scholarly journals Multiple rearrangements in T cell receptor alpha chain genes maximize the production of useful thymocytes.

1993 ◽  
Vol 178 (2) ◽  
pp. 615-622 ◽  
Author(s):  
H T Petrie ◽  
F Livak ◽  
D G Schatz ◽  
A Strasser ◽  
I N Crispe ◽  
...  
Keyword(s):  
T Cell ◽  
T Cell Receptor ◽  
Cell Receptor ◽  
Surface Expression ◽  
Model Systems ◽  
Allelic Exclusion ◽  
Alpha Chain ◽  
Enhanced Production ◽  
Germline Genes ◽  
Alpha Beta

Peripheral T lymphocytes each express surface T cell receptor (TCR) alpha and beta chains of a single specificity. These are produced after random somatic rearrangements in TCR alpha and beta germline genes. Published model systems using mice expressing TCR alpha and/or beta chain transgenes have shown that allelic exclusion occurs conventionally for TCR-beta. TCR alpha chain expression, however, appears to be less strictly regulated, as endogenous TCR alpha chains are often found in association with transgenic TCR beta chains in TCR alpha/beta transgenic mice. This finding, coupled with the unique structure of the TCR alpha locus, has led to the suggestion that unlike TCR beta and immunoglobulin heavy chain genes, TCR alpha genes may make multiple rearrangements on each chromosome. In the current study, we demonstrate that the majority of TCR-, noncycling thymocytes spontaneously acquire surface expression of CD3/TCR. Further, we show that cultured immature thymocytes originally expressing specific TCR alpha and beta chains may lose surface expression of the original TCR alpha, but not beta chains. These data provide evidence that not only must multiple rearrangements occur, but that TCR alpha gene rearrangement continues even after surface expression of a TCR alpha/beta heterodimer, apparently until the recombination process is halted by positive selection, or the cell dies. Sequential rearrangement of TCR alpha chain genes facilitates enhanced production of useful thymocytes, by increasing the frequency of production of both in-frame rearrangements and positively selectable TCR alpha/beta heterodimers.

scholarly journals Surface expression of functional T cell receptor chains formed by interlocus recombination on human T lymphocytes.

1994 ◽  
Vol 180 (5) ◽  
pp. 1685-1691 ◽  
Author(s):  
F Davodeau ◽  
M A Peyrat ◽  
J Gaschet ◽  
M M Hallet ◽  
F Triebel ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Receptor ◽  
Cell Receptor ◽  
Surface Expression ◽  
Structural Features ◽  
Gamma Delta ◽  
Cell Repertoire ◽  
Repertoire Selection ◽  
Alpha Beta

Structural diversity of lymphocyte antigen receptors (the immunoglobulin [Ig] of B cells and the alpha/beta or gamma/delta T cell receptor [TCR] of T cells) is generated through somatic rearrangements of V, D, and J gene segments. Classically, these recombination events involve gene segments from the same Ig or TCR locus. However, occurrence of "trans" rearrangements between distinct loci has also been described, although in no instances was the surface expression of the corresponding protein under normal physiological conditions demonstrated. Here we show that hybrid TCR genes generated by trans rearrangement between V gamma and (D) J beta elements are translated into functional antigen receptor chains, paired with TCR alpha chains. Like classical alpha/beta T cells, cells expressing these hybrid TCR chains express either CD4 or CD8 coreceptors and are frequently alloreactive. These results have several implications in terms of T cell repertoire selection and relationships between TCR structure and specificity. First, they suggest that TCR alloreactivity is determined by the repertoire selection processes operating during lymphocyte development rather than by structural features specific to V alpha V beta regions. Second, they suggest the existence of close structural relationships between gamma/delta and alpha/beta TCR and more particularly, between V gamma and V beta regions. Finally, since a significant fraction of PBL (at least 1/10(4)) expressed hybrid TCR chains on their surface, these observations indicate that trans rearrangements significantly contribute to the combinatorial diversification of the peripheral immune repertoire.

scholarly journals Fc gamma RII/III and CD2 expression mark distinct subpopulations of immature CD4-CD8- murine thymocytes: in vivo developmental kinetics and T cell receptor beta chain rearrangement status.

