ABSTRACT
We have characterized the 5' region of the CALLA/CD10 gene which has been shown to be identical to the membrane-associated enzyme neutral endopeptidase 24.11 (NEP). There is no CAAT or TATA box in the 5' flanking region, upstream of exon 1, but a GC rich region with several Sp1 binding sites. We have detected several putative initiation transcription sites by primer extension and by nuclease S1 analysis. Moreover by reverse transcriptase-polymerase chain reaction, we demonstrated the existence of a new exon: exon 1bis. This exon can be alternatively spliced as has already been described for exon 1 and exon 2.
Subject(s)
Neprilysin/genetics , Base Sequence , Deoxyribonuclease EcoRI , Exons , Humans , Molecular Sequence Data , Oligonucleotide Probes , Polymerase Chain Reaction , RNA, Messenger/metabolism , RNA-Directed DNA Polymerase , Single-Strand Specific DNA and RNA Endonucleases , TATA Box , Transcription, GeneticABSTRACT
A "new" rabbit immunoglobulin allotype belonging to the VHa series (a109) that seems particular to the Iberian O. cuniculus has been detected in a Portuguese wild rabbit population. This allotype was found in the wild population of Spain but not in those of France and Zembra island (Tunisia). Using antisera and monoclonal antibodies raised against already known VHa allotypes, we found that a 109 presents cross-reactivity with a1, a3, a100, a101, a107 and a108 allotypes. On the basis of studies of these cross-reactivities, we show that a109 is constituted of at least three variants (or subfamilies of variants) possessing determinants common with either a1 and a109, a3 and a109 or a1, a3 and a109 allotypes. These results are discussed according to recent data relative to generation of antibody diversity in rabbit.
Subject(s)
Immunoglobulin Allotypes/genetics , Immunoglobulin Heavy Chains/genetics , Immunoglobulin Variable Region/genetics , Rabbits/genetics , Rabbits/immunology , Animals , Cross Reactions , Genetic Markers , Immunoglobulin Allotypes/immunology , Immunosorbents , Pedigree , RadioimmunoassayABSTRACT
The common acute lymphoblastic leukemia antigen (CALLA, CD10) has been identified as neutral endopeptidase-24.11 (NEP), a mammalian ectoenzyme involved in the inactivation of regulatory peptides, such as the enkephalins and atrial natriuretic peptide. Twenty monoclonal antibodies directed against the human antigen, were tested for their ability to inhibit the enzymatic activity of the human and rat peptidases expressed by cell lines. Six anti-CALLA antibodies were found to inhibit 50% or more of the hydrolysis of D-Ala2-leucine enkephalin by the neutral endopeptidase present on the human leukemic cell line Reh6 and, to a lesser extent, the hydrolysis of atrial natriuretic peptide. This may indicate that their binding may affect regions of the active site more important for the dipeptidylcarboxypeptidase activity of the enzyme. Only four antibodies cross-reacted with the peptidase from the rat epithelial cell line Rat2, as shown by membrane immunofluorescence, and these also partially inhibited enzyme activity. No antibody was able to inhibit completely the activity of the human and rat enzymes and all the active antibodies appeared to behave as non-competitive inhibitors of substrate cleavage. These monoclonal antibodies could be used in mapping studies of NEP.
Subject(s)
Antibodies, Monoclonal/immunology , Antigens, Differentiation/immunology , Antigens, Neoplasm/immunology , Neprilysin/antagonists & inhibitors , Amino Acid Sequence , Animals , Atrial Natriuretic Factor/metabolism , Cell Line/enzymology , Cell Membrane/enzymology , Cross Reactions , Enkephalin, Leucine/metabolism , Fluorescent Antibody Technique , Humans , Kinetics , Molecular Sequence Data , Neprilysin/immunology , Rats , Sequence Homology, Nucleic AcidABSTRACT
We report a new rabbit IgVH allotype, designated a108, which was detected following studies of the progeny of a wild rabbit (Oryctolagus cuniculus) from Zembra Island (Tunisia). This allotype seems to be specific of this island, since it has not been detected in other wild rabbit populations (in Spain, Portugal or France). Its determinants are located on the Fd fragment of the immunoglobulin (Ig) heavy chain and it behaves like the product of an allele at the alpha locus. Allotype a108 was strongly related serologically to a1 and a107, and to a lesser extent to a101, a109 and a3 allotypes. We also detected determinants shared among the a1, a107, a108, a101 and a109 allotypes. These determinants were expressed by a large fraction of Ig molecules from rabbits of allotype a1, a107 and a108 and by a very small fraction of Ig from rabbits of allotype a101 and a109.
Subject(s)
Genes, Immunoglobulin , Immunoglobulin Allotypes/genetics , Polymorphism, Genetic , Animals , Cross Reactions , Immunoglobulin Fab Fragments , Pedigree , RabbitsABSTRACT
An allotype (a107) which strongly cross-reacts with a1 specificity has been detected in the wild rabbit population of Zembra Island, Tunisia. It is different from the a1 allotype since an anti-a1 monoclonal antibody recognizes a1 but not a107 specificity. Genetic data and localization on the Fd fragment are in agreement to designate this allotype to the a series. The a107 allotype has been found in wild rabbit populations of Spain and Portugal but not in France.
