What is the outcome when dendritic cells present antigens via class II molecules?

What is the outcome when dendritic cells present antigens via class II molecules?

• A. Activation of B cells
• B. Inhibition of T cells
• C. Stimulation of innate immunity
• D. Destruction of pathogens

Answer: (A)

When dendritic cells present antigens via class II major histocompatibility complex (MHC) molecules, the primary outcome is the activation of CD4+ T helper cells, which in turn plays a significant role in stimulating B cells. The interaction occurs as follows: dendritic cells process and present antigens from extracellular sources on their class II molecules, which are recognized by T cell receptors on CD4+ T cells. This recognition leads to the activation and proliferation of these helper T cells, which are crucial for orchestrating the immune response. Once activated, these T helper cells provide necessary signals—primarily through cytokine release—that promote the activation, differentiation, and proliferation of B cells. The B cells, stimulated by the cytokines and interactions with activated T cells, can then undergo class switching and affinity maturation, ultimately resulting in the production of antibodies specific to the presented antigen. This process is essential for generating a robust and effective adaptive immune response. Therefore, the correct outcome of dendritic cells presenting antigens via class II molecules is the activation of B cells through the mediation of CD4+ T helper cells.

When dendritic cells present antigens via class II major histocompatibility complex (MHC) molecules, the primary outcome is the activation of CD4+ T helper cells, which in turn plays a significant role in stimulating B cells. The interaction occurs as follows: dendritic cells process and present antigens from extracellular sources on their class II molecules, which are recognized by T cell receptors on CD4+ T cells.

This recognition leads to the activation and proliferation of these helper T cells, which are crucial for orchestrating the immune response. Once activated, these T helper cells provide necessary signals—primarily through cytokine release—that promote the activation, differentiation, and proliferation of B cells. The B cells, stimulated by the cytokines and interactions with activated T cells, can then undergo class switching and affinity maturation, ultimately resulting in the production of antibodies specific to the presented antigen. This process is essential for generating a robust and effective adaptive immune response.

Therefore, the correct outcome of dendritic cells presenting antigens via class II molecules is the activation of B cells through the mediation of CD4+ T helper cells.