TY - JOUR
T1 - Signals transduced by CD3ε, but not by surface pre-TCR complexes, are able to induce maturation of an early thymic lymphoma in vitro
AU - Carleton, Michael
AU - Ruetsch, Norman R.
AU - Berger, Marc A.
AU - Rhodes, Michele
AU - Kaptik, Steven
AU - Wiest, David L.
PY - 1999/9/1
Y1 - 1999/9/1
N2 - Development of immature CD4-CD8- (double-negative) thymocytes to the CD4+CD8+ (double-positive) stage is linked to productive rearrangement of the TCRβ locus by signals transduced through the pre-TCR. However, the mechanism whereby pre-TCR signaling is initiated remains unclear, in part due to the lack of an in vitro model system amenable to both biochemical and genetic analysis. In this study, we establish the thymic lymphoma Scid.adh as such a model system. Scid.adh responds to Ab engagement of surface IL-2Ra (TAC):CD3ε molecules (a signaling chimera that mimics pre-TCR signaling in vivo) by undergoing changes in gene expression observed following pre-TCR activation in normal thymocytes. These changes include down-regulation of CD25, recombinase-activating gene (RAG)-1, RAG-2, and pTα; and the up- regulation of TCRα germline transcripts. We term this complete set of changes in gene expression, in vitro maturation. Interestingly, Scid.adh undergoes only a subset of these changes in gene expression following Ab engagement of the pre-TCR. Our findings make two important points. First, because TAC:CD3ε stimulation of Scid.adh induces physiologically relevant changes in gene expression, Scid.adh is an excellent cellular system for investigating the molecular requirements for pre-TCR signaling. Second, Ab engagement of CD3ε signaling domains in isolation (TAC:CD3ε) promotes in vitro maturation of Scid.adh, whereas engagement of CD3ε molecules contained within the complete pre-TCR fails to do so. Our current working hypothesis is that CD3ε fails to promote in vitro maturation when in the context of an Ab- engaged pre-TCR because another pre-TCR subunit(s), possibly TCRζ, qualitatively alters the CD3ε signal.
AB - Development of immature CD4-CD8- (double-negative) thymocytes to the CD4+CD8+ (double-positive) stage is linked to productive rearrangement of the TCRβ locus by signals transduced through the pre-TCR. However, the mechanism whereby pre-TCR signaling is initiated remains unclear, in part due to the lack of an in vitro model system amenable to both biochemical and genetic analysis. In this study, we establish the thymic lymphoma Scid.adh as such a model system. Scid.adh responds to Ab engagement of surface IL-2Ra (TAC):CD3ε molecules (a signaling chimera that mimics pre-TCR signaling in vivo) by undergoing changes in gene expression observed following pre-TCR activation in normal thymocytes. These changes include down-regulation of CD25, recombinase-activating gene (RAG)-1, RAG-2, and pTα; and the up- regulation of TCRα germline transcripts. We term this complete set of changes in gene expression, in vitro maturation. Interestingly, Scid.adh undergoes only a subset of these changes in gene expression following Ab engagement of the pre-TCR. Our findings make two important points. First, because TAC:CD3ε stimulation of Scid.adh induces physiologically relevant changes in gene expression, Scid.adh is an excellent cellular system for investigating the molecular requirements for pre-TCR signaling. Second, Ab engagement of CD3ε signaling domains in isolation (TAC:CD3ε) promotes in vitro maturation of Scid.adh, whereas engagement of CD3ε molecules contained within the complete pre-TCR fails to do so. Our current working hypothesis is that CD3ε fails to promote in vitro maturation when in the context of an Ab- engaged pre-TCR because another pre-TCR subunit(s), possibly TCRζ, qualitatively alters the CD3ε signal.
KW - Animals
KW - Antibodies, Monoclonal/metabolism
KW - Cell Differentiation/genetics
KW - Cell Membrane/immunology
KW - Lymphoma, T-Cell/immunology
KW - Mice
KW - Mice, SCID
KW - Receptor-CD3 Complex, Antigen, T-Cell/genetics
KW - Receptors, Antigen, T-Cell/genetics
KW - Receptors, Interleukin-2/genetics
KW - Signal Transduction/genetics
KW - Tumor Cells, Cultured
UR - http://www.scopus.com/inward/record.url?scp=0033181325&partnerID=8YFLogxK
UR - https://www.webofscience.com/api/gateway?GWVersion=2&SrcApp=purepublist2023&SrcAuth=WosAPI&KeyUT=WOS:000082125400032&DestLinkType=FullRecord&DestApp=WOS
M3 - Article
C2 - 10452996
SN - 0022-1767
VL - 163
SP - 2576
EP - 2585
JO - Journal of Immunology
JF - Journal of Immunology
IS - 5
ER -