IMMUNOLOGY

Detailed explanation-1: -The immune system recognizes invaders by their antigens, which are proteins on the surface of the invading cells (see Figure 1). Every cell or substance has its own specific antigens, and a person’s cells carry “self-antigens” that are unique to that individual.

Detailed explanation-2: -The immune system recognizes and destroys, or tries to destroy, substances that contain antigens. Your body’s cells have proteins that are antigens. These include a group of antigens called HLA antigens. Your immune system learns to see these antigens as normal and usually does not react against them.

Detailed explanation-3: -The conserved microbe-specific molecules, referred to as microbe-or pathogen-associated molecular patterns (MAMPs or PAMPs), are recognized by the plant innate immune systems pattern recognition receptors (PRRs).

Detailed explanation-4: -A macrophage is the first cell to recognize and engulf foreign substances (antigens). Macrophages break down these substances and present the smaller proteins to the T lymphocytes. (T cells are programmed to recognize, respond to and remember antigens).

Detailed explanation-5: -Antigens, small molecules, or peptides capable of eliciting an immune response are key elements in this process of distinguishing self from nonself. Antigens serve as labels that enable the immune system to distinguish between a normal interaction (self) and an encounter with a foreign threat (nonself).