Innate Immunity: Immune Cells In Blood Flashcards
Outline the composition of blood
Formed elements 45%, and plasma 55%
Formed elements - platelets, white blood cells (leukocytes), red blood cells
Plasma - Proteins (antibodies/immunoglobulin), other solutes, water
Outline bone marrow stem cells
Are source of blood cells (hematopoiesis)
Cells are pluripotent = potential to become many different things
What are the 3 blood cell lineages derived from
Derived from hematopoetic stem cells in bone marrow
What are the 3 blood lineages
Erythroid - red blood cells (erythrocytes)
Myeloid - granulocytes, monocytes, dendritic cells, platelets (innate immune cells)
Lymphoid - B and T lymphocytes (adaptive immune cells)
Give example of granulocytes in blood
Neutrophils - 75% of all leukocytes, highly phagocytic (eat and kill), numbers in blood increase during inflammation, can move into tissue during inflammation
Outline granulocytes in tissue
Mast cells line mucosal surfaces.
Release granules that attract white blood cells to areas of tissue damage
Outline the relationship between monocytes and macrophages
Monocytes present in blood - low phagocytosis
Leave blood, develop into macrophages in tissues - high phagocytosis
Outline dendritic cells
Found in low numbers in blood and all tissues in contact with environment.
Low numbers due to very effective - large SA = good multicellular interaction
Phagocytic
Most important cell type to help trigger adaptive immune responses
How do cells of the immune system move around the body
Cells are carrier in the blood and in the lymph
Cells can leave blood to enter tissue
Lymph in tissues collects into lymphatic vessels, which drain lymph into lymph nodes
What are pathogen associated molecular patterns
Molecules with conserved motifs that are associated with pathogen infection that are recognised by immune pattern recognition cells
What are commmon building blocks and PAMS of virus’s
Common building blocks and PAMPS: viral ssRNA and dsRNA
What are common building blocks and PAMPS of bacterium
Common building blocks and PAMPS: Cell wall (lipopolysaccharide, endotoxins, lipoteichoic acid). Flagella: flagellen. Nucleic acic: unmethylated CpG DNA
Outline the process by which phagocytes bring about gene responses to pathogens
Phagocytic cells can recognise components that form bacterial or yeast cell walls by toll-like receptors present on cell surface. Receptors bind comments, send intracellular signals which signal for up-regulation of gene transcription for genes that encode molecules that help kill pathogen, and down regulate gene transcription for molecules that are not necessary, or might support pathogen growth.
Outline how phagocytic cells recognise pathogenic nucleic acid, and bring about gene transcription responses
Pathogens are “eaten” by ingestion through phagocytosis, forming membrane bound vesicle/lysosome. (Phagosome or phagolysosome) Pathogen is broken down within vessicel. Releases nucleic acid. Toll like receptors in vesicle recognise nucleic acid. Toll like receptors signal for up regulation or de regulation of genes to kill pathogen/help pathogen grow.
Why are nucleic acid recognising toll receptors only coated within phagocytic cells
Pathogen is intact outside cell, nucleic acid is protected inside pathogen, and can not be recognised. Can be recognised once broken down in phagocytic cell