1993 ◽  
Vol 177 (4) ◽  
pp. 1079-1092 ◽  
Author(s):  
H R Rodewald ◽  
K Awad ◽  
P Moingeon ◽  
L D'Adamio ◽  
D Rabinowitz ◽  
...  
Keyword(s):  
T Cell ◽  
T Cell Receptor ◽  
Fetal Development ◽  
Cell Receptor ◽  
Surface Expression ◽  
Cell Surface Expression ◽  
Immunoglobulin Gene ◽  
Beta Chain ◽  
Double Positive ◽  
Alpha Beta

We have recently identified a dominant wave of CD4-CD8- (double-negative [DN]) thymocytes in early murine fetal development that express low affinity Fc gamma receptors (Fc gamma RII/III) and contain precursors for Ti alpha/beta lineage T cells. Here we show that Fc gamma RII/III is expressed in very immature CD4low single-positive (SP) thymocytes and that Fc gamma RII/III expression is downregulated within the DN subpopulation and before the CD3-CD8low SP stage in T cell receptor (TCR)-alpha/beta lineage-committed thymocytes. DN Fc gamma RII/III+ thymocytes also contain a small fraction of TCR-gamma/delta lineage cells in addition to TCR-alpha/beta progenitors. Fetal day 15.5 DN TCR-alpha/beta lineage progenitors can be subdivided into three major subpopulations as characterized by cell surface expression of Fc gamma RII/III vs. CD2 (Fc gamma RII/III+CD2-, Fc gamma RII/III+CD2+, Fc gamma RII/III-CD2+). Phenotypic analysis during fetal development as well as adoptive transfer of isolated fetal thymocyte subpopulations derived from C57B1/6 (Ly5.1) mice into normal, nonirradiated Ly5.2 congenic recipient mice identifies one early differentiation sequence (Fc gamma RII/III+CD2(-)-->Fc gamma RII/III+CD2(+)-->Fc gamma RII/III-CD2+) that precedes the entry of DN thymocytes into the CD4+CD8+ double-positive (DP) TCRlow/- stage. Unseparated day 15.5 fetal thymocytes develop into DP thymocytes within 2.5 d and remain at the DP stage for > 48 h before being selected into either CD4+ or CD8+ SP thymocytes. In contrast, Fc gamma RII/III+CD2- DN thymocytes follow this same developmental pathway but are delayed by approximately 24 h before entering the DP compartment, while Fc gamma RII/III-CD2+ display accelerated development by approximately 24 h compared with total day 15.5 thymocytes. Fc gamma RII/III-CD2+ are also more developmentally advanced than Fc gamma RII/III+CD2- fetal thymocytes with respect to their TCR beta chain V(D)J rearrangement. At day 15.5 in gestation, beta chain V(D)J rearrangement is mostly, if not entirely, restricted to the Fc gamma RII/III-CD2+ subset of DN fetal thymocytes. Consistent with this analysis in fetal thymocytes, > 90% of adult thymocytes derived from mice carrying a disrupting mutation at the recombination-activating gene 2 locus (RAG-2-/-) on both alleles are developmentally arrested at the DN CD2- stage. In addition, there is a fivefold increase in the relative percentage of thymocytes expressing Fc gamma RII/III in TCR and immunoglobulin gene rearrangement-incompetent homozygous RAG-2-/- mice (15% Fc gamma RII/III+) versus rearrangement-competent heterozygous RAG-2+/- mice (< 3% Fc gamma RII/III+). Thus, Fc gamma RII/III expression defines an early DN stage preceding V beta(D beta)I beta rearrangement, which in turn is followed by surface expression of CD2. Loss of Fc gamma RII/III and acquisition of CD2 expression characterize a late DN stage immediately before the conversion into DP thymocytes.

scholarly journals Stringent V beta requirement for the development of NK1.1+ T cell receptor-alpha/beta+ cells in mouse liver.

1996 ◽  
Vol 183 (3) ◽  
pp. 1277-1282 ◽  
Author(s):  
T Ohteki ◽  
H R MacDonald
Keyword(s):  
T Cells ◽  
T Cell ◽  
Transgenic Mice ◽  
Beta Cells ◽  
T Cell Receptor ◽  
Cell Receptor ◽  
Allelic Exclusion ◽  
Stringent Requirement ◽  
Major Subset ◽  
Alpha Beta

