Chapter 6: Role of Lymphocytes in Adaptive Immunity Flashcards
What cells process antigens to present them to lymphocytes
Monocytes and macrophages (APCs)
Which cells respond to foreign antigens that have been processed by monocytes and macrophages?
Lymphocytes
General term for chemical messengers
involved in immune system communication
Cytokines
Cytokines secreted by lymphocytes
Lymphokines
Cytokines secreted by monocytes
Monokines
Cytokines that interfere with the multiplication of viruses within the cell (and adjacent cells)
Interferons
Cytokines that convey regulatory signals between cells
(including leukocytes) of the immune system
Interleukons
Cytokines that destroy foreign or abnormal cells,
including tumor cells; act early in inflammatory cytokine
signaling cascades
Tumor necrosis factors
Where do precursor cells of the lymphatic system form/
Bone marrow
What are the two fates of precurser cells of lymphocytes in the bone marrow?
1) Migrate to the thymus to become T lymphocytes (CD4+ or CD8+)
2) Remain in bone marrow and develop B lymphocytes.
What are the primary lymphoid organs?
Bone marrow and thymus
What types of T cells’ TCRs recognize Ag/MHC II?
CD4+
What types of T cells’ TCRs recognize Ag/MHC I?
CD8+
Which types of T cells are helper cells?
CD4+
Which types of T cells are cytotoxic?
CD8+
What is needed to stimulate CD4+ T helper cells?
Presentation of antigens from the processed (phagocytosed, lysomally digested, with surface displayiing MHC II carrier) pathogen by macrophages/APCs.
What happens when CD4+ T helper cells are stimulated?
1) They help the proper Ab-producing B cells proliferate, differentiate into plasma cells, and make Ab.
2) Activate CD8+ cytotoxic T cells that can eliminate infected cells by recognizing Ag with MHC I on their surface and destroying them.
Why are certain B cells chosen by stimulated CD4+ cells?
Their surface Ab could bind the foreign Ag, internalize it, and display pieces on their surface with MHC II to indicate they would be useful Ab-producing cells to expand
How do CD8+ cells eliminate infected cells?
Either by perforin or apoptosis
Make up 2/3 of circulating lymphocytes
T cells
Make up 10-15% of circulating lymphocytes.
Natural killer cells
True or false: Natural Killer cells need time to become activated and function effectively
False
True or false: B and T cells must already be immune competent in order to participate in immune responses.
True
True or false: The programming process by which lymphocytes acquire immune competence involves rearrangement of gene segments within the developing B and T lymphocytes; this occurs after Ag exposure
False: Occurs before Ag exposure
What are the antigen receptors on T cells?
TCRs
What are the antigen receptors on B cells?
Ab
What does the programming process by which B and T cells gain immune competence involve?
Rearrangement of gene segments resulting in antigen receptors on the cell surface that allow the lymphocyte to recognize and respond to a specific antigen.
