9 - T Cells Flashcards
Lymphocytosis?
Increased number of WBCs
Smear cells?
Large immature WBCs
Fragile and break up
What does lymhpocytosis and smear cell presence suggest
Problem with the development of the immune system. Not making all of the appropriate WBCas and too many of certain kinds i.e. immature B cells - indicates B cell production is not being regulated and controlled in the BM and so B cell precursors are spilling out into the blood
MAY be chronic lymphocytic leukaemia of B cell type
WHat is graft rejection mediated by
Cell mediated immunity (T cells)
What are the 3 T cell responses
- cytotoxic - kill cells
- helper - produce helper cytokines (immungological hormones) that assist other cells to respond
- regulator - produce inhibitory cytokines
What does how antigens are processed in the cell depend on
Whether they were ingested or originated in the cell
What are antigenic fragments that associate with class 1 MHC usually derived from
An infectious agent (virus i.e.) or normal breakdown of cell metabolic products
Virus infected cell
During an infection with a virus, virus-specific proteins are synthesised within the infected cell. Some of these are broken down in the cell and appear on the surface via the MHC 1 molecules - these peptide antigens can then be recognised by CD8 cells
MHC ll?
Antigenic material is taken up APCs (mphages/B cells) broken down into smaller fragments and these peptides presented on MHC ll and presented to Th cells with CD4
What do antigenic determinants that associate with class ll MHC usually result from
The processing of antigen that has been phagocytosed and degraded by APCs
Cytokines?
Low molecular weight glycoproteins that are secreted by CD4 cells and others. They regulate immune and inflam response through the quality, duration and amplitude of response. Often called interleukins. Produced transiently and act locally (para/auto not endocrine). Often have multiple and overlapping effects (not a linear response) depending on cytokine conc, nature of the cell type responding, other cytokines present, history of the receptive cell
Cytokines also affect other systems (nervous system) and influence behaviour i.e. sickness behaviour and so affects how you EXPERIENCE infection
hyperalgesic?
Sensitive to touch and pain
Graft rejection
Based on the differences in HLA molecules between people
Basis of allergy?
IS generates a vigorous antibody response of a particular class against innocuous substances that they shouldn't be responding to at all (basophils). Allergic hypersensitivity and symptoms occurring at the location you meet those substances (eczema, asthma, hay fever). Usually just locally but if it is a severe hypersensitivity you get systemic reactions that can affect breathing and blood flow i.e. the IS in inappropriately overreacting. This can cause mild local irritation > life threatening
Patient presents with painful swollen hands, lethargic, malar (butterfly) rash, lymphopenia (low WBCs), antinuclear antibodies and mild proteinuria (protein in urine)
- has made antibodies against nucleic acids
- when cells are normally broken down the nuclear antigens are released
- IS NOW sees these as foreign
- this is an autoimmune condition (may have been from previous infection)
- will find a high concentration of antigen-antibody complexes in the blood
- as already discussed these (auto)immune complexes will activate complement against her nucleic acids
- the complexes as in such a high conc get LODGED in capillaries and damage the tissues leading to lesions
- although the immune response isn’t against her skin, the resulting immune complexes are getting lodged and activated in this area causing local tissue damage and inflammation response to skin/tissue
- also circulating to kidney and causing kidney glomeruli and filtration apparatus damage hence proteinuria
- can stain for the antibody presence with fluorescence
- i.e. IS is responding to normal tissue as if it were foreign and is causing significant systemic effects
