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Biomedical subjects

M Potter

Publications and source records attributed to M Potter.

At least 307 records · Page 17Linked to original sources

Synthesis, surface deposition, and secretion of immunoglobulins by Abelson virus-transformed lymphosarcoma cell lines.

Three Abelson virus-transformed lymphoma cell lines were established in tissue culture and the immunoglobulin biosynthesis by these cell lines was studied. Two of the cell lines (ABLS-1 and ABLS-5) were found to synthesize monomeric IgM molecules which were deposited in the cell membrane, probably to serve as an antigen receptor. The third cell line (ABLS-8) was found to synthesize membrane-associated IgM as well as cellular IgG molecules. In addition, these cell lines were found to synthesize a protein of 35,000 molecular weight which is also membrane-associated and which has the capability to bind the immunoglobulin (MAID). It is speculated that this protein might play a role in adapting the receptor immunoglobulin molecule to the hydrophobic environment of the cell membrane. The kinetics of amino acid incorporation into immunoglobulins by these cell lines show that they produce immunoglobulins at a rate which is two orders of magnitude smaller than plasmacytoma cells (MOPC 104E). These results suggest that Abelson virus transforms thymus-independent lymphocytes in various stages of maturation and these lymphocytes might be of B cell origin. The T lymphoma (P1798) used as a control cell line was found occasionally to produce minute amounts of immunoglobulin.

Cell Line↗

A new, mouse-myeloma immunoglobulin A having specificity for beta-D-(1 yields 6)-linked D-galactopyranosyl residues.

The discovery of T601, a new mouse-myeloma immunoglobulin A having specificity for beta-D-(1 yields 6)-linked D-galactopyranosyl residues, brings the total number of known antigalactan immunoglobulins to seven. The interaction of T601 with a number of ligands has been investigated. For those ligands showing interaction with the immunoglobulin, the affinity constants have been quantitatively measured by tryptophanyl fluorescence. The values show that protein T601 behaves very similarly to protein X24.

Animals↗

Genetics of susceptibility to plasmacytoma induction. I. BALB/cAnN (C), C57BL/6N (B6), C57BL/Ka (BK), (C times B6)F1, (C times BK)F1, and C times B recombinant-inbred strains.

Plasmacytomas were found in 58% of 373 BALB/cAnN (C) mice given three 0.5-ml doses of mineral oil (Bayol F or light mineral oil) or 2,6,10,14-tetramethylpentadecane (pristane) ip. The incidence of plasmacytomas in C57BL/6N (B6), C57BL/Ka (BK), (C times B6)F1 and (C times BK)F1 was 6.4, 0, 11.5, and 16.5%, respectively. The plasmacytomas occurred in old B6 mice, in contrast to their early appearance in strain C mice. The incidence of plasmacytomas in mineral oil-treated or pristane-treated C times B recombinant-inbred (Rl) strain mice was 28.3% in C times BD, 17.5% IN C times BE, 36.5% IN C times BG, 0% in C times BH, 2.9% in C times Bl, 48% in C times BJ, and 4.3% in C times BK. C times BD, C times BG, and C times BJ strains were considered susceptible to plascytoma induction by mineral oil or pristane; C times BE had a low susceptibility, and C times BH, C times Bl, and C times BK were resistant. The results suggested that there were only a few gene difference between C and B6 or BK that determined susceptibility or resistance to plasmacytoma induction, and that B6 and BK have at least one dominant resistance gene. The distribution pattern of susceptibility and resistance in the C times B Rl strains suggested the presence of a resistance gene on chromosome 9, linkage group II.

Age Factors↗

Cell populations and known surface antigens of tumors induced by Abelson virus in pristane-primed BALB/c mice: an analysis by immunoelectron microscopy;.

