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Biomedical subjects

R G Krueger

Publications and source records attributed to R G Krueger.

At least 37 records · Page 2Linked to original sources
PubMed1976

Antibody differentiation: apparent sequence identity between variable regions shared by IgA and IgG immunoglobulins.

We have analyzed a pair of human myeloma immunoglobulins (biclonal proteins) of the IgG and IgA classes from a single patient, GR. The light chains are identical in amino-acid sequence over 40 residues at their NH2-terminus, hwereas the heavy chains are identical throughout 45 residues of their NH2-terminus. Additional chemical and serological studies suggest the light chains and variable regions of the heavy chains (VH) are very similar, if not identical. The implications of these and of other published studies are discussed with regard to (i) the association of one VH region with multiple constant regions of the heavy chain (CH regions), (ii) two alternative types of V-C joining mechanisms, (iii) the differentiation of antibody-producing cells, and (iv) three categories of biclonal immunoglobulins.

Amino Acid Sequence↗
PubMed1976

Tumor-associated antigens in human myeloma.

Antiserum was generated in rabbits to the RPMI 8226 tissue culture line of human myeloma cells, and its reactions with fixed smears of bone marrow aspirates from patients with multiple myeloma, macroglobulinemia, benign monoclonal gammopathy (BMG), leukemia, and nonneoplastic plasmacyosis was assessed by indirect immunofluorescence. After absorption with preparations of bone marrow from normal individuals, the antiserum reacted to a significantly higher titer with a specific subpopulation of plasma cells in smears from 81% of patients having multiple myeloma and 50% of patients having BMG than with cells in smears of bone marrow aspirates from normal individuals or patients having leukemia or nonneoplastic plasmacytosis, or than with cells in smears of peripheral blood from patients having Hodgkin's and non-Hodgkin's lymphoma. Absorption of the antiserum with RPMI 8226 cells or with a bone marrow preparation from a patient with multiple myeloma but not the Jijoye line of Burkitt's lymphoma reduced reactivity for cells in myeloma bone marrow. The antiserum reacted at a lower titer with the Jijoye and EB-3 lines of Burkitt's lymphoma, the RPMI 4098 cell line of normal human lymphocytes, and culture lines of human melanoma and osteogenic sarcoma than with the RPMI 8226 cells or bone marrow from certain patients having multiple myeloma. Approximately 50% of the cells reactive with antiserum to RPMI 8226 cells in the bone marrow of patients with multiple myeloma were not producing immunoglobulin, as assessed by double immunofluorescence assay. The data suggested that a subpopulation of plasma cells in the bone marrow of patients with multiple myeloma possesses a tumor-associated antigen.

Absorption↗
PubMed1976

Intracisternal A particles from FLOPC-1 BALB/c myeloma: presence of high-molecular-weight RNA and RNA-dependent DNA polymerase.

Intracisternal A particles from the FLOPC-1 line of BALB/c myeloma have been shown to contain high-molecular-weight RNA (60 to 70S) that is sensitive to RNase, alkali degradation, and heat but resistant to Pronase treatment. The intracisternal A-particle RNA contains tract of poly (A) approximately 180 nucleotides long. As shown in a reconstitution experiment, by antigenic analysis of A-particle preparation and the SC cytopathogenicity assay, the 70S RNA was not due to contamination by type C virus particles. The FLOPC-1 intracisternal A particles also possess an endogenous RNA-dependent DNA polymerase. The enzyme required Mn2+ or Mg2+, dithiothreitol, detergent, and four deoxyribonucleoside triphosphates for maximum activity. Enzymatic activity was maximally stimuated by poly (rC)-oligo (dG)12-18 and less with poly (rG)-oligo (dC)10 or poly (rA)-oligo (dT)12-18 as compare with synthetic DNA/DNA duplex templates such as poly (dA)-oligo (dT)12-18. The enzyme can utilize the A-particle endogenous RNA as template as shown by analysis of the early and late DNA products of the endogenous reaction by CsSO4 isopycnic gradient centrifuation and hybridization of purified 70S or 35S A-particle RNA with the purified complementary DNA product. Approximately 50% of the A-particle complementary DNA also hybridized with oncornavirus RNA.

Animals↗
PubMed1976

Development of monoclonal IgA and an apparent IgG in a patient with macroglobulinemia: sharing of individually specific antigenic determinants among IgM, IgA, and IgG.

