Exam 2 Cell Mediated Immunity Flashcards
Specific/adaptive immunity involves:
B cells (humoral, antibody mediated)
T-cells (CD4) that help humoral or CMI pathways
T cell (CD8) CMI
After activation, some B and T cells become:
Memory cells (Anamnestic)
Adaptive (specific) immunity allows for ______ immune response
More rapid and robust
All T cells have which CD?
CD3
Which type of T cells have CD8
Cytotoxic T cells
Which type of T cells have CD4
Helper T cells (Th1 and 2)
Which CD is used for T cell signaling?
CD3
CD4 T helper cells recognize:
MHC II
Exogenous or “found” antigens
Th2 cells are associated with:
B lymphocytes
Th1 cells are associated with:
Macrophages
True or false: HLA and MHC are different things
False - they are interchangeable terms
What is presented to T cells?
Antigen-antibody complex
An antigen is internalized into B cell via:
Receptor mediated BCR endocytosis via Signal 1 and 2
Foreign antigen is presented to T cell as:
Non self
What are antigen presenting cells?
Macrophages
B cells
Dendritic cells
B cell activation by CD4 T helper cell is achieved by:
Signal 1 and Signal 2
Signal 1 consists of:
BCR and TCR
Signal 2 consists of:
B7 and CD28
Biomarker of native T cells
CD45RA
Biomarker of memory T cells
CD45RO
What is anergy?
Partial activation without a co-receptor; unresponsive; sign for apoptosis to occur
Anergy prevents:
Most types of autoimmunity and unregulated responses
In a primary humoral response, the primary antibody response produces __ which takes ____
IgM; 7-10 days
In a secondary humoral response, the antibody made is ___ which takes ____
IgG; 1-4 days
IgG class switching requires:
IL-4 and IFN-gamma
IgA class switching requires:
IL-4 and TGF-beta
IgE class switching requires:
IL-4 only
Memory IgA cells and plasma cells are formed near:
Mucosae
What are some common features of lymphoid tissues?
- outer cortex, inner medulla
- B cells cluster at the cortex (follicle)
- T cells in paracortex
When does germinal center develop in lymphoid tissues?
When antigen enters; at this point B and T cells found in secondary follicle
Which cells are part of innate immunity?
- Macrophages
- NK cells
- Neutrophils
True or false: T cells are involved in both innate and specific immunity
True
Phagocytosis is done by:
Receptor mediated endocytosis
Th1 antigen processing and presentation involves what cellular response?
Inflammation (associated with macrophages)
Microglia
Macrophages in CNS
Kupffer cells
Macrophages in the liver
Alveolar cells
Macrophages in the lungs
Difference between monocytes and macrophages
- Monocytes found in blood
- Macrophages found in tissue
Microglia are activated by:
- IL-1
- IL-6
- IFN-gamma
Kupffer cells are activated by:
- IL-1
- IL-6
- IFN-gamma
Alveolar cells are activated by:
- IL-1
- IL-6
- IFN-gamma
Macrophages can perform what forms of phagocytosis?
- opsonin mediated
- complement mediated (C3b, C5b)
- antibody-mediated phagocytosis
True or false: macrophages are antigen presenting cells
True
T-helper subsets (Th1, Th2) are defined by:
The profile of cytokines released upon activation
Which Th response occurs first?
Th1 - locally
IL-2 is for:
Proliferation
IL-6 is for:
Inflammatory
IL-4 is for:
Class switching
What does Th1 typically secrete?
IFN-gamma, IL-2
Where is the clonal expansion and class switching happening?
- germinal centers in lymph nodes
- mucosal associated lymph tissues (MALT) like Peyers Patches and the tonsils
Cytokines
a number of substances, such as interferon, interleukin, and growth factors, which are secreted by T-Cells and have an effect on other cells.
