scholarly journals Interaction between CD8 and major histocompatibility complex (MHC) class I mediated by multiple contact surfaces that include the alpha 2 and alpha 3 domains of MHC class I.

1995 ◽  
Vol 182 (5) ◽  
pp. 1275-1280 ◽  
Author(s):  
J Sun ◽  
D J Leahy ◽  
P B Kavathas

The cell surface glycoprotein CD8 functions as a coreceptor with the TCR on cytotoxic T lymphocytes. Mutational analysis of the binding site of CD8 for MHC class I predicted that distinct surfaces of CD8 would interact with both the alpha 2 and alpha 3 domains of class I. Using a cell-cell adhesion assay, we identified three residues Q115, D122, and E128 in the alpha 2 domain of class I critical for interaction with CD8. The side chains of these residues point towards a cavity formed by the alpha 1/alpha 2 platform, the alpha 3 domain and beta 2-microglobulin (beta 2m) of class I. These residues were predicted to contact CD8 based on a bivalent model of interaction between one CD8 alpha/alpha homodimer and two MHC class I molecules. These results therefore provide support for the model.

1998 ◽  
Vol 274 (2) ◽  
pp. G227-G231 ◽  
Author(s):  
Richard S. Blumberg

The human major histocompatibility complex (MHC) on chromosome 6 encodes three classical class I genes: human leukocyte antigen-A (HLA-A), HLA-B, and HLA-C. These polymorphic genes encode a 43- to 45-kDa cell surface glycoprotein that, in association with the 12-kDa β2-microglobulin molecule, functions in the presentation of nine amino acid peptides to the T cell receptor of CD8-bearing T lymphocytes and killer inhibitory receptors on natural killer cells. In addition to these ubiquitously expressed polymorphic proteins, the human genome also encodes a number of nonclassical MHC class I-like, or class Ib, genes that in general encode nonpolymorphic molecules involved in a variety of specific immunologic functions. Many of these genes, including CD1, the neonatal Fc receptor for immunoglobulin G, HLA-G, the MHC class I chain-related gene A, and Hfe, are prominently displayed on epithelial cells, suggesting an important role in epithelial cell biology.


1991 ◽  
Vol 174 (2) ◽  
pp. 371-379 ◽  
Author(s):  
S K Sanders ◽  
R O Fox ◽  
P Kavathas

The T cell co-receptor, CD8, binds to the alpha 3 domain of HLA class I (Salter, R.D., R.J. Benjamin, P.K. Wesley, S.E. Buxton, T.P.J. Garrett, C. Clayberger, A.M. Krensky, A.M. Norman, D.R. Littman, and P. Parham. 1990. Nature [Lond.]. 345:41; Connolly, J.M., T.A. Potter, E.M. Wormstall, and T.H. Hansen. 1988. J. Exp. Med. 168:325; and Potter, T.A., T.V. Rajan, R.F. Dick II, and J.A. Bluestone. 1989. Nature [Lond.]. 337:73). To identify regions of CD8 that are important for binding to HLA class I, we performed a mutational analysis of the CD8 molecule in the immunoglobulin (Ig)-like variable domain. Our mutational analysis was based on our finding that using a cell-cell adhesion assay murine CD8 (Lyt-2) did not bind to human class I. Since the interaction of human CD8 with HLA class I is species specific, we substituted nonconservative amino acids from mouse CD8 and analyzed the ability of the mutated CD8 molecules expressed in COS 7 cells to bind HLA class I-bearing B lymphoblastoid cells, UC. Mutants with the greatest effect on binding were located in a portion of the molecule homologous to the first and second hypervariable regions of an antibody combining site. In addition, a panel of 12 anti-CD8 monoclonal antibodies were used to stain the 10 CD8 mutants, and amino acids that affected antibody binding were localized on the crystal structure of the Bence-Jones homodimer, REI. Support for an Ig-like structure of CD8 can be found in the pattern of substitutions affecting antibody binding. This work supports the similar tertiary structure of the CD8 alpha-terminal domain and an Ig variable domain.


