Study Guide Exam 2: N6030
Mechanisms of Infectious Disease
Terminology: colonization, infection, pathogen, virulence, incubation, Acute, chronic etc.
Colonization – presence of microorganisms
Infection – presence, multiplication and tissue injury from microorganisms
Virulence – potential to produce disease
Incubation –
Acute – new, recent
Chronic – long lasting
Courses/stages of infectious disease (e.g. incubation; prodrome….etc.)
Incubation – after initial entry of pathogen, begins multiplication
Prodromal – host experiences general signs and symptoms of illness (infectious)
Acute – signs and symptoms of disease are most obvious and severe
Convalescence – pt returns to normal functions, some diseases do damage that cannot be
repaired
For Microorganisms in lecture:
Bacteria: how replicate and survive the immune system
Exotoxins and endotoxins, attach by pili or fimbriae
Virus: steps of virus invasion, impact of virus replication on host cell; How do viruses evade our
immune system (i.e. what happens to the influenza virus each year)?
1st- attachment to cell surface proteins (receptors) 2nd- penetration 3rd- uncoating: release of
nucleic acid 4th- replication 5th- assembly 6th- release of new virions
Viruses live inside host cells, receptors and antigens on surface mutate and change, evading the
immune system
Inflammation and Immunity
What are the mechanical/chemical barriers known as the ‘first’ line of defense? (what type of
immunity is it?)
Innate immunity – physical barriers like skin, mucous membranes; chemical barriers like mucous
secretions, saliva, perspiration, and the normal flora/microbiome
Inflammation process
How does it start? Be able to describe the whole process of inflammation
(what elements do what including mast cells and substances they
release; phagocytes, and plasma protein systems)
Starts with cellular injury or a pathogenic invasion; activates mast cell degranulation, activation
of plasma systems, and release of cellular products; leading to vasodilation, vascular
permeability, cellular infiltration, thrombosis, stimulation of nerve endings
Mast cell release/synthesize what substances?
what do these substances do? How are mast cells activated?
Mast cells are granulocytes! They release histamine, chemotactic factors, and cytokines. They
are triggered by physical, chemical, immunologic, activation receptors by virus or bacteria.
, Actions of white blood cells in inflammation –
What are the names of the cells, what do they do?
Neutrophils (granulocytes, first to arrive), basophils, macrophages, eosinophils, dendritic cells,
monocytes (mature into macrophages, longer lifespan, APC, release substances that promote
healing
How do phagocytes (name some) recognize foreign cells/microorganisms?
Phagocytes recognize foreign cells by PAMPs on pattern recognition receptors. Neutrophils,
monocytes, and macrophages
What is active acquired immunity? Third line of defense, lymphocytes (T and B cells, cellular
and humoral immunity)
There are different kinds of antibodies; when do they appear (i.e. when during the infection) or
where in the body are they found? What do antibodies do to help destroy an invader?
IgG: appears later in initial infection, long term protection against infection, can cross the
placenta; IgA: in the body secretions; IgM: rises first; IgD: not much known; IgE: parasites and
allergic reactions
Antibodies mark foreign cells by matching on surface proteins on the pathogen. Flagging them
for B cells. They are used for Neutralization, Agglutination, Precipitation, Opsonization, Activate
complement (classic pathway)
What is cell mediated immunity? What cell plays an important role?
T-cell recognition of cells infected by virus; releasing Interleukins (cytokines)
Differentiate between the humoral vs the cellular response
Humoral response is important defense against bacteria, B cells stimulated into plasma cells –
release more antibodies; Cellular response is important for defense against viruses, fungi, and
mutated cells. T cells bind to an APC and MHC I, stimulating cytokines and T cytotoxic and T
memory cells. Can induce apoptosis.
How is the organism ultimately destroyed by the immune response.
Differentiate between how the humoral and cellular systems destroy
invaders T cells stimulate Apoptosis of cells, and B cells stimulate Endocytosis by
phagocytes
How does your body know what’s you and what is a foreign invader?
i.e. what is MHC-I;
what happens with MHC-I when cells are infected?
Major histocompatibility complex, I is on all cells, II is on APCs. When MHC-I are infected the
cell takes a piece of the invader and present that on the MHC so it can be recognized by T cell.
What is an antigen presenting cell? What is the role of APCs?
How do APCs present antigens and to what cells? What class MHC do they have?
What are helper T cells? How do they communicate with other T-cells?
Antigen presenting cells recognizes foreign antigens, processes it, and presents the foreign
antigen on MHC II or MHC I (for self-cells that are infected) T cells communicate through
interleukins
Mechanisms of Infectious Disease
Terminology: colonization, infection, pathogen, virulence, incubation, Acute, chronic etc.
