B-Cell Activation
- Innate Immunity
- Adaptive Immunity
- Macrophages
- Neutrophils
- Dendritic Cells
- Mast Cells
- Eosinophils
- Basophils
- Natural Killer Cells
- Antigens
- MHC I and II
- Antibodies
- B Lymphocytes Overview
- B Cell Stages
- B-Cell Activation
- Plasma B-Cells
- Memory B-Cells
- T-Lymphocytes Overview
- T-Cell Stages
- Types of Activated T-Cells
Summary
B-cell activation describes the steps needed to turn on B-cells, to generate an antibody response to a threat. This process starts with resting B-cells engulfing foreign particles via endocytosis in the lymph nodes. After engulfing these particles, B-cells process and digest them into smaller fragments called antigens inside the cell, and present these antigens on a surface complex called MHC II. Once displayed on MHC 2, helper T-cells will recognize the antigen to determine if it is a threat. If the T-cell finds a threat, it will release cytokines, which act as signals to activate the B-cell. B-cell activation involves proliferation or multiplication of B-cells, as well as differentiation of these B-cells into their active forms in order to produce antibodies against the threat.
Key Points
- B-cell Activation
- Upon antigen binding to B-cell receptors, the B-cell:
- (1) endocytoses the antigen, then breaks it down into smaller fragments
- (2) presents the antigen fragments on its surface to helper T cells.
- Antigen is presented on major histocompatibility class II (MHC II) complex
- (3) Helper T-cells release cytokines (signaling molecules) to activate the B-cell
- (4) Activated B-cell then proliferates and turns into plasma or memory cells (see video)
- Upon antigen binding to B-cell receptors, the B-cell: