Innate Immunity (Lecture 2) Flashcards
Innate lymphoid cells (ILCs)
• ILCs are the most recently identified family of innate immune cells.
• Although they belong to the ____ lineage (lymphocytes), they lack T- or B-cell antigen receptors and thus cannot respond in an ____ manner.
- ILCs are predominantly found at ____ surfaces (e.g., skin, airways, and intestine), where they regulate immunity, inflammation, and tissue repair.
- ILCs can additionally maintain immune tolerance toward the ____ in the gut.
lymphoid
antigen-specific
barrier
commensal microbiota
Innate lymphoid cells (ILCs) cont
• Different groups of ILCs express distinct sets of ____ and thus are responsible for ____ functions.
cytokines
specialized
ILCs are the innate counterparts of specific T cell subsets
NK (CD8+) > ____, ____
ILC1 (Th1) > ____
ILC2 (Th2) > ____, ____, ____, ____
ILC3 (Th17) > ____, ____
IFNgamma perforin IFNgamma IL-4 IL-5 IL-13 AREG IL-17 IL-22
ILCs are the innate counterparts of specific T cell subsets
NK/ILC1: Type I Defense against \_\_\_\_ pathogens and \_\_\_\_. Adverse outcomes: Inflammatory, \_\_\_\_ diseases.
ILC2: Type 2 Defense against \_\_\_\_ and \_\_\_\_. Homeostatic funcIon: \_\_\_\_ repair. Adverse outcomes: \_\_\_\_, \_\_\_\_.
ILC3:
Type 3
Defense against extracellular organisms (____ and extracellular ____). Homeostatic function: ____ maintenance.
Adverse outcomes: Inflammatory, ____ diseases.
intracellular
tumors
autoimmune
helminths venoms tissue asthma allergy
fungi
bacteria
epithelial barrier
autoimmune
Interferons
• Two types, produced in response to inflammation or infection
• Type1 or ____–produced by ____ cells and ____
• Type2 or ____–produced by mainly by ____.
• Responsible for much of host control of viral replication in ____ and other infections
alpha/beta epithelial fibroblasts gamma lymphocytes
colds
Interferons alpha/beta
induce resistacne in cells so they resist ____ synthesis, and increase ____ and activate ____ cells to kill virus-infected cells
viral
MHC class I
NK
Interferons alpha/beta induce antiviral proteins that suppress viral replication
cell infected with virus > leads to produce of ____ interferons; has been secreted and activated second cell (now prepared > induces production of antiviral proteins); virus wil not be able to esrtablish ____ like in first cell now
alpha/beta
infection
Time course of antiviral reaction
time course of antiviral response
first ____; and activation of ____ cells (from IFN); if NK cells are not enough, then induction of ____ immunity
as immmunity progresses, virus titer plateuas and goes down
alpha/beta IFN
NK cells
adaptive
Complement
• Group of proteins that circulate in the blood
• Important role in host defense but also implicated in inflammatory immunopathology (eg, ____).
– Help ____ phagocytes to site of inflammation and activate them
– ____ bacteria which are targeted to receptors on ____, for clearance
– Form ____ in targeted susceptible microbes
– Activate ____ to release histamine and other factors
sepsis
recruit opsonize phagocytes pores mast cells
Functions of Complement
lectin/alternative you don’t need ____
lectin > MBL (is PRM)
doesn’t matter which mechanism
everything goes through ____ (central complement compoentn) two products > ____ = opsonin; ____ = inflam molecule, binds to receptors on phaocytes/inflam cells > C5 is the same > helps inflam cells (macro’s neutros) to get to a tissue > leads to chemotaxis/vascular perm > ____
downstreamf rom C5 > complexes with 6, 7, 8 and 9 > ____ (membran-ettack complex); when binds bacterium > casues its ____
adaptive C3 C3B C3A inflammation
C5b-9
lysis
The complement system “complements” the ability of antibodies and phagocytic cells to clear pathogens
C5A > bring ____ > recognize bacteria that has been decorated by ____; if not opsonized doesn’t mean it can’t get phagocytosis
phagocytes
C3B
Cytokines
• Secreted ‘messenger’ proteins that mediate communication between cells and regulate immune and inflammatory responses.
• Induced during both ____ and ____ immune responses.
• Have many activities, either ____ or ____ inflammatory.
• Generally follow an ____ appearance, with important roles both in the ____ and ____ phases of the response.
innate adaptive pro- anti- ordered early late
Cytokines are messengers in the immune system
Induction and regulation of inflammatory responses
is just one of their functions.
Other functions include the development, differentiation, and proliferation of ____ cells
Cytokine ____
Do not have to learn this! Just appreciate
the intricate complexity
(in fact, quite simplified here).
immune
networks
Inflammation
Homeostatic process aiming to:
• Isolate and destroy the initial insult (e.g., infectious agent)
• Mitigate tissue damage
• Remove necrotic cells and tissue, repair damage
• Restore normal function
Also a potentially harmful process
• Components of inflammation capable of destroying microbes may also cause ____ injury
• Serious consequences if not properly controlled and ____
bystander tissue
self-limited
Cardinal signs of inflammation (inflammare: latin for set on fire)
Characterized by: Increase in temperature \_\_\_\_ \_\_\_\_ \_\_\_\_ \_\_\_\_ Loss of \_\_\_\_
heat redness swelling pain function
when you have inflam; if persistent infection > ____ inflammation > common denimoator of ____, ____ loss (rheumatoid arthritis), ____ (neurological diseases), ____ diseases (artheroscleoris, stroke), ____ disease (asthma, COPD), ____ disorders (multiple sclerosis)
chornic periodontitis bone alzheimers cardiovascular pulmonary autoimmune
