By means of a modified immune adherence (IA) technique, sera from melanoma patients were tested for the presence of antimelanoma antibodies. In total 13/73 sera tested showed a positive IA reaction of which 4/6 sera showed a positive reaction in the autologous situation. Sera from 33 patients with other tumors, 7 patients with non-neoplastic diseases and 50 healthy individuals did not show any IA reactivity towards melanoma cells. The reaction seemed to be selectively directed against tumor-associated antigens (TAA) on melanoma cells. No correlation with the stage of the disease could be found. Longitudinal studies indicated that conversions in antibody activity did not correlate with the clinical state of the patients. There was also no correlation with the corresponding in vitro data obtained in cell-mediated immunity tests. Cell lines and short-term cultures originating from tumors from different melanoma patients shared a common antigenicity. The expression of TAA on cells from a melanoma cell line fluctuated significantly during prolonged culture. The expression of TAA was influenced by the culture conditions and the growth state of the cells. A relation between TAA-expression and cell cycle phase was demonstrated.

Antibodies and antigen expression in human melanoma detected by the immune adherence test.

The density of antigens on the surface of allograft target cells seems to determine whether IgG antibody manifests predominantly its cytotoxic action or whether immunologicol enhancement can operate.

Effect of cell surface antigen density on immunological enhancement.

Publisher Summary This chapter provides an overview of the theoretical considerations and practical applications of complement research to tumor immunology in each of five projects—namely, (1) the immunological cell receptors, (2) immune adherence, (3) C1 fixation and transfer test, (4) complement fixation test, and (5) immune cytotoxicity test. Classical immunological concepts and methods that have been established and conducted by immunologists can now merge with new analytical methods based on molecular reactions. This has resulted in a renascence of immunology; and the precision and sensitivity of antigen–antibody reactions as analytical tools are recognized generally by researchers in the field of biological, physical, and behavioral sciences. During the past decade, extensive studies were carried out by many investigators in different laboratories on the isolation, purification, reaction mechanism, and submolecular fragmentation of each complement component and of intermediate antigen–antibody complement complexes. Consequently, it has become that complement is not merely a reaction system that kills bacterial and animal cells, but an immunopathological mediator or effector system in immunity and allergy.

Complement and tumor immunology.

The alloantibody response of LEW rats immunized with DA kidney homogenate or given vascularized DA kidney grafts was studied using an 125I-anti-Ig binding assay with kidney homogenate as the target tissue. A major component of the sera was found to be directed at a kidney-specific alloantigen. Analysis of LEW X (DA X LEW) F1 backcross rats showed that the locus coding for this antigen was not linked to the major histocompatibility complex (MHC). The use of these backcross rats, typed for both MHC and the kidney alloantigen, as kidney donors to LEW rats showed that the kidney alloantigen did not induce detectable graft damage and that only the DA MHC was involved in primary graft rejection of DA kidneys by LEW rats. Immunofluorescence studies localized the antigen to the basement membrane of proximal convoluted tubules, and to some Bowman's capsules. Strain distribution studies showed that only 2 of 11 strains were negative for the allele under study; these were the LEW and AS strains. Species cross-reactivity studies showed that rabbit, dog, and human kidneys could absorb this specificity, although more weakly than DA kidney.

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KIDNEY-SPECIFIC ALLOANTIGEN SYSTEM IN THE RAT Characterization and Role in Transplantation*

The future of tumor immunology.

SUMMARY The immune adherence technique was modified to permit a direct comparison between the reactivity of lymphocytes and kidney cells from the same person. These two cells were typed using 17 well characterized antisera. There were 82 significant discrepancies from a total of 234 direct comparisons. Absorptions with the negatively reacting cell resulted in diminished or absent serological activity against the positive cell type. The results support the concept that significant quantitative differences in the expression of isoantigens exist among different cell types.

Alice Siegel

Papers

Comparative typing of human kidney cells and lymphocytes by immune adherence1

SGLT2 Inhibitors are Associated with Improved Clinical and Hemodynamic Parameters in LVAD Patients