MSI Immunology Flashcards
A process in which epitopes relevant to the pathogen are shared with host antigens (seen as “self-antigens,” resulting in the subsequent development of AI dz
molecular mimicry
Which MHC class is typically involved in the presentation of viral peptides to a CD4 cell, leading to T cell activation?
MHC Class II
What type of immune cell reacts strongly to “self-peptides” and initiates a state of inflammation?
activated T cells
Autoimmune haemolysis that occurs after infection with Mycoplasma pneumonia is an example of
molecular mimicry
An inflammatory dz occurring about 1-5 weeks after Streptococcal infection (such as after untreated Strep throat or Scarlet fever) affecting heart, joints, skin, and brain is known as
Rheumatic fever
NB: another example of molecular mimicry
What type of antibodies are though to cross react with connective tissue in cases of Rheumatic fever?
anti-Streptococcal Abs
In a person who is genetically susceptible to developing T1DM, a viral infection may stimulate the production of Abs against a viral protein that triggers an AI response against antigenically similar ____ ____ molecules
beta cell
85% of T1DM patients have circulating _____ ____ Abs, and the majority also have detectable anti-insulin Abs before receiving insulin therapy.
islet cell
The most commonly found islet cell Abs are those directed against _______________, an enzyme found within pancreatic beta cells
glutamic acid decarboxylase
In T1DM, _______ _____ Abs are detectable for months/years before the onset of clinical disease
islet cell
Symptoms of hyperglycaemia typically don’t develop until about _____ % of the beta cells are destroyed.
80-90
The major defined genetic risk factor for T1DM are
HLA class II alleles (such as DR3 or DR4)
Which molecules are thought to present relevant islet cell antigens to CD4 T cells in the development of T1DM?
HLA class II DR3 and DR4
Protein 2C from the _________ virus has homology with islet cell Ag glutamic acid decarboxylase (as a potential precipitating event for the development of T1DM)
Coxackie virus
________________ may influence the activation of T cells and B cells that are potentially auto-reactive
Infection
Immune complexes are cleared by ______; the process is enhanced by phagoycte Fc receptors and C3b receptors
phagocytes
We use ____________ to detect the presence of autoimmunity in patients, either from a serum sample or tissue sample from a biopsy
immunofluorescence
Steps of ______ _____________: used to detect the presence of antibodies in the blood
1. Incubate: Patient serum containing (or not) relevant antibodies is placed on a glass slide with tissue of interest, harvested from an animal source 2. Detect: Add detection Ab labelled with fluorescent marker 3. Read: Look for fluorescence under a microscope (only happen while UV radiation is present)
Indirect immunofluorescence
________ _______________: Detects Abs bound to tissue
1. Prepare tissue biopsy/slide: Biopsy is taken from the affected tissue in the patient (eg skin, kidney). If damage is mediated by Ab, Ab will already be stuck to its Ag in the tissue 2. Detect: Add detection Ab labelled with fluorescent marker 3. Read: Look for fluorescence under the microscope (UV light)
Direct immunofluorescence
__________ ELISA: Sample is coated onto the plate and the Ag in the sample, also known as the analyte, is detected by antibodies. Sandwich and competitive ELISAs both have plates that are coated with Abs.
Direct
_________ ELISA: the plate is coated with capture Ab which binds the analyte and a second conjugated detection Ab binds the analyte and modulates that detection reaction
Sandwich
____________ ELISA: Utilises a conjugate, an analyte Ag coupled to a detection reagent, which competes with the analyte for binding. The more analyte is contained in the sample, the less conjugate will be bound and the lower the enzyme-mediated signal will be
Competitive
What is the importance of distinguishing monogenic diabetes from DM1 and DM2?
They all require a different approach to treatment
Immunologic ________ operates to prevent randomly generated self-reactive T and B cell receptors from triggering auto immunity
tolerance
_________ is accomplished by the induction of apoptosis in the lymphocyte expressing the autoreactive receptor or by the process of receptor _________, in which the autoreactive receptor is replaced with a newly rearranged one
Purging, editing
Purging and tuning of the autoreactive receptors are the two strategies used to maintain immunologic
tolerance
