Question

An important way in which effector T cells differ from naive T cells is that _____?

1) the cell-surface level of LFA-1 is lower on effector T cells
2) L-selectin is upregulated during differentiation of effector T cells
3) cellular proliferation occurs after effector T cells leave the secondary lymphoid tissues
4) the provision of co-stimulatory signals is not required to induce a response by effector T cells
5) effector T cells do not recirculate between lymph, blood, and secondary lymphoid tissues

Answer 1

Effector T cells differ from naive T cells in that they do not require co-stimulatory signals to induce an immune response, which is a key feature of their rapid reaction during an encounter with an antigen.

Step-by-step explanation:

An important way in which effector T cells differ from naive T cells is that the provision of co-stimulatory signals is not required to induce a response by effector T cells. Naive T cells, on the other hand, require these signals for activation. Effector T cells can immediately react upon encountering an antigen because they have already been primed during a previous encounter with the pathogen, thus forming part of the adaptive immune response's memory.

Effector T cells are the result of the differentiation of activated T cells and serve various functions in the immediate immune response. Unlike naive T cells, which circulate looking for their antigen, effector T cells can engage pathogens or infected cells immediately without the additional signals naive T cells require. Hence, their ability to respond without co-stimulation is a hallmark of their differentiation and specialization.