The liver of C57BL/6 mice contains a major subset of CD4+8- and CD4-8- T cell receptor (TCR)-alpha/beta+ cells expressing the polymorphic natural killer NK1.1 surface marker. Liver NK1.1+TCR-alpha/beta+ (NK1+ T) cells require interaction with beta2-microglobulin-associated, major histocompatibility complex I-like molecules on hematopoietic cells for their development and have a TCR repertoire that is highly skewed to Vbeta8.2, Vbeta7, and Vbeta2. We show here that congenic C57BL/6.Vbeta(a) mice, which lack Vbeta8- expressing T cells owing to a genomic deletion at the Vbeta locus, maintain normal levels of liver NK1+ T cells owing to a dramatic increase in the proportion of cells expressing Vbeta7 and Vbeta2 (but not other Vbetas). Moreover, in C57BL/6 congenic TCR-V Vbeta3 and -Vbeta8.1 transgenic mice (which in theory should not express other Vbeta, owing to allelic exclusion at the TCR-beta locus), endogenous TCR-Vbeta8.2, Vbeta7, and Vbeta2 (but not other Vbetas) are frequently expressed on liver NK1+T cells but absent on lymph node T cells. Finally, when endogenous V beta expression is prevented in TCR-Vbeta3 and Vbeta8.1 transgenic mice (by introduction of a null allele at the C beta locus), the development of liver NK1+T cells is totally abrogated. Collectively, our data indicate that liver NK1+T cells have a stringent requirement for expression of TCR-Vbeta8.2, Vbeta7, or Vbeta2 for their development.

scholarly journals A T-cell-specific transcriptional enhancer element 3' of C alpha in the human T-cell receptor alpha locus

1989 ◽  
Vol 86 (17) ◽  
pp. 6714-6718 ◽  
Author(s):  
I C Ho ◽  
L H Yang ◽  
G Morle ◽  
J M Leiden
Keyword(s):  
T Cell ◽  
T Cell Receptor ◽  
Simian Virus 40 ◽  
Cell Receptor ◽  
Simian Virus ◽  
Transcriptional Enhancer ◽  
Enhancer Element ◽  
Alpha Chain ◽  
Human T Cell ◽  
Alpha Beta

A transcriptional enhancer element has been identified 4.5 kilobases 3' of C alpha (constant region alpha chain) in the human T-cell receptor (TCR) alpha-chain locus. This enhancer is active on both a TCR V alpha (variable region alpha chain) promoter and the minimal simian virus 40 promotor in TCR alpha/beta Jurkat and EL4 cells but is inactive on a V alpha promoter in human TCR gamma/delta PEER and Molt-13 cells, clone 13 B cells, and HeLa fibroblasts. The enhancer has been localized to a 116-base-pair BstXI/Dra I restriction enzyme fragment, which lacks immunoglobulin octamer and kappa B enhancer motifs but does contain a consensus cAMP-response element (CRE). DNase I footprint analyses demonstrated that the minimal enhancer contains two binding sites for Jurkat nuclear proteins. One of these sites corresponds to the CRE, while the other does not correspond to a known transcriptional enhancer motif. These data support a model in which TCR alpha gene transcription is regulated by a unique set of cis-acting sequences and trans-acting factors, which are differentially active in cells of the TCR alpha/beta lineage. In addition, the TCR alpha enhancer may play a role in activating oncogene expression in T-lymphoblastoid tumors that have previously been shown to display chromosomal translocations into the human TCR alpha locus.

Expression of T-cell receptor alpha-chain genes in transgenic mice

1988 ◽  
Vol 8 (12) ◽  
pp. 5459-5469
Author(s):  
L J Berg ◽  
B Fazekas de St Groth ◽  
F Ivars ◽  
C C Goodnow ◽  
S Gilfillan ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Receptor ◽  
Cell Receptor ◽  
Surface Expression ◽  
Specific Monoclonal Antibody ◽  
Alpha Chain ◽  
Receptor Alpha Chain ◽  
Cell Receptor Alpha