1993 ◽  
Vol 178 (6) ◽  
pp. 1971-1980 ◽  
Author(s):  
J J Neefjes ◽  
G J Hämmerling ◽  
F Momburg

Major histocompatibility complex (MHC) class I molecules are heterotrimers consisting of a polymorphic H chain, beta 2-microglobulin (beta 2m) and peptide. Peptides are thought to associate early during biosynthesis but the order of assembly of class I molecules from their component subunits in intact cells is not settled. We have studied the assembly of MHC class I molecules in intact cells with or without peptide transporters. MHC class I H chain/beta 2m heterodimers can be efficiently recovered only 4 min after translation and are preceded by a folding intermediate. Approximately 2 min after their formation, the class I heterodimers are loaded with peptides resulting in stable class I heterotrimers. In these in vivo studies, no evidence was obtained that peptide binding to the H chain preceded the association with beta 2m. In contrast, nonassembled class I H chains could be recovered immediately after translation, but this pool did not participate in the formation of class I molecules.


1984 ◽  
Vol 160 (1) ◽  
pp. 317-322 ◽  
Author(s):  
T A Potter ◽  
C Boyer ◽  
A M Verhulst ◽  
P Golstein ◽  
T V Rajan

In this report we describe a variant of the C57BL/6 T lymphoma EL4 (EL4/Mar) which, in contrast to the parental cell line, expresses neither H-2Kb nor beta2-microglobulin (beta2m) but which does express H-2Db detectable by serology and by alloreactive cytotoxic T lymphocytes (CTL). This observation raises the possibility that H-2Db and perhaps other major histocompatibility complex class I molecules are normally not associated with beta2m on the cell surface. In addition, this report is the first to indicated that alloreactive CTL can interact with a beta2m-free class I antigen.


1994 ◽  
Vol 180 (2) ◽  
pp. 699-704 ◽  
Author(s):  
T Ohteki ◽  
H R MacDonald

Normal mouse liver contains prominent subsets of CD4+8- and CD4-8- T cell receptor (TCR)-alpha/beta+ cells with intermediate TCR levels. We show here that these cells express the natural killer (NK)1.1 surface antigen and have a restricted TCRV beta repertoire that is highly skewed to V beta 7 and V beta 8. Surprisingly, both CD4+8- and CD4-8- subsets of NK1.1+TCR-alpha/beta+ cells are absent in the liver of beta 2-microglobulin deficient mice, which do not express major histocompatibility complex (MHC) class I or "class I-like" molecules. Analysis of reciprocal radiation bone marrow chimeras established with beta 2-microglobulin deficient and wild-type mice demonstrates that MHC class I expression on radiosensitive (presumably hematopoietic) cells is required for the development of NK1.1+TCR-alpha/beta+ cells in the liver. In the liver of MHC class II deficient mice, the CD4+8- and CD4-8- subsets of NK1.1+TCR-alpha/beta+ cells develop normally. Collectively our data suggest that NK1.1+TCR-alpha/beta+ cells in liver require interaction with a MHC class I-related ligand on hematopoietic cells for their development. This unusual property of liver T cells is shared by a subset of CD4-8-NK1.1+TCR-alpha/beta+ thymocytes, suggesting a common lineage independent of the mainstream of T cell development.


1998 ◽  
Vol 187 (9) ◽  
pp. 1373-1381 ◽  
Author(s):  
Marcelo J. Kuroda ◽  
Jörn E. Schmitz ◽  
Dan H. Barouch ◽  
Abie Craiu ◽  
Todd M. Allen ◽  
...  

