MICB 4131 IMMUNOLOGY EXAM 4 QUESTIONS AND
VERIFIED ANSWERS
Mucosal tissues - Answers - tissues exposed to the outside and lined with epithelial
cells
think permeable barriers
-gas exchange
-absorption
-reproduction
-sensory activities
Mucosal tissues are - Answers - non-specific resistance, barriers to pathogen entry
Mechanical barriers - Answers - epithelial cells joined by tight junctions
longitudinal flow of air or fluid
movement of mucus by cilia
tears
nasal cilia
innate defense - Answers - epithelium (barrier function, rapid turnover, active
participants)
paneth cells (antimicrobial peptides)
goblet cells (mucus)
Why are mucosal tissues important? - Answers - Vulnerable to infection
Example pathogens and mucosal surface they enter host through - Answers - influenza-
respiratory
HIV- reproductive tract
normal flora, helminth, food poisoning bacteria- oral/gut
Portals of entry for antigens that are not pathogenic - Answers - gut- food proteins
lung- alveolar macrophages
, Where are most of the commensal microorganisms? - Answers - large intestine
(10^14 cells in body)
Commensals confer what host advantages? - Answers - metabolic
development (epithelial growth, mucosal immune system)
protection (competition)
Antigen exposure at mucosal surfaces - Answers - Good:
-tolerance (food antigens, endogenous flora)
-immunity (pathogenic microorganisms)
Bad:
-imbalance (IBD, Celiac disease, asthma)
Oral tolerance - Answers - the induction of non-reactivity to item ingested, such as food
antigens
High dose vs. low dose tolerance - Answers - high: high amounts of Ag will lead to
deletion or anergy of reactive cells
low: low amounts of repeated Ag can lead to the induction of Treg and/or activation of T
cells producing anti-inflammatory cytokines
Anatomical features increase - Answers - surface area
Organization of intestinal lymphoid tissues - Answers - effector vs. inductive
pp has similarity with peripheral LNs and non-lymphoid tissues (but PP are in direct
contact with outside world)
Naive and B cells are only in inductive, not effector sites
effector/memory T and B cells found in all areas
Microfold (M) cells - Answers - Folded luminal surface instead of microvilli
M cells do not secrete digestive enzymes or mucus and lack a thick surface glycocalyx
continuously taking up antigen and transporting across epithelia- TRANSCYTOSIS
antigen sampling in the small intestine - Answers - 1. m cells take up antigen by
endocytosis and phagocytosis
VERIFIED ANSWERS
Mucosal tissues - Answers - tissues exposed to the outside and lined with epithelial
cells
think permeable barriers
-gas exchange
-absorption
-reproduction
-sensory activities
Mucosal tissues are - Answers - non-specific resistance, barriers to pathogen entry
Mechanical barriers - Answers - epithelial cells joined by tight junctions
longitudinal flow of air or fluid
movement of mucus by cilia
tears
nasal cilia
innate defense - Answers - epithelium (barrier function, rapid turnover, active
participants)
paneth cells (antimicrobial peptides)
goblet cells (mucus)
Why are mucosal tissues important? - Answers - Vulnerable to infection
Example pathogens and mucosal surface they enter host through - Answers - influenza-
respiratory
HIV- reproductive tract
normal flora, helminth, food poisoning bacteria- oral/gut
Portals of entry for antigens that are not pathogenic - Answers - gut- food proteins
lung- alveolar macrophages
, Where are most of the commensal microorganisms? - Answers - large intestine
(10^14 cells in body)
Commensals confer what host advantages? - Answers - metabolic
development (epithelial growth, mucosal immune system)
protection (competition)
Antigen exposure at mucosal surfaces - Answers - Good:
-tolerance (food antigens, endogenous flora)
-immunity (pathogenic microorganisms)
Bad:
-imbalance (IBD, Celiac disease, asthma)
Oral tolerance - Answers - the induction of non-reactivity to item ingested, such as food
antigens
High dose vs. low dose tolerance - Answers - high: high amounts of Ag will lead to
deletion or anergy of reactive cells
low: low amounts of repeated Ag can lead to the induction of Treg and/or activation of T
cells producing anti-inflammatory cytokines
Anatomical features increase - Answers - surface area
Organization of intestinal lymphoid tissues - Answers - effector vs. inductive
pp has similarity with peripheral LNs and non-lymphoid tissues (but PP are in direct
contact with outside world)
Naive and B cells are only in inductive, not effector sites
effector/memory T and B cells found in all areas
Microfold (M) cells - Answers - Folded luminal surface instead of microvilli
M cells do not secrete digestive enzymes or mucus and lack a thick surface glycocalyx
continuously taking up antigen and transporting across epithelia- TRANSCYTOSIS
antigen sampling in the small intestine - Answers - 1. m cells take up antigen by
endocytosis and phagocytosis
