Immune System

Immune System {Function}

• Comprises of cells, tissues and molecules that cooperate to prevent and eradicate infection/tumor

• Tissue regeneration & scarring

• Perform immune surveillance

Autocrine

Signaling molecule that acts on itself

Paracrine

Signaling molecule that acts on nearby cells

Endocrine

Signaling molecule that acts on distant cells

Cytokines

1. Paracrine

2. Autocrine

3. Endocrine

Innate Immunity {Role, Examples}

Natural born, and acts as the first line of defense (nonspecific)

• Epithelial barriers

• Mast cells (release chemical mediators during inflammation/allergic reactions such as histamine, heparin, )

• Dendritic cells (activate T-cells by presenting small piece of pathogenic antigens to it)

• Innate Lymphoid cells: respond to infection or tissue damage by producing cytokines

• NK cells: eliminate infected/abnormal cells

• Complement system: promote inflammation that help destroy pathogens

• Phagocytic cells

Adaptive Immunity

Acquired immune defense hence it’s slow & specific due to involving cell activation, proliferation, differentiation

• B-lymphocytes

• T-lymphocytes

Humoral Immunity

Target extracellular microbes by immunoglobulin/Igs a.k.a antibodies/Abs produced by B-lymph cells

Cell-Mediated Immunity

Target intracellular microbes by T-lymph cells

Passive Immunity

Received Abs rather than self-produced therefore it’s fast & temporary

Active Immunity

The body produces Abs through microbial exposure/vaccination. It takes time but the memory retains

Lymphocyte Repertoire

• A characteristic of adaptive immunity where the cells have diversity (recognize variety antigens) & specitivity (distinguish antigens structure)