Introduction to the immune system Flashcards
What are the four kinds of pathogens?
• bacteria (Extracellular and intracellular)
• Viruses (Intracellular)
• Fungi (Extracellular)
• parasites
-Protozoans and helminths
-ExtracellularHost response that prevents or combat infection and cancer
Immunity
Foreign substance, including part of infectious agent, that induces a specific immune response
Antigens (immunogens) 
- ability to induce an immune response
- All around us in nature
Immunogenicity (Antigenicity) 
- A molecule too small to inflict an immune response unless attached to a larger molecule like a protein
- however it can be recognized by an existing immune response
Hapten
- The part of antigen that anybody or T cell receptor recognizes
- A single antigen can have several of the same or different __________.
Epitope (antigenic determinant) 
- protein that binds to a specific antigen which help eliminate the antigen
- produced by B cells
Antibody
- peptides produced by cells, often cells of immune system, that help activate, suppress, or regulate other cells
- Think of them as hormones of the immune system
Cytokines
What are examples of physical barriers?
Skin, tears, mucus, etc.
Innate immunity is also known as…
Non-specific “natural immunity”
What are the two subtypes of innate immunity?
- resident
- Induced (Inflammation, activated macrophages, etc.
What are the two subtypes of adaptive immunity?
- Humoral (Antibody-mediated)
- cell-mediated (effector T cells) 
True or false, there is a lot of interactions and overlap between innate and adaptive immunity?
True
What are three major components of innate immunity? 
- phagocytes (Neutrophils, Monocytes/macrophages)
- NK cells (Kill virally infected and tumor cells, produce cytokines)
- complement (Enhances phagocytosis, recruit cells, kills cells/bacteria)
- Inflammation
What are two major characteristics of adaptive immunity?
Specificity and memory
What is the major cell type In adaptive immunity?
Lymphocytes
• B lymphocytes that produce antibodies
• T lymphocytes that regulate immunity, kill infected cells, activates macrophages, etc.
Do B lymphocytes or a T Lymphocytesrecognize naïve (whole) antigens?
B lymphocytes
-They also are one of the antigen presenting cells to T cells
Recognizes antigenic peptides presented by antigen presenting cells (Dendritic cells, macrophages, and B cells) 
T lymphocytes
Regulates immunity, kills infected cells, activates macrophages, etc.
T lymphocytes
_______________ T cells (CD__+ T cells) kills virally infected and cancer cells, as well as cells with intracellular bacteria
Cytotoxic, 8
T helper cells (CD___+ T cells)
4
What cells play a major role in cell mediated immunity?
Antigen-specific T cells
• cytotoxic T cells
• activation of macrophages by Th1 cells
T cells recognize peptide bound to…..
Histocompatibility complex (MHC) Molecules on antigen presenting cells (APC) 
Interactions between other cells surface molecules on APC and T cells
Second co-Stimulatory signal
CD8+ T cells: MHC ___
- endogenous antigen
CD4+ T cells: MHC___
II exogenous antigen
What two things happen during clonal selection?
- Eliminate self reactive cells
- expand cells specific for antigen
For clonal selection, What else is required besides Antigen recognitionan for activation of lymphocytes?
- T cell recognize peptide bound to major MHC molecules on APC
- need second co-stimulators signal e.g. interactions between other cell surface molecules on APC and T cells (without secondary signal —-> anergy)
Co-stimulatory signal plus specific signal —-> activates T cell while….
Specific signal alone ———-> T cells becomes _______.
anergic
Type of immunity that is generated by the individual.
Long-term but takes time to generate
Active immunity
Ex: vaccination
Type of immunity that is transferred.
Rapid but transient
Passive immunity
Ex: anti-venom, maternal antibody (IgG)
Generation of immune response against another individual
Isoimmunization
