Question

During activation, naive CD4+ T cells

A) interact with antigen presenting cells
B) reduce movement
C) begin to divide
D) all of the above

Answer 1

Naive CD4+ T cells are activated through a process that includes interaction with antigen presenting cells, reduced movement, and cell division, culminating in the activation and proliferation of these cells to engage in immune response.

Step-by-step explanation:

During activation, naive CD4+ T cells interact with antigen presenting cells (APCs), reduce movement, and begin to divide. This multifaceted process, as illustrated in various figures, begins when CD4+ T cells engage with MHC II molecules on APCs, such as dendritic cells. As a result, the naive T cells become activated. This activation leads to the proliferation of T cells which then can activate other cells of the immune system including B cells and CD8+ T cells, the latter becoming cytotoxic T cells that are crucial in killing infected cells.

The activation process encompasses antigen uptake by APCs, followed by antigen processing and presentation in combination with MHC II molecules. This interaction is pivotal, as it primes the T cells to proliferate and diversify to perform their effector functions. Consequently, the correct answer to the student's question is D) all of the above.