University:
York University
Course:
SC/BIOL 3120 | Immunobiology
Academic year:

2023
Views:

415

Pages:

2
Author:

Niklas

Immune Response Kinetics Immune response timeline: Contract 1) Antigen recognition 2) Lymphocyte activation (3-10 days later) 3) Antigen elimination (several 7-10 days) 4) Contraction (homeostasis) 5) Memory Immunological Memory: Primary vs Secondary Responses Innate response doesn't change between primary and secondary exposure. Adaptive response is stronger (memory) after a primary exposure. The Initial Immune Response A diagram depicting the cellular and molecular interactions involved in the initial immune response. Differences between primary and secondary immune response to a pathogen Feature Primary (naive T cells) Secondary (memory T cells) Antigen-specific cells Small number Large number Chromatin Closed and not accessible to transcription factors Open and accessible to transcription factors Antibodies Delay before production Specific antibodies are immediately present Affinity Starts with low to medium affinity Antibodies are high-affinity and of high specificity Effector T cells Delay before activation Effector cells are efficient and act quickly Innate immunity Innate immunity is activated and ongoing There is close cooperation between innate and adaptive immunity from the start of infection Models of Activation and Memory CD62L: An adhesion protein that regulates homing to lymphoid organs. CCR7: A chemokine receptor that regulates homing to lymphoid organs. ICAM-1: A cell surface molecule involved in cell-cell interactions. CD40L: A co-stimulatory molecule that increases T cell-mediated activation signals. CD69: A C-type lectin involved in immune cell interactions and preventing cells from leaving a tissue. Models of Memory for Cell Differentiation Model 1: Expansion, survival, and differentiation of memory cells. Model 2: Every time a memory cell divides, one becomes an effector cell and the other a memory cell. Model 3: Memory cells become memory cells first and then, upon receiving more stimulation, will differentiate into effector cells.