When Abelson murine leukemia virus (MuLV-A) was inoculated into pristane-primed BALB/c mice, either plasmacytomas (PCT), lymphosarcomas, or their mixed form was induced with a shorter latent period than that for PCT induction in mice treated with pristane alone. All 3 neoplasms were designated Abelson's tumors. The morphology of the induced malignant cells and the presence of known surface antigens were analyzed by electron microscopy. The cell surface antigens (CSA) examined were PC1, X.1, Gross (GCSA), and Moloney (MCSA); viral envelope antigens (VEA) were xVEA, x1-VEA, sub-gsVEA, and MVEA. MuLV-A-pristane-induced PCT cells produced markedly fewer intracisternal type-A particles than did mineral oil-induced PCT cells. Most, if not all, mineral oil-induced PCT cells carried PC1 antigen and produced many extracellular type-C viruses carrying xVEA and x1-VEA, whereas Abelson's tumor cells had both a lower incidence and a smaller amount of PC1 and X.1 antigens and xVEA+ virus and lacked x1-VEA+ virus. In addition, most Abelson's tumors and their type-C viruses did not carry MCSA and MVEA ro GCSA and sub-gsVEA. All the macrophages in the PC1+ Abelson's tumors and many macrophages in PC1-Abelson's tumors contained various amounts of PC1 on their cell surfaces. For these reasons, Abelson's tumors were clearly distinct from pristane- or mineral oil-induced BALB/c PCT and from M-MuLV- ro G-MuLV-induced tumors.

AKR murine leukemia virus↗

A BALB/c mouse IgA myeloma protein that binds salmonella flagellar protein.

A BALB/c IgA mouse myeloma protein in ascites (MOPC-467) had been found to bind an antigen in heat extracts from Salmonella, Pasteurella, and Herellea cultures. MOPC-467 ascites was shown to immobilize motile S. adelaide, agglutinate formalin fixed S. MILWAUKEE, AND PURIFIED IgA (M467) was capable of precipitating column-purified flagella and flagellin from S. milwaukee.

Agglutination Tests↗

Genetics of a new IgVH (T15 idiotype) marker in the mouse regulating natural antibody to phosphorylcholine.

The idiotype present on the Fab of a phosphorylcholine-binding IgA myeloma protein TEPC 15 (T15) of BALB/c origin was found in normal serum of BALB/c mice. Molecules carrying the T15 idiotype in normal serum could be adsorbed with Sepharose phosphorylcholine beads and R36A pneumococci. The T15 idiotype is absent in germ-free BALB/c but appears when the mice are conventionalized. A survey of normal sera of inbred strains for the T15 idiotype showed it to be present in BALB/c, 129, C57L, C58, and ST and absent or in low levels in CBA, C3H, C57BL/6, C57BL/Ka, C57BL/10, SJL, B10.D2, DBA/2, RIII, A, AL, AKR, NZB, and NH inbred strains of mice. The T15 idiotype is associated with some but not all strains carrying the IgC(H) allotypes found in BALB/c. Linkage of genes controlling the T15 idiotype in normal serum to the IgC(H) locus of BALB/c was demonstrated in F(2) progeny of a BALB/c and C57BL cross, Bailey's recombinant inbred strains, C x BD, C x BE, C x BG, C x BH, C x BI, C x BJ, C x BK, and CB20 congenic strains. Among these strains, only those possessing the IgC(H) locus of BALB/c including the F(2) progeny consisting of BALB/c homozygotes and BALB/c/C57BL heterozygotes and C x BG and C x BJ recombinants showed the T15 idiotype.

Animals↗

Immunoglobulin structure: amino terminal sequences of mouse myeloma proteins that bind phosphorylcholine.

The amino terminal sequences of five light and heavy immunoglobulin chains from myeloma proteins of the BALB/c mouse with binding activity to phosphorylcholine are presented. Except for a single substitution in position 4, all five heavy chains have identical amino terminal sequences through the first hypervariable region. Proteins which share unique (idiotypic) antigenic determinants are identical through the first hypervariable region of their light and heavy chains. Proteins with differing idiotypic determinants have light chains of differing amino acid sequence. These observations suggest that the heavy chain plays a more important role than the light chain in determining the phosphorylcholine binding site.

Amino Acid Sequence↗

Immunochemical studies on mouse myeloma proteins reactive with dextrans or with fructosans and on human antilevans.

