[Influence of different types of experimental obesity on resistance of the mouse to infection by Salmonella typhimurium and Klebsiella pneumoniae]. / Influence de divers types d'obésité expérimentale sur la résistance de la souris à l'infection par Salmonella typhimurium et Klebsiella pneumoniae.

Resistance to infections inducing two types of immune response, humoral and cell-mediated, has been measured in mice after Salmonella typhimurium and Klebsiella pneumoniae inoculation; the animals exhibited different kinds of obesity: genetic, ob/ob and db/db mutants, induced by fat diet or gold thioglucose (aurothioglucose) injection (determining obesity of central origin). Klebsiella infection was aggravated in all types of obesity. Salmonella infection was aggravated in genetically diabetic and dietary-obese mice. The two kinds of genetically obese mice show an important functional decrease in splenic lymphocytes. In contrast, aurothioglucose-obese mice were more resistant than controls.

[Preparation of immunosorbents from lipopolysaccharides and polysaccharides extracted from various gram-negative and gram-positive bacteria]. / Préparation d'immunoabsorbants à partir de lipopolyosides et de polyosides extraits de différentes bactéries à gram négatif et à gram positif.

The method of binding of lipopolysaccharides (LPS) extracted from Salmonella typhimurium to aminohexyl-sepharose 4B by activation with benzoquinone was applied to three different LPS extracted from several enterobacteria species: S. seftenberg 1,3,19, S. cholerae suis 6(2),7 and Escherichia coli O141:H32. It was also used for two polysaccharides (PS) extracted from S. seftenberg 1,3,19 and Streptococcus agalactiae type II strain, respectively. Both PS were free from amino groups but exhibited the corresponding antigenic determinants of the cell wall. The use of these immunosorbents enabled us to obtain a monospecific antiserum. They may be a useful tool for serological identification of salmonella and group B streptococci. This method may be applied for other bacterial surface PS. The possible regeneration of such immunosorbents without appreciable loss of their antigen binding capacity makes possible their use for obtaining monospecific antibodies on a preparative scale.

[Preparation of monospecific anti-Salmonella LPS antibodies from bacteria immobilized in polyacrylamide gel]. / Préparation d'anticorps monospécifiques anti-LPS de Salmonella sur bactéries immobilisées dans un gel de polyacrylamide.

The use of an immunoabsorbent obtained by entrapping Salmonella cells into a polyacrylamide gel lattice enabled us to obtain anti-O monospecific immune sera which can be used for a quick serological identification of some species of Salmonella in the course of a diagnosis. In this paper we describe a method for immobilization of S. typhimurium as well as the preparation of monospecific anti-05 antibodies from plurispecific anti-S. haifa rabbit immune sera. This separation of anti-O monospecific antibodies avoids the repeated and often tedious adsorption of anti-Salmonella immune sera by the corresponding whole bacteria. Such Salmonella, entrapped into the polyacrylamide gel lattice, can be used several times without appreciable loss of their affinity properties.

Preparation of monospecific anti-Salmonella lipopolysaccharide antibodies by affinity chromatography.

The use of immunoadsorbent obtained by coupling aminohexyl-sepharose 4B with Salmonella lipopolysaccharide (LPS) by means of benzoquinone enabled us to obtain anti-O monospecific immune sera which can be used for a quick serological identification of some species of Salmonella in the course of a diagnosis. In this paper we describe a method for binding the LPS extracted from S. typhi-murium with aminohexyl-sepharose 4B, insoluble matrix as well as the preparation of monospecific anti-O5 antibodies from plurispecific anti-S. haifa rabbit immune sera. This separation of anti-O monospecific antibodies by affinity chromatography, avoids the repeated and often tedious adsorption of anti-Salmonella immune sera by the whole corresponding bacteria. Such immunoabsorbents can be used several times without appreciable loss of their affinity properties.

[Cellular response in the mouse to two antigenic extracts from "Vibrio cholerae" (author's transl)]. / Etude au niveau cellulaire, chez la souris, du mode d'action de deux antigènes extraits d'une souche de vibrion cholérique.

At the cellular level the primary response in Balb/c mice to an antigen prepared from a strain of Vibrio cholerae Ogawa was studied by a localized vibriolytic plaque procedures which permits the enumeration of immunocytes. The antibody response to a single injection with identical doses of antigen was comparatively studied by both intraperitoneal and subcutaneous immunization. The highest titre was noted two weeks after the intraperitoneal and three days after the subcutaneous injection. Inhibition experiments were performed to obtain an estimate of the average of avidity of the bactericidal antibodies against the different antigens extracted from the vibrio. A correlation between the avidity and the protective properties was noted. The antigen which had a better immunogenetic effect showed the better binding.

Comparative study of macrophage migration in different strains of mice: absence of migration in C3H mice.

In the course of studying the susceptibility of mice to Salmonella infection, we discovered that C3H/HeJ mice differ from other strains in both their susceptibility to infection and their response to prior vaccination. Others have noted the absence of the usual B cell stimulation by LPS in these mice. To investigate the status of delayed hypersensitivity in C3H/HeJ mice, we tried to use the technique of macrophage migration. Under conditions of normal migration for other strains, C3H/HeJ peritoneal and splenic macrophages failed to migrate, thus establishing another differentiating immunological trait for this strain.