The human Lyt-3 molecule requires CD8 for cell surface expression.

Disanto, James P.; Knowles, Robert W.; Flomenberg, Neal

doi:10.1002/j.1460-2075.1988.tb03221.x

Cited by 60 publications

(36 citation statements)

References 33 publications

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“…Although the DP phenotype can be induced in both CD4 and CD8 single-positive T cells, DP T cells with CD8␣␣ subunit are likely to derive from CD4 + T cells, since CD8 + T cells have the ␣␤ subunit. [7][8][9] In fact, mature CD4 + T cells were shown to become DP by stimulation with IL-4 and to have CD4 + CD8␣␣dim phenotype, 10,11 identical to the phenotype of DP LGLL cells. In addition, in our as well as Tonutti's cases, a significant proportion of the residual T cells other than DP T cells showed CD4 + , CD8 − phenotype, which also showed CD11b + , 56 + , 57 + phenotype expressed on the DP cells.…”

Section: Tablementioning

confidence: 99%

“…[7][8][9] Thymic DP T cells and peripheral CD8 single-positive T cells Correspondence: M Mizuki, Department of Hematology and Oncology, Osaka University Medical School, 2-2 Yamadaoka, Suita, Osaka 565, Japan; Fax: 81 6 879 3879 Received 1 July 1997; accepted 2 January 1998 express CD8␣␤, while CD4 single-positive T cells become DP on activation with IL-4, and the DP T cells express CD8 of ␣␣ type. 10,11 Intestinal epithelial lymphocytes (IEL) are a distinct T cell subset, which preferentially express CD8␣␣ and contain a DP population.…”

Section: Introductionmentioning

confidence: 99%

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Phenotypical heterogeneity of CD4+CD8+ double-positive chronic T lymphoid leukemia

et al. 1998

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Chronic T lymphoid leukemias are defined as leukemias of post-thymic T cells. The CD4 ؉ CD8 ؉ double-positive (DP) phenotype is seen in a few cases. Since DP generally occurs in thymic T cells, whether the DP T leukemia cells represent thymic or peripheral T cells has been a matter of controversy. To address this issue, we studied phenotypical features in eight cases of DP T cell leukemia. Thymic DP T cells and peripheral CD8 ؉ T cells have CD8 of ␣␤ subunit, while CD8␣␣ is induced in CD4 ؉ T cells on activation with IL-4. We found that two patients with DP T large granular lymphocyte leukemia (LGLL) showed dim expression of CD8␣␣, identical to the phenotype on IL-4-activated DP-T cells. The leukemic cells of these patients expressed IL-4 mRNA and produced high levels of IL-4. These findings suggest that they may be derived from peripheral CD4 ؉ T cells. Three patients with adult T cell leukemia/lymphoma (ATLL) showed CD8␣␣, suggestive of an activated peripheral T cell origin. One case expressed CD8␣␣ dim and IL-4 mRNA, while the other two cases expressed no IL-4 mRNA and showed CD8␣␣ bright phenotype, features not found in normal T cell populations. Three patients with T-prolymphocytic leukemia (T-PLL) expressed CD8␣␤. The DP phenotype is relatively common in T-PLL, and CD4 + CD8␣␤ + is characteristic of thymic T cells. The DP T-PLL cells did not express TdT,CD1 or recombination activating gene-1 (RAG-1), which is down-regulated at the late stage of thymic T cell development. On the basis of these findings, we propose a late thymic origin for DP T-PLL. The phenotype of DP T cells differed for each entity and appeared to correlate with minor normal DP T cell population.

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Section: Tablementioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Phenotypical heterogeneity of CD4+CD8+ double-positive chronic T lymphoid leukemia

et al. 1998

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“…CD8 is encoded by two distinct genes, termed CD8␣ (or Lyt 2) and CD8␤ (or Lyt 3) and expressed on the cell surface as a mixture of disulfide-linked CD8␣␣ homodimers and CD8␣␤ heterodimers (2)(3)(4)(5)(6)(7). CD8␣ is a 34 -37-kDa transmembrane glycoprotein whose extracellular segment contains a compact 122-amino acid (aa) N-terminal Ig-like domain and an extended 48-residue stalk region.…”

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confidence: 99%

Expression, Purification, and Functional Analysis of Murine Ectodomain Fragments of CD8αα and CD8αβ Dimers

