Search results for "epitope"
showing 10 items of 455 documents
Pyruvate dehydrogenase specific T cells in primary biliary cirrhosis show restricted antigen recognition sites
2002
: Background/Aims: The aim was to characterise the antigen recognition sites of the variable T cell receptor α-chain (TCRAV) and β-chain (TCRBV) of T cells specific to the pyruvate dehydrogenase (PDC) in primary biliary cirrhosis. Methods: In 21 PDC-specific T cell clones isolated from five patients we analysed TCRAV and TCRBV usage by RT-PCR and sequenced the CDR3 regions. Results: Preferential expression of the TCR elements BV6 (6 clones), BV12 (4 clones) and BV1 (3 clones), and frequent usage of the joining elements JB2.3 and JB2.1 were seen. Analysis of the α chain revealed rearrangement of AV2 in 7 clones (35%) and AV7 in 3 clones, however, distribution of the joining elements was het…
Analysis of the (H-2b x H-2k)F1Restricted Response to Insulin.
1984
The aim of these studies was to characterize the (H-2b X H-2k)F1-unique restriction element(s) responsible for presentation of bovine insulin (BI) to a long-term cultured T-cell line (BK-BI-1.2). (B10.BR X bm12)F1 spleen cells, which express a normal Ab alpha Ak beta molecule but a mutated Ak alpha Abm12 beta product on their cell surface, were perfectly able to act as BI-presenting cells. Antibody inhibition experiments with antibodies directed at I-Ak products revealed that monoclonal antibody 10-2.16, which reacts with the Ak beta polypeptide chain, abrogated BI-directed T-cell proliferation, whereas antibody H116-32.R5 with specificity for the Ak alpha chain was not inhibitory. These re…
Antigens and immunoevasins: opponents in cytomegalovirus immune surveillance
2002
CD8+ T cells are the main effector cells for the immune control of cytomegaloviruses. To subvert this control, human and mouse cytomegaloviruses each encode a set of immune-evasion proteins, referred to here as immunoevasins, which interfere specifically with the MHC class I pathway of antigen processing and presentation. Although the concerted action of immunoevasins prevents the presentation of certain viral peptides, other viral peptides escape this blockade conditionally or constitutively and thereby provide the molecular basis of immune surveillance by CD8+ T cells. The definition of viral antigenic peptides that are presented despite the presence of immunoevasins adds a further dimens…
Impact of CMV and EBV seropositivity on CD8 T lymphocytes in an old population from West-Sicily.
2007
Abstract Herpes viruses (particularly CMV and to some extent EBV) might play a role in accelerating the deterioration of immune functions with age. Indeed, it has been demonstrated that chronic infection with CMV causes an expansion of specific CD8 T lymphocytes and that this is related to a shrinkage of the T cell repertoire in very elderly people, predicting mortality. We have analysed CD8 T cells in young and old healthy Sicilians who were both CMV- and EBV-seropositive. Our data confirm expansions of T cells specific for the HLA-A2-restricted pp65 (495–503) CMV epitope up to nearly 14% of total peripheral CD8 cells in certain elderly individuals (range 0–14%). However, the mean percenta…
Identification of a Conserved HLA-A2-Restricted Decapeptide from the IE1 Protein (pUL123) of Human Cytomegalovirus
2002
Abstract Control of human cytomegalovirus (HCMV) infection is predominantly mediated by cytolytic CD8 + T lymphocytes (CTL). Among the roughly 200 HCMV-encoded polypeptides, the tegument protein pp65 (ppUL83) and the nonstructural IE1 protein are considered to be dominant CTL targets. Yet the importance of CTL against IE1 for protective immunity against HCMV reactivation and disease has remained elusive. Analyses have been difficult, as all MHC class I presented peptides of IE1 defined so far are located in parts of the protein that are variable between viral strains. In this study a conserved decameric peptide from IE1 (P6, IE1 354–363 ) that bound to HLA-A2 was identified. Using peptide-p…