They aid in the maturation of B-cells, signal T-cells to replicate, and recruit other cells to the area
TH1 (in specific tissues) secretes _____ to promote the proliferation of T-cells, it also uses _____ to reduce mRNA activity and also the production of TH2 cells
IL-2, IFN-γ
TH2 (found in lymph nodes and mucosal associated lymph tissues) uses _____ to facilitate clonal expansion and class switching, it also uses ____ to aid in the production of IL-4 and keep the production of TH1 at bay
IL-4, IL-10
Th2 (CD4) cells are activated by ____ and secrete cytokines ___ upon activation
B cells; IL-10 and IL-4
Th1 (CD4) cells are activated by ____ and secrete cytokines ____ upon activation
Macrophages or monocytes; IL-2, IFN-gamma
____ suppresses the formation of mRNA to reduce expression of proteins/viral proteins
IFN-gamma
Which cytokine inhibits Th2 cytokines (IL-10)?
IFN-gamma
Both IFN-gamma and IL-10 are involved with ____ responses and ____ signaling
Localized; autocrine and paracrine
IL-10 inhibits:
Th1 cytokines (IFN)
Cytotoxic T cells (CD8) recognize MHC ___ and ____
MHC I; endogenous antigens like viruses and cancer
Cytotoxic T cells (CD8) provide a mechanism to:
Check “inside” another cell
Complete activation of CTL (CD8) requires:
Both signal 1 and signal 2
When CTL (CD8) cells become activated, what happens?
What do they release, and where?
They release polarized secretion of lytic granules that contain cytotoxins, only towards the target cell to reduce any damage to neighboring cells
What are perforins?
Form transmembrane pores in target cells - similar to MAC attack from complement cascade proteins (C6-C9)
What are granzymes and what do they do?
- they are serine proteases (trypsin-like) that enter the target cell through perforin pores
- activate nucleases to initiate apoptosis
Granzymes do not cause ____ of target cells so as to not ____
lysis; release infective particles that are inside the target cell
What is a stimulus or “signal” to undergo apoptosis?
(CTL)
CTL granzymes secreted into perforins
In apoptotic cells, _____ is lost so that ___ becomes externalized. This induces a “ ___ “ signal
PS asymmetry; PS; eat me signal
IL-2 induces:
Lymphocyte proliferation
Tumor necrosis factor (TNF) promotes:
Apoptosis
Interferon-gamma function
Limits mRNA production and translation
Natural killer cells lack CD_
CD3 (they have CD16 and 56)
Natural killer cells are important in:
Cell mediated immunity (viral-infected cells, anti-cancer activity)
Many tumors demonstrate ____ activity. ____ is downregulated
DNMT3; DNMT1
methylation occurs on MHC I genes on chromosome 6p
Cancers are associated with lower ____ expression
MHC I (HLA I)
Many viruses produce pro-viral transcription factors, which lower ________ expression
MHC I/HLA I
Natural killer cells comprise ___ of WBC
10%
NK cells are ____ cells
Antigen non-specific lymphoid
NK cells are closely related to ____ cells and secrete ____
CTL (CD8); perforin and granzymes
What immune cells secrete perforin and granzymes?
CTL and NK cells
____ are the first responders and mainly PMN phagocytic cells
Neutrophils
____ are associated with acute inflammation
Neutrophils
Neutropenia is associated with:
Periodontitis
If a patient is taking immunosuppressants or is immune compromised, the 1st cells suppressed is:
Neutrophils
Agranulocytosis
100% probability of infection, risk of death is 100%
<200 uL of neutrophils
During phagocytosis, the fusion of phagosome and lysosome forms:
Phagolysosome
PMN granules contain ____ and are released during ____
Antimicrobial proteins/proteases; degranulation
Primary (azurophilic) granules released during ____. The contents are stored in _____ form, which include ___, ___, ____
Phagocytosis; ACTIVE; lysosome, defensins, cathepsin B
Cathepsin B
Inhibits peptidoglycan
Secondary degranulation is regulated release following phagocytosis and are stored in ____ form
Inactive
What occurs during respiratory burst?