Patient CM, who initially was diagnosed as having macroglobulinemia (IgM, kappa) was subsequently found to develop a monoclonal IgA(kappa) protein. Rabbit antisera directed against the patient's IgAm and IgM were rendered specific for individual antigenic (ind) determinants. The anti-IgAm and IgM ind sera reacted with both 131I labeled monoclonal proteins in a double antibody radioimmunoassay (RIA). In addition, both monoclonal immunoglobulins inhibited the reaction between labeled immunoglobulin and both ind antisera, and statistical analysis of the data suggested that the shared ind determinants were identical. The IgG fraction of patient CM's serum also contained a component which competed with both monoclonal IgA (CM) and IgM (CM) in the RIA specific for ind determinants. Analysis of serum samples taken over a 2-year period revealed that, in addition to IgM, both the IgA and IgG components possessing the shared ind determinant(s) were present in low concentrations in the earliest sample, although not detected by conventional techniques. The monoclonal IgA and the IgG component were found to increase in concentration over this time interval with a concomitant decrease in IgM. The regulation of immunoglobulin expression with respect to the proposed models of gene organization in antibody-producing cells was discussed.

Antibody-Producing Cells↗
PubMed1975

Studies on IgA and IgA monoclonal proteins derived from a single patient. Evidence for identical light chains and variable regions of the heavy chain.

Two immunoglobulins, IgA(K) and IgG(K), were isolated from the serum of a single patient with two monoclonal components (biclonal proteins). After chain separation, the light chains from each molecule were found to be identical by the following criteria: electrophoretic mobilities under various pH and dissociating conditions, amino acid compositon, fingerprint analysis of tryptic peptides and of 14C-succinylated chymotryptic peptides, and amino acid sequence of the N-terminal 40 residues. The heavy chains were indistinguishable for the N-terminal 45 amino acid residues. These data are consistent with the hypothesis that a single heavy chain variable (VH) region may be associated with two different heavy chain constant (CH) genes.

Amino Acid Sequence↗
PubMed1975

Regeneration of intact spleen in a heterotropic site in splenectomized mice.

The regeneration of intact spleens implanted in the sacrospinal areas of splenectomized mice was studied by light microscopy. The weight of the implanted tissue was not fully regenerated 50 days after implantation. The pattern of embryonic development of the spleen was investigated and the histologic appearance of the implant 46 days after implantation resembled that of normal spleen. The appearance of primitive myelopoietic stem in cells in the early phases of regeneration makes this an attractive model in which to study the biologic effects of tumour viruses.

Animals↗
PubMed1975

Host range studies of FLOPC-1 murine myeloma C particles.

The host range of the C particle produced by FLOPC-1 myeloma cells, FLOPC-1 murine myeloma-associated virus (FL-MuMAV), was assessed in terms of its ability to productively infect and/or induce new viral antigens in a variety of different cell lines. Production of C particle-like structures by cells exposed to FL-MuMAV) was determined by incorporation of [3H]uridine into particles with a density of 1.16 g/ml and/or measurement of RNA-dependent DNA polymerase activity in concentrated culture medium. to FL-MuMAV was capable of infecting NIH/3T3, normal rat kidney (NRK) cell, BALB/c 3T3, and the A31 clone of BALB/3T3 cells but not rabbit cell line, SIRC. Thus, it is an N, B-tropic murine virus as replication in NRK cells has been shown not to delineate a group of murine viruses with a separate host range (M. M. Lieber, C. J. Sherr, and G. J. Todero, 1974). Further neoantigens, reactive with anti-FL-MuMAV serum, were detected on infected cells. Production of the MuMAV-like particle and MuMAV-associated cell antigens in infected NIH/3T3 and NRK cells persisted for three subcultures. The limited production could not be explained by the lack of an RNA-dependent DNA polymerase or high-molecular-weight RNA as the particles possessed both of these properties. The particles produced by infected NIH/3T3 or NRK cells were antigenically and physicochemically similar to FL-MuMAV and not K-MuLV. The MuMAV-like particles produced by infected NIH/3T3 were capable of limited replication in NIH/3T3 and and BALB/3T3 cells, whereas NRK-MuMAV replicated for a limited period in NIH/3T3, NRK, and SIRC cells; i.e., they had a different host range than FL-MuMAV. The particles produced by infected BALB/3T3 and A31 cells had the same host range as FL-MuMAV. In certain situations, isotopically labeled particles with a density of 1.16 g/ml were produced which appeared to lack RNA-dependent DNA polymerase.

Animals↗
PubMed1974

Localization of coliphage MS2 A-protein.

The purification of coliphage MS2 dinitrophenol (DNP) conjugates provided a system for localization of the single molecule of A-protein in the capsid of the MS2 phage particle. Three A-protein preparations isolated from unconjugated MS2, overconjugated DNP-MS2, and purified 78S DNP-MS2 were tested for the presence of covalently bound DNP. The binding characteristics to Dowex 1-X8 and rabbit anti-DNP bovine serum albumin (DNP-BSA) immunoglobulin G of the 78S DNP-MS2 and overconjugated DNP-MS2 A-protein preparations indicate that the A-protein is located on the surface of the phage particle where it can be covalently conjugated with hapten. Extensive enzymatic iodination of the A-protein of intact unconjugated MS2 substantiates this conclusion.

Coliphages↗