Tcells/MHC Flashcards
Differences between Innate and Adaptive Immunity
Innate - Rapid, No memory, Non-Specific, ““phils””, Macs, NK
Adaptive - Slow, Memory, Specific, B/AB, T cells
Innate immunity deep dive
"(natural, native) - Evolutionarily less advanced - Same response regardless of stimuli - First line of defense - Rapid response - No memory - Same response every time - Pattern recognition receptors "
Adaptive immunity deep dive
” (specific)
- More advanced
- Each response is tailored to stimulus
- take longer to develop initially, but are much more effective
- Stronger responses with each exposure
- Ability to ““remember”” previous infections
“
What allows for speed/specificity/memory?
T cell receptors and B cell receptors
T cell receptors and B cell receptors**
having been made greater in size or value
Activation of CD4
- Activated by the TCR (T cell receptor)
- binding and recognizing its cognate ligand
- antigen presented by MHC II
• Make cytokines
Activation of CD8
“Activated by the TCR binding and
recognizing its cognate ligand antigen presented by MHC I
• Role: kill “infected” or damaged cells
“
Activation of BCR
“B cells have BcR= antibodies on surface • Upon activation, B cells proliferate and
can become plasma cells that secrete
antibodies “
Immunology
Study of the molecules, cells, organs (immune system) responsible for responding to foreign material
Immunology importance
Immune system recognizes and eliminated foreign / Non-self material (esp infectious agents) so we can survive
Breakdown the organization of the immune system
Immune cells + Lymphoid organs + Immune Arms
Organize immune cells by innate/adaptive arm
“Innate cells -
Adaptive cells - “
Describe different types of organs (simile)
“Primary lymphoid organ - Military school
Secondary lymphoid organs - Field bases
General organs - military bases “
Thymus vs bone marrow
“Both are primary lymphoid organs
Thymus - maturation and selection of T lymphocytes
Bone marrow - development of all hematopoietic stem cells (myeloid and lymphoid lines) “
Lymph node vs spleen
“Both are secondary lymphoid organs
Spleen - largest secondary lymphoid organ, filter antigens from blood
Lymph nodes - collection points of Lymph, filtration and generation of memory B-cells “
Function of the Cortex
contains B cells organized in follicles
Function of the paracortex
contains mostly T cells and some DCs
Function of the medulla
mostly contains macrophages/DCs
Track lymph fluid through the lymph node
“1 - afferent ducts direct flow into the node
2 - medullary cords flow past cortex/paracortex/medulla
3 - from hilus out of lymph node via efferent lymphatic duct “
track antigens through the lymph node
“1 - in via afferent lymphatic
2 - DCs and Macs in medulla present antigen
3 - DCs activate T cells that are in the paracortex
4 - Activated T cells give signals to promote cognate B cell proliferation in the follicles “
Hallmark feature of innate immune system
Pathogen-Associated Molecular Patterns (PAMPs)/ Danger associated molecular patterns (DAMPs)
what are Pamps and their importance
“Very common molecules in classes of microbes
• dsRNA in viruses
• Mannose (not common in mammalian cells) • Lipopolysaccharide • Lipoproteins
• Unique nucleic acid patterns • Unique lipids and carbohydrates
“
Whate are Damps and their importance
Produced by “damaged” cells; initiate a response to trauma, cancer and other settings of tissue damage in the absences of overt pathogen infection
PRR Function
“Receptors that recognize
PAMPs/DAMPs”
Cellular vs Soluble PRR
Important in inducing inflammatory response
• Cellular PRRs
• Soluble PRRs
• Found externally on the cell or internally (within phagosomes and within the cytoplasm)
• Can induce signaling within cell for activation
• Facilitate phagocytosis
• Bind to extracellular microbes
• Primarily serve as clearance mechanisms
• Facilitate phagocytosis
Steps of Phagocytosis
“1 - find infection
2 - engulf foreign particle (helped by opsonins
3 - pseudopodia forms, oxidative burst
4 - phagosome moves to cell center “
Difference between fusion/digestion during phagocytosis
Fusion - cytoplasmic granules + phagosome -> phagolysosome
Digestion/degratation - oxygen independent (granule proteolytic enzymes)/ oxygen dependent (toxic peroxidases)
