What is the primary function of Toll-like Receptors (TLRs)?

The primary function of Toll-like receptors (TLRs) is to recognize pathogen-associated molecular patterns (PAMPs) and damage-associated molecular patterns (DAMPs) which are critical for the innate immune response. TLRs play a vital role in the early detection of pathogens by being expressed on various immune cells, including macrophages and dendritic cells. When TLRs bind to their respective ligands, they initiate signaling pathways that lead to the activation of immune responses.

This activation primarily leads to the production of pro-inflammatory cytokines, which include both Th1 and Th2 cytokine responses. Th1 cytokines are typically associated with the cellular immune response, important in fighting intracellular pathogens, while Th2 cytokines are related to the humoral immune response, particularly in defense against extracellular pathogens and in facilitating allergic responses. Thus, the engagement of TLRs leads to a balanced induction of both Th1 and Th2 responses depending on the context of the immune challenge, making the option that indicates the induction of both Th1 and Th2 cytokine responses accurate.

In summary, TLRs are essential for the coordination of the innate immune response and facilitate communication between the innate and adaptive arms of the immune system, thereby promoting the activation of