How do B cells function as antigen-presenting cells?

Introduction. In addition to their role as secretors of antibodies, B cells function as professional antigen-presenting cells (APCs) for CD4+ T cells by expressing cell-surface major histocompatibility complex class II (MHCII) molecules with bound peptide, the ligand of the α/β T cell receptor.

Are B cells professional antigen-presenting cells?

B lymphocytes are regarded as professional antigen-presenting cells (APCs) despite their primary role in humoral immunity. As a result, B cells inactivate T cells that recognize nonspecific antigenic epitopes presented by B cells, or they induce regulatory T cell differentiation or expansion.

What is the role of B cells in an immune response?

Key Points. By producing antibodies, B cells are main players in the protective immune response against pathogenic infections. In response to antigens, they mature into antibody-producing plasma cells or into memory B cells, which can quickly be reactivated following secondary challenge.

Why is antigen presentation important in the immune system?

Antigen presentation serves to ensure adaptive immune responses are initiated to invading microorganisms. Therefore, in an effort to survive in the host, pathogens target antigen presentation pathways and disable their function.

What are professional antigen presenting cells?

Professional antigen presenting cells (APCs) are immune cells that specialize in presenting an antigen to a T-cell. The main types of professional APCs are dendritic cells (DC), macrophages, and B cells. The T-cell is activated when it interacts with the formed complex.

Which B cells are antigen presenting cells?

Antigen-Presenting B-1 Cells (26) first demonstrated evidence of the role of B-2 cells in the CD4+ T cell response by showing a failure of proliferative T cell responses to protein antigens in B cell-depleted mice.

Which cells are considered professional antigen presenting cells?

Professional antigen presenting cells (APC), i.e., dendritic cells (DC), monocytes/macrophages, and B lymphocytes, are critically important in the recognition of an invading pathogen and presentation of antigens to the T cell-mediated arm of immunity.

What are three professional antigen presenting cells?

The immune system contains three types of antigen-presenting cells, i.e., macrophages, dendritic cells, and B cells.

How do naive B cells recognize antigens?

When they recognize an antigen, naïve lymphocytes receive three types of signals: an antigen signal through the TCR or BCR, a co-simulatory signal, and a cytokine signal. If a naïve cell receives all three signals, it differentiates into an effector cell.

What makes a cell an antigen-presenting cell and what role does this type of cell play in an immune response?

An antigen-presenting cell (APC) is an immune cell that detects, engulfs, and informs the adaptive immune response about an infection. Sometimes a dendritic cell presents on the surface of other cells to induce an immune response, thus functioning as an antigen-presenting cell. Macrophages also function as APCs.

Do B cells make plasma cells?

B cells differentiate into plasma cells that produce antibody molecules closely modeled after the receptors of the precursor B cell. Once released into the blood and lymph, these antibody molecules bind to the target antigen (foreign substance) and initiate its neutralization or destruction.