Module 2.2 Innate and Adaptive Immunity Flashcards
“Pleiotropic” cytokines
producing more than one effect
“Redundant” cytokines
duplicating the effect of another cell
Cytokines
soluble proteins, mediate interaction between immune and tissue cells
3 main cytokines
interleukins (IL’s)
interferons (INF’s)
Tumor Necrosis Factor Alpha (TNA-a)
Interleukins are produced by
macrophages and lymphocytes
Function of interleukins
Enhances acquired immunity
Interferon functions
modulates inflammatory response.
{Primarily protects against viruses.
TNA-a function
Endogenous Pyrogen. Fever producer.
Chemokines primary function
Control migration of leukocytes to the primary site of action.
-muab suffix in a drug name indicates that it targets
chemokines
Colony-stimulating factors (type of chemokine)
Stimulate the growth and differentiation of BM progenitors of immune cells.
How are colony-stimulating factors named
According to the cell they target. (monocyte stimulating factor, granulocyte stimulating factor, etc.)
Lymphocyte primary function
specifically recognize and respond to foreign antigens.
Accessory cells include:
Macrophages, Dendritic cells
Dendritic cells are derived from? What do they do?
macrophages - Antigen presenting cells (APC’s)
Bridge between the innate and adaptive immune systems
What are band cells and when are they seen in highest number?
Immature granulocytes that eventually mature into neutrophils.
Most common WBC in most cases
Neutrophils
Cells of Innate immunity
Neutrophils Eosinophils Monocytes Macrophages > Dendritic cells NK cells
Innate immunity consists of:
epithelial barriers and the cells of innate immunity
Neutrophils are also known as
Polymorphonuclear neutrophils (PMN’s)
Neutrophils
Early responder cells, primarily in blood and not tissue
Eosinophils
Ingest antigen-antibody complexes and viruses.
Monocytes
released by bone marrow, migrate to tissues, mature into macrophages and dendritic cells
Macrophages
Essential for bacteria clearance. Limit spread of infection until adaptive immunity kicks in.
NK cells primarily target:
Intracellular (viral) or bacterial pathogenic organisms.
How do NK cells avoid killing our own cells
MHC-1 Receptor on human cells binds to inhibitory receptor on NK cell preventing activations.
How does an NK cell know a cell is compromised?
Infected cell will stop producing the MHC-1 receptor peptide and the NK cell is no longer prohibited.
What are PAMP’s and are they innate or immune?
Pathogen associated Molecular Patterns.
Innate
Patterns on the cell membrane of pathogens which are recognized by the PRR (Pattern Recognition Receptors of the innate immune system.)
Opsonin
molecules that coat the cell membrane. Activates phagocytosis after PRR attaches.
Inflammatory cytokines
Moderate the reaction between immune and tissue cells. Short duration.
Acute Phase proteins are produced:
In the Liver in response to inflammatory cytokines. They activate the alternate compliment pathway Mannose-binding Ligand.
Example of acute phase protein
C-reactive protein.
3 phases of the compliment system
- Initiation/activation of immune process
- Amplification of inflammation
- Membrane attack response
How does the compliment system render bacteria more susceptible to phagocytosis?
By increasing bacterial aggregation.
How much of plasma protein is involved in the compliment system
15%
When is the adaptive immune response activated?
When the INNATE response initiates the inflammatory process
2 receptors of the innate immune system
Mannose and Toll like
B-cell production is stimulated by
antigen detection
The two functional cell types of the immune system
effector and regulatory cells
Effector cells
Leukocytes (Activated T-lymphocytes, mononuclear phagocytes, etc.). Eliminate the antigen
Regulatory cells function
Orchestrate and control immune response
Lymphocytes comprise approximately what percentage of WBC’s
35%
Lymphocytes arise from the lymphoid stem cells in bone marrow and differentiate into
B and T cells
Cells of adaptive immunity
Lymphocytes (B and T)
Macrophages and Dendritic cells as APC’s
Major histocompatibility complexes (MHC’s)
Identification of self vs non self.
The principle antigen presenting cell is the
macrophage
Macrophages are derived from
Monocytes
What do dendritic cells and macrophages present antigens to?
CD4 T cells (Helper T cells)
Where do we primarily find Tissue Macrophages
Lungs (alveolar MP's) Liver (Kupffer Cells) Spleen Lymph Nodes Peritoneum CNS
HLA antigens
Important in self vs non-self identification. VERY important in transplant matching.
Class I HLA’s
Presented to CD8 T cells (Killer T’s)
Class II HLA’s
Present to CD4 T cells (Helper T’s)
B cells are produced and matured where? Where do they primarily function
Bone marrow. In the humor (blood). Mostly target extracellular microbes and toxins.
Humoral immunity
B cells - extracellular
Cell mediated immunity
T cells - intracellular
Where do T cells mature
Thymus
Active Immunity
Specific Protection induced by exposure and activation of B and T cells
Passive Immunity
Specific protection induced by transfer of protective antibodies.
IgG transfer
crosses placenta (only IgG readily crosses)
IgA transfer
in colostrum (IgG and IgA in normal breast milk).
HBiG
Hepatitis B immune globulin. Given if exposed to Hepatitis B (needle stick)
When does fetal immunity start to develop. (Including thymus)
5-6 weeks
Lymphoid cells colonize fetal liver
When does IgA and IgM production start
shortly after birth (adult levels reached by 1 year)
Why are premature infants usually immune deficient?
Maternal IgG crosses placenta in largest amounts during final weeks of pregnancy (full term)
Umbilical cord blood should contain what Immunoglobulins
Only IgG
IgA or IgM detected in cord blood may indicate what?
Intrauterine infection. These would only be of fetal origin.
When does thymus gland start to decrease in size?
At puberty. Eventually shrinks to 15% of largest size.
Immune system changes in elderly
- Smaller thymus.
- Decreased # of both T cell types.
- Altered T cell response to antigens
- Decreased # of B cells but response to antigens is unchanged.
