Studies in Cellular Immunology

Citation

Melvin, Susan Leah (1974) Studies in Cellular Immunology. Dissertation (Ph.D.), California Institute of Technology. doi:10.7907/krmh-a250. https://resolver.caltech.edu/CaltechTHESIS:07302021-215238238

Abstract

Antisera were prepared against pigeon thymus and bursa lymphocytes and against saline extracts of thymus and bursa. All unabsorbed sera were screened for differential reactivity against thymus and bursa-derived tissue by several techniques. Selected sera were absorbed with thymus and bursa tissue to demonstrate specificity. One serum with specificity against thymus extracts was identified by immunodiffusion. The thymus specificity was absent from extracts of pigeon bursa, brain, liver and breast muscle, but present in spleen extracts. This thymus specificity does not appear analogous to lymphocyte specificities identified in other species. Shared tissue specificities and a possible quantitative antigenic difference among the tissue extracts were also demonstrated by immunodiffusion and absorption analysis. In lymphocytotoxicity tests, fresh rabbit normal serum is highly toxic for pigeon thymus and bursa cells. This toxicity, in general, resembles the natural antibody present in rabbit and guinea pig sera against heterologous thymus cells. A rabbit anti-pigeon gamma globulin serum was rendered specific for bursa cells by absorption with thymus cells. Some standard antilymphocyte sera were shown to contain an antibody fraction specific for thymus cells. Some or all of these reagents may be useful for distinguishing cooperating cell populations in a variety of immune responses.

An antigen was demonstrated on red cells from all pigeon squabs less than four days old. The antigen appears not to be secondarily adsorbed to the red cells from the fluids of the egg or the embryo. In vitro, masking of the antigen by components of adult serum does not occur under the conditions tested. Although the squab antigen behaves similarly to a known fetal red cell antigen in doves, it is probably qualitatively different from that antigen and from the known chick red cell antigen. The squab antigen is not detectable on lymphocytes from the bursa or the thymus.

Virgin female CBA/J mice were obtained after a variety of treatments and observed for primary tumors until either tumor onset or death. Included were mice which were: (1) immunosuppressed as adults by injection of anti-thymocyte serum (ATS); (2) injected with normal rabbit serum; (3) immunized with an irrelevant antigen or (4) untreated. Data were collected on tumor histology, incidence and time of onset for all groups. No tumors appeared during the period of ATS-immunosuppression or for several months following treatment. The most frequently observed subsequent tumor was the typical mammary tumor. Although the first tumors appeared in ATS-treated mice, the mean age at tumor onset was not significantly affected by ATS-immunosuppression. No unusual tumors and no lymphomas were observed. Tumor incidences among groups of mice purchased at different times were different, but unrelated to ATS-immunosuppression. The failure of ATS-immunosuppression to affect growth is consistent with the fact that cellular immunity to mammary tumors is often specifically compromised.

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