Immunodeficency Flashcards
what are the principle function of the immune system
protect from infection. multilayer defence system network of pathogen recognition to detect which antigens are self. effective intracellular communication multiple mechanism to remove pathogen self regulation.
Is the innate immune system long term or short term
short term
Is the adaptive immune system long term or short term
long term
is the innate immune system specific or non specific
non-specific
Is the adaptive immune system specific or non specific
specific.
What are the 3 components of the innate immune system
PPR, Cellular, barrier and chemical mechanisms
What are the 2 components of the adaptive immune system
cellular and humoral.
Where are receptors in the innate system found.
On cells e.g. macrophages and dendritic cells.
What are the major components of the innate immune system and what do they tell us.
detect the type of pathogen e.g. gram +ve or -ve, virus but not the specific pathogen
PRR-pattern recognition receptor.
antimicrobial peptides, cells, complement components, cytokines.
Pattern recognition receptors include
TOL like receptors, NOD like receptors, Rigl like receptors, C type lectins, scavenger receptors.
Antimicrobial peptides include
defensins, cathelin, protegrin, granulysisn, histatin, secretory leukoprotease inhibitors and probiotics.
Cells
macrophages, dendritic cells, Nk cells, NK T cells, neutrophils, eosinophils, mast cells, basophils and epithelial cells.
Complement component
classic and alternative complememnt pathways and proteins that bind complement components
cytokines
Autocrine, paracrine, endocrine, cytokines and mediate host defines and inflammation as well as recruit, direct and regulate adaptive immune responses
Function of humoural aspect of adaptive immune system
– Kill, neutralise and recognise pathogen.
– Deal with extracellular orgnaism
What are the different types of T lymphocytes
Killer or cytotoxic T lymphocytes are able to kill.
Helper T lymphocytes secrete growth factors (cytokines) which control immune response: Help B lymphocytes and T lymphocytes (Helper T cells are target of HIV)
Organise other components of the immune system.
Deal with intracellular organism e.g virus.
Suppressor T lymphocytes may damp down immune response
What is the function of antibodies
• Neutralize bacteria • Agglutination • Precipitation of dissolved antigens. PHAGOCYTOSIS • Activate complement CELL LYSIS
What is the function of T cells.
- Cytotoxic t cells bind infected cell
- Perforin makes holes in cell membrane
- Infected cell is destroyed.
Do B cells deal with intra or extracellular infection
extracellular
Do T cells deal with intra or extracellular infection
intracellular.
How does the innate immune system communicate with the adaptive
cytokines
cells in the innate system which have engulfed the pathogen will express cytokines which trigger the adaptive immune system- instruct CD4 to make T cells.
define immunodeficiency.
• Clinical situations where the immune system is not effective enough to protect the body against infection
Causes of secondary or acquired immunodeficiency.
stress surgery/burns malnutrition Cancer Immunosuppressive effect of drug- chemotherapy irradiation AIDS.
Causes of primary immunodeficiency.
very rare- genetical
What is IRAK deficiency
innate system
IRAK is a toll like receptor recognises bacterial cell wall or viral component.
IRAK through intracellular signalling produces NF-Kb (transcriptional factor)- needed to make cytokines
What test determines the function of neutrophils
Nitroblue tetrazolium test.
Incubate neutrophil with dye and it should take up the dye creating free oxygen radicals forming dark blue circles.
This does not occur if defective.
What type of genetic disorder is the defect in NADPH oxidase complex
X-linked- defect in how phagocytes work.
How does NADPH oxidase complex work
NADPH- oxidase complex trasfers one hydrogen atom across the membrane
This forms free oxygen radicals
causes acidic conditions and a decrease in pH
Acidic pH releases prteolytic enzymes to destroy the infection.
Clinical symptoms of chronic granulomatous disease (CGD)
• Osteomyelitis- bone infection • Pneumonia • Swollen lymph nodes • Ginigivitis- (gum disease) • Non-malignant granulomas • Inflammatory bowel disease – Immune system tries to compensate for decreased neutrophils= secrete chemo/cytokines- so although they are immunodeficient also have overproduction of other mechanisms for coping resulting in IBD.
What defects in the complement pathway may result in immunodeficiency
lack of a factor C1, C9- without a factor a pore cannot be created in the bacterial membrane.
How to diagnose a lack of complement factor deficiency
- Sheep RBC don’t have anything to inhibit complement whereas human RBC do
- Sheep RBC and patient serum- complement should activate and RBC should lysis.
What types of infections of defects in B cells predispose you too.
respiratory infections
recurrent bacterial infection with pyogenic organisms.
what cell type defect results in X-linked agammaglobulinaemia
Primary B cell deficiency
Is X-linkes agammagloinaemia a recessive or dominant condition.
autosomal recessive.
what immunoglobulins are deficient in X-linked agammaglobinaemia
IgA IgG (subclass deficency)
Which cell type deficiency is worse- B or T cell
T cell- B cells also require T cell help.
What are the common symptoms of T cell deficiency
• Symptoms are recurrent infection with opportunistic infections, bacteria, viruses,
What is the name of the deficiency which has both B and T cell deficiency.
– Severe Combined Immunodeficiency (SCID) syndromes
How do you treat SCID (severe combined immunodeficiency)
bone marrow transplant.
Gene therapy- replace faulty gene using viral plasmid and patient stem cells, virus incorporates genome into patients.
What are the primary T cell deficiencies
Severe combine immunodeficency syndromes (SCID)
Adenosine deaminase deficency
Purine nucleoside phosphorylase deficncncy
MHC Class II deficencny
WiskottAldrich Syndrome
