scholarly journals The presentation of a hepatitis C viral peptide by distinct major histocompatibility complex class I allotypes from two chimpanzee species.

1996 ◽  
Vol 183 (2) ◽  
pp. 663-668 ◽  
Author(s):  
S Cooper ◽  
H Kowalski ◽  
A L Erickson ◽  
K Arnett ◽  
A M Little ◽  
...  

A cytotoxic T lymphocyte (CTL) line, derived from the liver of a common chimpanzee (Pan troglodytes) with hepatitis C, specifically recognized a hepatitis C viral 9-mer peptide (KHP-DATYSR in single-letter amino acid code) bound by the major histocompatibility complex (MHC) class I molecule, Patr-A04. This same CTL line also recognized the identical peptide bound by a structurally different class I molecule, Papa-A06, derived from the separate chimpanzee species, Pan paniscus or pygmy chimpanzee. These class I allotypes differ by six amino acids but, in spite of the structural differences, share the same antigen-presenting function. This is the first observation of antigen presentation to a given T cell receptor by different MHC class I allotypes from separate species.

1997 ◽  
Vol 8 (1) ◽  
pp. 47-57 ◽  
Author(s):  
E Stang ◽  
J Kartenbeck ◽  
R G Parton

Simian virus 40 (SV40) has been shown to enter mammalian cells via uncoated plasma membrane invaginations. Viral particles subsequently appear within the endoplasmic reticulum. In the present study, we have examined the surface binding and internalization of SV40 by immunoelectron microscopy. We show that SV40 associates with surface pits which have the characteristics of caveolae and are labeled with antibodies to the caveolar marker protein, caveolin-1. SV40 is believed to use major histocompatibility complex (MHC) class I molecules as cell surface receptors. Using a number of MHC class I-specific monoclonal antibodies, we found that both viral infection and association of virus with caveolae were strongly reduced by preincubation with anti-MHC class I antibodies. Because binding of SV40 to MHC class I molecules may induce clustering, we investigated whether antibody cross-linked class I molecules also redistributed to caveolae. Clusters of MHC class I molecules were indeed shown to be specifically associated with caveolin-labeled surface pits. Taken together, the results suggest that SV40 may make use of MHC class I molecule clustering and the caveolae pathway to enter mammalian cells.


2016 ◽  
Author(s):  
Douglas M. Templeton ◽  
Michael Schwenk ◽  
Reinhild Klein ◽  
John H. Duffus

2002 ◽  
Vol 76 (22) ◽  
pp. 11623-11636 ◽  
Author(s):  
Thorsten U. Vogel ◽  
Thomas C. Friedrich ◽  
David H. O'Connor ◽  
William Rehrauer ◽  
Elizabeth J. Dodds ◽  
...  

ABSTRACT It is now accepted that an effective vaccine against AIDS must include effective cytotoxic-T-lymphocyte (CTL) responses. The simian immunodeficiency virus (SIV)-infected rhesus macaque is the best available animal model for AIDS, but analysis of macaque CTL responses has hitherto focused mainly on epitopes bound by a single major histocompatibility complex (MHC) class I molecule, Mamu-A*01. The availability of Mamu-A*01-positive macaques for vaccine studies is therefore severely limited. Furthermore, it is becoming clear that different CTL responses are able to control immunodeficiency virus replication with varying success, making it a priority to identify and analyze CTL responses restricted by common MHC class I molecules other than Mamu-A*01. Here we describe two novel epitopes derived from SIV, one from Gag (Gag71-79 GY9), and one from the Nef protein (Nef159-167 YY9). Both epitopes are bound by the common macaque MHC class I molecule, Mamu-A*02. The sequences of these two eptiopes are consistent with the molecule's peptide-binding motif, which we have defined by elution of natural ligands from Mamu-A*02. Strikingly, we found evidence for the selection of escape variant viruses by CTL specific for Nef159-167 YY9 in 6 of 6 Mamu-A*02-positive animals. In contrast, viral sequences encoding the Gag71-79 GY9 epitope remained intact in each animal. This situation is reminiscent of Mamu-A*01-restricted CTL that recognize Tat28-35 SL8, which reproducibly selects for escape variants during acute infection, and Gag181-189 CM9, which does not. Differential selection by CTL may therefore be a paradigm of immunodeficiency virus infection.


