Final answer:
Activated Th1 cells enhance the immune response by secreting cytokines that stimulate cytotoxic CD8+ T cells, increase the efficiency of macrophages and neutrophils, and augment NK cell functions, leading to the destruction of infected or dysfunctional cells.
Step-by-step explanation:
Activated Th1 cells can produce a variety of molecules that play critical roles in the immune response, particularly in killing infected or dysfunctional cells. Upon activation by an antigen-presenting cell (APC), Th1 cells secrete cytokines that perform different functions. One of their main roles is to stimulate cytotoxic T cells (CD8+ T cells), enhancing their ability to destroy infected cells. Additionally, Th1 cytokines can promote these cytotoxic T cells to differentiate into memory cytotoxic T cells, which are long-lived and can respond swiftly to secondary exposures to the same pathogen.
Furthermore, Th1 cells play a supportive role in stimulating macrophages and neutrophils, making them more efficient at killing intracellular bacteria. They also enhance the killing capacity of Natural Killer (NK) cells. It's important to note that Th1 cells themselves are a type of helper T cell, which express the CD4 glycoprotein on their surface, but the actual process of killing infected cells is generally carried out by the cytotoxic T cells, or CD8+ T cells, that have been activated by Th1-secreted cytokines.