A unique murine CD43 epitope Lp-3: distinct distribution from another CD43 epitope S7.
In foregoing studies, we found a unique B cell differentiation antigen Lp-3 which is expressed on pre-B and premature B cells in the bone marrow, but is negative on bone marrow mature B cells and peripheral resting B cells. Nonetheless, Lp-3 was clearly positive on the majority of CD5 B(B1) cells. When we examined the biochemical nature and partial amino acid sequences of purified 132-kDa Lp-3 molecules and the nucleotide sequence of the cDNA clones, we found that Lp-3 is an epitope of CD43. Thus, the monoclonal antibody (mAb) Lp-3 may be the first mAb to murine CD43 defined by primary target structure analysis. Comparison of tissue distribution of Lp-3 and S7, an epitope previously suggested to associate with murine CD43, showed that they were similarly distributed on thymocytes, peripheral B and T cells, granulocytes, and platelets. In the bone marrow, while both Lp-3 and S7 were negative on mature B cells, the former was positive on all B lineage cells at an early ontogeny and the latter was positive only on the minor population of pre-B cells and pro-B cells. Lp-3 and S7 epitopes also showed different distributions on basement membranes of renal glomerulus, bronchus, and endometrium, lining cells of choroid plexus and muscular cells of arterioles in a variety of tissues. As CD43 has various isoforms generated by different degrees of glycosylation of the common core peptide, it is likely that Lp-3 and S7 are associated with different CD43 isoforms.
Shiota
J
J
Department of Pathology, Juntendo University School of Medicine, Tokyo, Japan.
Nishimura
H
H
Okamoto
H
H
Yu
B
B
Hattori
S
S
Abe
M
M
Okada
T
T
Nozawa
S
S
Tsurui
H
H
Hirose
S
S
D000595:Amino Acid Sequence; D000818:Animals; D000911:Antibodies, Monoclonal; D015703:Antigens, CD; D001483:Base Sequence; D002454:Cell Differentiation; D000939:Epitopes / Q000235:genetics* / Q000276:immunology; D005434:Flow Cytometry; D005455:Fluorescent Antibody Technique; D051917:Leukosialin; D051379:Mice; D008807:Mice, Inbred BALB C; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000737:chemistry; D017421:Sequence Analysis; D012795:Sialoglycoproteins / Q000235:genetics* / Q000276:immunology; D014018:Tissue Distribution; D014407:Tumor Cells, Cultured
D000911:Antibodies, Monoclonal; D015703:Antigens, CD; D000939:Epitopes; D051917:Leukosialin; D010446:Peptide Fragments; D012795:Sialoglycoproteins; C497863:Spn protein, mouse