Localization of T-Lymphocyte Areas in Human Lymphoid Tissues by Fluorochrome-Labelled Helix pomatia A Haemagglutinin

Abstract

Fluorochrome-labeled H. pomatia A hemagglutinin (HP) stained T-dependent areas in cryostat tissue sections of human lymph node, tonsil and spleen, and thymocytes within thymic medulla but not within thymic cortex. Neuraminidase treatment of the tissue section was a prerequisite for the positive cell staining. The staining was cell membrane-associated, and the histological pattern was essentially the same as that observed in parallel sections treated with monoclonal antibodies to T cells (OKT3, Leu-1). Blood vessel walls and connective tissue were also stained by HP conjugates. The latter staining was independent of neuraminidase treatment, resistant to .alpha.-galactosidase treatment and was not blocked by pretreatment with anti-fibronectin antibody. Both types of staining reaction were specific inasmuch as unlabeled HP and the competitive sugar hapten N-acetyl-D-galactosamine blocked the reaction. Frozen, formalin-fixed tissue sections showed the same stainability and reaction pattern as unfixed sections.