Lecture 17 part 1- soical behaviors

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What is the primary function of B cell receptors (BCRs) on the surface of B cells?

Inhibit B cell proliferation

Bind to antigens (correct)

Secrete cytokines

Promote helper T cell activation

Why is antigen binding to BCRs alone often insufficient for full B cell activation?

Absence of co-stimulatory signals (correct)

Lack of cytokine production

Excessive helper T cell activity

Overexpression of IgM

What role do helper T cells play in the activation of B cells?

Inhibit B cell proliferation

Promote antigen recognition

Provide co-stimulatory signals (correct)

Directly secrete antibodies

Why is the microenvironment of secondary lymphoid organs crucial for B cell activation?

To provide signals necessary for B cell activation Signup and view all the answers

Which stimuli are involved in promoting B cell proliferation and differentiation besides antigens?

Cytokines and co-stimulatory molecules Signup and view all the answers

What is the ultimate fate of differentiated B cell clones in the humoral immune response?

Differentiate into memory B cells Signup and view all the answers

Which type of immune cell presents antigens to T cells via MHC molecules?

Dendritic cells Signup and view all the answers

Where do activated B cells and CD4+ T cells migrate and interact within lymphoid organs?

At the boundary between T cell and B cell zones within lymphoid follicles Signup and view all the answers

What is the role of follicular helper T (Tfh) cells in B cell responses?

Tfh cells interact with B cells in germinal centers to promote affinity maturation and memory B cell generation. Signup and view all the answers

What is the primary function of germinal centers within B cell follicles?

Germinal centers are where B cells undergo somatic hypermutation to increase their affinity for the antigen. Signup and view all the answers

What is the primary mechanism by which B cells increase the affinity of their B cell receptors (BCRs) during an immune response?

B cells undergo somatic hypermutation of their BCR genes, leading to the selection of higher affinity variants. Signup and view all the answers

Which two key events occur in the late stages of a B cell response?

Affinity maturation and class switching Signup and view all the answers

Which type of immune cell is primarily responsible for capturing and presenting antigens to B cells?

Dendritic cells Signup and view all the answers

What is the primary signal that triggers B cell proliferation and differentiation upon antigen binding?

Binding of the antigen to the B cell receptor Signup and view all the answers

Which of the following is a key process involved in the generation of memory B cells during the humoral immune response?

Somatic hypermutation Signup and view all the answers

What is the primary function of antibodies produced by plasma cells during the humoral immune response?

Neutralizing pathogens Signup and view all the answers

Which of the following processes is responsible for improving the affinity of antibodies for their target antigens over time during the humoral immune response?

Affinity maturation Signup and view all the answers

What is the primary function of memory B cells generated during the humoral immune response?

Producing high-affinity antibodies Signup and view all the answers

Which of the following statements accurately describes T-dependent responses?

They contribute to long-term immunity through high-affinity antibodies and memory B cells. Signup and view all the answers

Which of the following statements accurately describes T-independent responses for multivalent antigens?

They are triggered by multivalent antigens with repeating epitopes, without T cell help. Signup and view all the answers

Which of the following statements accurately describes the antibodies generated in T-independent responses?

They are primarily of the IgM isotype and have low affinity. Signup and view all the answers

Which of the following statements accurately describes the involvement of follicular B cells in immune responses?

Follicular B cells are involved in T-dependent responses, interacting with helper T cells in germinal centers. Signup and view all the answers

Which of the following B cell subsets are involved in T-independent responses?

Marginal zone B cells and B1 cells Signup and view all the answers

Which of the following statements accurately compares T-dependent and T-independent responses?

T-dependent responses involve follicular B cells and generate high-affinity antibodies, while T-independent responses involve marginal zone B cells and B1 cells and generate low-affinity antibodies. Signup and view all the answers

Which of the following statements accurately describes the process of antigen recognition by B cells?

B cells capture protein antigens through receptor-mediated endocytosis or phagocytosis, and the internalized antigens are processed within endosomes or lysosomes. Signup and view all the answers

What is the role of helper T cells in the interaction with B cells during antigen recognition?

Helper T cells express T cell receptors (TCRs) that specifically recognize peptide-MHC complexes presented by B cells, leading to their activation. Signup and view all the answers

Which of the following statements accurately describes the process of antigen presentation by B cells to helper T cells?

Processed antigen peptides are loaded onto class II MHC molecules within endosomes or lysosomes, and these complexes are then transported to the cell surface for recognition by helper T cells. Signup and view all the answers

What is the role of co-stimulatory signals provided by B cells in the activation of helper T cells?

Co-stimulatory signals provided by B cells, such as the interaction between CD80/86 (B7) on B cells and CD28 on T cells, further enhance the activation of helper T cells initiated by the recognition of peptide-MHC complexes. Signup and view all the answers

Which of the following statements accurately describes the role of B cells in the immune response?

B cells capture and process protein antigens, and present them to helper T cells, which in turn provide co-stimulatory signals to activate B cells for antibody production. Signup and view all the answers

What is the significance of the interaction between B cells and helper T cells in the context of the immune response?

The interaction between B cells and helper T cells is crucial for the development of germinal centers and the generation of long-lived plasma cells and memory B cells. Signup and view all the answers