Immune System Overview Flashcards
What are various agents that can cause disease/replicate inside of a host?
Viruses, bacteria, fungi, parasites (protazoa, helminths), archaea, Prions
What are prions?
Abnormally folded protein form that form plaques causing entanglement of neurofibrils and interfere with synaptic transmission; cause bovine spongiform encephalopathy in cows and Creutz-feldt Jakob disease in humans
What defenses do we have against pathogens?
Physical barriers, chemical barriers, commensal microbiota, innate immune system, and adaptive immune system
Describe mucus
Viscous fluid Contains mucins (many glycoproteins) Prevent attachment of organisms Expulsion of organisms in respiratory tract and GI tract Flows in clearing infection
What cells are involved in the innate immune system?
Monocytes/macrophages (phagocytic, antigen presenting)
Neutrophils (professional killers, phagocytic)
Natural killer cells (killers)
Dendritic cells (phagocytic)
Complement system (form MACs)
What cells are involved in the adaptive immune system?
B cells (make antibodies) T cells
What are 4 major functions of antibodies?
Neutralization
Opsonization
Compliment activation
Antibody-dependent cell-mediated cytotoxicity
What are the types of T cells?
T helper cells
T killer cells
Regulatory T cells
What is the classical pro-inflammatory cytokine trio?
IL-1, IL-6, TNF alpha
What do cytokines (like TNF alpha) do?
Recruit fluid, cells, and molecules to site of infection
What is a cognate antigen?
What antibodies (B cell receptors) and T cell receptors are looking for their match to bind to = proliferation of T cells and B cells
What is clonal selection?
Making a certain kind of B cell on demand
What cells are antigen presenting cells?
Dendritic cells
Macrophages
B cells
Do T cells require antigen presentation for activation?
Yes
What are the 2 kinds of major histocompatability complex (MHC) proteins?
Class I
Class II
What are Class I major histocompatabilitiy complex proteins and where are they found?
Found on virtually all cells of the body
Displays what cells are producing inside
Scanned by killer T cells which can kill virus infected cells
What are Class II major histocompatability complex proteins and where are they found?
Found typically only on antigen presenting cell
Displays what has been killed at battle site
Informs T helper cells about battle
What are cytokines?
Hormone-like messengers (proteins) produced by certain immune cells (especially T helper cells) that communicate with other cells (both immune and non-immune cells) and affect the immune response
What are examples of cytokines?
Interleukins (IL-1, IL-2…), interferon y (INFy), Tumor necrosis factor (TNF)
What does IL-1 cause?
Hypothalamic fever response
What does TNF from macrophages cause?
Inflammation
What are facts about the innate immune response?
Fast/immediate
Non specific
Pattern recognition receptors
Sense danger-activate adaptive immune response
Integrates invader info
Determines weapons to be used (B vs T cells)
Hard wired memory
What are facts about the adaptive immune response?
Slow
Specific
Antigen receptors unfocused looking for cognate antigen
Individualized plastic memory
What cells are part of myeloid lineage?
Granulocytes
- Neutrophils
- basophils
- Mast cells
- Eosinophils
Myeloid Antigen-presenting cells
-Monocytes (macrophages, dendritic cells)