Colonization – presence of microorganisms
Infection – presence, multiplication and tissue injury from microorganisms
Virulence – potential to produce disease
Incubation –
Acute – new, recent
Chronic – long lasting
Courses/stages of infectious disease (e.g. incubation; prodrome….etc.)
Incubation – after initial entry of pathogen, begins multiplication
Prodromal – host experiences general signs and symptoms of illness (infectious)
Acute – signs and symptoms of disease are most obvious and severe
Convalescence – pt returns to normal functions, some diseases do damage that cannot be
repaired
For Microorganisms in lecture:
Bacteria: how replicate and survive the immune system
Exotoxins and endotoxins, attach by pili or fimbriae
Virus: steps of virus invasion, impact of virus replication on host cell; How do viruses evade our
immune system (i.e. what happens to the influenza virus each year)?
1st- attachment to cell surface proteins (receptors) 2nd- penetration 3rd- uncoating: release of
nucleic acid 4th- replication 5th- assembly 6th- release of new virions
Viruses live inside host cells, receptors and antigens on surface mutate and change, evading the
immune system
Inflammation and Immunity
What are the mechanical/chemical barriers known as the ‘first’ line of defense? (what type of
immunity is it?)
Innate immunity – physical barriers like skin, mucous membranes; chemical barriers like mucous
secretions, saliva, perspiration, and the normal flora/microbiome
Inflammation process
How does it start? Be able to describe the whole process of inflammation
(what elements do what including mast cells and substances they
release; phagocytes, and plasma protein systems)
Starts with cellular injury or a pathogenic invasion; activates mast cell degranulation, activation
of plasma systems, and release of cellular products; leading to vasodilation, vascular
permeability, cellular infiltration, thrombosis, stimulation of nerve endings
Mast cell release/synthesize what substances?
what do these substances do? How are mast cells activated?
Mast cells are granulocytes! They release histamine, chemotactic factors, and cytokines. They
are triggered by physical, chemical, immunologic, activation receptors by virus or bacteria.
, Actions of white blood cells in inflammation –
What are the names of the cells, what do they do?
Neutrophils (granulocytes, first to arrive), basophils, macrophages, eosinophils, dendritic cells,
monocytes (mature into macrophages, longer lifespan, APC, release substances that promote
healing
How do phagocytes (name some) recognize foreign cells/microorganisms?
Phagocytes recognize foreign cells by PAMPs on pattern recognition receptors. Neutrophils,
monocytes, and macrophages
What is active acquired immunity? Third line of defense, lymphocytes (T and B cells, cellular
and humoral immunity)
There are different kinds of antibodies; when do they appear (i.e. when during the infection) or
where in the body are they found? What do antibodies do to help destroy an invader?
IgG: appears later in initial infection, long term protection against infection, can cross the
placenta; IgA: in the body secretions; IgM: rises first; IgD: not much known; IgE: parasites and
allergic reactions
Antibodies mark foreign cells by matching on surface proteins on the pathogen. Flagging them
for B cells. They are used for Neutralization, Agglutination, Precipitation, Opsonization, Activate
complement (classic pathway)
What is cell mediated immunity? What cell plays an important role?
T-cell recognition of cells infected by virus; releasing Interleukins (cytokines)
Differentiate between the humoral vs the cellular response
Humoral response is important defense against bacteria, B cells stimulated into plasma cells –
release more antibodies; Cellular response is important for defense against viruses, fungi, and
mutated cells. T cells bind to an APC and MHC I, stimulating cytokines and T cytotoxic and T
memory cells. Can induce apoptosis.
How is the organism ultimately destroyed by the immune response.
Differentiate between how the humoral and cellular systems destroy
invaders T cells stimulate Apoptosis of cells, and B cells stimulate Endocytosis by
phagocytes
How does your body know what’s you and what is a foreign invader?
i.e. what is MHC-I;
what happens with MHC-I when cells are infected?
Major histocompatibility complex, I is on all cells, II is on APCs. When MHC-I are infected the
cell takes a piece of the invader and present that on the MHC so it can be recognized by T cell.
What is an antigen presenting cell? What is the role of APCs?
How do APCs present antigens and to what cells? What class MHC do they have?
What are helper T cells? How do they communicate with other T-cells?
Antigen presenting cells recognizes foreign antigens, processes it, and presents the foreign
antigen on MHC II or MHC I (for self-cells that are infected) T cells communicate through
interleukins
