Notes: Partial Characterization of anti-H L A Class II Antibodies Isolated by Aid of Sepharose-Peptide Immunoadsorbents

1991 ◽  
Vol 46 (3-4) ◽  
pp. 321-324
Author(s):  
Alberto Chersi ◽  
Maria Cristina Morganti-Kossmann
Keyword(s):  
Immune Response ◽  
Amino Acid ◽  
Membrane Proteins ◽  
Synthetic Peptides ◽  
Class Ii ◽  
Late Response ◽  
Early Immune Response ◽  
Hla Dq ◽  
Class Ii Antigens

Synthetic peptides selected from HLA-DQ and HLADP glycoproteins were coupled to Sepharose, and used for the isolation of anti-HLA Class II antibodies from the immune sera of rabbits immunized with human lymphoblastoid cells expressing Class II antigens. Antibodies from early and late bleedings displayed remarkable differences in affinity for peptides and for soluble membrane proteins: these differences might be due to an early immune response directed preferentially against surface linear determinants, and to a late response to assembled (discontinuous) sites. The possibility that such antibodies might be used for the identification of amino acid stretches involved in the formation of the same assembled determinant is considered.

scholarly journals HLA-DQB1 codon 57 is critical for peptide binding and recognition.

1996 ◽  
Vol 183 (3) ◽  
pp. 1253-1258 ◽  
Author(s):  
W W Kwok ◽  
M E Domeier ◽  
M L Johnson ◽  
G T Nepom ◽  
D M Koelle
Keyword(s):  
Amino Acid ◽  
T Cell ◽  
Cell Clone ◽  
Peptide Binding ◽  
Class Ii ◽  
Binding Studies ◽  
Peptide Complex ◽  
Mhc Molecules ◽  
Hla Dq ◽  
T Cell Clone

The association of specific HLA-DQ alleles with autoimmunity is correlated with discrete polymorphisms in the HLA-DQ sequence that are localized within sites suitable for peptide recognition. The polymorphism at residue 57 of the DQB1 polypeptide is of particular interest since it may play a major structural role in the formation of a salt bridge structure at one end of the peptide-binding cleft of the DQ molecules. This polymorphism at residue 57 is a recurrent feature of HLA-DQ evolution, occurring in multiple distinct allelic families, which implies a functional selection for maintaining variation at this position in the class II molecule. We directly tested the amino acid polymorphism at this site as a determinant for peptide binding and for antigen-specific T cell stimulation. We found that a single Ala-->Asp amino acid 57 substitution in an HLA-DQ3.2 molecule regulated binding of an HSV-2 VP-16-derived peptide. A complementary single-residue substitution in the peptide abolished its binding to DQ3.2 and converted it to a peptide that can bind to DQ3.1 and DQ3.3 Asp-57-positive MHC molecules. These binding studies were paralleled by specific T cell recognition of the class II-peptide complex, in which the substituted peptide abolished T cell reactivity, which was directed to the DQ3.2-peptide complex, whereas the same T cell clone recognized the substituted peptide presented by DQ3.3, a class II restriction element differing from DQ3.2 only at residue 57. This structural and functional complementarity for residue 57 and a specific peptide residue identifies this interaction as a key controlling determinant of restricted recognition in HLA-DQ-specific immune response.

Molecular characterization of MHC class II antigens (? 1 domain) in the BB diabetes-prone and -resistant rat

1989 ◽  
Vol 29 (4) ◽  
pp. 231-234 ◽  
Author(s):  
Nelson J. Chao ◽  
Luika Timmerman ◽  
Hugh O. McDevitt ◽  
Chaim O. Jacob
Keyword(s):  
Molecular Characterization ◽  
Mhc Class Ii ◽  
Class Ii ◽  
Mhc Class Ii Antigens ◽  
Class Ii Antigens

Molecular characterization of MHC class II DRA cDNA in Deoni cattle

2018 ◽  
Author(s):  
K. Swathi ◽  
M. Gnana Prakash ◽  
D. Sakaram ◽  
T. Raghunandan ◽  
A. Sarat Chandra ◽  
...  
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Mhc Class Ii ◽  
Signal Peptide ◽  
Class Ii ◽  
Glycosylation Site ◽  
Amino Acid Sequences ◽  
Conserved Residues ◽  
A2 Domain

The present study was undertaken to clone and characterize DRA gene in Deoni cattle. The cDNA for the DRA gene was amplified by using specific primers designed based on available cattle sequences and purified products were cloned in competent E.coli (DH5á) strain. The full length 1013bp product of cDNA of DRA contained a single ORF of 762 nucleotides that coded for 253 amino acids translated product. Twenty four amino acids formed signal peptide while 229 constituted mature peptide. The deduced amino acid sequences resembled those of class II molecules of other species for all the conserved residues having critical functional role. But a single N-linked glycosylation site in á1 was observed in cattle and buffalo when compared to human and swine which contain a second site in á2 domain. The signal peptide was found more variable among the species compared. Comparison of nucleotide and amino acid sequences among related species and dendrogram constructed revealed that the cattle sequences are more similar to buffalo sequences.

scholarly journals Biochemical and Immunological Characterization of MP65, a Major Mannoprotein Antigen of the Opportunistic Human PathogenCandida albicans

