Expression of T-cell receptor (TCR)alpha chain on normal human tonsils and T-cell lymphomas

We analyzed immunohistologically the expression of T-cell receptor (TCR)alpha chain on human tonsils and on T-cell lymphoma (T-ML) tissues using the avidin-biotin-peroxidase method. A murine monoclonal antibody alpha F1, specific for the constant region of the TCR alpha chain, was employed. On normal tonsil, alpha F1-positive cells were observed mainly in T-zones and germinal centers. In T-zones, the staining intensities varied markedly, with heavy staining evident in less than one fourth. In germinal centers, a proportion of stained cells showed a histiocytic pattern with small cytoplasmic projections. All the T-ML tissues expressed TCR alpha, whereas the staining intensities varied among cases and among lymphoma cells. No correlations were observed in the expressions of TCR alpha chain and other T-cell markers including CD3, CD4 and CD8.