Biomaterial Database

Unexpectedly complex regulation of CD4/CD8 coreceptor expression supports a revised model for CD4+CD8+ thymocyte differentiation. 1996

B Lucas, and R N Germain

Laboratory of Immunology, National Institute of Allergy and Infectious Diseases, Bethesda, Maryland 20892-1892, USA.

CD4+ CD8+ TCRlo thymocytes are the precursors of CD4+ and CD8+ mature T cells, whose receptors show specific recognition of peptide-MHC class II and MHC class I complexes, respectively. How T cells emerge from the intrathymic differentiation process with selective expression of either CD8 molecule or CD4 molecule coordinated with the MHC class specificity of the TCR has been the subject of intense examination. Many previous studies of this question have been based on the assumption that extinction of CD4 or CD8 expression by the precursor thymocytes was a steady, uninterrupted process. Here we show that this is an incorrect assumption, with CD4 and CD8 expression undergoing an unexpectedly complex series of expression changes involving down-modulation, kinetically asymmetric up-regulation, and then selective loss. Based on these data, we propose a model for the differentiation pathway of alphabeta TCR thymocytes that explains previous, apparently contradictory findings and establishes useful parameters for future studies at the cellular and gene level.

UI	MeSH Term	Description	Entries
D008810	Mice, Inbred C57BL	One of the first INBRED MOUSE STRAINS to be sequenced. This strain is commonly used as genetic background for transgenic mouse models. Refractory to many tumors, this strain is also preferred model for studying role of genetic variations in development of diseases.	Mice, C57BL,Mouse, C57BL,Mouse, Inbred C57BL,C57BL Mice,C57BL Mice, Inbred,C57BL Mouse,C57BL Mouse, Inbred,Inbred C57BL Mice,Inbred C57BL Mouse
D008817	Mice, Mutant Strains	Mice bearing mutant genes which are phenotypically expressed in the animals.	Mouse, Mutant Strain,Mutant Mouse Strain,Mutant Strain of Mouse,Mutant Strains of Mice,Mice Mutant Strain,Mice Mutant Strains,Mouse Mutant Strain,Mouse Mutant Strains,Mouse Strain, Mutant,Mouse Strains, Mutant,Mutant Mouse Strains,Mutant Strain Mouse,Mutant Strains Mice,Strain Mouse, Mutant,Strain, Mutant Mouse,Strains Mice, Mutant,Strains, Mutant Mouse
D002454	Cell Differentiation	Progressive restriction of the developmental potential and increasing specialization of function that leads to the formation of specialized cells, tissues, and organs.	Differentiation, Cell,Cell Differentiations,Differentiations, Cell
D005260	Female		Females
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D013950	Thymus Gland	A single, unpaired primary lymphoid organ situated in the MEDIASTINUM, extending superiorly into the neck to the lower edge of the THYROID GLAND and inferiorly to the fourth costal cartilage. It is necessary for normal development of immunologic function early in life. By puberty, it begins to involute and much of the tissue is replaced by fat.	Thymus,Gland, Thymus,Glands, Thymus,Thymus Glands
D015496	CD4-Positive T-Lymphocytes	A critical subpopulation of T-lymphocytes involved in the induction of most immunological functions. The HIV virus has selective tropism for the T4 cell which expresses the CD4 phenotypic marker, a receptor for HIV. In fact, the key element in the profound immunosuppression seen in HIV infection is the depletion of this subset of T-lymphocytes.	T4 Cells,T4 Lymphocytes,CD4-Positive Lymphocytes,CD4 Positive T Lymphocytes,CD4-Positive Lymphocyte,CD4-Positive T-Lymphocyte,Lymphocyte, CD4-Positive,Lymphocytes, CD4-Positive,T-Lymphocyte, CD4-Positive,T-Lymphocytes, CD4-Positive,T4 Cell,T4 Lymphocyte
D015704	CD4 Antigens	55-kDa antigens found on HELPER-INDUCER T-LYMPHOCYTES and on a variety of other immune cell types. They are members of the immunoglobulin supergene family and are implicated as associative recognition elements in MAJOR HISTOCOMPATIBILITY COMPLEX class II-restricted immune responses. On T-lymphocytes they define the helper/inducer subset. T4 antigens also serve as INTERLEUKIN-15 receptors and bind to the HIV receptors, binding directly to the HIV ENVELOPE PROTEIN GP120.	Antigens, CD4,CD4 Molecule,CD4 Receptor,CD4 Receptors,Receptors, CD4,T4 Antigens, T-Cell,CD4 Antigen,Receptors, Surface CD4,Surface CD4 Receptor,Antigen, CD4,Antigens, T-Cell T4,CD4 Receptor, Surface,CD4 Receptors, Surface,Receptor, CD4,Surface CD4 Receptors,T-Cell T4 Antigens,T4 Antigens, T Cell
D016693	Receptors, Antigen, T-Cell, alpha-beta	T-cell receptors composed of CD3-associated alpha and beta polypeptide chains and expressed primarily in CD4+ or CD8+ T-cells. Unlike immunoglobulins, the alpha-beta T-cell receptors recognize antigens only when presented in association with major histocompatibility (MHC) molecules.	Antigen Receptors, T-Cell, alpha-beta,T-Cell Receptors alpha-Chain,T-Cell Receptors beta-Chain,T-Cell Receptors, alpha-beta,TcR alpha-beta,Antigen T Cell Receptor, alpha Chain,Antigen T Cell Receptor, beta Chain,Receptors, Antigen, T Cell, alpha beta,T Cell Receptors, alpha beta,T-Cell Receptor alpha-Chain,T-Cell Receptor beta-Chain,T-Cell Receptor, alpha-beta,T Cell Receptor alpha Chain,T Cell Receptor beta Chain,T Cell Receptor, alpha beta,T Cell Receptors alpha Chain,T Cell Receptors beta Chain,TcR alpha beta,alpha-Chain, T-Cell Receptor,alpha-Chain, T-Cell Receptors,alpha-beta T-Cell Receptor,alpha-beta T-Cell Receptors,alpha-beta, TcR,beta-Chain, T-Cell Receptor,beta-Chain, T-Cell Receptors
D016827	CD8 Antigens	Differentiation antigens found on thymocytes and on cytotoxic and suppressor T-lymphocytes. T8 antigens are members of the immunoglobulin supergene family and are associative recognition elements in MHC (Major Histocompatibility Complex) Class I-restricted interactions.	Antigens, CD8,Leu-2 Antigens,T8 Antigens, T-Cell,CD8 Antigen,Antigen, CD8,Antigens, Leu-2,Antigens, T-Cell T8,Leu 2 Antigens,T-Cell T8 Antigens,T8 Antigens, T Cell