1. Lecture 6 Humoral Immune Response

2. The Antibody Response

3. Antibody Protection of the Host

4. Immunologic Memory Virgin lymphocyte pool PRIMARY RESPONSE SECONDARY RESPONSE effector cells memory cell pool effector cells memory cell pool

5. Immunologically Naive No previous experience No memory Must be educated No previous experience No memory Must be educated

6. The Primary Immune Response antigen challenge lag log phase plateaudecline antibody titer time

7. Class Switching antibody titer time IgG IgG IgM IgM

8. Four phases of the primary response a lag phase where no antibody is detected a lag phase where no antibody is detected a log phase in which the antibody titer rises logarithmically a log phase in which the antibody titer rises logarithmically a plateau phase during which the antibody titer stabilizes a plateau phase during which the antibody titer stabilizes a phase (decline) during which the antibody is cleared or catabilized a phase (decline) during which the antibody is cleared or catabilized

9. The Anamnestic Immune Response Time 1 10 100 1000 antibody titer Primary Response Secondary Response

10. Comparison of Primary and Secondary Responses Time course Time course Antibody titer Antibody titer Antibody class Antibody class Antibody affinity Antibody affinity

11. Terms to remember Opsonization Opsonization Neutralization Neutralization Complement activation Complement activation Primary response Primary response Secondary/ anamnestic/ booster response Secondary/ anamnestic/ booster response Lag phase Lag phase Log phase Log phase Plateau period Plateau period Memory cells Memory cells Class switching Class switching Affinity maturation/ change in affinity with time Affinity maturation/ change in affinity with time