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M Michel

Publications and source records attributed to M Michel.

At least 163 records · Page 9Linked to original sources
PubMed1969

Idiotypy of rabbit antibodies. I. Comparison of idiotypy of antibodies against Salmonella typhi with that of antibodies against other bacteria in the same rabbits, or of antibodies against Salmonella typhi in various rabbits.

Sera of rabbits immunized against Salmonella typhi have been studied for the idiotypy of certain of their components, i.e., the property of these components to possess an antigenic specificity which is different in individual rabbits, and which varies with the antigens against which these rabbits have been immunized. The reagent used (precipitating anti-idiotypic sera) have been prepared by injecting rabbits with bacteria agglutinated by anti-S. typhi sera (immunizing sera) as was done in the first observations by the authors of the phenomenon in the rabbit. These first observations have been confirmed and extended. In contrast to allotypy, the anti-idiotypic sera precipitate the corresponding immunizing sera, but not the sera taken in the immunizing rabbits prior to their immunization against S. typhi, nor the immunizing sera absorbed with the somatic antigen of S. typhi, demonstrating that idiotypes are antibodies. The idiotypic specificities of the antibodies of one rabbit against S. typhi are not detected in the antibodies of the same rabbit against another noncross-reacting Salmonella (S. tranoroa) and vice versa; nor are they detected in the anti-pneumococcal antibodies of the same rabbit. Each anti-idiotypic serum fails to precipitate anti-S. typhi sera of rabbits other than the immunizing one except for certain extremely faint reactions, the significance of which has not been established. The idiotypic specificities of anti-S. typhi antibodies of three rabbits were not found in anti-S. typhi antibodies of their parents. This lack of a sign of hereditary transmission of idiotypic specificities contrasts with allotypy. The apparent role of random chance in the determinism of the idiotypic patterns or of the idiotypic determinants has been discussed. Unless it were admitted that antibodies with similar functions do not exist in different individuals, idiotypy apparently adds an order of magnitude to the antibody variability which had been previously envisaged. In one given individual, the heterogeneity of the idiotypic specificities seems to be less extended than that of the antibody functions. The possible relationships between these two levels of molecular variability and between the corresponding levels of cellular variability have been discussed.

Animals↗
PubMed1969

Idiotypy of rabbit antibodies. II. Comparison of idiotypy of various kinds of antibodies formed in the same rabbits against Salmonella typhi.

The idiotypic patterns detected in the anti-Salmonella typhi serum of one given bleeding have been sought in other bleedings of the same rabbit. Idiotypic patterns carried by antibodies of the second bleeding are not always found in those of the first bleeding. Bifurcated precipitation zones in gels (double diffusion in cells) have been observed in the reaction of several anti-idiotypic sera with the sera of the first and second bleedings of three rabbits, and apparently indicate that idiotypic patterns which were carried by the same molecule in the first bleeding were carried by two separate molecules in the second bleeding. In a comparison of idiotypy of two anti-S. typhi serum samples of one rabbit, the collection of which had been separated by a very long interruption of the immunization, all the idiotypes detected in the early bleeding were also detected in the late bleeding; several idiotypes were detected in the serum of the late bleeding and not in that of the early bleeding. Idiotypy has been observed and compared in IgM and in IgG antibodies. There are, in each of these two classes, antibodies that are not distinguished from antibodies of the other class by anti-idiotypic sera, and consequently that carry the same idiotypic patterns. A comparison has been made between the idiotypy of the two kinds of antibodies which, in anti-S. typhi sera, are precipitated and not precipitated by the polysaccharide. Certain idiotypic patterns are carried only by the antibodies of the first kind. There are also idiotypic patterns which are carried by antibodies of these two kinds, among which certain anti-idiotypic antibodies do not discriminate. Possible cellular implications of observations made on idiotypy at different stages of the immunization of one individual have been discussed.

Animals↗
PubMed1967

[Cystathioninuria].

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Amino Acid Metabolism, Inborn Errors↗