Detection of HLA class II-dependent T helper antigen using antigen phage display

Area of Science:

• Immunology
• Molecular Biology
• Vaccine Development

Background:

• Major histocompatibility complex (MHC) class II-dependent antigens activate CD4+ T helper (Th) cells, cytolytic T lymphocytes, and innate immune cells.
• These antigens are promising candidates for vaccines against cancer and infectious diseases.

Purpose of the Study:

• To develop a novel strategy for cloning MHC class II-dependent Th antigens.
• To establish a phage display system for presenting Th antigens to T cells.

Main Methods:

• A cDNA library encoding part of tetanus toxoid (TT) light chain with a Th epitope was displayed on phage (TT-phage).
• TT-specific Th cells were stimulated by TT-phages presented by autologous Epstein-Barr virus-transformed B cells (APCs).
• T cell activation was assessed using [3H]thymidine incorporation and cytokine release assays.

Main Results:

• TT-phages specifically activated two different TT-specific CD4+ Th cell lines.
• Significant Th cell stimulation was observed at a ratio of one TT-phage in 50 irrelevant phages.
• The phage display system demonstrated effective presentation of Th antigens.

Conclusions:

• The developed phage display approach provides a novel strategy for cloning MHC class II-dependent Th antigens.
• This method allows cloning using available Th cells and offers advantages over existing antigen cloning techniques.
• The strategy holds potential for advancing vaccine development against cancer and infectious agents.