Exam 1 9/21 Kingsley Immuno Flashcards
Cells and tissues of the immune response
Cluster of Differentiation
- membrane-bound proteins present on different cell types
- often have a known/specific function
- may have overlapping functions
- ~350 CD markers identified by monoclonal antibodies
Monoclonal antibodies
- made by a single clone of B cells against one epitope
- antibodies from resulting plasma cell (B-cell) react with the same antigen in the same way
Two main branches of immune response:
- Lymphoid
- Myeloid
What cells are common lymphoid progenitor cells (CLP)?
B cells, T cells, natural killer (NK) cells
Lymphoid cell types
- common lymphoid progenitor CLP
- Hemopoietic/hematopoietic stem cells (HSC)
- B (bone marrow) humoral; T (thymus) T-helper, CTL (cytotoxic T lymphocytes)
- lymphoblasts (immature lymphocytes)
White blood cells (WBC) also called:
leukocytes
___ of leukocytes are lymphocytes
30%
Majority of lymphocyte are:
T-lymphocytes (T-helper, CTL); 70% of lymphocytes
Characteristics of innate immunity
- non-specific
- rapid action, readily available
- no long term memory
Specific immunity
- specific response to specific pathogen
- adaptive to the organism - takes time
- immunologic memory (secondary/anamnestic response)
What is an anamnestic response?
secondary response
Antibody
protein/immunoglobulin binds antigen
Antibodies are _______ response
humoral (B-cell)
Substance (foreign) bound by antibody
Antigen
Epitope
Specific part (sequence) of antigen
Immunogen
Substance that stimulates immune response (either CMI T cell or antibody humoral response)
CMI =
cell mediated immunity
Majority of leukocytes are:
innate immune cells (neutrophils, basophils, eosinophils –> PMN)
What kind of appearance do innate immune cells have?
Granular appearance
What appearance do lymphocytes have?
Agranular
Natural killer cells are not ____
Lymphocytes (they are granular)
BCR
B cell antigen receptor (when secreted it is an immunoglobulin or antibody)
CD79 function
Forms BCR-CD79 complex; intracellular signaling
CD79 has a similar role to:
CD3 on T cells
CD21
complement receptor
CD19
Co-receptor for CD21, lost in plasma cells (antibody secreting)
What immune cells are found in the oral cavity?
Macrophages, B cells, T cells, neutrophils
Describe the nucleus of B lymphocytes
Huge nucleus
If a B cell has never been activated before, it has bound ____
IgM
Explain this image
- BCR composed of IgM and Iga/Igb/Syk (CD79) forms BCR complex
- CD21/CD19 complement receptor/coreceptor
CD21 and CD19 are a part of:
Complement pathway; innate immunity
How do CD21 and CD19 help in B cell activation?
Enhances both signaling pathways (BCR-CD79, CD21-CD19); reduces B-cell activation threshold
True or false: complement is necessary for B cell activation
False - although it helps reduce B cell activation threshold
Which T-lymphocytes have CD4 on their cell surface?
Th1, Th2, Treg cell
Th1
Helper T cells type 1
Th2
Helper T cells type 2
Which T-lymphocyte has CD8 on their cell surface?
CTL (cytotoxic T cell)
CD3 has a similar role to what B-cell component?
CD79 - intracellular signaling
TCR-CD3 is found on:
all T cells (Helper T cells 1 and 2, CTL, Treg cell)
TCR
T cell receptor
CD3
Signaling (TCR-CD3); similar role to CD79 B cells
CD4 T-helper cells recognize:
MHCII on APC; exogenous or “found” antigens
TH1 is associated with which APC?
Macrophages
TH2 is associated with which APC?
B-lymphocytes
TH1 function
Aids in inflammation and innate immunity
TH2 function
Aids in humoral and adaptive (specific) immunity
CTL recognizes:
- MHC I on APC
- endogenous antigens (viruses, cancer)
CTL cells provide a mechanism to check:
“inside” another cell
Differences between BCR and TCR
- BCR binds “soluble” or non-complexed/presented antigens; TCR binds antigen-MHC “bound” or presented antigen
- BCR is 4 chains, TCR is 2 chains
- CD79 in BCR, TCR has CD3
Describe how memory B cells are formed
Naive B lymphocytes bind antigen (antigen recognition), proliferate, differentiate/secrete antibodies (plasma cell) –> memory B cell
Describe how memory T cells are formed
Naive T lynphocytes recognize antigen via APC, proliferate, differentiate, form memory T cell
Plasma cells secrete:
antibodies (BCR)
Polyclonal antibody
From multiple clones, many epitopes
Memory B cells retain ____ in order to:
BCR; to remember the antigen
Memory B cells aid in:
greater number for faster, bigger anamnestic response
Compare naive/activated B cell morphology
Naive B cell has large nucleus, activated B cell has large cytoplasm and golgi apparatus
Antibody-mediated humoral immunity is produced by ___ with assistance from ____
B cells (plasma); Th2 (T-cells)
Antibody-mediated immunity is a protective response against:
Extracellular immunogens (bacteria, viruses - viremic stage, toxins)
Cell mediated immunity is mediated by:
CTL
Cell mediated immunity protects against:
intracellular pathogens: viruses and bacteria (mycobacteria)
Natural killer cells lack which cluster of differentiation?
CD3 (they have CD56 and CD16)
Phagocytosis occurs via:
Receptor mediated endocytosis
Which immune cells perform phagocytosis?