2000 ◽  
Vol 68 (2) ◽  
pp. 694-701 ◽  
Author(s):  
Maria J. Gomez ◽  
Bruno Maras ◽  
Alessandra Barca ◽  
Roberto La Valle ◽  
Donatella Barra ◽  
...  
Keyword(s):  
Amino Acid ◽  
Amino Acid Sequence ◽  
Synthetic Peptides ◽  
Mononuclear Cells ◽  
Human Peripheral Blood ◽  
Amino Acid Sequences ◽  
Antigenic Determinants ◽  
Cell Mediated Immunity ◽  
Antigenic Peptides

ABSTRACT In the search of the antigenic determinants of a 65-kDa mannoprotein (MP65) of Candida albicans, tryptic fragments of immunoaffinity-purified MP65 preparations were tested for their ability to induce lymphoproliferation of human peripheral blood mononuclear cells (PBMC). Five major peptides (T1 to T5) were shown to induce a vigorous proliferation of PBMC from the majority of the eight healthy human subjects tested. With the use of synthetic peptides, critical amino acid sequences of the two most immunoactive (T1 and T2) peptides were determined. Similar to what was found for the MP65 molecule, no PBMC multiplication was induced by the antigenic peptides in cultures of naive cord blood cells. The amino acid sequence analysis of tryptic and chymotryptic peptides of MP65 demonstrated a substantial homology with the deduced sequences of two cell wall proteins ofSaccharomyces cerevisiae, encoded by the genesYRM305C and YGR279C. However, the antigenic peptides were those showing the least similarity with the corresponding regions of the above proteins. In particular, the lymphoproliferation-inducing sequence of the T1 peptide scored only 20% identity with the homologous regions of S. cerevisiaeproteins. Besides disclosing the amino acid sequence of MP65, this study provides an initial characterization of some of its antigenic determinants, as well as of synthetic peptides of potential use to detect specific immune responses against MP65, a major target of anticandidal cell-mediated immunity in humans.

Notes: Specificity of anti-MHC Class II Antibody Binding to Synthetic Peptides

1989 ◽  
Vol 44 (9-10) ◽  
pp. 886-889
Author(s):  
Alberto Chersi ◽  
Teresa F. Romano ◽  
Emilio Ruocco
Keyword(s):  
Amino Acid ◽  
Mhc Class Ii ◽  
Sequence Homology ◽  
Synthetic Peptides ◽  
Class Ii ◽  
Amino Acid Sequences ◽  
Beta Chain ◽  
Small Peptides ◽  
Histocompatibility Antigens ◽  
High Sequence Homology

Abstract This study indicates that antibodies raised against a DR4 , w6; DQw 1,3 positive cell line may bind to synthetic peptides selected from the polymorphic amino acid se­quences 51 -59 and 63 -79 on the DQw 2 beta chain. This cross-reaction may be explained by the relatively high sequence homology of these sequences in the beta chains of class II histocompatibility antigens, and suggests that anti­ body binding to small peptides may be scarsely selective. Based on the observations of the reactivity of the anti­ bodies with several cell lines, and comparison of the amino acid sequences of beta chains of DR and DQ molecules, an attempt to identify the cross-reacting epitope is presented.

Serological and biochemical characterization of class II antigens in B10.W lines

1982 ◽  
Vol 19 (1) ◽  
pp. 40-52
Author(s):  
Sujay K. Singh ◽  
Edward K. Wakeland ◽  
Jan Klein
Keyword(s):  
Biochemical Characterization ◽  
Class Ii ◽  
Class Ii Antigens

scholarly journals The Association of Myasthenia Gravis with HLA class II Antigens in Iraqi Patients

2013 ◽  
Vol 10 (1) ◽  
pp. 126-132
Author(s):  
Baghdad Science Journal
Keyword(s):  
Myasthenia Gravis ◽  
Class Ii ◽  
Hla Class Ii ◽  
Control Group ◽  
P Value ◽  
Hla Dq ◽  
Healthy Control ◽  
Hla Dr3 ◽  
Class Ii Antigens ◽  
Hla Dq2

The nature and intensity of the association of myasthenia gravis (MG) with distinct human leukocyte antigen (HLA) haplotypes differ between ethnic populations, so this study determined the association of HLA class II antigens with myasthenia gravis (MG) in Iraq.The study included Iraqi patients diagnosed with MG and two control groups the first of 54 insulin dependent diabetes mellitus patients and the second of 237 subjects as a normal control group. The test used was microlymphocytotoxicity test.The work was done in the Teaching Laboratories/Medical City/Baghdad.Results: positive associations were observed (etiological risk factors) as follows: 1. HLA-DR locus showed one positively associated allele when compared to healthy control and this was HLA-DR3 (RR: 21.05, EF0.73, & P value ? 0.05), While when compared to IDDM control no significant association appeared (since the same allele is positively associated with IDDM). 2. HLA-DQ locus showed only one positively associated allele when compared to healthy control; this was HLA-DQ2 (RR 4.67, EF 0.50, and P value ? 0.05). While no significant association appeared when compared to IDDM control. Other important clinical association were observed; association with age, gender, strong stressful events, thymoma, and other autoimmune disorders. Conclusion: The positively associated antigens which were found as follows HLA-DR3 and HLA-DQ2, while no negative association was detected.

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