2001 ◽  
Vol 75 (2) ◽  
pp. 738-749 ◽  
Author(s):  
Todd M. Allen ◽  
Bianca R. Mothé ◽  
John Sidney ◽  
Peicheng Jing ◽  
John L. Dzuris ◽  
...  

ABSTRACT It is becoming increasingly clear that any human immunodeficiency virus (HIV) vaccine should induce a strong CD8+ response. Additional desirable elements are multispecificity and a focus on conserved epitopes. The use of multiple conserved epitopes arranged in an artificial gene (or EpiGene) is a potential means to achieve these goals. To test this concept in a relevant disease model we sought to identify multiple simian immunodeficiency virus (SIV)-derived CD8+ epitopes bound by a single nonhuman primate major histocompatibility complex (MHC) class I molecule. We had previously identified the peptide binding motif of Mamu-A*012, a common rhesus macaque MHC class I molecule that presents the immunodominant SIV gag-derived cytotoxic T lymphocyte (CTL) epitope Gag_CM9 (CTPYDINQM). Herein, we scanned SIV proteins for the presence of Mamu-A*01 motifs. The binding capacity of 221 motif-positive peptides was determined using purified Mamu-A*01 molecules. Thirty-seven peptides bound with apparentKd values of 500 nM or lower, with 21 peptides binding better than the Gag_CM9 peptide. Peripheral blood mononuclear cells from SIV-infected Mamu-A*01+ macaques recognized 14 of these peptides in ELISPOT, CTL, or tetramer analyses. This study reveals an unprecedented complexity and diversity of anti-SIV CTL responses. Furthermore, it represents an important step toward the design of a multiepitope vaccine for SIV and HIV.


1997 ◽  
Vol 185 (7) ◽  
pp. 1223-1230 ◽  
Author(s):  
Michael P. Crowley ◽  
Ziv Reich ◽  
Nasim Mavaddat ◽  
John D. Altman ◽  
Yueh-hsiu Chien

Recent studies have shown that many nonclassical major histocompatibility complex (MHC) (class Ib) molecules have distinct antigen-binding capabilities, including the binding of nonpeptide moieties and the binding of peptides that are different from those bound to classical MHC molecules. Here, we show that one of the H-2T region–encoded molecules, T10, when produced in Escherichia coli, can be folded in vitro with β2-microglobulin (β2m) to form a stable heterodimer in the absence of peptide or nonpeptide moieties. This heterodimer can be recognized by specific antibodies and is stimulatory to the γδ T cell clone, G8. Circular dichroism analysis indicates that T10/β2m has structural features distinct from those of classical MHC class I molecules. These results suggest a new way for MHC-like molecules to adopt a peptide-free structure and to function in the immune system.


1998 ◽  
Vol 188 (10) ◽  
pp. 1841-1848 ◽  
Author(s):  
Russell E. Vance ◽  
Jennifer R. Kraft ◽  
John D. Altman ◽  
Peter E. Jensen ◽  
David H. Raulet

Natural killer (NK) cells preferentially lyse targets that express reduced levels of major histocompatibility complex (MHC) class I proteins. To date, the only known mouse NK receptors for MHC class I belong to the Ly49 family of C-type lectin homodimers. Here, we report the cloning of mouse NKG2A, and demonstrate it forms an additional and distinct class I receptor, a CD94/NKG2A heterodimer. Using soluble tetramers of the nonclassical class I molecule Qa-1b, we provide direct evidence that CD94/NKG2A recognizes Qa-1b. We further demonstrate that NK recognition of Qa-1b results in the inhibition of target cell lysis. Inhibition appears to depend on the presence of Qdm, a Qa-1b-binding peptide derived from the signal sequences of some classical class I molecules. Mouse NKG2A maps adjacent to CD94 in the heart of the NK complex on mouse chromosome six, one of a small cluster of NKG2-like genes. Our findings suggest that mouse NK cells, like their human counterparts, use multiple mechanisms to survey class I expression on target cells.


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.


2015 ◽  
Vol 167 (3-4) ◽  
pp. 166-170
Author(s):  
Larissa Sarmento dos Santos ◽  
Juliana Pinto da Silva Mol ◽  
Auricélio Alves de Macedo ◽  
Ana Patrícia Carvalho Silva ◽  
Diego Luiz dos Santos Ribeiro ◽  
...  

Sign in / Sign up

Export Citation Format

Share Document