Lecture 2 Flashcards
Describe the differentiation of the lymphoid stem cell.
Lymphoid stem cell differentiates into a natural killer cell and a small lymphoid cell. The small lymphoid cell differentiates into a T and B cell then into plasma
What cells are part of the innate system?
In order of differentiation: myeloid stem cells, leukocytes, granulocytes, and agranulocytes
What cells are considered granulocytes?
basophils, eosinophils, neutrophils, and monocytes
What is the function of basophils and eosinophils?
to release toxins that poison microbes
What is the function of neutrophils and monocytes?
to engulf and destroy microbes by phagocytosis
What is the product of monocytes differentiation?
macrophages and dendrites
What cells are considered a link between the innate and adaptive immune systems?
macrophages and dendrites
Describe the process that neutrophils undergo when killing microbes.
they undergo cell death called netosis so they can spread antimicrobials and trap microbes in nets
What is a normal vs. elevated leukocyte count?
normal: 4500 - 11 000, elavated: 12 000 - 30 000
What is the percentage of basophiles, eosinophiles, monocytes, neutrophiles, and lymphocytes in the blood?
> 1%, 1-3%, 3-7%, 54 - 62%, and 25 - 33%
How do natural killer cells destroy infectous cells?
it recognizes cells that do not have the MHC class 1 antigen, then attaches and releases perforins and granzyme toxins to destroy cell membrane
What is the process of phagocytes eating cells?
it recognizes microbe via receptors and traps the microbe within a phagosome vesicle. Phagosome then fuses with a lysosome to form a phagolysosome. Finally, the phagolysosome is destroyed and pieces of the destroyed microbes are expelled from the cell
How do phagocytes kill the phagolysosome in the oxygen-independent pathway?
uses defence/ antimicrobial peptides, iron sequestering proteins, and other enzymes
How do phagocytes kill the phagolysosome in the oxygen-dependent pathway?
uses toxic ROS and RNS to create an oxidative burst in the phagolysosome
How do phagocytes recognize invaders?
recognizes microbes that lack the CD47 glycoprotein, the innate immune system can help by tagging damaged microbes with C3b, and pattern recognition receptors (PRRs) can recognize PAMPs
What are toll-like receptors?
PRRs that recognize PAMPs and cause host cell to release cytokines, and induces production of antimicrobial
Describe TLR4.
recognizes bacterial PAMPs such as LPS and heat shock response proteins
Describe NLRP4.
recognizes bacterial and viral PAMPs such as peptidoglycan, CpG, and dsRNA
What process can prevent phagocytosis?
some bacteria inhibit phagosome-lysozyme fusion, capsules and bioflims mask PAMPs
How is inflammation developed cellularly?
damaged cells secrete bradykin which stimulates cells to degranulates and release histamine, histamine increases the permeability of cell wall and then prostaglandin is released
How does the body react to chronic inflammation?
the body walls off the site of inflammation by forming a granuloma
What cells are fevers induced by?
pyrogens which stimulate prostaglandin production
What cells are the link between the adaptive and innate immune system?
macrophages and dendritic cells
What stems cells are specifically associated with the innate and adaptive immune system?
myeloid: innate
lymphoid: adaptive
What cells are found in both the adaptive and innate immune system?
natural killer cells
What may cause an elevation of neutrophils within the body?
bacterial infection
What may cause an elevation of basophils within the body?
Allergies
What may cause an elevation of eosinophils within the body?
parasitic infection
What may cause an elevation of lymphocytes within the body?
viral infection
What may cause an elevation of monocytes within the body?
chronic infection
What is the difference between PRRs and PAMPs?
immune system cells have PRRs to enhance phagocytosis, PAMPs are the located on pathogen and are what the PRRs recognize on the pathogen
What do antigens stimulate?
B cells to differentiate into antibody producing cells
What is the difference between epitopes and antigens?
an epitope is the part of the antigen to which antibodies bind