To examine the influences responsible for shaping the T-cell repertoire in vivo, we have introduced T-cell receptors of defined specificity into mice. In this report, we analyze transgenic mice carrying a T-cell receptor alpha-chain gene from a pigeon cytochrome c-reactive T-cell line. A variant of this construct, which has the immunoglobulin heavy-chain enhancer inserted into the JC intron, was also introduced into mice. Addition of the enhancer increased the steady-state level of transgene-encoded mRNA three- to fivefold in cultured T cells, leading to a two- to threefold increase in surface expression. In vivo, the difference between these two constructs was even more significant, increasing the number of transgene-positive cells from approximately 5 to 70% and the T-cell receptor surface density two- to threefold. Surprisingly, while surface expression of either type of transgene was limited to T cells, we found little tissue specificity with respect to transcription. In T cells expressing the alpha chain from the enhancer-containing construct, immunoprecipitation with a 2B4 alpha-specific monoclonal antibody revealed the expected disulfide-linked dimer. Costaining of these T cells with the 2B4 alpha-specific monoclonal antibody versus anti-CD3 indicated that expression of the transgene-encoded alpha chain precludes expression of endogenous alpha chains on the majority of cells; in contrast, 2B4 alpha-chain expression from the construct lacking the enhancer is inefficient at suppressing endogenous alpha-chain expression. In mice of the enhancer lineage, Southern blot analysis indicated suppression of endogenous alpha-chain rearrangements in T-cell populations, consistent with the observed allelic exclusion at the cellular level. Interestingly, newborn, but not adult, mice of this lineage also showed an increase in retention of unrearranged delta-chain loci in thymocyte DNA, presumably resulting from the suppression of alpha-chain rearrangements. This observation indicates that at least a fraction of alpha:beta-positive T cells have never attempted to produce functional delta rearrangements, thus suggesting that alpha:beta and gamma:delta T cells may be derived from different T-cell compartments (at least during the early phases of T-cell differentiation).

scholarly journals Surface expression of a T cell receptor beta (TCR-beta) chain in the absence of TCR-alpha, -delta, and -gamma proteins.

1991 ◽  
Vol 174 (4) ◽  
pp. 775-783 ◽  
Author(s):  
J A Punt ◽  
R T Kubo ◽  
T Saito ◽  
T H Finkel ◽  
S Kathiresan ◽  
...  
Keyword(s):  
T Cell ◽  
T Cell Receptor ◽  
Transmembrane Proteins ◽  
Cell Receptor ◽  
Surface Expression ◽  
Gamma Delta ◽  
Cell Interior ◽  
T Cell Receptor Beta ◽  
Alpha Beta ◽  
Receptor Beta

The antigen receptor expressed by mature T cells has been described as a disulfide-linked alpha/beta or gamma/delta heterodimer noncovalently associated with CD3, a complex of transmembrane proteins that communicates signals from the T cell receptor (TCR) to the cell interior. Studies suggest that all component chains must assemble intracellularly before surface expression can be achieved. We described, however, a CD4+/CD8+ transformed murine thymocyte, KKF, that expresses surface TCR-beta chains in the absence of gamma, delta, and alpha proteins; these beta chains are only weakly associated with CD3-epsilon and CD3-zeta. Furthermore, KKF responds differently to stimulation through TCR-beta and CD3-epsilon, a functional dissociation that has been ascribed to a CD4+/CD8+ subpopulation of normal thymocytes. KKF's unique TCR structure may offer an explanation for the functional anomalies observed.

scholarly journals A novel subset of human lymphocytes with a T cell receptor-gamma complex.

1987 ◽  
Vol 166 (4) ◽  
pp. 1192-1197 ◽  
Author(s):  
S Jitsukawa ◽  
F Faure ◽  
M Lipinski ◽  
F Triebel ◽  
T Hercend
Keyword(s):  
T Cell ◽  
T Cell Receptor ◽  
Human Lymphocytes ◽  
Cell Receptor ◽  
Surface Expression ◽  
Gamma Chain ◽  
A Cells ◽  
Wide Range ◽  
Circulating Lymphocytes ◽  
Alpha Beta

We have previously characterized a CD3+ T cell receptor (TCR) alpha/beta- human fetal cloned cell line, termed F6C7, which surface-expresses a CD3-associated gamma chain identified by anti-NKFi, an mAb with a restricted clonotypic reactivity. Here, we have produced an additional antibody, anti-Ti-gamma A, which recognizes a public epitope of the gamma molecule defined by anti-NKFi. Ti-gamma A is present on approximately 3% of circulating lymphocytes with a wide range (1-15%) among 30 healthy individuals tested. Two-color immunofluorescence experiments performed with anti-Ti-gamma A and BMA 031 mAb (a reagent specific for the TCR-alpha/beta receptor) showed that surface expression of Ti-alpha/beta and Ti-gamma A is mutually exclusive. Moreover, it was found that most Ti-gamma A+ cells are CD2+, CD3+, CD4-, CD5+, NKH1-, HLA class II-negative. In contrast, the expression of the CD8 molecule on these T lymphocytes appears to be variable from one individual to another. Finally, we found that Ti-gamma A+ cells represent a majority of peripheral lymphocytes that express CD3 proteins but not the TCR-alpha/beta heterodimer. The delineation of this unique lymphocyte subset should help further studies on the biology of cells with a CD3-associated gamma complex.

scholarly journals Expression of T-cell receptor alpha-chain genes in transgenic mice.

