Page 461 - Atlas of Histology with Functional Correlations

Cytokines secreted by helper T cells increase the proliferation of activated B

cells
B cells differentiate into plasma cells and secrete antibodies to destroy
foreign substances
Other activated B cells remain as memory B cells for future defense against
the same antigens

Natural Killer (NK) Cells and Antigen-Presenting

Cells (APCs)

Develop from the same precursors as B cells and T cells
NK cells attack virally infected cells and cancer cells as do cytotoxic T cells
APCs phagocytose and present antigens to T cells for response
APCs belong to the mononuclear phagocytic system

APCs include connective tissue macrophages, perisinusoidal macrophages
(Kupffer cells) in the liver, Langerhans cells (dendritic) in the skin, and
macrophages in the lymphoid organs

TYPES OF IMMUNE RESPONSES

Innate Immune Response

First line of defense that limits the spread of infection
Response composed of the rapid response of phagocytic cells and their
functions

Response is nonspecific and does not produce memory cells

Adaptive Immune Response

Targets specific invading organisms and provides specific or adaptive

response
Response is slower than innate response but produces memory cells that can
respond to secondary encounters
Production of long-lived memory cells is main function of adaptive immunity

Two types of specific responses are humoral and mediated immune responses

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