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Biomedical subjects

M Sela

Publications and source records attributed to M Sela.

At least 343 records · Page 19Linked to original sources
PubMed1969

The genetic control of antibody specificity.

The immune response to a synthetic polypeptide built on multichain polyproline, poly-L-(Tyr,Glu)-poly-L-Pro-poly-L-Lys [(T,G)-Pro--L], in the offspring of a cross between DBA/1 and SJL mice is under a genetic control superficially similar to the one operating for the immune response to a similar synthetic polypeptide built on multichain polyalanine, poly-L-(Tyr,Glu)-poly-D,L-Ala-poly-L-Lys [(T,G)-A--L], in the offspring of a cross between CBA and C57 mice. In both cases, the genetic control is a quantitative trait in which the major gene(s) is (are) dominant and the trait is not linked to any of the known structural genes coding for mouse immunoglobulin heavy chains. However, the genetic control of response to (T, G)-Pro--L, designated immune response-3 (Ir-3), is qualitatively different from the one operating for (T,G)-A--L [immune response-1 (Ir-1)] in that it is not linked to the histocompatibility-2 (H-2) locus. A study of the immune response to a related polypeptide built on multichain polyproline, poly-L-(Phe,Glu)-poly-L-Pro-poly-L--Lys [(Phe, G)-Pro--L], in the DBA/1 x SJL cross has shown a genetic control of antibody specificity. F(1) x DBA/1 backcross anti-(Phe, G)-Pro--L sera segregate in their ability to bind (T,G)-Pro--L, and there is no linkage of anti-(T,G)-Pro--L binding capacity with the H-2(s) allele of the SJL grandparent. F(1) x SJL anti-(Phe, G)-Pro-L sera segregate in their capacity to bind poly-L-(Phe,Glu)-poly-D,L-Ala-poly-L-Lys [(Phe, G)-A--L] and the ability to bind (Phe, G)-A--L is clearly linked to the H-2(q) allele from the DBA/1 grandparent. Thus, in mice all responding well to a given antigen [(Phe, G)-Pro--L], the specificity of the antibodies produced [i.e., anti-(Phe,G) or anti-prolyl] is genetically determined. Cross-inhibition of binding m (DBA/1 x SJL)F(1) anti-(Phe,G)-Pro--L antisera indicates that the anti-(Phe,G) and anti-prolyl specificities are a function of two separate and largely non-crossreacting antibody populations.

Alleles↗
PubMed1969

The nature of the antigenic determinant in a genetic control of the antibody response.

The response of inbred mouse strains to two polypeptides derived from multichain polyprolines, (T,G)-Pro--L and (Phe,G)-Pro--L, is different from the response of the same mouse strains to a similar series of polymers built on multi-poly-D,L-alanyl--poly-L-lysine, although the same short sequences of amino acids are attached to the side chains of the polypeptides in the two series. These results indicate that a portion of the side chain (e.g. polyalanine or polyproline) participates in the antigenic determinant. This was confirmed by studying the response of different mouse strains to two kinds of polypeptides: (T,G)-Pro-A--L 717 and 718 and (T,G)-A-Pro--L 719 and 721. Antibody assay of antisera to (Phe,G)-Pro--L with the cross-reacting antigens (T,G)-Pro--L and (Phe,G)-A-L indicates that different inbred mouse strains make antibodies specific for different parts of the same polypeptide. Thus, antibody from DBA/1 mice reacts almost exclusively with the (Phe,G) sequence, while SJL antisera bind only (T,G)-Pro--L and fail to bind (Phe,G)-A-L. The immune responses to the same amino acids on two different polypeptides (i.e. A--L and Pro--L) appear to be under separate genetic control.

Amino Acids↗
PubMed1969

Protein-bacteriophage conjugates: application in detection of antibodies and antigens.

Covalent attachment of proteins to bacteriophage yielded modified phage preparations with which it is possible to detect antibodies to proteins at concentrations as low as 0.5 to 2.0 nanograms per milliliter. Similarly, antibodies may be linked covalently to phage, and the resulting antibody-phage conjugate is useful in detecting proteins. An alternative method for quantitative determination of proteins is suggested, in which the inactivation of protein-phage by antibodies to protein is inhibited by the protein tested. With rabbit immunoglobulin G as the protein, as little as 0.3 nanogram per milliliter could he determind.

Animals↗
PubMed1969

Antibodies to a unique region in lysozyme provoked by a synthetic antigen conjugate.

A synthetic conjugate, prepared by covalent binding of a lysozyme fragment (sequence 64-83, denoted "loop" peptide) to a synthetic branched polypeptide, elicited in rabbits the formation of antibodies with specificity directed against a unique region in native lysozyme. These anti-"loop" antibodies were isolated immunospecifically on a lysozyme-cellulose immunoadsorbent. Antibodies with a similar specificity were isolated from antilysozyme sera with an immunoadsorbent prepared from the same "loop" peptide. The capacity of the anti-"loop" antibodies to distinguish between the "loop" peptide, containing a disulfide bridge, and the open-chain peptide derived from it suggests that they are directed against a conformation-dependent determinant.

Animals↗
PubMed1968

Studies on the competence of single cells to produce antibodies of two specificities.

Two series of experiments were performed, utilizing a modification of the hemolysin plaque technique which registers 19S antibody, in an attempt to determine the frequency of cells capable of simultaneously producing antibody to two non-cross-reacting antigens. Mice were immunized i.v. with rabbit and camel RBC and their spleens assayed for cells producing antibody against both antigens. 16,904 cells producing antibody of one or the other specificity, from 26 mice, were counted. Not one cell was detected which produced antibody of two specificities. Rabbits were immunized intradermally with HSA to which polyalanyl and p-azobenzenearsonate groups were chemically attached. The individual haptens, polyalanyl, and p-azobenzenearsonate groups were coupled to separate aliquots of SRBC, and the lymph nodes of immunized rabbits were assayed for cells releasing antibody against both haptens. In a study of 11 rabbits, after counting 27,845 cells producing antibody, we detected no "double" plaques.

Animals↗
PubMed1967

Genetic control of the antibody response. II. Further analysis of the specificity of determinant-specific control, and genetic analysis of the response to (H,G)-A--L in CBA and C57 mice.

CBA and C57 mice were tested for their ability to make an immune response to a related series of branched, multichain synthetic polypeptide antigens in which the antigenic determinants on the amino termini of the branched side chains were systematically varied. Neither strain responded to the polyglutamic acid determinant. Both strains responded well and equally to the poly(phenylalanine, glutamic acid) determinants. CBA mice responded poorly, and C57 mice responded well to two different antigens bearing poly(tyrosine, glutamic acid) determinants. CBA mice responded well, and CS7 mice responded poorly to two different antigens bearing poly(histidine, glutamic acid) determinants. The genetic control of the immune response to (H,G)-A--L appears to be dominant and polygenic, as it has been shown to be for (T,G)-A--L. The related antigens used in this study show extensive cross-reactions with antisera against other members of the related series.

Alanine↗