Prognostic Significance of Activated CD8⁺ T Cell Infiltrations within Esophageal Carcinomas

Fig. 1.

Presence of CD8⁺ T cells within esophageal carcinomas is often scattered (A) or CD8⁺ T lymphocytes are located mainly in the stroma surrounding epithelial complexes (B), whereas infiltration within the epithelial tumor cell nests can be colocalized with proliferation markers (C) and IFN-γ immunoreactivity (D). Immunofluorescence analysis of frozen sections was performed with CD8 (A–D), Mib-1 (C), and IFN-γ (D) as described in “Materials and Methods.” Alexa Fluor 488-conjugated goat antirat IgG (green) was used as a second-step reagent for CD8 cell detection. Alexa Fluor 568-conjugated goat antimouse IgG (red) served for detection of IFN-γ and Mib-1 immunofluorescence, respectively. Nuclear counterstaining was performed with propidium iodide (red, A and B) or DAPI (blue, D) or was not performed (C), and overlays of the stainings are shown. A, SC presence of CD8⁺ T cells within a UICC stage IV SCC. B, p.t. localization of CD8⁺ T cells within a UICC stage III SCC. D, colocalization of IFN-γ secretion and CD8 T cell presence in a UICC stage II SCC patient with i.t. CD8⁺ T cell infiltrations. Results obtained by quantitative mRNA analysis of this patient (P1) are shown in Table 2 <$REFLINK> . Note also the presence of proliferative CD8⁺ T cells within the tumor (C). Original magnifications: B, ×200; A, C, and D, ×400.