Lecture 19 (Immunity to Bacteria & Fungi) Flashcards
referred to as acquired or specific
a) adaptive immune response
b) innate immune response
a) adaptive immune response
what goes wrong in Johne’s disease?
a) M1 activation is achieved
b) TH1 cells produce IFNy
c) Th2 cells produce proinflammatory cytokines
d) M2 activation occurs
d) M2 activation occurs
*there is an inappropriate TH2 response producing regulatory cytokines
which is not one of the 3 major types of fungal infections:
a) Primary of the skin
b) Primary of the respiratory tract
c) Secondary opportunistic infections
d) Secondary obligate infections
d) Secondary obligate infections
fungal persistence will lead to _______ signaling TH17 cells to release IL-17 and activate inflammation & neutrophil recruitment
a) IL-2
b) IL-12
c) IL-23
d) IL-25
c) IL-23
fungal infections usually require a [humoral mediated/cell mediated] response
cell mediated response
defense against intracellular bacteria requires that macrophages are activated via the [M1/M2] pathway and that [CD4+/CD8+/ Both CD4+ and CD8+] are involved
M1
definitely CD4+ (Need TH1); some use both
referred to as native, natural, or non-specific
a) adaptive immune response
b) innate immune response
b) innate immune response
t/f: many bacteria are essential for the animal’s well-being
true
recognition of bacteria through TLRs and other receptors induces inflammation, cytokine release, and complement activation
a) early innate response
b) sustained adaptive response
a) early innate response
sustained adaptive response:
if the innate response is insufficient in clearing bacteria, __________ cells and ____________ ingest invading bacteria, and initiate adaptive immunity by producing cytokines and triggering both T and B cell responses
dendritic cells; macrophages
-quick
-not specific to antigen
-no immunologic memory
a) innate immunity
b) adaptive immunity
a) innate immunity
-slower
-specific
-has immunologic memory
a) innate immunity
b) adaptive immunity
b) adaptive immunity
dendritic cells, macrophages/monocytes, neutrophils
a) phagocytes
b) granulocytes
a) phagocytes
neutrophils, eosinophils, basophils, and mast cells
a) phagocytes
b) granulocytes
b) granulocytes
_________ are responsible in large part for the initial recognition of invading bacteria
TLRs
binding of microbial PAMPs to TLRs triggers a signal cascade that activates __________ genes that are critical in host defense
cytokine
in Rhodococcus equi infection, dendritic cells and macrophages secrete _________ which promotes __________ cell differentiation
secrete: IL-23
promotes: TH17
________ cells confer protection against extracellular bacteria and fungi, by triggering inflammation
TH17
Type I interferons are also readily produced in response to bacterial PAMPs, and boost macrophage responses enhancing their production of _________, _________, and _________
IFNγ, NO, and TNFα
____________ in very young horses is caused by Rhodococcus equip, a typical soil organism that has adapted to mammalian hosts. R. equip is common in the intestine of adult horses
pneumonia
_______ cells do not express antigen specific receptors. instead, they have receptors to ligand displayed by distressed cells
NK cells
some bacteria cause upregulated expression of NKG2D ligands on infected cells. causes activation of NK cells. activated NK cells produce a large amount of _________ that activate both macrophages and dendritic cells
IFNγ
bacteria can be destroyed by Complement acting through the alternate or lectin pathways. as a result, these bacteria are either ________ or _________
opsonized or lysed
what does mycobacterium cause?
tuberculosis
talk about immunity to Tuberculosis and Vitamin D
vitamin D receptors are up-regulated on activated macrophages
5 basic mechanisms for adaptive immunity to bacteria
- neutralization of toxins/enzymes by antibody
- killing of bacteria by the classical complement pathway
- opsonization of bacteria
- destruction of intracellular bacteria by activated macrophages
- killing of bacteria by cytotoxic T cells & NK cells
in diseases caused by _____________ bacteria such as Clostridium tetanus and Bacillus anthracis the immune response must not only stop the invading bacteria but also must neutralize the toxin
toxigenic
neutralization occurs when an antibody prevents the toxin from binding to its __________ on a target cell
receptor
this type of bacteria is able to get into the bloodstream from tissues
invasive bacteria
protection against invasive bacteria is usually mediated by antibodies directed against ________ ________
surface antigens
antibodies not only are effective opsonins themselves but also increase the binding of ________ by activating the classical complement pathway
C3b
antibodies generated against capsular antigens neutralize the _________ property of bacterial capsules, thus permitting their destruction of phagocytic cells
antiphagocytic
t/f: many antibodies have direct antimicrobial activities
true
antibodies against E. coli interfere with production of ______-binding protein enterochelin and thus prevent bacterial _________ scavenging
iron
________ and ________ antibodies against Borrelia burgdorferi (Lyme disease) damage surface proteins on the bacteria and are bactericidal in the absence of complement
IgM and IgG
when exposed to fever from the host, bacteria express certain proteins when under heat stress. what is this protein called?
