Characterization of thymic nurse-cell lymphocytes, using an improved procedure for nurse-cell isolation.
Thymic nurse cells (TNC), multicellular complexes consisting of lymphoid cells enclosed within cortical epithelial cells, were isolated from mouse thymus by a modified procedure allowing immunofluorescent labeling and flow cytometric analysis of their lymphoid contents (TNC-L). Collagenase was the only protease used for tissue digestion, to ensure that surface antigen markers remained intact. Zonal unit-gravity elutriation was used to enrich the TNC on the basis of their high sedimentation rate, followed by immunomagnetic bead depletion to remove residual mononuclear cell contaminants and a density separation to remove debris. The TNC-L were then released from inside TNC by a short period of culture. The measured contamination of TNC-L with exogenous thymocytes was around 0.5%. Three-color immunofluorescent labeling revealed that TNC-L included, as well as a majority of immature CD4+8+3low thymocytes, about 12% of apparently mature CD4+8-3high and CD4-8+3high thymocytes. TNC are located in the cortex, where mature cells are rare; the occurrence of mature phenotype cells within these structures suggests that they represent a microenvironment for the selection and generation of mature T cells.
Lahoud
M
M
Walter and Eliza Hall Institute of Medical Research, Melbourne, Victoria, Australia.
Vremec
D
D
Boyd
R L
RL
Shortman
K
K
D000818:Animals; D015415:Biomarkers; D017252:CD3 Complex / Q000032:analysis; D015704:CD4 Antigens / Q000032:analysis; D015496:CD4-Positive T-Lymphocytes / Q000166:cytology / Q000502:physiology; D016827:CD8 Antigens; D002469:Cell Separation / Q000379:methods*; D005260:Female; D005434:Flow Cytometry; D051379:Mice; D008808:Mice, Inbred CBA; D010641:Phenotype; D016176:T-Lymphocyte Subsets / Q000166:cytology / Q000502:physiology; D013601:T-Lymphocytes / Q000502:physiology*; D013950:Thymus Gland / Q000166:cytology* / Q000502:physiology
D015415:Biomarkers; D017252:CD3 Complex; D015704:CD4 Antigens; D016827:CD8 Antigens