Evaluating Human T-Cell Therapy of Cytomegalovirus Organ Disease in HLA-Transgenic Mice
2015
Reactivation of human cytomegalovirus (HCMV) can cause severe disease in recipients of hematopoietic stem cell transplantation. Although preclinical research in murine models as well as clinical trials have provided 'proof of concept' for infection control by pre-emptive CD8 T-cell immunotherapy, there exists no predictive model to experimentally evaluate parameters that determine antiviral efficacy of human T cells in terms of virus control in functional organs, prevention of organ disease, and host survival benefit. We here introduce a novel mouse model for testing HCMV epitope-specific human T cells. The HCMV UL83/pp65-derived NLV-peptide was presented by transgenic HLA-A2.1 in the conte…
Tissue invasiveness and non-acidic pH in human candidiasis correlate with "in vivo" expression by Candida albicans of the carbohydrate epitope recogn…
2004
Background: The morphogenetic conversion between yeast and hyphal growth forms appears to be crucial in the pathogenesis of invasive candidiasis, and can be regulated by environmental signals such as extracellular pH. Aims: To characterise the epitope recognised by monoclonal antibody 1H4, and to evaluate the expression of its corresponding epitope in Candida albicans cells under different conditions of pH and temperature, and “in vivo”, in tissue samples from patients with human candidiasis. Methods: Monoclonal antibody 1H4 was generated against the 58 kDa cell wall mannoprotein of C albicans (mp58), and was further characterised by immunoblot analysis, periodate treatment of the antigenic…
Anti-Idiotypic Antibodies Against the Kinin Receptor
1992
Three sets of monoclonal antibodies against bradykinin (MBK1, MBK2, MBK3) were generated by somatic cell fusion, characterized by their peptide specificity and compared to the known ligand specificity of the kinin receptor subtypes. By these criteria the paratope of MBK3 resembled the B2 receptor binding site whereas MBK1 shared principal binding characteristics with the B1 recrptor. Anti-idiotypic antibodies against MBK1, MBK2 and MBK3 were raised in rabbit and sheep. Specificity of the network components was verified by inhibition experiments on the level of peptide, idiotype and anti-idiotype. Anti-idiotypic antibodies against MBK3 recognized a conformation-dependent epitope which was bi…
Sodium Solute Symporter and Cadherin Proteins Act as Bacillus thuringiensis Cry3Ba Toxin Functional Receptors in Tribolium castaneum*
2013
Understanding how Bacillus thuringiensis (Bt) toxins interact with proteins in the midgut of susceptible coleopteran insects is crucial to fully explain the molecular bases of Bt specificity and insecticidal action. In this work, aminopeptidase N (TcAPN-I), E-cadherin (TcCad1), and sodium solute symporter (TcSSS) have been identified by ligand blot as putative Cry3Ba toxin-binding proteins in Tribolium castaneum (Tc) larvae. RNA interference knockdown of TcCad1 or TcSSS proteins resulted in decreased susceptibility to Cry3Ba toxin, demonstrating the Cry toxin receptor functionality for these proteins. In contrast, TcAPN-I silencing had no effect on Cry3Ba larval toxicity, suggesting that th…
Keyhole limpet hemocyanin (KLH): a biomedical review
1999
In this review we present a broad survey of fundamental scientific and medically applied studies on keyhole limpet hemocyanin (KLH). Commencing with the biochemistry of KLH, information on the biosynthesis and biological role of this copper-containing respiratory protein in the marine gastropod Megathura crenulata is provided. The established methods for the purification of the two isoforms of KLH (KLH1 and KLH2) are then covered, followed by detailed accounts of the molecular mass determination, functional unit (FU) structure, carbohydrate content, immunological analysis and recent aspects of the molecular genetics of KLH. The transmission electron microscope (TEM) has contributed signific…