GENERAL HISTOLOGY

Detailed explanation-1: -In previous studies researchers identified a special group of T cells, called suppressor T cells, which can shut down the normal function of other important immune system cells called monocytes and dendritic cells. Normally, monocytes and dendritic cells help trigger immune responses.

Detailed explanation-2: -Regulatory T cells (Treg cells) also have CD4 on their surface, but they do not activate the immune system like helper T cells do. Instead, regulatory T cells play a protective role by shutting off the immune response when it is no longer needed.

Detailed explanation-3: -T cells require two signals to be activated. The first signal comes through their antigen receptor, and the second signal comes through CD28 and is typically provided by APCs: monocytes, macrophages, dendritic cells, or B cells.

Detailed explanation-4: -Abstract. Regulatory T cells (Tregs), either natural or induced, suppress a variety of physiological and pathological immune responses.