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Biomedical subjects

R Lieberman

Publications and source records attributed to R Lieberman.

At least 91 records · Page 5Linked to original sources

A mouse IgM allotypic determinant (Igh-6.5) recognized by a monoclonal rat antibody.

Two monoclonal rat anti-mouse IgM antibodies, Bet 1 and Bet 2, are described in this paper. Bet 1 defines a new allotypic determinant, Igh-6.5, expressed on IgM molecules in serum and on B lymphocytes, whereas Bet 2 recognizes a determinant on IgM molecules of all mouse strains tested. Both reagents bind to the IgM myeloma protein MOPC104E, but not to IgG myeloma proteins, including FLOPC21, MOPC21, and UPC10. Using serum from various mouse strains to inhibit the binding of Bet 1 to MOPC104E, 3 distinct inhibition patterns were found. BALB/c, DBA/2, and CBA sera inhibited strongly, C56BL/6 (B6), SJL, AKR, and NZB sera inhibited weakly, and A and AL sera showed no inhibition of binding of BET 1 to MOPC104E. All sera tested were equivalent in their inhibition of the binding of Bet 2 to MOPC104E. When spleen cells from different mouse strains were reacted with fluorescein-conjugated Bet 1 (F-Bet 1) and subjected to flow microfluorometry analysis, 3 types of staining patterns, corresponding to those obtained with the serum inhibition assay, were also found. The determinant recognized by Bet 1 is controlled by a gene linked to the Igh-C gene complex. C.AL20 behaved like AL, and C.B20 and BAB/14 behaved like B6, both in the serum inhibition assay and in flow microfluorometry analysis of spleen cells stained with F-Bet 1. In addition, the capacity of serum from individual (BALB/c X B6) X B6 backcross progeny to inhibit the binding of Bet 1 to MOPC104E was linked to the expression of the Ig-1a marker.

Animals↗

Computerized intravenous arteriography: a technique for visualizing the peripheral vascular system.

A unique method of computerized fluoroscopic enhancement allows direct visualization of the entire vascular system by intravenous injection of standard contrast agents, thereby avoiding the need for arterial puncture or hospitalization. This technique has been used to satisfactorily visualize the intra- and extracranial carotid and vertebral arteries, the aortic arch and upper extremity vessels, the abdominal aorta and its branches, as well as lower extremity vasculature. Although the technique is still under development, occlusions, stenoses, ulcerated plaques, and aneurysms have been visualized. Qualitative evaluation of these studies indicates a promising correlation with standard arteriography. This technique has great promise as a method of diagnostic screening in the management of peripheral vascular disease.

Aneurysm↗

Allelic forms of anti-phosphorylcholine antibodies.

Anti-idiotype antisera were prepared to 2 phosphorylcholine (PC) binding myeloma proteins, T15 of BALB/c origin and C3 of C57BL origin. These antisera were shown to recognize the respective determinants on induced anti-PC antibodies in the 2 parental strains. Genetic analysis of these V region markers in backcross progeny of (BALB/c X C57BL/6) X BALB/c demonstrated that the 2 determinants segregated as simple Mendelian alleles linked to the allotype locus. The genetic data are consistent with previously reported structural studies suggesting the allelic nature of the T15 and C3 heavy chain variable regions. The expression of the T15 and C3 antigenic determinants in Ig congenic and recombinant inbred strains derived from BALB/c-C57BL/6 crosses further supports the concept of allelism although a single exception was observed. Strain distribution analysis has indicated the potential existence of other alleles of the T15 gene in addition to C3.

Alleles↗

Regulation of the anti-inulin antibody response by a nonallotype-linked gene.