A tetrameric recombinant major histocompatibility complex (MHC) class I–peptide complex was used as a staining reagent in flow cytometric analyses to quantitate and define the phenotype of Gag-specific cytotoxic T lymphocytes (CTLs) in the peripheral blood of simian immunodeficiency virus macaque (SIVmac)-infected rhesus monkeys. The heavy chain of the rhesus monkey MHC class I molecule Mamu-A*01 and β2-microglobulin were refolded in the presence of an SIVmac Gag synthetic peptide (p11C, C–M) representing the optimal nine–amino acid peptide of Mamu-A*01–restricted predominant CTL epitope to create a tetrameric Mamu-A*01/p11C, C–M complex. Tetrameric Mamu-A*01/p11C, C–M complex bound to T cells of SIVmac-infected, Mamu-A*01+, but not uninfected, Mamu-A*01+, or infected, Mamu-A*01− rhesus monkeys. Specific staining of peripheral blood mononuclear cells (PBMC) from SIVmac-infected, Mamu-A*01+ rhesus monkeys was only found in the cluster of differentiation (CD)8α/β+ T lymphocyte subset and the percentage of CD8α/β+ T cells in the peripheral blood of four SIVmac-infected, Mamu-A*01+ rhesus monkeys staining with this complex ranged from 0.7 to 10.3%. Importantly, functional SIVmac Gag p11C-specific CTL activity was seen in sorted and expanded tetrameric Mamu-A*01/p11C, C–M complex–binding, but not nonbinding, CD8α/β+ T cells. Furthermore, the percentage of CD8α/β+ T cells binding this tetrameric Mamu-A*01/p11C, C–M complex correlated well with p11C-specific cytotoxic activity as measured in both bulk and limiting dilution effector frequency assays. Finally, phenotypic characterization of the cells binding this tetrameric complex indicated that this lymphocyte population is heterogeneous. These studies indicate the power of this approach for examining virus-specific CTLs in in vivo settings.


2001 ◽  
Vol 194 (7) ◽  
pp. 967-978 ◽  
Author(s):  
Daniel G. Kavanagh ◽  
Marielle C. Gold ◽  
Markus Wagner ◽  
Ulrich H. Koszinowski ◽  
Ann B. Hill

Both human cytomegaloviruses (HCMVs) and murine cytomegaloviruses (MCMVs) encode multiple genes that interfere with antigen presentation by major histocompatibility complex (MHC) class I, and thus protect infected targets from lysis by virus-specific cytotoxic T lymphocytes (CTLs). HCMV has been shown to encode four such genes and MCMV to encode two. MCMV m152 blocks the export of class I from a pre-Golgi compartment, and MCMV m6 directs class I to the lysosome for degradation. A third MCMV gene, m4, encodes a glycoprotein which is expressed at the cell surface in association with class I. Here we here show that m4 is a CTL-evasion gene which, unlike previously described immune-evasion genes, inhibited CTLs without blocking class I surface expression. m152 was necessary to block antigen presentation to both Kb- and Db-restricted CTL clones, while m4 was necessary to block presentation only to Kb-restricted clones. m152 caused complete retention of Db, but only partial retention of Kb, in a pre-Golgi compartment. Thus, while m152 effectively inhibited Db-restricted CTLs, m4 was required to completely inhibit Kb-restricted CTLs. We propose that cytomegaloviruses encode multiple immune-evasion genes in order to cope with the diversity of class I molecules in outbred host populations.


2000 ◽  
Vol 355 (1400) ◽  
pp. 1085-1092 ◽  
Author(s):  
Franziska Lechner ◽  
John Sullivan ◽  
Hans Spiegel ◽  
Douglas F. Nixon ◽  
Belinda Ferrari ◽  
...  

Hepatitis C virus (HCV) infection is a major public health problem, affecting an estimated 3% of the world's population, and over 10% in some countries. Infection in most cases becomes persistent, and can lead to hepatic inflammation, fibrosis and liver failure. The T lymphocyte reponse, in particular that mediated by cytotoxic T lymphocytes (CTLs), is likely to be involved in determining the outcome of infection, although its overall role is not clear. The use of major histocompatibility complex (MHC) class I peptide tetrameric complexes (tetramers) to study antiviral CTL responses has revolutionized our approach to the study of human infection. We have used a panel of MHC class I tetramers to analyse immune responses in HCV–infected individuals at various stages of disease. We find that the CTL response against HCV is vigorous in its early phases but dwindles over time both in terms of lymphocyte number and function. A number of potential explanations for this ‘CTL failure’ are discussed.


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