Naive and memory T cells migrate in comparable numbers through the normal rat lung: only effector T cells accumulate and proliferate in the lamina propria of the bronchi.
T cells reach the lung via the pulmonary and bronchial arteries that supply the alveolar and bronchial regions. Although these regions are differentially affected by T cell-mediated diseases, the migration of T-cell subsets in these two regions has not been studied. Naive, memory, and effector T cells were injected into congenic rats and traced in sections of normal lung. All three T-cell subsets were found in large numbers in the alveolar region and exited again quickly. Only effector T cells accumulated in the lamina propria of the bronchi. Further, 72 h after injection 6% of the effector T cells still proliferated in the lung, whereas apoptotic effector T cells were only observed 1 h after injection (0.2%). Thus, not only effector and memory but also naive T cells continuously migrated through the lung. The preferential accumulation of effector T cells in the bronchial lamina propria may explain why some diseases preferentially affect the bronchial region.
Luettig
B
B
Department of Anatomy, Medical School of Hannover, Hannover, Germany.
Kaiser
M
M
Bode
U
U
Bell
E B
EB
Sparshott
S M
SM
Bette
M
M
Westermann
J
J
D000818:Animals; D017209:Apoptosis; D001980:Bronchi / Q000166:cytology* / Q000276:immunology; D002455:Cell Division; D002465:Cell Movement; D007156:Immunologic Memory; D020287:In Situ Nick-End Labeling; D008168:Lung / Q000166:cytology* / Q000276:immunology; D051381:Rats; D011919:Rats, Inbred Strains; D016176:T-Lymphocyte Subsets; D013601:T-Lymphocytes / Q000276:immunology*