Flow cytometric analysis of the Hermes homing-associated antigen on human
lymphocyte subsets
J de los Toyos, S Jalkanen and EC Butcher
Department of Pathology, Stanford University Medical Center, CA 94305-
5324.
The homing of lymphocytes is controlled by interactions with high
endothelial venules (HEV), specialized vessels that define sites of
lymphocyte extravasation into lymph nodes and inflamed tissues. In humans,
lymphocyte-HEV binding involves a lymphocyte surface glycoprotein (GP) of
85 to 95 kd (CD44, H-CAM), defined by monoclonal antibody (MoAb) Hermes-1.
To define the expression of this homing- associated adhesion molecule
during human lymphocyte development, we performed two-color
immunofluorescence analyses of human bone marrow (BM), thymus, peripheral
blood (PB), and tonsillar lymphocytes. The highest levels of Hermes-1
antigen are displayed by circulating B and T cells in the blood, which are
uniformly positive and bear roughly twice the level of antigen present on
mature lymphocytes within organized lymphoid tissues and BM. "Immature"
(CD4+, CD8+) T cells in the thymus are Hermes-1lo to-, whereas thymocytes
of mature phenotype (CD4+ or CD8+) are positive. The Hermes-1 antigen is
present at high levels on the same population of thymocytes that bears high
surface levels of CD3, a component of the T-cell antigen receptor complex,
suggesting that levels of T-cell homing and antigen receptors
characteristic of mature peripheral T cells appear coordinately during
thymocyte maturation/selection. Essentially all T cells in the periphery
are Hermes-1hi, including T blasts, and the homing-associated antigen is
maintained at high levels on T cells stimulated in vitro by
phytohemagglutinin (PHA) and on interleukin-2 (IL-2) maintained T-cell
clones and lines. In contrast, although most resting IgD+ B cells are
positive a significant fraction of B cells in tonsils are Hermes-1lo to- ;
these cells are predominantly PNAhi, IgD-, and CD20hi, a phenotype
characteristic of sessile, activated B cells in germinal centers. In all
lymphocyte populations examined, there is a linear correlation in staining
for Hermes-1 and for Hermes-3, an antibody that defines a distinct
functionally important epitope on this molecule. The results demonstrate a
precise regulation of this homing-associated antigen during lymphocyte
differentiation.
Volume 74,
Issue 2,
pp. 751-760,
08/01/1989
Copyright © 1989 by The American Society of Hematology
