text: There are two types of interferons produced during a viral infection. Type I interferons (alpha and beta) inhibit viral replication in neighbouring cells so you would see this more in neighbouring cells. Type II interferons (gamma) are involved in activating the immune response, as are the other cytokines listed.
  After activation, B cells undergo a series of cell divisions where the DNA for the antibody undergoes changes to increase its avidity for the antigen - a process called clonal selection. This process is believed to be a cause of auto-immunity, whereby some of the clones produce antibodies that start to detect self-antigens.
  Which of the following cytokines is directly responsible for causing fever during an immune response?
  IL-1 and TNF-alpha also cause fever (source: 'Instant Notes Immunology' by Lydyard, Whelan and Fanger; 'The Immune System' by Peter Parham)
  C5b is produced by C3b and goes on to bind to the infected cell as well. Some sources say that C4b can also opsonise a targeted cell; however, that requires activation of C4 by C1 binding to an antibody whereas C3 can be activated by PAMPs and C reactive protein as well so is more likely to be the first molecule to bind.
  What are the two main structural elements to an immunoglobulin? Which one depending on the immunoglobulin type?
  Each immunoglobulin molecule consists of two heavy chains and two light chains. The nature of the heavy chains determines whether the molecule is IgA, IgD, IgE, IgG or IgM. There are also two types of light chain (kappa and lambda) but they don’t change the classification of the immunoglobulin type.
  Primary immune response is slower, predominantly involves IgM and the antibodies tend to be less specific for an antigen.
  The secondary immune response is faster and bigger, involves IgG, and the antibodies are more specific to the antigen.
  The binding of molecules such as antibodies and complement to a microbe which enhances its rate of phagocytosis.