Cytokines are small proteins that transfer information within the immune system. List the actions of ...

1.   Cytokines are small proteins that transfer information within the immune system. List the actions of cytokines given in this Topic:
a.      
b.      
c.      
d.      
e.      
   2.   Interleukin 1, a cytokine, acts as a chemical alarm to alert the immune system to the presence of a pathogen. List the three actions given for interleukin 1 in this Topic:
1.   _________________________
2.   _________________________
3.   _________________________
   3.   Interleukin 2, released by helper T cells, causes proliferation of activated lymphocytes. This process is called _________________________.
   4.   The two major classes of lymphocytes that mediate cellular immunity are based on the presence of surface proteins called _______ proteins. The most common are those with the _______ markers.
   5.   Below are the two major classes of cells with CD protein markers. List what the cells become and what class of MHC proteins they bind.
CD4 cells:   Most become _____________ cells but some become _____________ cells
      Bind to ______________ MHC proteins
CD8 cells:   All become ______________ cells
      Bind to ______________ MHC proteins
   6.   The HIV virus binds to CD4 surface proteins and destroys the ______________ cells.
   7.   The _______ proteins are one major class of self-antigens. Thus, before an organ transplant, the donor’s and the recipient’s ________ proteins are matched as closely as possible to decrease the chance of organ _______________.
   8.   ______________ cells circulate through the body searching for infected or cancerous cells by examining the antigenic determinant on ______________ MHC proteins on the cell surface. Fragments of ______________, degraded proteins are loaded onto these proteins in the endoplasmic reticulum. If the antigenic peptide is a/an ______________ antigen, the body cell will be destroyed.
   9.   Unlike class I MHC proteins, which can be displayed on any nucleated cell, class II MHC proteins are displayed only on select cells. Name the antigen-presenting cells that have class II MHC proteins:
a.   _________________________
b.   _________________________
c.   _________________________
      These cells communicate with CD4 cells, which will become ______________ cells. Antigens presented on class II cells are ______________ antigens.
   10.   Class II MHCs are produced in the _________________________ and pick up the exogenous antigens when they fuse with the ______________.
   11.   Name two results of presenting the exogenous antigen on class II MHC proteins:
1.   CD4 cells are converted to helper T cells when ______________ cells and ______________ present the antigen.
2.   ______________ cells and ______________ present antigens to helper T cells to request further activation.
   12.   Dendritic cells are responsible for activating most T cells. Choose the correct answer for each of the following:
      They can capture antigens found ______________ (extracellularly, intracellularly, or both extra- and intracellularly).
      They can activate ______________ (CD4, CD8, or both CD4 and CD8) cells.
      They can express ______________ (MHC I, MHC II, or both MHC I and MHC II) proteins.
   13.   Exception: Normally, when cells express endogenous foreign antigens on class I MHC proteins on their cell membrane, they are marked for destruction. This is not true for ______________ cells. On these cells the presentation acts as an activation signal for ______________ cells.
   14.   List the two steps necessary for T cell activation:
1.      
2.      
   15.   Once T cells are activated they undergo proliferation (called ____________ __________________) and differentiation. ______________, a type of cytokine, is necessary for the proliferation.
   16.   Antigen-presenting cells will express co-stimulatory molecules when they have been signaled by the ______________ defense mechanisms that an infection is present. However, if there is no infection, the antigens on the MHC protein are likely to be ______________. Thus, without co-stimulation, the T cells become inactivated, a process called ______________.
   17.   There are two ways to induce a process of self-destruction in a cell, which is called ______________:
1.   Cytotoxic T cells look for the presence of MHCs with foreign antigens and release ______________ and ______________ or they bind to a/an ______________ ______________ receptor (Fas receptor) on the surface of the cell.
2.   Natural killer cells look for the absence of ______________ and are thus able to eliminate abnormal cells that cytotoxic T cells cannot detect.
   18.   Helper T cells are critical for the activation of ______________ and ______________ T cells.
   19.   The helper T cell can help activate the CD8 cell to become a/an ______________ T cell in two ways:
1.   It stimulates the dendritic cells to express additional ______________ molecules.
2.   It secretes ______________ (including interleukin 2) to help activation.
   20.   TH1 cells secrete ______________ interferons, which increase the effectiveness of ______________ and ______________ T cells. TH2 cells secrete interleukins _______ and _______, which promote activation of _____ cells.
   21.   Regulatory T cells suppress the activity of other T cells by direct ____________________ contact or by releasing ____________________. They are important in helping to prevent ___________________ diseases.