David W. Talmage

ANTIGENIC COMPETITION: CELLULAR OR HUMORAL.

The injection of one antigen into mice inhibited the response to a second when 1 to 10 days separated the two injections. When the same type of inhibition was attempted in γ-irradiated mice reconstituted with normal spleen cells, the inhibition was greater in mice receiving 50 million spleen cells than in those receiving 10 million. The results are interpreted as favoring a humoral mechanism of inhibition.

Thymectomy: Prolongation of Immunological Tolerance in the Adult Mouse

The loss of acquired immunological tolerance of mice to bovine gamma globulin depended on the presence of the thymus. Mice were repeatedly injected with bovine γ-globulin from birth until the age of 5 to 10 weeks and then thymectomized or sham operated. After 130 to 160 days without antigen, an accelerated (immune) disappearance of I125 bovine γ-globulin could be uniformly induced in controls while thymectomized mice remained tolerant. Adult thymectomized mice made tolerant by a single injection of bovine γ-globulin lost tolerance more slowly than sham-operated controls.

Cell interaction in antibody synthesis

Publisher Summary This chapter reviews the recent observations on the interactions of separate populations of cells from inbred mice and relates these observations to experiments with congenital dysfunction of the immune system in humans and surgical removal of the thymus in mice. The chapter focuses on the three related phenomena: antigenic competition, the carrier effect of multiple antigenic determinants, and the suppressive and enhancing effects of passively administered antibodies. In the past few years, it has been possible to demonstrate with separated cell populations that an interaction between two or more living cells that is required for the antibody response to at least some antigens both in vivo and in vitro . The chapter tabulates the relationship between the phenomenon of antigenic competition and cell interaction. The chapter concludes with a discussion of the significance of thymus-independent antigens and the immune responses in neonatally thymectomized mice and in athymic humans.

T cell rosette formation in primates, pigs, and guinea pigs: The influence of immunosuppressive agents

Abstract Out of 144 combinations of lymphocytes from 8 species and erythrocytes from 18, significant numbers of rosettes were found in only 14 . Human and chimpanzee lymphocytes formed rosettes in the greatest number of combinations (5), pig lymphocytes with 3, and guinea pig lymphocytes with only one erythrocyte (rabbit). In all positive combinations tested, the percentage of rosette-forming cells was highest in the thymus, intermediate with lymph node and peripheral blood lymphocytes, and lowest in the spleen. Using the guinea pig rosette-forming cell as an experimental test for T lymphocytes, the effect of several immunosuppressive drugs on the percentage of lymphocytes that are T cells was measured. Cyclophosphamide injected into guinea pigs increased this percentage the most, cortisone and tilorone increased the percentage of rosette-forming cells slightly, and azathioprine and vinblastine caused no change. After in vitro incubation with the lymphocytes, cyclophosphamide, azathioprine, and tilorone increased the percentage of rosette-forming cells and vinblastine reduced this percentage.

The requirement for biotin and fatty acids in the cytotoxic T-cell response.

Abstract Dialyzed fetal calf serum (FCS) was a poor source of serum supplement for in vitro cytotoxic T lymphocyte (CTL) generation. Serum dialysate or biotin fully restored dialyzed FCS to activities comparable to FCS. It was concluded that the active principal in serum dialysate was biotin because its further dialysis was prevented by addition of avidin, a biotin binding protein. Avidin inhibited CTL generation only when added during the early stages of mixed lymphocyte cultures, whereas biotin could restore activity even if added at a later time. When FCS enriched in a fatty acid mixture, or in palmitic acid alone, was used as the serum supplement, avidin-mediated inhibition of CTL generation was markedly reduced. Avidin also inhibited CTL generation in cultures containing killed macrophages as the stimulating cell, and supplemented with Con-A-induced spleen cell supernatant, a source of helper factor(s). These experiments suggest that fatty acid biosynthesis and the attendant synthesis of structural lipids of appropriate fatty acid composition play a prominent role in the generation of CTL

Acceptance or rejection of male skin by isologous female mice, effect of injection of sperm.

Female C57B1/6J mice given one intraperitoneal injection of 1 to 8 million isologous epididymal sperm cells may exhibit either delayed or accelerated rejection of isologous male skin, depending on both the number of sperm cells injected and the time of application of the graft. A long time interval or a large dose of sperm cells results in maintenance of the male graft or delayed rejection, while a small dose and short time interval produces an accelerated rejection phenomenon.

Is the macrophage the stimulating cell

Using CAF1 spleen cells to stimulate parental strain BALB/c spleen cells in a mixed lymphocyte culture, column separation of responding cells increased their response whereas the same treatment of stimulating cells reduced their activity approximately 95 per cent. Peritoneal macrophages from CAF1 mice were found to stimulate BALB/c spleen cells poorly if present in comparable numbers or if they were cultured for 24 hours before adding responding cells. However, if the F1 macrophages were in contact with the BALB/c cells for only 4 hours, their stimulating effect was increased strikingly. Under these conditions BALB/c macrophages had no effect. It is concluded that the macrophage is probably the most effective stimulating cell and may be the only cell with this capability.

Comparative immunochemical studies of primate hemoglobins.

The antigenic properties of a number of chromatographically purified primate hemoglobins were compared to those of normal human hemoglobin using a sensitive radioimmunochemical procedure. The degree of inhibition of the antigen-antibody reaction with heterologous hemoglobins appeared to be related to the structural similarity of these proteins to the normal human hemoglobin immunogen. With the exception of the baboon hemoglobin, the antigenicity of the hemoglobins paralleled the phylogeny of the primates. The gorilla and chimpanzee hemoglobins were antigenically identical to normal human hemoglobin, whereas the gibbon and orangutan hemoglobins were substantially more variable. Of the Old World monkey hemoglobins examined, the baboon produced lower inhibition values, suggesting a greater degree of structural dissimilarity than other Cercopithecoidea hemoglobins, which is compatible with a greater rate of evolutionary change occurring in this protein. Using the known amino acid sequences of human and other primate hemoglobins, we have attempted to identify antigenic determinant areas of the proteins.

Thymocytes, macrophages, and erythrocytes

Abstract Lymphocyte-macrophage and lymphocyte erythrocyte interactions were examined in the 4 homologous and 12 heterologous combinations of mice, rats, guinea pigs, and rabbits. There was a highly species-specific interaction between thymic lymphocytes (T cells) and homologous peritoneal macrophages. Distinct red cell rosettes were formed only between thymus-derived cells of the guinea pig and rabbit erythrocytes.

The inhibition of the primary interaction between 1 2 5I-labeled human hemoglobin and rabbit anti-human hemoglobin sera: A sensitive radioimmunoassay technique

A rapid and sensitive radioimmunoassay technique for hemoglobin based upon a modification of the Farr test is described. Since hemoglobin is soluble in ammonium sulfate whereas antibody is precipitated, the amount of free and antibody-bound radiolabeled human hemoglobin can be quantitatively measured after ammonium sulfate precipitation. Nanogram quantities of hemoglobin can be detected by the addition of unlabelled human hemoglobin to the antiserum before the labeled hemoglobin, thus establishing a competition reaction between labeled and unlabeled antigen for antibody. If sufficient quantities of unlabeled human hemoglobin are present, all of the antibody combining sites become saturated and the primary interaction between 125-I-labeled hemoglobin and antibody is completely inhibited. The method can be employed to discriminate various normal human hemoglobins, non-human primate hemoglobins as well as sickle-cell hemoglobin (HbS). Other possible applications of the technique are discussed.