Ex 1: Immunology 1 Introduction to the immune system Flashcards
What is immunity?
resistance to infectious disease
What is an immune response?
coordinated reaction of the immune system to infectious microbes
What is Immunology?
study of the immune system, including its responses to microbial pathogens and damaged tissues and its role in disease
What is the main role of the immune system that is discussed in this class?
defense against infections
What is the immune system?
collection of cells, tissues, and molecules that mediate resistance to infections
What can a deficient immune system result in?
increased susceptibility to infections
What is used to boost immune defenses and protects against infections?
Vaccination
What cells are part of the innate immune response?
- Epithelial barriers
- Phagocytes and Sentinel cells (Neutrophils, Monocytes / Macrophages, Dendritic cells)
- Complement
- Natural Killer (NK) cells.
- IFN α/β (Type I interferons)
Is the innate immune system specific to antigens?
No!
- recognizes “Pathogen -associated molecular patterns” (PAMPs) that are shared by many different microbes, and Damage-associated molecular patterns (DAMPs)
Genes encoding receptors that recognize PAMPs are present in the…
germ line
- they do not use somatic recombination or hyper mutation
What does the innate immune response do in terms of clonal expansion, self reactive, and memory?
No clonal expansion
Nonreactive to self
No memory
What are the two parts of the adaptive immune system?
- humoral response
- cell-mediated response
What are the cells of the adaptive immune system?
Humoral response
- Antibodies produced by B cells
Cell-mediated response
- Cytotoxic T cells (CTLs)
- Helper T cells
How long does it take for the adaptive immune response to become effective?
days to weeks
Functional genes encoding antigen
receptors are or are not present in the germ line?
ARE NOT
What does the adaptive immune response recognize?
- highly antigen-specific
- Recognizes specific epitopes on specific proteins of specific pathogens
Functional antigen receptor genes are generated by somatic recombination and mutation of germ line genes during maturation of B cells and T cells before or after exposure to antigens?
before!
Clonal selection and proliferation of B and T lymphocytes specific for particular antigens before or after exposure to antigens?
after exposure to antigens
What does the adaptive immune response do in terms of clonal expansion, self reactive, and memory?
- clonal selection
- nonreactive to self
- has immunologic “memory”
What does the humoral immunity do?
- block infections and eliminate extracellular microbes
What does the cell-mediated immunity do?
- elimination of phagocytosed microbes
- kill infected cells and eliminate reservoirs of infection
What is the specificity part of the adaptive immune response?
ensures the distinct antigens elicit specific responses
What is the diversity part of the adaptive immune response?
enables immune system to respond to a large variety of antigens
What is the clonal expansion part of the adaptive immune response?
increased number of antigen-specific lymphocytes from a small number of naive lymphocytes
What is the memory part of the adaptive immune response?
leads to enhanced responses to repeated exposures to the same antigens
What is the specialization part of the adaptive immune response?
generates responses that are optimal for defense against different types of microbes
What is the contraction and homeostasis part of the adaptive immune response?
allows immune system to respond to newly encountered antigens
What is the nonreacticity to self part of the adaptive immune response?
prevents injury to the host during responses to foreign antigens
What are the steps of clonal selection?
- lymphocyte clones with diverse receptors arise in lymph organs
- clones of mature lymphocytes specific for many antigens lymph tissues
- antigen-specific clones are activated by antigens
- antigen-specific immune responses occur
What do B lymphocytes do?
mediators of humoral immunity
What do T lymphocytes do?
- mediators of cell-mediated immunity
- activation of phagocytes, killing infected cells
What do dendritic cells do?
initiation of T cell responses
What do macrophages do?
- effector phase of cell-mediated immunity
- phagocytosis and killing of microbes
What do follicular dendritic cells do?
display of antigens to B lymphocytes in humoral immune responses
What do granulocytes do?
killing microbes
What is the key mediator of the adaptive immune response?
B lymphocyte
Where do B lymphocytes mature?
bone marrow
Where do T lymphocytes mature?
thymus
Where do mature B and T lymphocytes circulate?
- lymph nodes
- spleen
- mucosal and cutaneous lymphoid tissues
What cell type is in the parafollicular cortex of the lymph node?
T cell
What cell type is in the lymphoid follicle of the lymph node?
B cell
What cells enter and pass through the lymph node quickly?
effector/memory T cells
What cells enter and pass through the lymph node slowly?
Naive T cell
What does the adaptive immune system secrete?
(secreted antibodies, phagocytes & helper T cells, cytotoxic T cells)
Does active immunity have specificity and memory?
Yes both
Does passive immunity have specificity and memory?
Specificity but not memory
