Lecture 4 - Overview of the Immune System Flashcards
Which type of immunity is the first line of defense and fast but nonspecific?
Innate
Which type of immunity is slower to develop, usually taking 5-6+ days?
Adaptive
Which type of immunity uses a limited number of receptors to detect pathogens that are encoded in the germline?
Innate
Which type of immunity uses randomly generated antigen receptors that are highly specific to individual molecules?
Adaptive
Which type of immunity induces local inflammation?
Innate
Which type of immunity is responsible for specific immune responses, clears infections, and results in memory?
Adaptive
The whole immune response can be split up into 8 general phases. Listed below are these 8 phases. What order do they occur in?
- Activation of antigen-specific B-cells.
- Elimination of pathogen by effector cells and antibody.
- Emigration of effector lymphocytes from peripheral lymphoid organs.
- Inflammation, complement activation, phagocytosis, and destruction of pathogen.
- Maintenance of memory B-cells and T-cells and high serum or mucosal antibody levels. Protection against reinfection.
- Formation of effector and memory T-cells.
- Interaction between antigen-presenting dendritic cells and antigen-specific T-cells: recognition of antigen, adhesion, co-stimulation, T-cell profileration, and differentiation.
- Interaction of T-cells with B-cells, formation of germinal centers. Formation of effector B-cells (plasma cells) and memory B-cells. Production of antibody.
4, 7, 1, 6, 8, 3, 2, and 5
What do pattern recognitino receptors (PRRs) recognize?
PRRs recognize broad categories of molecules that are commonly found in pathogens (pathogen associated molecular patterns, PAMPs).
What do dendritic cells use to recognize pathogens?
PRRs
How do sensor cells induce an inflammatory response?
Sensor cells induce an inflammatory response by producing mediators such as chemokines and cytokines.
Redness, heat, swelling, and pain are all hallmarks of what?
Inflammation
Where do immature dendritic cells reside? Where do they migrate to?
Immature dendritic cells reside in peripheral tissues. They migrate (via lymphatic vessels) to regional lymph nodes.
What do mature dendritic cells activate? Where do they do this?
Mature dendritic cells activate naive T-cells inlymphoid organs such as lymph nodes.
Through which 3 signal steps do antigen presenting cells (APCs) activate T-cells?
Activation, Survival, Differentiation
Which molecule presents antigen to T-cells?
Antigen is presented using a major hisocompatibility complex (MHC), which interacts with TCR.
True or False?:
The epitope of an antigen is always easily accessible.
False
The epitope of an antigen can be a piece of peptide buried within a protein.
What is the secreted form of the BCR also called?
Antibody or Immunoglobulin
Where do antibodies circulate?
Antibodies circulate in the serum (fluid component of blood).
True or False?:
B-cells and T-cells arise and mature in the bone marrow.
False.
B-cells arise and mature in the bone marrow. T-cells arise from bone marrow progenitors but are generated and mature in the thymus.
How do BCRs and TCRs differ in the forms they exist in?
BCRs can be membrane-bound or secreted as antibodies while TCR only exists membrane-bound.
How do BCRs and TCRs differ in their ability to see antigen?
BCR can see Ag in its natural form while TCR can only see small pieces of the Ag bound to molecules of the MHC on the surface of APCs.
True or False?:
Individual B- and T-cells each have an individual specificty for a single antigen. Each lymphocytes expresses many identical copies of one receptor with specificity for one antigen.
True
How are potentially self-reactive immature lymphocytes removed?
Lymphocytes are removed by clonal deletion if they react to self antigen?
What happens when a naive B- or T-cell interacts with it specific antigen?
When a naive B- or T-cell interacts with its specific antigen, it is selected and becomes activated. Activation results in proliferation, producing a large number of clones. Each clone is reactive against the antigen that initially stimulated the original lymphocyte.
What gives rise to effector cells?
Effector cells are formed from T- and B-cells that have been activated in lymphoid organs.
What is the difference between humoral immunity and cell-mediated immunity?
Humoral immunity combats pathogens via antibodies. Cell-mediated immunity involves primarily T lymphocytes.
True or False?:
Cell-mediated immunity is mediated by B-cells.
False
Cell-mediated immunity is mediated by T-cells.
True or False?:
Humoral immunity is mediated by antibodies produced by B-cells.
True
True or False?:
Helping to activate B-cells, helping to activate macrophages, and directly killing infected cells are all activites of T-cells in which type of immunity?
Cell-Mediated Immunity
How does humoral immunity contribute to adaptive immunity?
Humoral immunity contributes to adaptive immunity by producing specific antibodies.