Four BALB/c IgA mouse myeloma proteins (W3129, W3434, QUPC 52, and UPC 102) reactive with dextran, four myeloma proteins reactive with fructosans, three IgA (W3082, UPC 61, and Y5476), and one IgG2a (UPC 10), and two human antilevans were studied immunochemically. Quantitative precipitin and inhibition assays showed that W3129, W3434, and QUPC 52 had specificities for isomaltose oligosaccharides similar to those previously found with alpha(1 --> 6)-specific human antidextrans. W3129 and W3434 were most complementary to IM5 but W3129 reacted equally with IM4 and IM3 while W3434 had a greater affinity for IM4 than IM3. QUPC 52 had a larger combining region and was most complementary to IM6. Protein UPC 102 (IgA), like MOPC 104E (IgM) (27), was most complementary to the alpha(1 --> 3)-linked trisaccharide, nigerotriose, and thus differed from J558 (29), which was inhibited best by nigeropentaose. UPC 102 was similar to J558 but they differed from MOPC 104E in their reactions with non-alpha(1 --> 3)-linked disaccharides. The fructosan-specific myeloma proteins fell into two groups with different specificities. The first group, W3082 (IgA), UPC 61 (IgA), and the previously studied J606 (IgG3) (28, 29), reacted with inulin and W3082 and UPC 61 appeared to have identical specificities for beta(2 --> 1)-linked fructofuranosyl residues with maximum complementarity for the tetrasaccharide betaDfructofuranosyl (2 --> 1)betaDfructofuranosyl(2 --> 1)betaDfructofuranosyl(2 --> 6)Dglucose while protein J606 was inhibited best by the trisaccharide betaDfructofuranosyl(2 --> 1)betaDfructofuranosyl(2 --> 6)Dglucose. W3082 and UPC 61 also differed from J606 in their behavior toward sucrose and betaDfructofuranosyl(2 --> 6)Dglucose as compared with alphaDglucosyl(1 --> 3)Dfructose (turanose). The second group containing myeloma proteins UPC 10 (IgG2a) and Y5476 (IgA) behaved similarly to human antilevans in that neither reacted with inulin nor were they inhibited by the beta(2 --> 1)-linked fructose oligosaccharides. Unlike the beta(2 --> 1)-specific proteins, they reacted with perennial rye grass levan that contained over 90% beta(2 --> 6)links. The differences in specificity and site size among homogeneous mouse myeloma proteins reactive with the same antigenic determinant are completely consistent with the concept that they represent products of homogeneous clones selected from the known heterogeneous population of antibody-forming cells.

Animals↗

The three-dimensional structure of a phosphorylcholine-binding mouse immunoglobulin Fab and the nature of the antigen binding site.

The structure of the Fab of McPC 603, a mouse myeloma protein with phosphorylcholine binding activity, has been determined to 3.1-A resoltuion. The four domains are found to be structurally similar with a well-defined double-layer structure. A large cavity exists at one end of the fragment, the walls of which are formed exclusively of hypervariable residues. Phosphorylcholine binds in this cavity and forms specific interactions with several well-defined amino-acid side chains of the protein. The hapten is bound asymmetrically and interacts more with the heavy chain than with the light chain.

Amino Acid Sequence↗

Rapid viral induction of plasmacytomas in pristane-primed BALB-c mice.

Strain BALB/c mice were injected intraperitoneally with 0.5 milliliter of pristane, and 39 to 56 days later they were infected with Abelson murine leukemia virus, which is a lymphosarcomagenic variant of Moloney virus. Fifty-eight percent of the mice developed lymphosarcoma, and 28 percent developed immunoglobulin-producing plasmacytomas within 20 to 93 days (77 to 149 days after the pristane injection). Two of 57 control mice developed plasmacytomas at days 138 and 166 after a single injection of pristane; no plasmacytomas were found in mice treated with virus alone.

Alkanes↗

Six BALB-c IgA myeloma proteins that bind beta-(1-6)-D-galactan. Partial amino acid sequences and idiotypes.

Six IgA myeloma proteins of BALB/c origin which bind antigens containing beta-(1 --> 6)-D-galactan side chains have been isolated by affinity chromatography on galactoside-BSA-Sepharose columns. Partial amino acid sequences of of the light chains to residue Cys23 and the heavy chains to reside 30 were determined on the automated sequencer. No differences were found among the six V(K) sequences. Among some 50 partial V(K) sequences that have thus far been determined these six chains are the only ones thus far identified in this subgroup; at least 25 V(K) subgroups in the mouse have been identified so far. The heavy chain partial sequences were also very closely related but two differences were found. One protein differed from the other five by having isoleucine instead of leucine at position 5, a second protein differed from the others by having an unidentified amino acid at position 19. Using the highly sensitive inhibition of hemagglutination method it was found that each of the proteins possessed a unique inidividual antigenic determinant.

Amino Acid Sequence↗