Human thymic epithelial cells directly induce activation of autologous immature thymocytes.

AUTOR(ES)

Denning, S M

RESUMO

To study the role that epithelial cells of the thymic microenvironment play in promoting activation of immature CD7+, CD2+, CD4-, CD8- (double-negative) human thymocytes, we have isolated thymocyte subsets from normal postnatal thymus and have cocultured autologous double-negative thymocytes with pure populations of thymic epithelial (TE) cells. We report that TE cells directly activate double-negative thymocytes to proliferate and that TE cells enhance the ability of double-negative thymocytes to proliferate in response to stimulation with exogenous interleukin 2. Activated double-negative thymocytes that proliferated in vitro in the presence of TE cells and interleukin 2 remained double-negative after 23 days in culture. Moreover, TE-cell culture supernatants in the absence of intact TE cells contain interleukin 1, interleukin 3, and granulocyte/macrophage-colony-stimulating factor activity for human bone marrow cells and can activate double-negative thymocytes to proliferate. Antibodies against interleukin 1 and against granulocyte/macrophage-colony-stimulating factor inhibited TE-cell-induced thymocyte activation. These data indicate that one role of TE cells in vivo may be to activate double-negative thymocytes to proliferate.

Documentos Relacionados

• Human thymocytes bind to autologous and allogeneic thymic epithelial cells in vitro.
• Immature human thymocytes can be driven to differentiate into nonlymphoid lineages by cytokines from thymic epithelial cells.
• High-Level Replication of Human Immunodeficiency Virus in Thymocytes Requires NF-κB Activation through Interaction with Thymic Epithelial Cells
• Human T-cell leukemia virus type I-induced proliferation of human immature CD2+CD3- thymocytes.
• Identification of mRNAs associated with programmed cell death in immature thymocytes.