Philip R. B. McMaster

SEPARATION OF MICROSOMAL RNA INTO FIVE BANDS DURING AGAR ELECTROPHORESIS.

Microsomal RNA from rabbit livers and lymph nodes separate into five major bands during agar-gel electrophoresis. The electrophoretic method may be used either as an analytical or preparative tool. The 33S and 19S peaks of microsomal RNA from sucrose-gradient zone centrifugation divide into two bands each during simple agar electrophoresis.

Genetic Influence on Experimental Allergic Thyroiditis in Guinea Pigs

After immunization with low doses of guinea pig thyroid extract, incidence of experimental allergic thyroiditis is greater in the Hartley strain of guinea pig than in strain 13.

Contact Sensitivity and Immunologic Tolerance in Germfree Guinea Pigs

Summary The poorly developed lymphoid system of germfree guinea pigs did not prevent the development of contact sensitivity and immunologic tolerance to two simple chemicals, dinitrochlorbenzene and dinitrothiocyanatebenzene. Germfree animals responded in a manner similar to conventionally reared animals when these chemicals were applied to the skin or injected in complete Freunds adjuvant. We thank Mr. Michael Hooton for his technical assistance and Miss Theresa Wilson for carrying out the serum protein electrophoreses.

The preparation and characterization of a thymic independent antigen: ϵ-dinitrophenyl-L-lysine-ficoll

Abstract The preparation of a hapten-polysaccharide conjugate, ϵ-dinitrophenyl- L -lysine-Ficoll, is described. Conditions yielding different substitution ratios were studied. Ultracentrifuge and gel filtration studies have shown a very broad range size heterogeneity. The conjugates were shown to elicit both immediate and delayed skin reaction in guinea pigs previously immunized with dinitrophenylated keyhole limpet hemocyanin. The presence of antibody forming cells in the spleens of mice immunized with the conjugates was established by the demonstration of plaque-forming cells when assayed with trinitrophenylated sheep red blood cells. The immunogenicity, as shown by the plaque-forming cell response, was shown to be markedly dependent on the size of the conjugates.

The role of B lymphocytes in cell-mediated immunity: II. Delayed hypersensitivity induced by dinitrophenyl-Ficoll in dinitrophenyl-keyhole limpet hemocyanin-immunized guinea pigs

Abstract Dinitrophenyl (DNP)-Ficoll will elicit typical delayed hypersensitivity skin reactions in guinea pigs immunized with DNP-keyhole limpet hemocyanin (KLH). We observed that lymph node cells (LNC) from these animals produced the lymphokine, monocyte chemotactic factor (MNL CTX) when stimulated by DNP-Ficoll in vitro . This response was antigen and hapten specific since LNC from nonimmune guinea pigs or those immunized with nonDNP containing antigens were not stimulated by DNP-Ficoll. Lymph node cells were fractionated into T- and B-cell-enriched populations to determine the nature of the DNP-Ficoll-responsive cell. Only the B-lymphocyte-enriched population produced MNL CTX in response to DNP-Ficoll. The purity of the B-cell population was demonstrated by its failure to respond to PHA and by the fact that B cells derived from DNP-although they could no longer respond without T-cell help to the T-dependent antigen, DNP-OVA. These findings suggest that the hapten-specific response of guinea pigs to DNP-Ficoll may be a form of B-cell-mediated delayed hypersensitivity.

A comparison of autoimmunity and experimental allergic thyroiditis in strain 2 and Hartley strain guinea pigs.

Abstract The response of Strain 2 guinea pigs to immunization with thyroid extract in complete adjuvant was compared with the response of the Hartley strain. The Strain 2 did not develop thyroiditis as frequently or in as great a degree as the Hartley strain. This difference in degree of thyroiditis between these two strains occurred consistently even when the animals were immunized with a wide range of doses of thyroid extract and of mycobacteria in adjuvant, and was independent of the strain origin of the antigen used for immunization. Although the Strain 2 made less thyroiditis than the Hartley strain, it made as much agglutinating antibody, and often as much delayed sensitivity as the Hartley strain. The genetic controls regulating autoimminity to the thyroid and production of thyroiditis appear to differ from those regulating production of experimental allergic encephalomyelitis.

Tolerance to Type III Pneumococcal Polysaccharide in Monkeys

Rhesus and owl monkeys were injected intramuscularly with 10 to 10,000 γ of Type III pneumococcal polysaccharide. The monkeys were bled weekly, and then reinoculated with the polysaccharide at suitable intervals. The antibody content of their sera was measured by radioimmunoassay and the antigen content of selected sera estimated by the inhibitory effect of the serum upon the capacity of rabbit antisera to precipitate the polysaccharide. Ten γ of the polyeaccharide immunized the monkeys. Ten thousand γ did not immunize them but instead reduced their serum antibody to very low levels. One thousand γ also reduced their serum antibody to very low levels, but not uniformly as far as 10,000 γ. These findings indicate that 1,000 to 10,000 γ of this polysaccharide appear to cause immunologic tolerance in primates.