1988 ◽  
Vol 8 (12) ◽  
pp. 5459-5469 ◽  
Author(s):  
L J Berg ◽  
B Fazekas de St Groth ◽  
F Ivars ◽  
C C Goodnow ◽  
S Gilfillan ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Receptor ◽  
Cell Receptor ◽  
Surface Expression ◽  
Specific Monoclonal Antibody ◽  
Alpha Chain ◽  
Receptor Alpha Chain ◽  
Cell Receptor Alpha

To examine the influences responsible for shaping the T-cell repertoire in vivo, we have introduced T-cell receptors of defined specificity into mice. In this report, we analyze transgenic mice carrying a T-cell receptor alpha-chain gene from a pigeon cytochrome c-reactive T-cell line. A variant of this construct, which has the immunoglobulin heavy-chain enhancer inserted into the JC intron, was also introduced into mice. Addition of the enhancer increased the steady-state level of transgene-encoded mRNA three- to fivefold in cultured T cells, leading to a two- to threefold increase in surface expression. In vivo, the difference between these two constructs was even more significant, increasing the number of transgene-positive cells from approximately 5 to 70% and the T-cell receptor surface density two- to threefold. Surprisingly, while surface expression of either type of transgene was limited to T cells, we found little tissue specificity with respect to transcription. In T cells expressing the alpha chain from the enhancer-containing construct, immunoprecipitation with a 2B4 alpha-specific monoclonal antibody revealed the expected disulfide-linked dimer. Costaining of these T cells with the 2B4 alpha-specific monoclonal antibody versus anti-CD3 indicated that expression of the transgene-encoded alpha chain precludes expression of endogenous alpha chains on the majority of cells; in contrast, 2B4 alpha-chain expression from the construct lacking the enhancer is inefficient at suppressing endogenous alpha-chain expression. In mice of the enhancer lineage, Southern blot analysis indicated suppression of endogenous alpha-chain rearrangements in T-cell populations, consistent with the observed allelic exclusion at the cellular level. Interestingly, newborn, but not adult, mice of this lineage also showed an increase in retention of unrearranged delta-chain loci in thymocyte DNA, presumably resulting from the suppression of alpha-chain rearrangements. This observation indicates that at least a fraction of alpha:beta-positive T cells have never attempted to produce functional delta rearrangements, thus suggesting that alpha:beta and gamma:delta T cells may be derived from different T-cell compartments (at least during the early phases of T-cell differentiation).

scholarly journals Regions of the T cell receptor alpha and beta chains that are responsible for interactions with CD3.

1991 ◽  
Vol 173 (5) ◽  
pp. 1247-1256 ◽  
Author(s):  
L Tan ◽  
J Turner ◽  
A Weiss
Keyword(s):  
T Cell ◽  
T Cell Receptor ◽  
Cell Activation ◽  
Cell Receptor ◽  
Surface Expression ◽  
Functional Coupling ◽  
Beta Chain ◽  
Alpha Beta ◽  
Chimeric Molecules ◽  
Stimulation Of

The T cell antigen receptor consists of the Ti alpha/beta heterodimer which recognizes antigen, and the associated CD3 chains, thought to be involved in signal transduction. To understand the nature of the interaction between Ti and CD3, chimeric molecules which included the COOH-terminal segments of Ti alpha or beta linked to the extracellular segment of CD8, were transfected into a mutant T cell deficient in Ti beta chain expression and cell surface CD3. Both chimeric chains were required to express the chimeric Ti and to restore CD3 surface expression. CD8/Ti and CD3 cointernalized and coimmunoprecipitated. Stimulation of the chimeric receptor induced transmembrane signaling events and cell activation. These results demonstrate that the Ti alpha and beta COOH termini containing the transmembrane domains are sufficient for structural and functional coupling of Ti to CD3.

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