Cells of the Acquired Immune System Immunology Review 377
CELL
T lymphs
Helper/inducer T cells
Cytotoxic/suppressor T cells
T regulatory cells
B lymphs
Plasma cells
Memory cells
FUNCTION
Cell-mediated immunity.
Orchestrate cell-mediated immunity. Activate B
cells, cytotoxic cells, & NK cells.
Suppressor cells inhibit helper T cells. Cytotoxic
cells kill other cells.
Suppress immune response to self.
After antigenic challenge, transform into blasts
that give rise to plasma cells & memory cells.
Ab production.
Respond to ag when encountered again with
↑speed & intensity.
COMMENTS
Derived from cells in bone marrow. Develop T-cell–
specific surface ags in thymus. 60%–80% of lymphs.
CD4+. 2/3 of peripheral T cells. Normal CD4 = 1,000/μL.
In AIDS, <200/μL.
CD8+. 1/3 of peripheral T cells. (Normal CD4/CD8 ratio
2:1. In AIDS, <0.5:1).
CD4+& CD25+.
Develop in bone marrow. When mature, have surface
Igs (IgM, IgD) that act as receptors for ags. 10%–20%
of lymphs.
In peripheral lymphoid organs. Nondividing. Die in a
few days.
In peripheral lymphoid organs. Live months to years.