Question

Cancer/Viral Scenarios Worksheet: For each scenario, diagram and/or explain the activities of the cells involved including the self cell, Cytotoxic T cell, Natural Killer Cell and/or T helper cell along with any pertinent cytokines and proteins.

1. The Human Papilloma Virus has infected the cervical cells of a patient and the cancerous cells have stopped producing MHC. Diagram the immune system’s response to these changes in the cervical cells
2. The Herpes Simplex Virus has infected your patient’s mucosal cells of the genitals and those infected cells are actively replicating the virus
3. The Hepatitis B Virus has infected the liver cells of your patient. Due to the viral infection and early cancerous changes in the liver cells, they have begun to make stress proteins:

Answer 1

A. HPV Virus

B. HSV INFECTED CELLS:

• Virus infected cells process the antigen (viral particle) in the rough endopalsmic reticulum and load into onto MHC 1 complex. Together MHC1- viral particle are secreted from the ER and an invariant chain is attached to the the MHC1 molecule. The whole complex sits on the plasma membrane
• The complex is recognized by natural killer cells which produce perforins and granzymes to induce apoptosis of viral infected cell.
• Additionally, antigen presenting cell (dendritic cell/langerhan cell) process the antigen and present it to T cells. They use MHC1 for presenting to Cd8+ cytotoxic T cells, and MHC 2 for presenting to CD4+ T cells. The cytotoxic T cells directly attack the infected cell.
• Cd4+ T cell differentiates into Th1 helper cell and produces interferon-gamma and IL-12 to activate macrophages and cytotoxic cells. Macrohages are the main mediators of chronic inflammation and produce TNF-alpha and IL-12 to further activate Th1 helper cells and NK cells.
• CD4+ cells also activate B cells which class switch to produce antibodies (IgA, IgG) that prevent bacterial adherence (IgA) and fixes complement (IgG).

C. HEPATITIS B infected liver cells:

• Major stress proteins produced by human cells are heat shock proteins, also known as chaperone proteins. Their main function is to assemble and disassemble proteins.
• During intense viral replication and cancerous changes, these proteins will regulate the assembly of proteins such as T cell receptor proteins, MHC I and II proteins, cytokines (IL-12, IFN-gamma, TNF-alpha) to increase function of antigen presentation.
• They also increase transcription of genes necessary for production of MHC complexes and cytokines.