importance of antibodies Flashcards
attachments to antibodies
to the non-specific part: can attach enzymes, fluorescent probes, magnetic beads (purify substances by magnetism) and drugs
indirect labelling
the primary antibody binds to an antigen, and a secondary antibody with an attachment (ANTI-ANTIBODY) binds to the primary antibody- thus a single anti-antibody can bind to multiple primary antibodies
two ways of making antibodies
produced by patient in autoimmune disease/defence against infection/diagnosing infection
manufacturing antibodies using antiserum from animals that were immunised/ monoclonal antibodies/ genetically engineering antibodies (with recombinant DNA)
DIAGRAM how to produce monoclonal antibodeis
animal has antigen put in it, causing it to produce antibodies- the spleen cells (B cells) are extracted, and because they replicated only a FEW times before dying, they are fused with myeloma cells (tumour cells) to form HYBDRIDOMAS- they are cultured and those that produce the antibodies are selected
genetically engineering antibodies
use recombinant DNA to produce genes encoding antibody regions, and attach the protein encoded to bacteriophages- add a mixture of bacteriophages to a plate which has antigens attached: those that don’t have the specific protein are washed off, leaving only bacteriophages with the desired protein
therapeutic uses of manufactured antibodies
protect against micrboes (IVIG is intravenous antibodies for those who can’t produce their own)
anti-cancer.
removal of T cells.
block cytokine activity (anti-TNF alpha for rheumatoid arthritis)
anti-calcitonin gene related peptide for treating MIGRAINES
uses of manufactured antibodies diagnostically
blood group serology
quantitative immunoassays for hormones/antigens
immunodiagnosis for infectious disease, allergy (IgE) + autoimmunity and cancer (MYELOMA)
ELISA test (enzyme linked immunosorben assay)
antibody bound binds to antigen in sample, then 2ndary antibody binds to antigen, and will cause colour change- amount of colour change proportional to amount of antigen, hence QUANTITATIVE
DIAGRAM how strip tests work
blood drop with antigen binds to conjugated antibodies, which travel along to test line (antibodies) and bind- there is also a control line to ensure the test WORKS
symptoms and associated immunological concerns
aches and pain imply immune complexes deposited in skin
glands in neck imply immune activation
fever/rash imply acute phase+ immune complexes
immune complexes
indicate inflammation- if deposited in kidney can cause glomerulonephritis- also deposite in skin/lungs
how to detect immunodeficiency and methods used
look at certain antibodies (Ig G/M/A) and subclasses, either by ELISA or serum electrophoresis
look at specific antibdoies against tetanus/haemophilus (to see if vaccine worked) using ELISA
look at lymphocyte subsets (CD3/4 etc) using FLOW CYTOMETRY eg CD4 for HIV
use of serum electrophoresis for cancer
if a certain band is very dark, indicates a MONOCLONAL expansion of a single antibody= possible myeloma
DIAGRAM natural history of HIV infection
primary infection causes rise in HIV, decrease in CD4- immune system then recovers, so CD4 rises and HIV decreases, but then LATENCY occurs, where CD4 gradually goes down, and viruses gradually goes up, until CD4 so low that HIV rises rapidly= many diseases (AIDS)
treatment for HIV
if patient has HIV antibodies, if CD4 count low, and viral load high, ART (1st line) begun, and CD4/viral load measured every 3 months- if still low, 2nd line therapy given
