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Biomedical subjects

E Lederer

Publications and source records attributed to E Lederer.

At least 127 records · Page 7Linked to original sources

Isolation and properties of a macromolecular, water-soluble, immuno-adjuvant fraction from the cell wall of Mycobacterium smegmatis.

Trypsin- and chymotrypsin-treated delipidated cell walls of Mycobacterium smegmatis were digested overnight with lysozyme. The water-soluble products thus obtained were filtered on a column of Sephadex G-50; the first peak, excluded from the column, has immunological adjuvant activity. The material of the excluded peak is obtained after lyophilization as a snow-white, fluffy material, soluble in water and insoluble in organic solvents. It behaves as a slightly polydisperse macromolecule in an ultracentrifuge, with an approximate molecular weight of 20,000. All the constituents of this material are typical bacterial cell-wall constituents; thus, the water-soluble adjuvant is considered to be an "oligomer" of the cell wall. When added to Freund's incomplete adjuvant with an antigen (e.g., ovalbumin) and injected into hind-foot pads of guinea pigs, this water-soluble adjuvant increases the amount of precipitating antibodies and induces hypersensitivity to ovalbumin and the biosynthesis of gamma(2)-type precipitating antibodies. The water-soluble material has a stronger adjuvant activity than equal amounts of whole bacteria, cell walls, or wax D, and seems to be the first well-defined, water-soluble, adjuvant-active fraction isolated from Mycobacteria.

Adjuvants, Immunologic↗

Cellular reaction in the footpad and draining lymph nodes of mice induced by mycobacterial fractions and BCG bacilli.

Ten micrograms of trehalose-6, 6'-dimycolate (cord factor), injected into the footpad of mice, induced histological changes similar to those following injection of living BCG bacilli. Both materials induced in the draining lymph nodes the formation of granulomas composed of epitheloid cells, macrophages, and small numbers of lymphocytes. Apart from the granulomatous inflammatory process, marked hyperplasia of the lymphoid tissue in the paracortical zone of the nodes and accumulations of macrophages were evident. In some cases, the macrophages were very numerous and replaced part of the lymphoid tissue. Compared to cord factor, wax D showed weak granulomagenic activity. Only slight and transient inflammation was found in the footpads as well as transient slight lymphoid hyperplasia. Wax D also induced small accumulations of macrophages. Complete Freund's adjuvant induced, under the same experimental conditions, large accumulations of macrophages in the draining lymphnode and lymphoid hyperplasia in the paracortical zone. No cellular reaction was seen in the liver, spleen, and lungs after injection of cord factor and BCG into the footpads of the animals. The results and implications are discussed.

Animals↗

Immune response to sheep red blood cells in mice pretreated with mycobacterial fractions.

Ten micrograms of trehalose-6,6' -dimycolate (cord factor) injected into the footpads of mice increased the antibody response to sheep red blood cells (SRBC) subsequently injected into the same sites. There is a relationship between the antibody response and the cellular reaction induced locally and in the draining lymph nodes by cord factor, as judged by a much weaker response when antigen is injected into the contralateral footpads. The time intervals between injection of cord factor and antigen were from 5 to 20 days. A similar increased antibody response to SRBC was evident after preliminary administration of Freund's complete adjuvant or living BCG bacilli into the footpads. There was no increased antibody response in mice pretreated with living BCG or Freund's adjuvant to SRBC injected into the contralateral footpads. Administration of wax D from human strains Peurois and Test was without any effect. Administration of SRBC emulsified in incomplete Freund's adjuvant containing 5 mug of cord factor induced a very strong antibody response in the mice as compared to that after injection of the same amount of antigen in incomplete Freund's adjuvant containing wax D or mycobacteria. The results are discussed.

Animals↗