Exploring the molecular switches that govern immune defense and homeostasis.
Immune receptors constitute a diverse group of cell surface and intracellular molecules essential for antigen recognition, signal initiation, and immune regulation. Through precise ligand binding, these receptors enable the immune system to distinguish self from non-self with surgical precision.
Figure 1: Complex signaling pathways initiated by immune receptor engagement.
The BCR complex is the primary sensor for B lymphocytes. It pairs membrane-bound immunoglobulin (mIg) with signaling subunits Igα (CD79a) and Igβ (CD79b).
Unlike BCRs, TCRs recognize antigenic peptides presented by MHC molecules. This process requires a sophisticated co-receptor system to maintain signal fidelity.
The TCR itself lacks signaling domains and relies on the CD3 complex to transduce activation signals, leading to effector subset differentiation.
Fc receptors bridge humoral and cellular immunity by recognizing the constant region of antibodies:
| Receptor Type | Function |
|---|---|
| FcεRI | Mediates immediate hypersensitivity (Allergic responses). |
| FcγRIIB | Inhibitory receptor; prevents excessive inflammation. |
Checkpoints like PD-1 act as the "brakes" of the immune system. While essential for preventing autoimmunity, tumor cells often exploit these pathways to evade immune detection.
Biofargo team
