C. Holzinger et al., ARE T-CELLS FROM HEALTHY HEART REALLY ONLY PASSENGERS - CHARACTERIZATION OF CARDIAC TISSUE T-CELLS, Immunology letters, 53(2-3), 1996, pp. 63-67
Numerous studies have dealt with the occurrence of dendritic cells in
various nonlymphoid organs such as kidney, liver or heart, whereas lym
phocyte patterns in these organs have not been analyzed in detail. In
the present study, leukocytes were quantified as cells/mm(2) in the pe
rivascular, interstitial and parenchymal tissue sections of normal hea
rt. We measured an overall mean leukocyte count in normal heart tissue
of 17.0 +/- 2.7 CD45(+) leukocytes/mm(2), 9.1 +/- 1.8 thereof being C
D4(+) T-helper cells (T-h). By comparison, CD8(+) T-cytotoxic/suppress
or cells (T-s) and CD14(+) macrophages each accounted for only similar
to 2.5 cells/mm2, and CD20(+) B cells for only 1.3 cells/mm(2). These
T cells were further characterized as either CD45RA(+) naive T cells
or as CD45RO(+) memory T cells. Segmentation of the tissue as defined
in Section 2 yielded an ascending number of CD45RO(+) memory T cells f
rom perivascular (0.4 +/- 0.2 cells/mm(2)) through parenchymal (12.8 /- 3.0 cells/mm(2)) to interstital (21.0 +/- 5.3/mm(2)). By contrast,
the number of CD45RA(+) and Leu-8(+) cells decreased from perivascular
to parenchymal. Peripheral T cells showed a reverse pattern of CD45RA
/CD45RO antigen expression. Only similar to 3% of T cells expressed ac
tivation markers IL-2R and IL-7R. Our data demonstrate that the majori
ty of T cells in normal heart tissue are resting memory tissue T cells
and not contaminating T cells from the peripheral blood. The increase
in CD45RO(+) cells from perivascular to parenchymal with a correspond
ing decrease in CD45RA(+) and Leu-8(+) heart-tissue T cells argues in
favor of T-cell traffic in normal heart tissue.