T cell interaction Flashcards
which cell type is primarily responsible for eliminating viral infections?
CD8+ T cells
What encodes MHC class I
HLA-A, HLA-B, HLA-C
which process is interrupted so that the result is a deficient CD8+ T cell population?
positive selection
A patient has a normal delayed-type hypersensitive response to tuberculin and Candida. Why?
Because the CD4+ T cell response is intact and active. She has seen the pathogens before.
Development of post-transplant lymphoproliferative disorder is characterized by the uncontrolled replication of EBV in immunosuppressed transplant recipients. Presentation is similar to that seen during a primary EBV infection. Down regulation of which cellular mechanism allows EBV to grow unchecked in these cases?
EBV is a viral infection of B cells. Therefore the main response to this type of disease would be CD8+ which induces cell death either through the activation of Fas or induction of granzyme and perforin release.
in virto EBV transformation of B cells form umbilical cord blood rarely fails while transformation of B cells in blood cultures from some adults is difficult. Why?
most adults have seen the pathogen before and thus have memory T cells present. this will lead to an immune response against B cells infected with the virus. this is the reason why cord blood is better because the virus has not been seen and thus there will be no response.
Males with X-linked agammaglobulinemia (XLA) are not able to be infected with EBV. How do you explain this?
XLA is caused by a defect of Btk involved in pre-B cells receptor signal allowing pre-B cell survival. Without signal, maturing B cells die by apoptosis leading to no B cell development. Immunosuppressed.
Treatment with which cytokine might be beneficial to this patient with lepromatous leprosy?
IFN-gamma: induces macrophages to kill intracellular microbes (TH1 response)
Why would ursula be prone to asthma?
increased Th2 response leading to increase of IL-4 involved in class switching of B cells to IgE. This Ab is responsible for activation of mast cells. IL-13 is also involved as it increase mucus secretion, smooth muscle activation, and inflammation.
Which other cellular deficiency would lead to similar susceptibilities to mycobacterial infections?
IFN-gamma receptor deficiency
Which cytokine would be responsible for the vascular depletion observed after infection with super antigen?
TNF-alpha, followed by IL-1 and IL-6
If T cells are sequenced from an individual with toxic shock syndrome, what will be a characteristics of T cells?
T cells that were activated will all have the same V-beta chain. This is what superantigens bind to to cause activation. Activation of superantigen leads to suppression of immune response because of cytokine storm and multiple signals (leads to apoptosis and more)
A 12 month-old child presents with pneumonia due to an opportunistic pathogen. She has a history of repeated respiratory infections over the past two months that have resolved upon treatment with antibiotics. Which additional finding would suggest the child has a deficiency of MHC class II molecules?
absent B cells
