1 - Intro to Immunology - Partridge Flashcards
Give examples of external threats the immune system deals with.
bacteria, virus, fungi, parasites
Give examples of internal threats the immune system deals with.
cancerous/tumour cells (altered self cells), danger from damaged tissue; necrosis from trauma, ischaemia
What is ischaemia?
Lack of blood flow to certain tissues therefore causing damage
Give 3 examples of when the immune system is inappropriately activated
asthma, rheumatoid arthritis, allergies
all autoimmune diseases
Give the 3 characteristics of the INNATE & ADAPTIVE immune systems
INNATE;
quick response (hrs)
limited specificity
resistance not improved upon reinfection
ADAPTIVE;
slow response (days-weeks)
highly specific
resistance improved upon reinfection
Name the leucocytes involved in both the INNATE & ADAPTIVE systems
INNATE;
phagocytes, natural killer cells
ADAPTIVE;
B/T lymphocytes
Name the soluble factors involved in both the INNATE & ADAPTIVE systems
INNATE;
interferons, complement, defensins
ADAPTIVE;
antibodies
From which cell are all the cells in the immune response derived from and name the 2 cell lineages from this.
pluripotent stem cells giving rise to myeloid/lymphoid progenitor
What are professional phagocytes?
Give some examples
Have the sole job of taking up pathogens. Unlike other cells (eg epithelial cells, fibroblasts) that have other functions but can still uptake foreign material.
Eg neutrophils, mononuclear phagocytes
Describe neutrophils
main phagocyte in blood, normally short-lived (upon infection when they live for longer) and fast-moving, can release contents of lysosomes eg H2O2
Describe the 2 types of mononuclear phagocyte and briefly describe them overall
MONOCYTES - exist in tissues
when migrate to tissues known as MACROPHAGES
Can help to initiate adaptive responses and are long-lived
In the brain, what are the mononuclear phagocytes know as?
microglial cells
NK cell receptors recognise _____ self cells and therefore may play a role in ____ recognition. They kill infected cells ____-_______
altered
tumour
non-specifically
What infections are NK cells effective against?
intracellular bacteria/viral
What are the names of the receptors on phagocytes and other myeloid cells and what do they recognise?
PRRs (pattern recognition receptors) recognising PAMPs (pathogen associated molecular patterns)
What are PAMPs?
molecules not naturally occurring in human body and are associated w/ pathogens eg LPS
What is the inflammatory response?
integrated local response to infection
Briefly describe these 3 soluble factors
- defensins
- interferons
- complement
DEFENSINS;
can insert into bacterial membranes and kill
INTERFERONS;
secreted by virally infected cells and are proteins that interfere with viral replication
COMPLEMENT;
opsonise pathogen for phagocytosis, inducer of inflammation, directly kill pathogen
In ADAPTIVE immunity, where do the B/T cells mature?
B - bone marrow
T - thymus
Both in central (primary) lymphoid tissue, independent of antigens
Where do B/T cells gain their receptors and what are their receptors called?
both in the peripheral (2ndry) lymphoid tissue. dependent on antigens.
B - antibody
T - T cell receptor
What are the responses of T/B cells?
T - make cytokines and kill infected host cells
B - produce Abs
What types of infections are T/B cells effective against?
T - intracelular bacteria, viral, intracellular parasitic
B - extracellular, 2ndry viral
Describe the 2 major sub populations of T cells
CD4+ve/Helper T cells
CD8+ve/Cytotoxic T cells
What are cytokines?
small secreted proteins that allow communication between cells of the immune response. produced and act locally by binding by specific cytokine receptors on target cells
What are the 3 main groups of cytokines?
Interleukins, chemokines, interferons
