Consistent infiltration of thymus-derived T cells into the parenchymal space of the liver in normal mice.
We previously reported that extrathymic T cells (intermediate T-cell receptor cells [TCR(int) cells]) are in situ generated in the parenchymal space of the liver in mice. They subsequently migrate to the sinusoidal lumen. In this study, we characterized how such extrathymic T cells, natural killer (NK) cells, and thymus-derived T cells (high T-cell receptor cells [TCR(high) cells]) localized in the parenchymal space or the sinusoidal lumen of mice. To this end, liver irrigation with physiological saline from the portal vein was performed and the distribution of lymphocyte subsets was compared between the liver (i.e., lymphocytes in the parenchymal space) and the irrigation solution (i.e., lymphocytes in the sinusoidal lumen). Extrathymic T cells and NK cells were found to be abundant in both the liver and sinusoidal lumen. As expected, thymus-derived T cells were abundant in the sinusoidal lumen. However, a significant proportion of thymus-derived T cells were always present in the parenchymal space, even after intensive irrigation with or without collagenase. These results suggest that thymus-derived T cells may consistently infiltrate the parenchymal space from the sinusoidal lumen in normal mice. This possibility was confirmed by (1) the injection of B6 splenic cells (TCR(high) cells) or the thymus graft into B6-nu/nu mice (presence of only TCR(int) cells) and by (2) using parabiotic mice of B6.Ly5.1 and B6.Ly5.2 strains (sharing circulation) in conjunction with immunofluorescence tests and immunohistochemical staining. In other words, inverted routes of migration and homing between extrathymic T cells and thymus-derived T cells exist in the liver.
Yamamoto
S
S
Department of Immunology, Niigata University School of Medicine, Niigata, Japan.
Sato
Y
Y
Shimizu
T
T
Halder
R C
RC
Oya
H
H
Bannai
M
M
Suzuki
K
K
Ishikawa
H
H
Hatakeyama
K
K
Abo
T
T
D000818:Animals; D000941:Antigens / Q000032:analysis; D000954:Antigens, Surface; D017252:CD3 Complex / Q000032:analysis; D002465:Cell Movement; D037181:Lectins, C-Type; D008099:Liver / Q000166:cytology*; D017710:Lymphocyte Transfusion; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D008819:Mice, Nude; D055651:NK Cell Lectin-Like Receptor Subfamily B; D011506:Proteins / Q000032:analysis; D015375:Receptors, Interleukin-2 / Q000032:analysis; D013601:T-Lymphocytes / Q000502:physiology*; D007507:Therapeutic Irrigation; D013950:Thymus Gland / Q000166:cytology*
D000941:Antigens; D000954:Antigens, Surface; D017252:CD3 Complex; D037181:Lectins, C-Type; D055651:NK Cell Lectin-Like Receptor Subfamily B; D011506:Proteins; D015375:Receptors, Interleukin-2