Delayed type hypersensitivity to allogeneic cells in mice. II. Cell transfer studies

Area of Science:

• Immunology
• Cellular Immunology
• Transplantation Immunology

Background:

• Cell-mediated immunity plays a crucial role in recognizing and responding to foreign antigens.
• T lymphocytes are key mediators of adaptive immune responses, including those against allogeneic cells.

Purpose of the Study:

• To investigate the cellular mechanisms underlying the transfer of sensitivity to allogeneic cell surface antigens.
• To identify the specific lymphocyte subsets responsible for mediating this transfer of immune sensitivity.

Main Methods:

• Transfer of lymphoid cells from sensitized mice to naive recipients.
• Assessment of sensitivity via antigen challenge and observation of cellular infiltration.
• Characterization of responsible cells using T lymphocyte enrichment and antibody-mediated depletion (anti-Thy-1.2 serum and complement).
• Analysis of T cell subsets (Lyl+, Ly2+3+) and Ia+ cells.

Main Results:

• Immune sensitivity was successfully transferred to naive mice via lymphoid cells from sensitized donors.
• Sensitivity manifested as mononuclear cell infiltration 24-48 hours post-antigen challenge.
• T lymphocytes were identified as the primary mediators of this transfer.
• Both Lyl+ (helper) and Ly2+3+ (cytotoxic) T cell subsets were involved.
• Depletion of Ia+ (MHC class II) cells did not affect the transfer of sensitivity.

Conclusions:

• T lymphocytes are sufficient to transfer allogeneic cell surface antigen sensitivity.
• Both helper and cytotoxic T cell populations contribute to this immune transfer.
• The transfer mechanism is independent of Ia+ antigen-presenting cells, suggesting direct T cell recognition or effector function.