Table 36-1. Cells involved in inflammation Figure 36.1 The complement cascade. Activating stimuli bear surfaces that trigger complement activation, and to which the activated component can attach itself. The late components of the cascade do not show enzymatic activity. Instead, they coalesce to form a polymeric macromolecule (the membrane attack complex), which can insert itself into the activating surface (the cell wall in the case of bacteria), breach its integrity and cause osmotic lysis. Figure 36.2 Structure of the ?/?, ?/? T-cell receptors. V and C refer to the variable and constant sequence domains, respectively, of each of the ?, ?, ? and ?chains. Modified from Roitt IM et al. Immunology, 5th edn. London: Mosby, 1998. Figure 36.3 Structure of B-cell antigen receptor. Figure 36.4 Immunoglobulin variable gene recombination events. The apparent requirement for a huge number of genes required for antibody diversity is resolved by using a gene rearrangement strategy. The variable domains of both the heavy (H) and light (L) chains are encoded by a number of gene segments, two for the L chain (Variable L [VL] and Junctional L [JL]) and three for the H chain (Variable H [VH], Diversity H [DH], and Junctional H [JH]). The constant domains that make up the majority of the heavy chain molecules and half the light chain molecules are coded for by single gene segments, CH and CL, respectively. Figure 36.5 Clonal selection in B cells. Antigen-specific (Ag-specific) secretory immunoglobulin (sIg) on the B-cell membrane has a shape reciprocal to the antigen. Antigen-immunoglobulin binding leads to activation and proliferation to produce a clone of antigen-specific B cells. Each member of the specifically activated clone then undergoes differentiation into a plasma cell, which produces large quantities of a single homogeneous immunoglobulin with identical specificity to the sIg that triggered the response in the first instance. Figure 36.6 The integrated cellular immune response. T-helper cells (Th cells) are involved in many aspects of the cellular immune response. Cytokine and direct Th cell-mediated activation of B cells leads to differentiation to plasma cells, which secrete antibody. AG:AB, antigen-antibody; APC, antigen presenting cell; Tc, cytotoxic T cell; Th, T helper cell. Figure 36.7 Genetic organization of the MHC and expressed products. Genes of the MHC in humans are located on chromosome 6. The gene products are the human leukocyte antigens (HLA). Figure 36.8 Class I and II MHC (HLA) structure. On the left there are class I and class II MHC molecules. In class I molecules ?2-microglobulin (?2 m) provides the fourth domain. On the right, this is related to the types of protein conformation in the MHC molecules. Figure 36.9 Complement activation pathways. There are three possible pathways of complement activation. Only the classical pathway is triggered by the specific immune response. The mannose binding ligand (MBL) pathway and the alternative activation pathway are triggered directly by microbes and their products. Table 36-2. Effector functions of antibodies. Figure 36.10 Summary of the specific immune response. Interrelationships between cellular and humoral components of the specific immune response. APC, antigen presenting cell; Th, T-helper cell; Tc, cytotoxic T cell; MHC, major histocompatibility complex; TCR, T-cell receptor. Table 36-3. Disorders of immune regulation Summary Body_ID: HC036079 page 521 page 522 Body_ID: P0522 Integrated immune response to non-self or altered-self elements (antigen(s)) is made up of a number of components. Some of these show unique specificity for the particular stimulating antigen(s) and comprise the specific or adaptive immune response, whilst others do not and comprise the nonspecific or innate immune response. The nonspecific response represents the first line response and can be considered cruder and more primitive. The cells and soluble mediators involved are primarily those associated with the processes of acute inflammation and endothelial cell activation. The specific response is more refined and usually invoked only in the face of either failure/continued stimulation of the nonspecific response. The cells responsible for the specific immune response are the lymphocytes; T, B and NK. The specificity they show for the inciting antigen is achieved via the use of specific antigen receptors, T cell and B cell receptors, expressed on cell surface. T cells recognize processed antigen via the TcR interacting with antigen presented by MHC-bearing cells, leading to the secretion of additional cytokines and the generation of effector functions such as T cell help and T cell-mediated cytotoxicity brought about by the T-helper and T-cytotoxic subsets