Kern¹,

Hussey

Spoerl

et al. 1999

Journal of Biological Chemistry

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Soluble mouse CD8␣␣ and CD8␣␤ dimers corresponding to the paired ectodomains (CD8 f ) or their respective component Ig-like domains (CD8) were expressed in Chinese hamster ovary cells or the glycosylation variant Lec3.2.8.1 cells as secreted proteins using a leucine zipper strategy. The affinity of CD8␣␣ f for H-2K b as measured by BIAcore revealed a ϳ65 M K d , similar to that of CD8␣␤ f . Consistent with this result, CD8␣␣ f as well as CD8␣␤ f blocked the effector function of N15 T cell receptor transgenic cytolytic T cells in a comparable, dose-dependent fashion. Furthermore, both Lec3.2.8.1-produced and Chinese hamster ovary-produced CD8 homodimers and heterodimers were active in the inhibition assay. These results suggest that the Ig-like domains of CD8 molecules are themselves sufficient to block the requisite transmembrane CD8-pMHC interaction between cytolytic T lymphocytes and target cells. Moreover, given the similarities in co-receptor affinities for pMHC, the findings suggest that the greater efficiency of CD8␣␤ versus CD8␣␣ co-receptor function on T cells is linked to differences within their membranebound stalk regions and/or intracellular segments. As recently shown for sCD8␣␣, the yield, purity and homogeneity of the deglycosylated protein resulting from this expression system is sufficient for crystallization and x-ray diffraction at atomic resolution.CD8 has been shown to function in mediating signal transduction and adhesion on a subset of cells within the T cell compartment and is critically involved in the development of T cells expressing MHC class I-restricted T cell receptor (TCR) 1 (1). CD8 is encoded by two distinct genes, termed CD8␣ (or Lyt 2) and CD8␤ (or Lyt 3) and expressed on the cell surface as a mixture of disulfide-linked CD8␣␣ homodimers and CD8␣␤ heterodimers (2-7). CD8␣ is a 34 -37-kDa transmembrane glycoprotein whose extracellular segment contains a compact 122-amino acid (aa) N-terminal Ig-like domain and an extended 48-residue stalk region. A 28-aa cytoplasmic domain, including a cysteine motif responsible for interaction with p56 lck , follows a canonical hydrophobic transmembrane anchor. CD8␤ is a 32-kDa glycoprotein sharing a similar architecture as CD8␣ but with Ͻ20% sequence identity (4, 5). The stalk regions of the CD8␣ and ␤ chains are quite different in length, with the CD8␤ stalk being 10 -13 residues shorter than that of CD8␣. Interestingly, the sialic acid content of O-linked glycans adducted to CD8␤ selectively decreases on thymocytes and activated T cells compared with that found on resting T cells. For its cell surface expression, CD8␤ requires association with the CD8␣ subunit, forming a CD8␣␤ heterodimer (6, 8). Moreover, CD8 genes are selectively expressed. Although CD8␣␤ heterodimers are predominantly found on the surface of TCR␣␤ T cells and thymocytes, CD8␣␣ homodimers are additionally expressed on a subset of ␥␦ T cells, intestinal intraepithelial lymphocytes and natural killer cells (9, 10). Hence, it is safe to conclude that the two sets of CD8 co-r...

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“…A putative N-glycosylation site was found at position Asn-81 as described for the human molecule. 4 We examined the expression of the feline CD8b by Northern blot analysis using our FTb-6 clone as a probe. We detected the presence of an approximately 1 .…”

Section: Discussionmentioning

confidence: 99%

“…2 The glycoprotein is expressed on the surface of suppressor/cytotoxic T lymphocytes either as a homodimer or multimer of the a -chain (CD8aa) or as a heterodimer of the a -and b -chains (CD8ab). 3 A predicted molecular weight of the human CD8b molecule is approximately 34 000 with a polypeptide chain of 210 amino acids, 4 while the mouse (Lyt-3) and rat (OX-8) molecules are 28 000-30 000 and 37 000 MW, respectively. 5,6 Functional studies on the human CD8b molecule demonstrated that the molecule is necessary for maturation of CD8 + cells 7 and its external portion might play an important role in augmenting interleukin-2 (IL-2) production.…”

Section: Introductionmentioning

confidence: 99%

Molecular cloning of the feline CD8β‐chain

et al. 1996

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Human, mouse and rat CD8 have been described as being disulphide‐linked heterodimers of α and β chains. More recently the chicken α and β chains were described. In the bovine and feline immune system only the α‐chain was reported. In this study we have cloned and determined the nucleotide sequence of a cDNA encoding the β‐chain of the feline T‐cell surface antigen CD8. Using a nested polymerase chain reaction (PCR) and two primer pairs designed from the human CD8β cDNA nucleotide sequence, we amplified a 430 base pair fragment from a feline thymus cDNA library which was used as a probe for screening the feline library at high stringency. After three rounds of screening, five clones were isolated. A clone, named FTb‐6, containing a 3.8 kilobase pair insert was mapped, sequenced and compared with the published sequences of the genes encoding the human, mouse, rat and avian CD8β. We have determined the primary structure of the feline CD8β. The feline CD8β has an open reading frame, 630 nucleotides in length encoding a protein with 210 amino acid residues and its composition showed that the feline molecule is a member of the immunoglobulin gene super family.

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The human Lyt-3 molecule requires CD8 for cell surface expression.

Cited by 60 publications

References 33 publications

Phenotypical heterogeneity of CD4+CD8+ double-positive chronic T lymphoid leukemia

Phenotypical heterogeneity of CD4+CD8+ double-positive chronic T lymphoid leukemia

Expression, Purification, and Functional Analysis of Murine Ectodomain Fragments of CD8αα and CD8αβ Dimers

Molecular cloning of the feline CD8β‐chain

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