T-cell receptor expression in the T-cell malignancies

Abstract

Twenty-eight cases with T-cell neoplasms (10 with T-cell acute lymphoblastic leukemia [T-ALL], 10 with T-lymphoblastic lymphoma, and 8 with peripheral T-cell lymphomas) and 2 cases with reactive lymph nodes were immunohistochemically stained with monoclonal antibodies beta F1, delta TCS1, and WT31; beta F1 antibody recognizes the beta-subunit of T-cell receptor (TCR), whereas delta TCS1 and WT31 recognize the delta- and alpha beta-subunits of TCR, respectively. Five cases with T-ALL, four with T-lymphoblastic lymphoma (T-LL), and seven with peripheral T-cell lymphomas were positive for beta F1. None showed positive reactivity for delta TCS1. One case with T-LL and four cases with peripheral T-cell lymphomas were positive for WT31. Of the nine cases positive for beta F1 among T-ALLs and T-LLs, six were also positive for CD1 (OKT6), whereas six of seven positive cases for CD1 were positive for beta F1. The authors therefore suggest that TCR beta is expressed in the immature T-cells just earlier than or around the same stage of differentiation as those expressing CD1. The authors' immuno-electron microscopy study revealed that positive reactivity for beta F1 was localized predominantly in the cytoplasm of the neoplastic cells in the cases with T-ALL, T-LL and peripheral T-cell lymphomas, and in the cytoplasm of the reactive T-cells. However, it was not localized on the surface membrane. In contrast, positive reactivity for WT31 was localized on the surface membrane of the neoplastic and reactive T-cells. Only half of the cases of peripheral T-cell lymphomas showed positive reactivity for WT31. The authors consider that it may not be a very useful antibody for the detection of TCR alpha beta on the T-cell neoplasms using frozen tissue sections.