Clinical microbiology and Immunology

by killing their target cells

cytotoxic T lymphocytes

when its TCR recognized the correct combination of MHC class 1 and peptide on the target cell

peptides from intracellular pathogens will be presented on MHC class 1 to CD8+ cells

is is better to have a stronger response because it leads to better immunity against that virus

people who are infected with the HIV virus but never progress to AIDS

they had a specific allele of an MHC class 1 gene called HLA-B that could present certain HIV peptides that activate CD8+ T cells to kill the HIV infected cells

herpesvirus family

double stranded DNA

50-90%

occurs when a pregnant woman becomes infected for the first time (or infected with a new strain) during pregnancy. The absence of protective maternal antibodies leads to uncontrolled growth and vertical transmission to the fetus

spot - like hemorrhages in the skin, hepatosplenomegaly, pneumonia, retinitis, neurological abnormalities

cell surface proteins that signal infected cells to T cells to kill infected cells

viruses inhibit the expression of MHC class 1 on the surface of infected cells

• 1. intracellular proteins degraded by proteasome
• 2. TAP transporter translocates peptides to the ER
• 3. MHC class 1 synthesized with peptides in the ER
• 4. MHC+peptide complex is moved to cell's surface through the golgi

• US2
• US3
• US6
• US11

reroutes MHC class 1 a-chains to the proteasome for degradation

retains MHC class 1 in the ER

blocks TAP-mediated translocation of peptides into the ER

reroutes MHC class 1 a-chains to the proteasome for degradation

• 1.To cope with MHC polymorphisms: US2 binds to HLA-A proteins but not HLA-B or HLA-C proteins
• 2.Cell-type specific adaptaEon: US11 is more effecEve at targeEng MHC class I to the proteasome in DCs than is US2
• 3. cooperation
• 4.Temporal regulaEon: CMV proteins are expressed at different Emes in the replicaEon cycle

• microscopy
• molecular methods
• immunologic tests

• serology
• immunofluorescence

gram stain and acid fast stain

hybridoma cells

the part of the antigen that is recognized by the immune system

they recognize a single epitope and fluoresce

• fluorescent-antibody (FA) technique
• indirect fluorescent anibody (IFA) technique

fluorescent molecule binds to the antibodies that attach to infected cells

• 1. immune cell surface antigens
• 2. lymphocyte biology
• 3. production of monoclonal antibodies
• 4. development of sensitive antibody-binding reporter systems

use of serum antibodies to detect and identify other molecules. It can be used to differentiate servers or serotypes of microbes that differ in antigenic composition of a structure or product.

visible clumps or aggregates of cells or particles

binding of complement to an antigen antibody complex to see if there is any antibodies in the serum

• 1. heat the serum to destroy existing amount of complement proteins in it
• 2. a measured amount of complement proteins and antigens are then added to the serum
• 3. the antibodies, antigen, and complement complex are formed (if there are no antibodies, the complex does not form)
• 4. sheep red blood cells and antibodies are added to the serum
• 5. if there are free complement proteins, they will bind to the antibodies and cause lysis and turn the solution pink. IF NOT, the redblood cells will sink to the bottom of the solution

used to detect antigens in a sample

the addition of chromogen visualizes the reaction

• 1. antigen is absorbed into the well
• 2. serum samples with unknown antibodies are added to the well. the antibodies stick to the well if it matches with the antigen
• 3. the well is washed out to remove unbound antibodies
• 4. another antibody with a linked enzyme is added to attach to any bound antibody
• 5. a colorless substrate is added
• 6. enzymes on the second antibody hydrolyze the substrate which releases a dye
• 7. wells that are positive for the antibody develop color

• 1. antibody is absorbed into the well
• 2. antigen is added
• 3. if complementary, it will bind to the antibody already in the well
• 4. and antibody with an enzyme on it is added to bind to the antigen
• 5. substrate is added
• 6. enzyme reaction with substrate produces a color change

• INDIRECT= antigen is absorbed into wall and the enzyme linked antibody attaches to the first antibody
• DIRECT = antibody is attached to the wall and the enzyme linked antibody attaches to the antigen

• 1. use beads with antibodies attached to them
• 2. plate them on a flat surface
• 3. add serum with antigen
• 4. if the antigen matches with the antibodies, the solution should form clumps

detects soluble Ag reacting with Ab because the binding of Ag to Ab forms a lattice that precipitates

• forces suspension of cells through a laser beam and measures amount of light scattering of fluorescence
• it can detect heterogeneous microbial populations with different response to antimicrobial treatments.