Lymphocytes and Co-stimulatory receptors Flashcards
What type of immune response do T & B cells have?
Adaptive
What type of immune response do NK cells have?
Innate
Three lymphocytes?
NK cells = innate
T cells = cellular
B cells = humoral
Lymphocyte locations?
lymphoid organs, bone marrow, lymph nodes, intestine, peyers patches/ spleen, blood
Lymphocytes originate from
bone marrow stem cells
T cells from
thymus
Plasma cells produce
antibodies
B cells are from
Bursa
All adaptive immune response starts in the
secondary lymphoid organs
Memory B cells
recognize antigen & divide in plasma cells
T helper cells that help trigger immune response
Th1, 2, 17
Th1 stimulation will trigger
cellular immune response
Th2 stimulation will develop
antibodies humoral immune response
Th17 stimulation is only
humoral but not as important as Th2
Thymus
- T cells
- Paracortex lymph nodes
- Periarteriolar lymphoid sheets of spleen
- interfollicular areas in peyers patches
- 60-80% lymphocytes in blood
Bone marrow/ Bursa of Fabricus
- B cells
- Follicles in peyers patchs
- Cortex of lymph nodes
- Marginal zone in white pulp of spleen
- 10-40% lymphocytes in the blood
Tolerance
lack of immune response
Effector T cells
cytotoxic T cells to recognize infected cells w/ intracellular pathogens
-works on cancer cells, transplants, skin grafts rejected
B cells
- BCR-immunoglobulin
- immunoglobulins
- free foreign proteins
- Difficult tolerance induction
- Plasma cells, memory cells progeny cells
- immunoglobulins secreted
T cells
- TCR-protein (CD3, CD4, CD8)
- Processed foreign proteins in MHC antigens
- easy tolerance induction
- effector T cells, memory T cells progeny cells
- Cytokines secreted
TCR (T cell antigen receptor) types:
TCR α/β
TCR γ/δ
BCR (B cell antigen recpetor) types:
BCR α BCR γ BCR μ BCR ε BCR δ
Antibodies and B cell receptors are the same except
antibodies are free and B cell receptors are attached to cell membrane
What is the main function of T & B cell receptors?
to bind/recognize specific antigens
CD3
present in all T cells
CD4
present in all Th cells
-receptor for MHC II
CD8
present in all cytotoxic T cells (Tc)
-receptor for MHC I
T cell receptor function?
recognize the antigen
Transport receptor
transferrin CD71
Regulatory Receptors (T cells):
- Histamine-H3
- Immunoglobulins-FcR
- Complement- CD35, C3b, C4b
- IL-2 - CD25
- CD58 - CD2
What could be the effects on T cells activation?
- cell division, proliferate
- cell differentiation
- macrophages are activated release of cytokines
B cell receptors:
Complement receptors (IL-2, 4, 5) Antigen receptor (BCR) Cytokine receptors (C3b, C4b) Immunoglobulin receptors (IgM, IgG, IgE)
B cell activation effects?
produce antibodies, dividing, differentiating plasma Vs memory cells
Integrins
B1 (integrins, fibronectin, laminin, collagen)
B2 (integrins, intracellular adhesion molecule 1)
Selectins in vascular endothelial cells
P-selectin
L-selectin
E-selectin
Lymphocyte mitogens
Phyytohemagglitinin Concanavalin Pokeweed Lipopolysaccharide Bacille Calmette-Guerin Red Kidney Bean Jackbean Gram - bacteria Mycobacterium
Molecules/receptors that can regulate the lymphocyte functions:
cytokines, antibodies, compliment, antigen- can all modify behavior of T & B cells
CD4 & CD8 are expressed on
T cells, NOT B cells
