B cells and Antibodies Lecture Review

This set of flashcards covers essential concepts related to B cells and antibodies, including their structure, function, activation, and roles in the immune response.

What is the primary function of antibodies in the immune response?

Antibodies neutralize toxins, opsonize microbes, and prevent infections.

Describe the structural similarities between B Cell Receptors (BCR) and T Cell Receptors (TCR).

Both BCR and TCR have variable regions for antigen recognition, but BCR is secreted as antibody while TCR is never secreted.

What determines the function of an immunoglobulin (Ig)?

The C-terminal constant regions of heavy and light chains determine Ig function.

What is somatic hypermutation?

It is a process that improves the binding affinity of antibodies for antigens through random DNA mutations primarily in the variable regions.

What triggers B cell activation and subsequent differentiation?

B cell activation occurs when BCR binds to an antigen and additional signals are provided through coreceptors and kinases.

What is the role of class switching in B cells?

Class switching allows B cells to switch the heavy chain constant region while retaining the same antigen-binding specificity.

What are the distinguishing features of IgG?

IgG is the most abundant immunoglobulin in blood, has a monomeric structure, and is crucial for long-lived B cell memory.

How do antibodies provide protection against viruses like influenza?

Pre-existing antibodies can bind to virus particles and block their ability to bind to cell surface receptors, preventing infection.

What is opsonization?

Opsonization is the coating of microbes with antibodies to enhance their phagocytosis by immune cells such as macrophages.

What is the significance of clonal expansion in B cell responses?

Clonal expansion allows for rapid proliferation of B cells to create large populations of functionally identical cells for effective immune responses.