Immunology Flashcards
Where is the site of B-cell localization and maturation?
Follicle of lymph node
Which part of the lymph node contains contain Reticular cells and Macrophages
Medulla
The region of the cortex between follicles and medulla is called
Paracortex
Where is T cells housed in the lymph node
Paracortex
Lymphatic drainage for the head and neck
Cervical Lymph node
Lymphatic drainage for the LUNGS
Hilar Lymph node
Lymphatic drainage for the Trachea and esophagus
Mediastinal Lymph Node
Lymphatic drainage for the Upper limb, breast, skin above umbilicus
Axillary Lymph node
Lymphatic drainage for the Liver, stomach, spleen, pancreas, upper duodenum
Celiac Lymph node
Lymphatic drainage for Lower duodenum, jejunum, ileum, colon to splenic flexure
Superior Mesenteric Lymph node
Lymphatic drainage for Colon from splenic flexure to upper rectum
Inferior Mesenteric Lymph Node
Lymphatic drainage for Lower rectum to anal canal (above pectinate line), bladder, vagina (middle third) cervix, prostate
Internal Iliac Lymph Node
Lymphatic drainage for Testes, Ovaries, Kidneys, Uterus
Para-aortic Lymph Node
Lymphatic drainage for Anal canal (below pectinate line), skin below umbilicus (except popliteal area), scrotum, vulva
Superficial Inguinal Lymph Node
T and B-cell activation is through
APC (antigen presenting cells)
What are the antigen presenting cells
B-cells, Dendritic cells, Langerhans cells, Macrophages
Which cells require Two signals before they can be activated
T-cells, B-cells and Class switching
Which SPECIALIZED APC cells sample antigens, processes antigens and migrates them to the draining lymph node
Dendritic Cells
What is the 1st signal in T-cell activation?
- Antigen is presented on MHC II and recognized by
TCR on Th (CD4+) cells— ( exogenous synthesized) - Endogenous or cross-presented antigen is presented
on MHC I to Tc (CD8+) cell
What is the 2nd signal in T-cell activation?
- Co-stimulatory signal via interaction of B7 protein on
dendritic cells (CD80/86) and CD28 on naive T cell.
** The cells activate and produce cytokines.
** Tc cells activate and is able to recognize and kill
virus-infected cells
What is B-cell receptor-mediated endocytosis
Foreign antigen is presented on MHC II and recognized by TCR on Th cell
Which receptor binds the CD40L on Th cell during B-cell receptor mediated endocytosis
CD40 receptor
What happens in B-cell receptor endocytosis after the binding of CD40 and CD40L
Th cell secretes cytokines that determine Ig class switching of B-cell
What determines the unique antigen-binding pocket
Fab region
What determines the Isotype (eg. IgM, IgD etc)
Fc region
Which cytokine when secreted causes 1. Fever, 2. acute inflammation, 3. activates endothelium to express adhesion molecules and 4. Induce chemokine secretion to recruit WBC’s
Interleukin -1
Interleukin-6 causes
Fever and stimulate production of acute phase proteins
Cytokine for Major Chemotactic factor for neutrophils
Interleukin-8
Interleukin-12
- Induces differentiation of T cells into Th1 cells and
2. Activates NK cells
What does Tumor necrosis factor-alpha do
- Activates endothelium 2. Causes WBC recruitment
3. Vascular leak
Which cytokines are secreted by T-cell
- Interleukin-2 and 2. Interleukin-3
Cytokine for Stimulating GROWTH of 1. Helper,
2. Cytotoxic and 3. Regulatory T cells and 4. NK cells
Interleukin-2
Interleukin-3 secretion is for
Supporting growth and differentiation of bone marrow stem cells. Function like GM-CSF
What are the components of innate immunity?
- Neutrophils
- Macrophages
- Dendritic Cells
- Natural Killer Cells (NK) - lymphoid origin
- Complement
How does innate immunity respond to pathogens?
- Nonspecific
- Rapid response (Minutes –> Hours)
- No memory response
What are the secreted proteins associated with innate immunity?
- Lysozyme
- Complement
- C-reactive protein (CRP)
- Defensins
What are the components of adaptive immunity?
- T cells
- B cells
- Circulating antibodies
How does adaptive immunity respond to pathogens?
- Highly specific
- Refined over time
- Develops over long periods
- Memory response that is faster and more robust
What are the secreted proteins associated with the adaptive immune response?
Immunoglobulins (Ig)
What cytokine is secreted by NK cells and T cells in response to antigen or IL-2 from macrohages
Interferon-gamma
Which cytokine stimulates macrophages to kill phagocytosed pathogens and inhibit differentiation of Th2 cells
Interferon-gamma
Cytokine that 1. Activates NK cells to kill virus-infected cells and 2. Increases MHC expression and antigen presentation by all cells
Interferon-gamma
Which cytokines is produced from Th2 cells
Interleukin-4, Interleukin-5 and Interleukin-10
Function of interleukin-4
- Induces differentiation of T cells into Th2 cells
- Promote growth of B cells
- Enhances class switching to IgE and IgG