Lecture 10 - function of white blood cells Flashcards
What are leukocyte
cells of the immune system that are involved in protecting the body against both infectious disease and foreign invaders
What are leukocyte classified into
granulocytes and agranulocyte
What are granulocyte classified into
Neutrophils, eosinophils and basophils
What are agranulocyte classified into
lymphocyte and monocytes
What happens when there is an infection
the increase of neutrophils
What happens when there is a parasite infection
eosinophils increase
what is the lifespan of neutrophils
4 - 10h
What are the kill mechanism of neutrophil
They will detect for bacteria via receptors on the surface layer
3 ways to kill 1. Phagocytic-phagolysosome 2. Secretory granules with antibacterial products 3. NETs-core DNA element immobilize bacteria
how to kill bacteria using Phagocytic-phagolysosome work
taken into the phagolysosome, release predominant lysis
how to kill bacteria using Secretory granules with antibacterial
products
they will have secretary granules that release toxic to kill the bacteria
how to kill bacteria using NETs-core DNA element immobilize
bacteria
excrete DNA items and capture the bacteria which then brought into the cell and phagocytose
What are inside the basophils
ã Contain coarse cytoplasmic granules
ã Histamine, heparin, serotonin, hyaluronic acid, hydrolytic enzymes,
chemotactic factors
What are the functions of basophil
ã Major role in allergic and inflammatory reactions
ã Surface receptors for IgE
ã Limited phagocytic and bactericidal activity
ã Predominant source of IL-4 and IL-13
in allergic disease
What are the characteristics of eosinophil
ã Contain coarse cytoplasmic granules
ã Major granule proteins: myelin basic protein
ã Life-span is 6-12h in blood & 2-3 days in tissues if
not stimulated
Eosinophil function
ã Major role in controlling parasitic infestation
ã Possible roles against bacterial and viral infections
ã Role in allergic responses
What is stored performed in cytoplasmic granules of eosinophil
major basic protein, eosinophil cationic protein
What are the major lipid mediators produced on eosinophil activation
Leukotrienes C4, D4. E4
What are the cytokines produced on eosinophil activation
IL-3, IL-5, GM-CSF, IL-8, IL-10, RANTES. MIP
What does major lipids mediators in eosinophil do
prolonged brochoconstriction, mucus secretion, increased vascular permeability
Where are monocyte located
mostly in blood
What are the function of macrophage
Macrophage function: ã Highly phagocytic • Ingest and kill microbes • Clearance of damaged dying cells ã Antigen presenting cells (APC) – initiate immune response ã Produce cytokines – signalling and amplification of immune response
What is the function of dentritic cells
ã Arise from monocyte dendritic precursor ã APC - activate T cells ã Present in tissues that are in contact with the external environment (skin, intestines )
How do innate cells recognise
pathogens?
Pattern-recognition receptors (PRRs) & pathogenassociated molecular patterns (PAMPs)
How does PRRs work
expressed by cells of innate
immune system
• Present on macrophages, dendritic cells,
granulocytes, endothelial cells, mucosal epithelial
cells
How does PAMPs work
Recognize unique microbial molecules
(PAMPs) shared by groups of related
microbes not found associated with
mammalian cells.
What response does PRRs and PAMPs do
inducing innate immunity
What differentiates a bacteria by leukocyte
By the bacteria outer layer, eg lipoprotein, flagellin tail
What does PAMP usually detects
Bacteria
What does PRR usually detects
microbes by binding to pathogen-associated moecular patterns (PAMP)
What kind of receptors are there
membrane receptors and intracellular receptors
What is an example How does innate cell kill a pathogen
- Recognize using PRR, binding to something like lipoprotein
- Result in the neutrophil activation
- phagocytose the pathogen
- enzymes like lysosomal enzyme in phagolysosomes or ROS and NO, can be killed using secretary granules as well
where does B cells devrived from?
ã Derived from the bone marrow (or Bursa of Fabricius in birds, Ileal Peyer’s patches ruminants )
What are B cells for
produce antibodies to attached to viruses, so macrophage can eat them or secretary glands. Against viruses scattered around, not infiltrated
What are T cells for
mediated immunity
Where do the T cells develop from?
Develop in the thymus & recognize
antigens via their T cell receptor (TCR)
What are the 3 subsets of T cells?
§ CD4 “helper” (ab TCR)
§ CD8 “cytotoxic” (ab TCR)
§ gd TCR cells
What are NK cells for
cytotoxic; cell-mediated, innate immune response
How does NK cells kill pathogens
Kill adjacent cells by release of
cytotoxic granules and induction of
apoptosis
What are the classes of lymphocyte
- B lymphocyte
- Helper T lymphocyte
- Cytotoxic T Lymphocyte
- Regulatory T lymphocyte
- Natural killer (NK) cell
What is the diversity of innate response
enormous
What is the specificity of innate response
high
What is the specificity of adaptive response
some specificity
What is the diversity of adaptive response
some diversity
What are the cells in
the adaptive side of the immune system
B cells
T cells
NK cells
What does Cytotoxic T cells do
attack cell/viruses that infiltrated
What can activate helper T cell
best one is dentritic cell
How does helper T cell work
the receptor (T cell receptor) bind to dentritic cell specific to it. Due to specific immune system
What happens when helper T cell get activated?
It start proliferating and some subset of those copies differentiates into effector cell and memory helper T cell
What is the use of memory helper T cell
it is produced to attack against similar viruses in the future
What does activated effector T cell do
proliferate, release cytokines
What does cytokines do
proteins, raising chemical alarm bells, enter cells and multiply the cell. cause cytotoxic
What is autoimmune disease
happens when b cells random shuffling a antibody that actually attacks the naturally present cells in the body
What can prevent autoimmune disease
To damage the body’s healthy cell, both helper T and B cell must have a specific antibody to attach to the cell. There is a very unlikely chance where both cell match the specificity of the body cell.
What does MHCII do
it attached the macrophaged remnant from the outside of b cell to it and present itself on the membrane surface. Which then activate the helper T cell
What is MHCI for
All cells with nucleus have it,
attaches proteins within cancerous cells and present itself of the membrane surface for cytotoxic T cell to recognize it
What happen it Cytotoxic T cell detects a cancerous cell or infected cell
It will start to multiply into memory cell and effector cell(ones that latches on the cell)
release hormones like perforins, form gaps in the membrane, cause it to kill itself
What is another work for effector B cell
plasma cell
What does CD4 positive T cell do
CD4 receptor communicate with MHCII receptor most of the time. Normally callled a helper T cell. Alarm when activated
What does CD8 positiveT-cell do
CD8 receptor communicates with MHCI most of the time. Normally called a cytotoxic T cell.
