Immunity: molecular and cellular basis

Chapter 6

Immunity: molecular and cellular basis

14 topics, 6 written so far

  1. 46Innate immunityThe defences we are born with, ready in minutes and the same every time: barriers, the cells and molecules that sense what is foreign, phagocytes and complement, inflammation and fever, and the natural killer cells.
  2. 47Structure of antibodiesFour chains folded into a Y: two arms that bind one antigen exactly, a hinge that lets them reach, and a stem that tells the body what to do with what they hold. The same plan, varied, makes the five classes.
  3. 48Functions of antibodiesAn antibody does no harm by itself. Its arms bind and block; once they have bound, its stem calls in complement, phagocytes and killer cells. The stem also works with no antigen bound: it arms mast cells with IgE, and carries antibody into secretions and across the placenta.
  4. 49Molecules of cell-mediated immunityA T cell cannot see a whole microbe. Most T cells see a short peptide held out by an MHC molecule on another cell's surface, read by the T-cell receptor, and a naive T cell acts only if a second signal says the danger is real.
  5. 50Cytotoxic and helper T lymphocytesA T cell that meets its peptide on a dendritic cell divides into thousands of copies, and they become effector cells. CD8 T cells kill infected cells. CD4 T cells, the helpers, direct the rest of the response with cytokines and with contact.
  6. 51Genetic basis of antibodies and T-cell receptorsNo one inherits a whole antibody gene. Each young lymphocyte builds its receptor gene by cutting pieces of DNA out of its chromosome and joining the rest, a little differently every time, so a few hundred gene segments give every person a different receptor in almost every B and T cell.
  7. 52Lymphocyte differentiation in central lymphoid organsNot written yet
  8. 53Lymphocyte differentiation in peripheral lymphoid organs. Immune responseNot written yet
  9. 54Immune memoryNot written yet
  10. 55Immune tolerance. Regulatory T lymphocytesNot written yet
  11. 56Transplantation immunityNot written yet
  12. 57Antitumor immunity. Evolution of immunityNot written yet
  13. 58Blood group alloantigens. ABO and H blood groupsNot written yet
  14. 59Rhesus blood groupsNot written yet