respectively. Historically, T cell responses have been termed the cellular immune response. B cells recognize native antigen and secrete soluble forms of the individual B cell antigen receptors which we recognize as antibodies. Historically, B cells and their antibody products have been termed the humoral immune response. Both T and B cells and their products are able to recruit and utilize components of the nonspecific response in a more effective and targeted manner, with the aim of eliminating or eradicating the antigen. In addition to demonstrating specificity, the specific immune response also demonstrates another critically important characteristic not seen with the nonspecific response - the memory for its encounter with all types of antigen. The benefit of this is that, on subsequent contact with the same antigen, the antigen can be eliminated more quickly and effectively, and with less tissue damage, than on the previous occasion. Body_ID: PB36008 ACTIVE LEARNING Body_ID: B036004 Compare T and B lymphocytes. What are adhesion molecules and what is their role in the immune response? Can one distinguish T and B lymphocytes under a microscope? What is the role of the Fc fragment of an immunoglobulin? What is the role of the thymus in the immune response? Body_ID: PB36009 Further reading Body_ID: None Roitt IM. Immunology, 5th edn. London: Mosby, 1998. Body_ID: R036001 Janeway C, Traver P, Hunt S, Walport M. Immunobiology, 5th edn. London: Garland, 2002. Body_ID: R036002 Chapel H, Heaney M, Misbah S, Snowden N. Essentials of Clinical Immunology, 4th edn. Oxford: Blackwell; 1999. Body_ID: R036003 Parkin J, Cohen B. An overview of the immune system. Lancet 2001;357:1777-1789. Full article Essentials of Clinical Immunology 2006 Chapel H., Haeney M., Misbah S. 2_169/Essentials of Clinical Immunology5ed2006.pdf Черно-белое Иллюстрации: Young B., Lowe J.S., Stevens A., Heath J.W., Eds. Wheater's Functional Histology: A Text and Colour Atlas, 5th ed., 2006 2_34/Histology_Text_Atlas5ed2005.CHM immty1_1.jpg = Figure 11.1 The organs of the immune system; Ag antigen APC antigen presenting cell B B lymphocyte IL interleukin MAC membrane attack complex MHC major histocompatibility complex PA processed antigen sIg surface immunoglobulin Tc cytotoxic T cell TCR T cell receptor Th T helper cell immty2_1.jpg = Figure 11.2 The basics of the immune response immty3_1.jpg = Figure 11.3 Lymphocytes and antigen presenting cell (a) Schematic diagram (b) EM ?18 000; AP antigenic peptide APC antigen presenting cell B bacterium CE cytoplasmic extensions EE early endosome ER endoplasmic reticulum L lymphocyte Ly lysosome MHC I major histocompatibility complex class I MHC II major histocompatibility complex class II P phagosome PL phagolysosome PM plasma membrane Pr proteasome Tc cytotoxic T cell TCR T cell receptor Th T helper cell VP viral peptide VPr viral protein immty4_1.jpg = Figure 11.4 Lymphocyte surface markers (таблица) immty5_1.jpg = Figure 11.10 Structure of the lymph node (a) Schematic diagram (b) Reticulin method ?30 immty6_1.jpg = Два отсюда 2_116/Essentials of Obstetrics and Gynecology2004.chm 7 Maternal Physiologic and Immunologic Adaptation to Pregnancy Brian J. Koos Bahij S. Nuwayhid J. George Moore 7 Maternal Physiologic and Immunologic Adaptation to Pregnancy immty7_1.jpg = Figure 7-4 Summary of innate immunity. Surface antigens of viruses, bacteria, and tumors induce innate immune system function. In this system, natural killer (NK) cells and phagocytes, such as macrophages, can recognize certain antigens in a nonspecific fashion and either lyse the offending infected cells or tumor cells or ingest and destroy the offending organisms. Note that only the foreign nature of the antigen is required; antigen processing and major histocompatibility antigen participation are not necessary. Reproduced with permission from Silver R, Branch DW: Immunology of Pregnancy. In Creasy RK, Resnick R (eds): Maternal-Fetal Medicine. Philadelphia, WB Saunders, 1999. immty8_1.jpg = Figure 7-5 Summary of adaptive immunity. Adaptive immune responses initially require antigen processing and subsequent presentation to T cells. A T cell with a receptor specific for an inciting antigen will be activated and undergo clonal proliferation. In part, the type of cytokine produced by the activated T cell dictates the nature of the subsequent response. Interleukin-2 is the primary growth factor required for clonal proliferation of T cells and stimulates the proliferation of cytotoxic and memory T cells. Interleukin-4 and -5 stimulate B-cell proliferation, differentiation and antibody production. Reproduced with permission from Silver R, Branch DW: Immunology of Pregnancy. In Creasy RK, Resnick R (eds): Maternal-Fetal Medicine. Philadelphia, WB Saunders, 1999.