1Are critical to immune system function and develop from stem cells in bone marrow
Leukocytes (white blood cells)
2What are the 2 types of cells that stem cells develop into?
myeloid and lympoid
3Are largely responsible for innate immunity
Contain polymorphonuclear leukocytes (PMNs), monocytes/macrophages, and mast cells
myeloid cells
4Lymphocytes
Are largely responsible for adaptive immunity
Contain B cells, T cells, NK cells
lymphoid cells
5Neutrophils (most common leukocyte [60% of WBCs], phagocytic)
Eosinophils, basophils (induce inflamation)
polymorphonulcear leukocytes (PMNs)
6phagocytic, present antigen to T-helper cells
monocytes, macrophages
7inflammation, allergic responses
mast cells
9mature in thymus, function as T-helper (CH4+) or T-cytotoxic (CD8+) cells
T cells
10monitor for intracellular infections
NK cells
11development of all blood cell types
hematopoiesis
12sites of leukocyte development/maturation
primary lymphoid organs/tissue (bone marrow, thymus)
13sites where leukocytes screen for/ interact with pathogens
secondary lympoid organs/tissue (spleen [screens blood], lymph nodes [screen lymph], MALT/Mucosa-Associated Lymphoid Tissue [screens mucosal surfaces)
14T cell flow chart
Immature T cells (from bone marrow) -->
Thymus (T cell education and selection) -->
T-helper cells (CD4+) --> guide adaptive response
OR
T-cytotoxic cells (CH8+) --> find/destory cell with intracellular infections, cancer cells
15Are layered to maximize barriers to pathogen entry and growth
immune defenses
16layer 1: innate defense barriers are non-specific
physical barriers
chemical barriers
normal microflora
inflammation
17skin, mucous membranes, cilia, urine flow
physical barriers
18gastric acid, lysozyme enzyme
chemical barriers
19inhibit pathogen attatchment, growth
normal microflora
20a nonspecific (innate) response
inflammation
21what is the process of inflammation
initiated by tissue trauma
responding macrophages release vasoactive factors (e.g. histamine) and cytokines (e.g. TNF) that promote inflammation
results in blood vessel vasodilation + increased permeability in inflamed tissue
extravasation: leukocytes start 'rolling' along inflamed vessel wall, stop, exit vessel, chemotax to site of tissue damage
22binds/ neutralizes TNF (anti-TNF antibody)
used to treat arthritis, psoriasis, Crohn's disease
humira
23layer 2: phagocytes/phagocytosis
primarily by neutrophils and macrophages
patrol body's portals of entry, migrate to sites of inflammation
24What are the 2 steps of phagocytosis?
adherence/endocytosis: stimulated by antibody (inhibited by bacterial capsule)
digestion: phagosome fuses with lysosome, pathogen destruction (some intracellular pathogens can defeat phagocytosis)
25forms due to inefficient phagocytosis + chronic inflammation (common in TB, syphilis)
granuloma
26What allows phagocytes to 'see' and bind to their targets?
aherence facilitated by phagocyte's pattern recognition receptors that recognize microbe specific molecules (LPS, peptidoglycan)
antibodies bound to target cells also facilitate phagocyte adherence to target (called opsonization)
27a specific, final line of defense
adaptive immunity
28engages upon ineffective innate response
customized response against specific pathogen
utilizes lymphocytes (B and T cells)
results in immunological memory
characteristics of adaptive immunity
292 different parts of adaptive immunity
humoral and cell mediated
30what does humoral immunity rely on?
antibody (Ig) from B cells
31what is humoral immunity effective against?
extracellular pathogens
32(humoral immunity) proteins composed of 2 heavy (H) and 2 light (L) chains
antibodies (immunoglobulins)
33on antibody and are formed by variable regions of H and L chains
antigen-binding sites
34antibody binding to foreign antigens inhibits pathogen via mechanisms such as
neutralization (inhibits attatchment to body)
opsonization (stimulates phagocytosis)
35the part of an antibody that reacts with compliment or binds to the surface of cells such as macrophages
Fc region
36examples of antibody (Ig) classes
IgG: most abundant in blood, opsonizes, crosses placenta
IgA: present in body secretions (mucous, saliva, breast milk), main neutralizing Ig
IgE: binds mast cells, mediates allergic responses
37how the 'right' antibody is produced
clonal selection of naïve B cells stimulates (with T-helper cell help) cell division of only naïve B cells producing correct antibody able to bind specific antigen; results in the production of plasma B cells and memory B cells
38secrete antibody for immediate neutralization, opsonization
plasma B cells
39allow immunological memory (long-lived, possess membrane Ig)
basis for acquired long term immunity
secondary immune responses result from activation
memory B cells
40the process by which B cells become triggered to respond to an infection
occurs when a B cell receptor (BCR) on the surface of the B cell binds to a specific antigen
B cell activation
41two ways of B cell activation
T-cell dependent: activated T cell binds to B cell, providing additional signals that fully activate the B cell
T-cell independent: activated by certain antigens
42primary vs secondary humoral immune response
secondary responses are faster, greater magnitude with more specific antibody produced
43cell-mediated immunity eliminates
intracellular pathogens, cancer cells
44cell-mediated immunity responsible for
graft rejection
45cell-mediated immunity requires
T-cytotoxic and T-helper cells
46(chat) the process by which specific immune cells, like B cells and T cells, are selected and multiplied in response to an antigen
clonal selection
47Two types of acquired adaptive immunity
active (own antibodies)
passive (ready-made antibodies)
48active acquired adaptive immunity
natural: exposure to infectious agant
artificial: immunizations (vaccines)
49passive acquired adaptive immunity
natural: maternal antibodies
artificial: antibodies from other sources
50stimulate active immunological memory by inducing primary immune response
vaccines
51types of vaccines
-killed/inactivated bacteria or virus
-live but attenuated (weakened) pathogens
-specific antigens from pathogens
-toxoids are inactivated bacterial toxins
-DNA or mRNA vaccines
52goal of vaccination
increasing herd immunity
53what are hypersensitivities (allergies)
-an inappropriate immune response
-most common (type 1) involve antigen (allergen), IgE antibody, mast cells
-inapprotpriate inflammation responsible for symptoms
54Type 1 hypersensitivity reaction
immediate
55depends on allergen, sit of allergen exposure, number of sensitized mast cells degranulating
severity of reaction