细胞期刊(Cell)2013-09-22 1:05 AM

Lck Availability during Thymic Selection Determines the Recognition Specificity of the T Cell Repertoire

Abstract Thymic selection requires signaling by the protein tyrosine kinase Lck to generate T cells expressing αβ T cell antigen receptors (TCR). For reasons not understood, the thymus selects only αβTCR that are restricted by major histocompatibility complex (MHC)-encoded determinants. Here, we report that Lck proteins that were coreceptor associated promoted thymic selection of conventionally MHC-restricted TCR, but Lck proteins that were coreceptor free promoted thymic selection of MHC-independent TCR. Transgenic TCR with MHC-independent specificity for CD155 utilized coreceptor-free Lck to signal thymic selection in the absence of MHC, unlike any transgenic TCR previously described. Thus, the thymus can select either MHC-restricted or MHC-independent αβTCR depending on whether Lck is coreceptor associated or coreceptor free. We conclude that the intracellular state of Lck determines the specificity of thymic selection and that Lck association with coreceptor proteins during thymic selection is the mechanism by which MHC restriction is imposed on a randomly generated αβTCR repertoire.

KEYWORDS

SHARE & LIKE

COMMENTS

ABOUT THE AUTHOR

细胞期刊(Cell)

0 Following 3 Fans 0 Projects 125 Articles

SIMILAR ARTICLES

Epigenetic mechanisms have been proposed to play crucial roles in mammalian development, but their precise functions are only partially understood. To

Read More

Summary Replenishing insulin-producing pancreatic β cell mass will benefit both type I and type II diabetics. In adults, pancreatic β cells are gene

Read More

Summary Replenishing insulin-producing pancreatic β cell mass will benefit both type I and type II diabetics. In adults, pancreatic β cells are gene

Read More

Summary 5-methylcytosine is a major epigenetic modification that is sometimes called “the fifth nucleotide.” However, our knowledge of how offspring

Read More

Summary 5-methylcytosine is a major epigenetic modification that is sometimes called “the fifth nucleotide.” However, our knowledge of how offspring

Read More

Summary All metazoan guts are subjected to immunologically unique conditions in which an efficient antimicrobial system operates to eliminate pathog

Read More

Summary All metazoan guts are subjected to immunologically unique conditions in which an efficient antimicrobial system operates to eliminate pathog

Read More

Summary Alterations of symbiosis between microbiota and intestinal epithelial cells (IEC) are associated with intestinal and systemic pathologies. I

Read More

Summary Alterations of symbiosis between microbiota and intestinal epithelial cells (IEC) are associated with intestinal and systemic pathologies. I

Read More

Summary The most common form of heart failure occurs with normal systolic function and often involves cardiac hypertrophy in the elderly. To clarify

Read More