Figure 1.

Immune activation of mammalian system with phage display antigens. (1) Particulate nature of phage activates the antigen-presenting cells (APC), which process the antigens for immune presentation. (2) Presentation of processed antigens by major histocompatibility complexes (MHC) class I molecules to CD8 T cells, which leads to T-cell activation. (3) Antigens are presented by MHC class II molecules to CD4 T cell, which in turn activates T_h1 and T_h2 effector cells. (4) T_h1 cells generate cytotoxic T-cell (CTL) responses and help produce interferon γ (IFN-γ). (5) T_h2 cells activate B cells to make antibodies. (6) Direct activation of B cells by phage vaccines also leads to massive antibody response. T-cell receptors are denoted by TCR.