The antibody response to the inulin [(In), beta-(2 leads to 1) fructosan] determinant of bacterial levan [(BL), a beta-(2 leads to 6) polyfructosan that contains beta-(2 leads to 1) branch points] requires the presence of the a haplotype of the Igh gene complex. BALB/c (Igh a) mice immunized with BL produce IgG anti-In antibodies of a single spectrotype by isoelectric focusing analysis. C57BL/6 mice, which possess the b haplotype of the Igh gene complex and which fail to produce anti-In antibodies, nevertheless possess a gene, spectrotype regulation gene 1 (Sr-1), that regulates the isoelectric focusing (IEF) pattern of anti-In antibodies in mice of the a haplotype. Thus, the IEF patterns of anti-In antibodies of (BALB/c x C57BL/6)F1 mice and of B.C8 mice (C57BL/Ka . Igh-Ca) are considerably more complex than those of BALB/c. Backcross analysis indicates that Sr-1 is not linked to the Igh complex, the major histocompatibility complex, or to the genes that code for coat color. Studies of the heterogeneity of anti-In antibodies in recombinant inbred lines and their progeny from matings to BALB/c and C.B20 (BALB/c . Igh-Cb) suggest the existence of other regulatory genes.

Animals↗

IgD allotypic determinants. I. Determinants expressed on murine IgD of the a allotype.

Allotypes of membrane IgD of 27 strains of mice were determined with a series of anti-delta reagents, each capable of binding to the IgD of BALB/c spleen cells. One of these reagents is a newly defined allospecific rabbit anti-mouse-delta a. Typing with these reagents reveals the strain distribution of the previously described IgD.36 (Ig5.1) and IgD.43 (Ig5.4) specificities and demonstrates the existence of a new specificity, IgD.45 (Ig5.5). The results confirm the previous subdivision of the Igh-Ce haplotype into Igh-Ce, to which A mice are assigned, and Igh-Cn, to which NZB and NZW mice are assigned. In addition, it is shown that the Igh-Cd haplotype must also be subdivided. AKR mice, which express the a allele at the Igh-5(delta) locus, are designated as possessing the Igh-Cd haplotype while AL/N and C.AL20 mice, which have the e allele at the Igh-5(delta) locus, are assigned a new Igh-C haplotype designation, o.

Absorption↗

IgD allotypic determinants. II. Determinants expressed on IgD of mice of the b, e, and o Igh-C haplotypes.

Allotypic determinants expressed on membrane IgD of 27 strains of mice representing each of the major Igh-C haplotypes of inbred mice were examined with reagents specific for the IgD of mice of the b, e, and o Igh-C haplotypes. The distribution of two specificities, IgD.44 (Ig5.2) and IgD.37 (Ig5.3), recognized by two monoclonal anti-delta reagents was determined. In addition, a new specificity, IgD.46, expressed on mice of the o Igh-C type, but not of the b or a types, was detected by a BALB/c anti-AL/N spleen cell antiserum. The results also confirmed the description of the new Igh-C haplotype o, by demonstrating that the mice of this group express the IgD.37 determinant. This determinant is also expressed by mice of the b and e types, but not by mice of the d haplotype, from which the o haplotype was subdivided.

Animals↗

Preparation of functionalized derivatives of inulin: conjugation of erythrocytes for hemagglutination and plaque-forming cell assays.

A method is described for preparing derivatives of alkali-stable polysaccharides for coupling to immunogen carriers or to sheep red blood cells (SRBC) for use in hemagglutination (HA) and plaque-forming cell (PFC) assays. Inulin, a beta (2 leads to 1)-linked polyfructosan was partially derivatized with carboxyl, aminoethyl or (p-aminophenyl)butyryl groups; the latter derivative was coupled to SRBC following diazotization. Optimal conditions for the sensitization of SRBC with inulin were given. The immunological reactivity of the inulin molecule was unaffected by the derivatization reactions, and high, reproducible anti-inulin HA titers for inulin-binding myeloma proteins were found using these specifically sensitized SRBC. The sensitized SRBC were stable for assays for over 2 weeks. Problems with spontaneous agglutination or distortion of sensitized SRBC, normally seen in other procedures, e.g., methods using stearoyl-inulin, were not encountered.

