like vessels expressing sialyl 6-sulfo LeX were detected in 27 of 41 (65.9%) OSCC cases, and these vessels were more frequently found in early disease (T1/T2 stages) compared with advanced (T3/T4) stages. The number of T cells attached to the inner surface of these HEV-like vessels was significantly greater than that of B cells, while the number of CD4+ helper T cells and CD8+ cytotoxic T cells did not differ significantly. Interestingly, sialyl 6-sulfo LeX was also expressed on the membrane of a fraction of OSCC cells, and CD8+ cytotoxic T cells were almost exclusively found attached to these carcinoma cells. CONCLUSIONS: Sialyl 6-sulfo LeX is displayed not only on HEV-like vessels but also on OSCC cells and may potentially function in antitumor immunity against OSCC.
BACKGROUND: Tumor-infiltrating lymphocytes (TILs) reportedly play a pivotal role in antitumor immunity against oral squamous cell carcinoma (OSCC); however, mechanisms governing TIL recruitment to OSCC tissues remain to be clarified. This study was undertaken to assess a potential association between TILs and high endothelial venule (HEV)-like vessels that express sialyl 6-sulfoLewis X (LeX). METHODS: OSCC tissue sections (n=41) were subjected to immunohistochemistry for sialyl 6-sulfoLeX and CD34 to allow quantitation of HEV-like vessels. Triple immunohistochemistry for sialyl 6-sulfoLeX and either CD3 and CD20 or CD4 and CD8 was conducted to determine which lymphocyte subset is more closely associated with HEV-like vessels. RESULTS: HEV-like vessels expressing sialyl 6-sulfoLeX were detected in 27 of 41 (65.9%) OSCC cases, and these vessels were more frequently found in early disease (T1/T2 stages) compared with advanced (T3/T4) stages. The number of T cells attached to the inner surface of these HEV-like vessels was significantly greater than that of B cells, while the number of CD4+ helper T cells and CD8+ cytotoxic T cells did not differ significantly. Interestingly, sialyl 6-sulfoLeX was also expressed on the membrane of a fraction of OSCC cells, and CD8+ cytotoxic T cells were almost exclusively found attached to these carcinoma cells. CONCLUSIONS: Sialyl 6-sulfoLeX is displayed not only on HEV-like vessels but also on OSCC cells and may potentially function in antitumor immunity against OSCC.