release of reactive oxygen species, such as superoxide (O2-), hydrogen peroxide, hydroxyl radical
True or false: respiratory burst may damage host
True - liquifies anything around it
IL-2 is required for:
Proliferation and clonal expansion of activated T cells
IL-2 acts in ___ and ___ manner
- Autocrine (binds to receptors on same cell
- Paracrine (binds to other nearby cells including Th, CTL, B cells, NK)
Diapedesis
Leukocyte extravasation; movement through intact capillary wall (inflammation)
Chemotaxis
Movement along concentration gradient
Chemotaxis is ___ mediated
Receptor
(IL-1, IL-6)
IL-1, IL-6, and TNF-alpha are:
Bone resorptive
IL-1 and TNF-a are produced by:
CTL, macrophages, Th1 cells
IL-1 and TNF-a are found in increased levels in patients with:
periodontitis GCF and gingival tissues
(Bone loss and resorption)
IL-8 serves as a chemoattractant for:
PMN (neutrophils)
IL-8 binds to
GPCR to initiate cellular response
Cytokine related diseases
Over or underexpression of cytokines
Bacterial septic shock involves ____ due to tissue pooling of fluids. Symptoms include:
Hypotension; disseminated intravascular coagulation, fever, multiple organ failure
What is responsible for many of the disease processes of septic shock?
Endotoxins (LPS) from gram-negative bacteria - stimulate release of cytokines (IL-1 and TNF-alpha)
Which bacteria produce superantigens that can bypass anergy?
S. aureus TSST-1 and S. pyogenes exotoxin A
True or false: No antigen recognition is involved for superantigens to bind
True - many T cells are activated to produce excessive amounts of cytokines (IL-1, TNF-alpha, IL-6)
What diseases are related to T-cell deficiency?
XL-SCID
DiGeorge syndrome
MHC deficiency
Omenn syndrome
True or false - XL-SCID can be inherited
True
Genetic deficiency of XL SCID
IL-2 receptor on X chromosome (required for IL-7R so IL-7 becomes non-functional)
Is XL-SCID common or rare?
Rare (but males more commonly affected)
XL SCID treatment
Pooled gamma globulins (passive immunization) to treat primary immunodeficiency (PID)
Which T-cell related disease is likely not inherited?
DiGeorge syndrome (90% is de novo deletion of 22q11.2)
____ is associated with thymic aplasia, cleft palate, and craniofacial disorders
DiGeorge syndrome
BLS1
MHC 1 deficiency
BLS1 is a mutation of
TAP1
BLS II
MHC II deficiency
Both Bare lymphocyte syndrome I and II are ____
Rare
BLS I is associated with what types of infections
Intracellular parasites, viral infections
Does BLS affect CMI?
Yes (both)
BLS II and Quie syndrome are a form of ____
SCID
______ are non functional in BLS II
Th1 and Th2
Chronic Granulomatous disease is also known as
Bridges-Good syndrome or Quie syndrome
Quie syndrome is associated with _____
Neutrophil dysfunction (can’t do respiratory burst but can do primary degranulation, inflammation, phagocytosis)
Kostmann syndrome inheritence pattern
Autosomal recessive
_____ is common with Kostmann syndrome
Periodontitis
Also neurological problems, seizures, learning disabilities, developmental delays
If you see a kid with periodontitis, it is likely that they have:
Kostmann syndrome
(kids don’t usually have periodontitis)
Chediak-Higashi syndrome inheritence pattern
Autosomal recessive
Chediak-Higashi syndrome - _____ is common
Periodontitis
If a patient has red eyes, light skin, hypopigmentation, and silvery hair with atypical recurrent gingivitis or periodontitis, they likely have what syndrome?
Chediak-Higashi syndrome
Severe congenital neutropenia (SCN) inheritence pattern
Autosomal dominant
Severe congenital neutropenia (SCN) is associated with ____ and is often fatal. and often requires ____ transplant
- common abscesses (cutaneous, internal organs)
- bacterial sepsis
- often requires bone marrow transplant
