Positive Selection by Thymic Nurse Cells Requires IL-1β and Is Associated with an Increased Bcl-2 Expression

Thymic Nurse Cells Forming a Dynamic Microenvironment in Spontaneous Thymoma BUF/Mna Rats.

“…Our findings suggest a possibility that macrophages may also play crucial roles in various functions of TNCs, such as either positive (PEZZANO et al, 1996) or negative selection (TOUSSAINT-DEMYLLE et al, 1991), or the clearance of apoptotic thymocytes (AGUILAR et al, 1994). This provides further supporting evidence for our previous hypothesis, that of multicellular interactions within the TNC complexes (EZAKI et al, 1991b).…”

“…They are defined as the specialized epithelial or stromal cells that form unique multi-cellular complexes by enclosing thymocytes within these (WEKERLE et al, 1980). In vitro studies have revealed the possible roles of TNCs as one of the most important components of the thymic microenvironment for T cell development, such as the presentation of self antigens (LORENZ and ALLEN, 1989) and non-self antigens (MARRAcK et al, 1989), both positive selection (RIEKER et al, 1995;PEZZANO et al, 1996) and negative selection (AGUILAR et al, 1994;HIRAMINE et al, 1995), or triggering leukemogenesis (HOUBEN-DEFRESNE et al, 1982). However, controversy remains on their actual status and functions being manifested in situ (RITTER et al, 1981;KYEWSKI and KAPLAN, 1982; VAN DE WIJINGAERT et al, 1983;TOUSSAINT-DEMYLLE et al, 1990).…”

Nurse-like cells from bone marrow and synovium of patients with rheumatoid arthritis promote survival and enhance function of human B cells.

“…Thymic nurse cells form unique complexes with bone marrow-derived T cell precursors, and play an important role in thymocyte maturation and differentiation, eventually leading to the generation of positively (3,4) or negatively (5) selected T cells that subsequently migrate to the T cell-dependent areas of secondary lymphoid organs. After initial adhesion to thymic nurse cells, thymocytes crawl beneath them in vitro (6,7).…”

Questionable Thymic Nurse Cell

“…Cells from both cell lines expressed cytokeratins and class I and class II MHC antigens. The long-term cultures of tsTNC-1 cells, another TNC line generated through SV40 transformation with freshly isolated thymocytes, resulted in the maturation of ␣␤TCR lo CD69 Ϫ triple positives into ␣␤TCR hi CD69 hi cells (39). SV40-derived TNC lines were also shown to express the neuroendocrine marker A2B5, which was previously shown to be a characteristic of freshly isolated TNCs.…”