When T cells are stimulated by antigens, the cell-mediated reaction is initiated by
the b______ing of antigen with an antigen r______r on the s_______e of a
sensitized T lymphocyte. Binding of the T cell receptor may occur d____ly or may
be mediated by m____ge-bound antigen.
Helper cells (Th) proliferate and function to pr___t antigen to a____y-forming B
cells in such a way to facilitate the interaction between antigen and the B cell. The
cells also aid in c____l-mediated immune responses.
Suppressor cells (Ts) are defined as cells capable of a___ing an otherwise
anticipated immune response and of t____ting an ongoing immune response. It
has been shown that there exists Ts cells which are specific for the c____l-
mediated immune response and other Ts cells specific for h____l immune
The mechanism by which Tc cells kill target cells is not well understood. Direct
contact between killer and target cell m_____nes, via undefined receptors,
apparently leads to m____e changes that cause l____is. These Tc cells are
important in t_____tion and t____or immunity.
Another mechanism by which T cells bring about cell-mediated immune reactions
is through proliferation of delayed h_____ty T cells (Tdh).
The final event is the generation of m____y T cells which function in the
anamnestic response upon subsequent encounter with a_____n.
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