Animals↗

The immune response to the alpha 1-6 epitope of dextran is determined by a gene linked to the IgCH locus.

There is a marked strain variability in the immune response against the alpha 1-6 epitope of dextran B512. Responsiveness was independent of the H-2 genotype of the strains but completely determined by the IgCH allotypes of the strains. Thus, IgCHb and IgCHj allotypes characteristic of C57BL and CBA strains, respectively, determined high responsiveness, whereas strains possessing all other allotypes studied were low responders. Backcross analysis indicated that a gene(s) determined responsiveness and that this gene was linked to allotypes of the IgCH locus. F1 hybrids between high and low responder strains always gave a response, but the number of plaque-forming cells was approximately half of that obtained in the high responder strains.

Animals↗

Lyb-7, a new B cell alloantigen controlled by genes linked to the IgCH locus.

Anti-Lyb-5.1 serum contains antibodies against two different B cell surface antigenic determinants, Lyb-5.1 and Lyb-7.1, which are defined in cytotoxicity and functional tests, respectively. The antibody against Lyb-7.1 is identified by its ability to specifically inhibit in vitro primary antibody responses to TNP-Ficoll. Anti-Lyb-5.1 serum can be made monospecific for anti-Lyb-7.1 activity by absorption with spleen cells from AL/N mice which have been typed as Lyb-5.1+, Lyb-7.1-. Lyb-5.1 and Lyb-7.1 are each under control of one or one set of closely linked genes. The loci specifying Lyb-5.1 and Lby-7.1 are not linked to each other nor to M1s and H-2 loci. However, the gene controlling the expression of Lyb-7.1 is linked to the genes coding for the constant region of immunoglobulin heavy chains.

Animals↗

Immune response to levan. II. T independence of suppression of cross-reactive idiotypes by anti-idiotype antibodies.

Pretreatment of BALB/c mice with antisera to a cross-reactive idiotype (E109IdX) expressed on many anti-bacterial levan (BL) and anti-inulin (Inu) antibodies leads to a prolonged suppression in production of IdX-bearing molecules in response to BL immunization. There is a comparable suppression in numbers of plaque-forming cells secreting IdX-bearing anti-BL and anti-Inu molecules. Furthermore, spleen cells from anti-E109IdX pretreated mice are unable to transfer to irradiated recipients the ability to produce IdX-bearing anti-BL and anti-Inu antibodies. These results indicate that the suppressive effect is at the precursor level and not simply a clearance of antibodies bearing the IdX. Suppression of IdX production can be achieved by pretreating nu/nu BALB/c mice with anti-E109IdX antibodies. Furthermore, spleen cells from pretreated mice do not inhibit the capacity of spleen cells from normal mice transferred to irradiated recipients to produce E109IdX in response to BL. This indicates that the suppression of IdX production in the anti-BL system is T independent and probably represents direct inhibition of precursors by anti-IdX.

Animals↗

Idiotypes of inulin-binding myeloma proteins localized to variable region light and heavy chains: genetic significance.

Idiotypes of inulin-binding myeloma proteins (InuBMP) were determined primarly by variable region light chains (VL) or by variable region heavy chains (VH) but needed both chains to be expressed. Recombinant molecules were used to show that individual idiotypes (IdI) of U61, E109, T957, and A4 InuBMP and cross-specific idiotypes (IdXB) of U61 were primarily determined by VL while cross-specific idiotype (IdXA) of A4 was determined mainly by VH. The assignment of genes controlling idiotypes to VH based on allotype linkage (e.g., IdXB) is dubious until the role of the L chain in determining that idiotype is assessed. IdXB has been shown to be a VL-VH marker which presumably is controlled by two unlinked genes. However IdXB can be used as a L chain marker in combinations of strains differing in their L chain genes but having the same permissive H chain genes. Conversely IdXB can be used as a H chain marker in strains having the same permissive L chain genes but differing in their H chain genes.

Animals↗