Question

B lymphocytes arise from hematopoietic stem cells that commit to the B cell lineage in response to signals from a variety of soluble factors and as a result of interactions with cells in their environment. Antigen binding by surface immunoglobulin is insufficient on its own to activate B cells. The activation of B cells is modulated by co-receptors, which include receptors for what?

Complement
Protein A
Pilin
Phytohemagglutinin
C-reactive protein

Answer 1

B cells require co-receptor engagement for full activation, with one important group being receptors for complement proteins.

Step-by-step explanation:

B cells, also known as B lymphocytes, are a crucial component of the adaptive immune system and play a pivotal role in humoral immunity. They produce antibodies and can act as antigen-presenting cells (APCs). For a B cell to be fully activated, the engagement of its B cell receptor (BCR) with a specific antigen is not enough.

Activation requires additional signals through co-receptors. One key co-receptor group includes receptors for complement proteins, such as the complement receptor 2 (CR2/CD21), which binds to fragments of complement proteins that are bound to antigens. This interaction enhances the B cell's response to the antigen.