Chapter 1: The Immune System
Summary
- Cells of the primitive innate immune system and the antigen-specific adaptive immune system act as a cooperative network to bring about a coordinated and tightly regulated immune response to foreign antigens
- The former uses a limited pattern of recognition molecules and, although it retains no memory, is able to mount a rapid response
- The latter recognises a huge diversity of different specific antigens and elicits a response that is highly specific and retains memory
- Diversity and antigen specificity in both the TCR and BCR result from somatic recombination and the random splicing of a selected number of gene segments
- When naive B-cells encounter an antigen, further antigen specificity is added by somatic hypermutation in the germinal centre of secondary lymphoid organs
- Only the most avidly antigen-binding cells mature to become either antibody-producing plasma cells or memory B-cells
- Antibodies may switch to different classes with differing effector functions and tissue locations while retaining the same antigen specificity in their variable regions
- In response to antigen, T-cells differentiate to effector T-cells that may augment the immune response, cytotoxic T-cells that destroy altered self-cells, or regulatory T-cells
- Cytokines regulate the immune response by autocrine, paracrine, and endocrine mechanisms
- Cooperative interactions of both facets of the immune response result in efficient effector mechanisms that clear foreign antigen with residual immunological memory
Further Reading
- Fugmann SD, Lee AI, Shockett PE, et al. The RAG proteins and V(D)J recombination: complexes, ends, and transposition. Annu Rev Immunol 2000;18:495–527.
- Helbert M. Flesh and Bones of Immunology. Edinburgh: Mosby Ltd., Elsevier; 2006.
- Jaffe ES, Harris NL, Stein H, et al. Introduction and overview of the classification of lymphoid neoplasm. In: Swerdlow SH, Campo E, Harris NL, et al (Eds). WHO Classification of Tumours of Haematopoietic and Lymphoid Tissues. Fourth edition. Lyon: International Agency for Research on Cancer, 2008; 158–166.
- Klein U, Dalla-Favera R. Germinal centres: role in B-cell physiology and malignancy. Nat Rev Immunol 2008; 8:22–33.
- Kracker S, Durandy A. Insights into the B cell specific process of immunoglobulin class switch recombination. Immunol Lett 2011; 138:97–103.
- Mucida D, Cheroutre H. The many face-lifts of CD4 T helper cells. Adv Immunol 2010; 107:139–152.
- Owen J, Punt J, Stranford S. Kuby Immunology. Seventh Edition. W. H. Freeman, 2013.
- Parham P. The Immune System. Fourth edition. New York: Garland Science Publishing; 2014.
- Rathmell JC, Thompson CB. The central effectors of cell death in the immune system. Annu Rev Immunol 1999; 17:781–828.
- Sun JC, Lanier LL. NK cell development, homeostasis and function: parallels with CD8 T cells. Nat Rev Immunol 2011; 11:645–657.