Monocytes, macrophages, neutrophils, dendritic cells
Mononuclear phagocytes
monocytes, macrophages
Mononuclear phagocytes are ___ specific
Tissue
Microglia cells found in:
CNS
Kupffer cells found in:
Liver
Alveolar cells found in:
Lungs
Which cells are derived from myeloid (myeloblasts)?
- macrophages and monocytes
- dendritic cells
- PMNs (neutrophils, Eosinophils, Basophils and mast cells)
What are langerhans cells
Dendritic cells found in skin
What are follicular dendritic cells?
DC found in lymph
DC cell types (red)
- langerhans cells
- follicular DC
- interdigitating DC
PMN leukocytes
Neutrophils, basophils, eosinophils
Basophils are associated with:
allergy
Eosinophil
worms (helminths)
____ are extremely important in non-specific innate immunity
Neutrophils
Neutrophils are primarily _____ cells and ______
phagocytic; first responders
True or false: neutrophils make up about 50% of all leukocytes
True
What myeloid cells are found in high concentrations in skin, respiratory, and GI tract?
Eosinophils, basophils, mast cells
FCeRI degranulation in eosinophils releases:
major basic protein and eosinophil cationic protein, which is toxic to helminths
What component on eosinophils facilitates FCeRI access?
Bound IgE on eosinophil that comes into contact with helminth
FCeRI degranulation in basophils and mast cells releases:
histamine
Histamine function
increases vascular permeability (swelling, inflammation)
Rank granulocytes, monocytes, and lymphocytes regarding their front and side scatter (flow cytometry analysis)
Lymphocytes < monocytes < Granulocytes (most)
Front scatter
Size
Side scatter
Granularity
Hemopoietic or Hematopoietic stem cells come from:
bone marrow
True or false: HSC come from common lymphoid progenitors
True
Where does the thymus originate from?
3rd pharyngeal pouch
The thymus is the site of:
T-cell processing, differentiation
True or false: most T cells survive
False - most do not survive (T-cell selection)
Most T cells are active during:
first two years of life
T-cell processing and differentiation is involuted by:
puberty
epithelial reticular cells (ERC) are in the:
thymus
ERC contain:
thymic hormones
Hassall’s corpuscle
Contains thymic hormones ERC type VI, site of dendritic cell maturation
When you are little, thymus is
Large - allows child to make a lot of antibodies.
- thymus is filled with fat when you get older
Primary lymphoid tissues
Bone marrow, thymus
Secondary lymphoid tissues
Lymph node, spleen
Function of lymph nodes
Filter antigens in lymph, which drains the tissues
In the lymph node, B and T cells are found in the:
secondary follicle
During lymphatic circulation. interstitial fluid enters ______ and ultimately enters either ____ or _____
network of lymphatic vessels; thoracic duct or right lymphatic duct
What happens when antigen enters afferent lymph vessel?
- Flows through sinuses, enters lymph node
- germinal center develops
- B-cells and T-cells in secondary follicle
Lymphoid hyperplasia
Increased number of lymphocytes in lymph nodes due to infection of bacteria/viruses
- increased number of secondary lymphoid follicles, germinal centers
Right lymphatic duct drains _____ and empties into ____
upper right quadrant; right subclavian vein
Thoracic duct drains ____, empties into ____
All except UR quadrant; left subclavian vein
Spleen function
removes old red blood cells from circulation, major site of antibody synthesis
Spleen location
Left upper quadrant (under ribcage, above stomach)
Spleen contains:
white pulp, germinal centers, red pulp
White pulp of spleen contains:
Periarterial lymphatic sheath or PALS (T-cells); lymphoid nodules (B cells)
Spleen germinal centers contain:
activated B/T cells, encapsulated bacteria
Red pulp splenic sinuses filled with:
blood; up to 1 cup stores
Cords of billroth
Connective tissue; functions to filter blood, removes defective RBC
Loss of spleen increases:
risk/susceptibility to bacterial infection
Asplenia incurs the highest risk to bacteria that have:
Capsules
Mucosal associated lymphoid tissues (MALT)
Organized centers of lymphoid tissue; high concentrations of microfold or M-cells
Peyer’s patches are associated with:
lowest portion of small intestine (jejunum, ileum)
Describe M-cells structure
Unique type of epithelial cell, lack microvilli, thinner cell body, highly concentration in areas of MALT
MALT
Mucosal associated lymphoid tissues
Function of M cells
transfer soluble and particulate exogenous antigens across mucosa (transcytosis); “sample” extracellular environment
Waldeyer’s ring
Pharyngeal tonsil (adenoid), tubal tonsils (2), palatine tonsils (2), lingual tonsil
What type of tissue is found in adenoid pharyngeal tonsil?
Pseudostratified epithelium
True or false: palatine tonsils contain pseudostratified epithelium
False
Tonsil near roof of nasopharynx
Adenoid (pharyngeal tonsil)
Tonsils at right and left sides at the back of throat
Palatine tonsils
What connective tissue is found in palatine tonsils?
Stratified squamous non-keratinized epithelium
Two small mounds of lymphatic tissue at base of tongue (either side)
Lingual tonsils
What are some mononuclear phagocytes
How do mononuclear phagocytes process antigens?
Through phagocytosis - receptor mediated endocytosis
Thymic hormones - name 2
thymosin, thymulin
Thymic humoral factor name?
Thymopoietin