Exam 4 Concepts Flashcards
1
Q
Antigens
A
- Any molecule that can stimulate a response by T and B cells
- Consist of protein, polysaccharide, and other compounds from cells and viruses
- Can also be environmental chemicals
2
Q
Major Histocompatibility Complex
A
- Known as Human Leukocyte Antigen (HLA)
- MHC molecules - series of glycoproteins
- Found on all cells EXCEPT RBCs
- 2 Classes of MHC
- Class I - Code for markers that display unique characteristics of self and allow for the recognition of self molecules and the regulation of immune reactions
- Class II - code for immune regulatory receptors; antigen-presenting cells (APCs)
Includes macrophages, dendritic cells, and B cells
3
Q
What are antigen presenting cells? What do they do?
A
- MHC-II: Macrophages, dendritic cells, and B cells
- Dendritic are most common
- Modify antigens so it will be more immunogenic and recognizable
- Once antigen is processed, it moves to the surface of the APC bound to the MHC-II receptor to make it accessible to T cells during presentation
4
Q
What is opsonization?
A
- Antibodies called opsonins
- When antibodies (opsonins) coat a cell
- Microorganisms or other particles are coated with specific antibodies so that they will be more readily recognized by phagocytes, which will dispose of them
5
Q
What is antibody neutralization?
A
Antibodies fill the surface receptors on a virus or the active site on a bacterial protein, which prevents them from attaching to their target cells
6
Q
What is agglutination?
A
- Antibodies can aggregate cells by cross-linking them into large clumps
- Renders microbes immobile and enhances their phagocytosis
7
Q
What are monoclonal antibodies (MABs)? What do they do?
A
Originate from a single clone and have a single specificity for antigen
8
Q
What are hybridomas?
A
- An artificial cell line that produces monoclonal antibodies
- Formed by fusing (hybridizing) a normal antibody-producing cell with a cancer cell, and it can produce pure antibody indefinitely
9
Q
What is active immunity?
A
- Active: when an individual receives an immune stimulus (microbe that activates specific lymphocytes, causing an immune response such as production of antibodies
- It is an essential attribute of an immunocompetent individual
- It creates a memory that renders the person ready for quick action upon reexposure to that same microbe
- It requires several days to develop
- Can last for a relatively long time, sometimes for life
10
Q
What is passive immunity?
A
- Passive: when an individual receives immune substances (primarily antibodies) that were produced actively by the immune system of another human or animal donor; recipients are protected for a time even though they have not had actual exposure to the microbe
- Lack of memory for the original antigen
- No production of new antibodies against that disease
- Immediate onset of production
- Short-term effectiveness because antibodies have a limited period of function; recipient’s body disposes them
11
Q
What is natural immunity?
A
Encompasses immunity that is acquired during any normal biological experience of an individual but not through medical intervention
12
Q
What is artificial immunity?
A
- Protection from infection obtained through medical procedures
- Vaccines and immune serum
13
Q
Artificial Passive Immunity
A
- Immunotherapy
- A patient at risk for acquiring a particular infection is administered a preparation that contains specific antibodies against that infectious agent
- Pooled human serum from donor blood (gamma globulin) and immune serum globulins containing high quantities of antibodies are the usual sources
- Immune serum globulins are used to protect people who have been exposed to certain diseases such as hepatitis A, rabies, and tetanus
14
Q
What are antitoxins?
A
- Special types of antibodies that neutralize bacterial exotoxins
- Globulin fraction of serum that neutralizes a specific toxin
- Botulism