heat-shock protein
examples of heat-shock proteins
HSP90, HSP70, and HSP60
t/f: heat-shock proteins are highly antigenic
true
Give an example of an intracellular bacteria that can grow inside macrophages
-Brucella abortus
-R. equi
protection against intracellular bacteria is mediated by macrophages activated through the [M1/M2] pathway
M1
M1 polarization of macrophages has been shown to be important in resistance to…
-Listeria monocytogenes
-Salmonella enterica Typhi and Typhimurium
-mycobacteria
-chlamydia
both _______ and ________ cells are involved in immunity to Listeria
CD4+ and CD8+
cell-mediated responses are required to control intracellular bacteria since only activated ___________ can prevent their growth
macrophages
macrophage activation requires that TH1 cells produce _____________
IFNγ
if an animal mounts an inappropriate TH2 response, cell mediated immunity fails to develop, [M1/M2] macrophages are generated, and chronic progressive disease may result
M2
what is Mycobacterium avid subsp. (MAP)
agent of Johne’s disease in cattle and other ruminants
Mycobacterium avid subsp. (MAP) infects and grows within the lining of the _________ in cattle and other ruminants
intestine
how is Mycobacterium avid subsp. (MAP) passed on?
passed through the milk of infected animals
t/f: there is no treatment or efficient vaccine for Johne’s disease in cattle
true
what is the mortality rate for Johne’s Disease in cattle?
100%
an exaggerated TH2 response causes equine asthma. how is the immune response shifted to Treg (less inflammatory)?
a) mutation of TLR molecule
b) activation of eosinophils
c) stabling only outside
d) the protective effects of low doses of inhaled microbial antigens
d) the protective effects of low doses of inhaled microbial antigens
used toward toxigenic bacteria
a) neutralizing antibodies
b) antibodies activate classical complement pathway leading to opsonization
c) activation of macrophages by T cells
d) antibodies interfere with bacterial metabolism
a) neutralizing antibodies
used toward intracellular bacteria
a) neutralizing antibodies
b) antibodies activate classical complement pathway leading to opsonization
c) activation of macrophages by T cells
d) antibodies interfere with bacterial metabolism
c) activation of macrophages by T cells
Vitamin D receptors are up-regulated in tuberculosis. how does this suppress infection?
a) more TLR 2/1 are produced
b) vitamin D makes you see better
c) byproduct produced is antimicrobial (cathelididins)
d) gun slingers don’t get enough milk
c) byproduct produced is antimicrobial (cathelididins)
three major types of fungal infections:
- primary infections by fungi that affect the skin
- primary infections by dimorphic fungi that mainly cause respiratory infections
- secondary infections by opportunistic fungi
the body uses both _______ and ________ mechanisms to defend itself against primary infections
innate and adaptive
neutrophils are activated by ______________ axis during fungal infections
*activates adaptive immune response
IL-23/IL-17 axis
both _______ and _______ responses are important in cellular immunity to fungi by enhancing pro-inflammatory reactions
TH1 and TH17
t/f: antibodies can neutralize bacterial toxins
true
t/f: antibodies alone will opsonize bacteria
true
antibodies and complement may opsonize bacteria or kill them directly through the terminal __________ complex
complement
what is the host defense to a bacterial infection process attaching to host cells?
blockage of attachment by secretory IgA antibodies
what is the host defense to a bacterial infection proliferating?
-phagocytosis (Ab- and C3b-mediated) -opsonization
-complement-mediated lysis
-localized inflammatory response
what is the host defense to a bacterial infection invading host tissues?
antibody-mediated agglutination
what is the host defense to a bacterial infection causing toxin-induced damage to host cells?
neutralization of toxin by antibody
cell-mediated immune responses are usually required to protect against _________ infections
fungal
