Related Experiment Videos
Metabolically dependent and independent cell surface antigens
International Archives of Allergy and Applied Immunology
|January 1, 1977
Summary
Metabolically dependent antigens (MDA) require active cells for antibody binding, unlike blood group A and Forssman antigens. MDA antibodies induce cell death without complement, suggesting a vital cellular role.
Area of Science:
- Immunology
- Cell Biology
- Biochemistry
Background:
- Cell surface antigens vary in their dependence on cellular metabolic activity.
- Metabolically dependent antigens (MDA) are only accessible on metabolically active cells.
- Universally distributed antigens like blood group A and Forssman-type are accessible regardless of cell metabolism.
Purpose of the Study:
- To investigate the differential accessibility and cytotoxic effects of antibodies against metabolically dependent antigens (MDA) versus universally distributed antigens (blood group A, Forssman-type).
- To elucidate the role of complement in antibody-mediated cytotoxicity for different antigen types.
- To explore the potential functional significance of MDA in cellular processes.
Main Methods:
- Utilized cultured cells with varying metabolic activity.
- Applied antibodies against MDA, blood group A, and Forssman-type antigens.
- Assessed cytotoxicity through morphological changes (cell sheet disorganization) and release of radioactive labels.
- Investigated the effect of complement addition on cytotoxic reactions.
Main Results:
- Antibodies against MDA induced cell sheet disorganization without significant radioactive release, independent of metabolic activity.
- Complement enhanced radioactive release in MDA reactions but did not alter cell disorganization.
- Cytotoxicity for blood group A and Forssman-type antigens required complement and resulted in extensive release of cellular contents.
- Anti-MDA antibodies induced cytotoxicity without complement, unlike antibodies against the other tested antigens.
Conclusions:
- The accessibility and cytotoxic impact of cell surface antigens are antigen-specific and can be independent of cellular metabolic state.
- Metabolically dependent antigens (MDA) may play essential roles in cellular function, as indicated by their antibody-induced cytotoxicity without complement.
- Complement is crucial for the cytotoxic effects of antibodies against universally distributed antigens (blood group A, Forssman-type), leading to cell lysis.