GN 3.3.3 Flashcards
What is the most abundant white cell in the blood?
Neutrophil
What is the primary function of the neutrophil?
Destruction of tumor cells and pathogens
What is the difference between a macrophage and a monocyte?
A macrophage is a matured monocyte that has penetrated into the tissue
What are characteristics of NK cells?
These are activated by encounter with infected cells or tumor cells, kill target cells and secrete INF gamma
What are the two subsets of T-cells?
CD4+ and CD8+
CD4 T-cells are known as what?
Helper T-cells
CD8 T-cells are known as what?
Cytotoxic t-cells
Why can inflammation be referred to as a double edged sword?
Inflammation is required for tumor formation and destruction, but can contribute to tumorgenesis
What are the characteristics of acute inflammation?
Happens within minutes, vasodilation and leads to recruitment of neutrophils
What are the characteristics of chronic inflammation?
Fibrosis, angiogenesis, tissue remodeling Also leads to the recruitment of macrophages and lymphocytes
What is the process by which asbestos can lead to mesothelioma?
Small fibers of asbestos can be inhaled, and these are phagocytosed by macrophages and induce chronic inflammation. This then leads to activation of fibroblasts that cause fibrosis. Asbestos cannot be destroyed so the inflammation continues
How do T cells recognize tumor cells?
T-cells recognize antigen via the TCR (T cell receptor).
What is an antigen?
A peptide derived from degraded protein
How is an antigen presented to the T-cell?
Via the major histocompatability complex (MHC).
MHC I is expressed by what cells and presented to what cells?
Most nucleated cells and are presented to CD8+ T-cells
MHC II is expressed by what cells and presented to what cells?
MHC is expressed by professional antigen presenting cells (APCs - macrophages, dendritic and B cells) and are presented to CD4+ T cells
Tumor cells tend to express which type of MHC?
Class 1
Stimulation through the TCR alone leads to what?
Anaergy - a state of unresponsiveness