【英文】医学免疫学-名解简答重点

1、【名解】Immunity: refers to all mechanisms used by the body as protection against environmental substances that are foreign to the body.(to recognize and eliminate foreign substances)【名解】Lymphocyte homing: the migration of lymphocytes from central immune organ to peripheral immune organ【名解】Lymphocyte re

2、cirulation：lymphocyte cirulation between blood lymph other tissues【名解】Antigen: the substances that are recognized by TCR/BCR or antibody and induce a specific immune response【名解】Hapten（半抗原）：have the property of immunoreactivity but not immunogenicity . 【名解】epitope (antigenic determinant )：the portio

3、n of the antigen that binds specifically with the binding site of an antibody or a receptor on a lymphocyte.【名解】idiotypic Ag：The combined antigenic determinants (idiotopes) found on antibodies of an individual that are directed at a particular antigen; such antigenic determinants are found only in t

4、he variable region. 【名解】superantigen： antigens ，only need very low concentration ,can polyclonally activate some subtypes of the T cells (up to 20%). 【名解】Adjuvants: A substance that when mixed with an immunogen, enhances the immune response against the immunogen.【名解】Antigen: Globulin produced by pla

5、sma cells in response to antigen and binds specifically to particular Ag.【名解】Immunoglobulins (Ig)：The Igs are globulin which function as Abs or similar to Abs in chemical structure.【名解】idiotype,id:Variation in the V domain ,particularly in CDR, produces idiotype.【名解】Major histocompatibility complex,

6、MHC A cluster of genes on chromosome 6 in humans, encoding major histocompatibility antigen which lead to rapid graft rejection.【名解】Cytokine (CK)： Cytokines are small soluble proteins that mediate immune and inflammatory reactions and are responsible for communications between leukocytes and other c

7、ells【名解】Leukocyte differentiation antigen(LDA) :The cell surface markers which express or disappear on the different leukocytes in the different stage of differentiation and activation.【名解】CD (cluster of differentiation) : Cell surface molecules of leucocytes that are distinguishable with monoclonal

8、 antibodies as an immunologic marker.【名解】CAM: A group of proteins involved in adhesion of cell to cell or cell to extra-cellular matrix (ECM), such as ICAM-1, ICAM-2, ICAM-3, VCAM-1 and PECAM etc. 【名解】Integrin:Mediate adhesion of cell and extracellular matrix，Elementary structure: heterodimer of a,

9、b chain【名解】ADCC：NK cell FcR recgonize antibody Fc region binding with target cell,and directly kill the target cell.【名解】opsonization:antibody such as IgG Fc region binding with neutrpilic cell or macrophage IgG FcR to increase phagocytosis.【名解】APC:A variety of cells specialized in capturing、processi

10、ng and present the antigen to the T lymphocytes, causing either tolerance or immunity. 【名解】cross presention: APC can capturingprocessing exogenous antigen and presenting to CD8 T cell by MHC1 pathway.【名解】Positive selection:DP cells that bind, with moderate affinity, to MHC-Ag on thymic stroma cells

11、survive-MHC restriction MHC I-CD8+ T cells MHC II-CD4+ T cellsNegative selection:Cells that bind to MHC-Ag on thymic stroma cells (or auto-reactive T cells, ART) with high affinity will undergo apoptosis-Formation of central immune tolerance【名解】ALLELIC EXCLUSION：Expression of a gene on one chromosom

12、e prevents expression of the allele on the second chromosome，Ensures only one specificty of Ab expressed per cell.WHY: Allelic exclusion prevents unwanted responses;Allelic exclusion is needed for efficient clonal selection; Allelic exclusion is needed to prevent holes in the repertoire 【名解】Affinity

13、 maturation ：Affinity maturation is the process by which the affinity of Abs produced in response to a protein Ag increases with prolonged and repeated exposure to that Ag.【名解】Treg: Down-regulation of immune response by inhibiting the activation and proliferation of CD4+ or CD8+ T cells.【名解】FoxP3+ :

14、is the transcription factor that program the development of Tregs （IPEX综合症）【名解】Immune tolerance :is the process by which the Immune system does not attack an antigen. Is an active process which is different from immunodeficiency or immunosuppression.【名解】AICD: Activation-induced Cell Death,recognitio

15、n and deletion of T lymphocytes that have been induced to proliferate by receptor-mediated activation, preventing their overgrowth.【名解】AIRE(autoimmune regulator): transcription factor that enables ectopic expression in the thymus of genes usually considered tissue-specific.【名解】Immuno-labeling techni

16、ques：Specific Abs (or Ags ) labelled with fluorescein, enzymes or radioisotopes are used as probes for the detection of Ags (or Abs).【名解】ELASA【简答】Functions of V regions：Recognition and binding to antigen by HVR (CDR) - neutralization of toxins (e.g. diphtheria, tetanus); - immobilization of microorg

17、anisms; - neutralization of viral activityFunction of C regions (Fc portion)1. Activation of complement: IgM, IgG Ab( IgM、IgG )+Ag- C1q-补体经典途径 IgG4、IgA和IgE的凝聚物-补体旁路途径2. Binding to Fc receptor of cellsOpsonization: enhancement of Ag uptake by macrophages (M?)Antibody-dependent cell-mediated cytotoxic

18、ity (ADCC): NK cells.Participation in type I hypersensitivity: IgE3. Passage through the placenta (IgG, CH2) and mucosa (sIgA)【简答】Biologic function of complement plement mediates anti-infection immunity (1) Lysis of cell or microorganisms (2) opsonization C3b, C4b, iC3b cell: phagocyte en

19、hance phagocytosis (3) inflammation symptoms: redness, swelling, heat and pain inflammation mediators: C5a, C3a, C4a ( anaphylatoxins) C5a (chemotaxis)2. Complement maintains homeostasisclearance of IC: C3belimination of apoptosis cells C1q, C3b, iC3b3. Complement mediates adaptive immunity4. Comple

20、ment interacts with other enzyme systems【简答】MHC molecules difference1) HLA class I molecules Genes: A, B, C Distribution: every nucleated cell Structure: chain (45k) 2m (12kD) chromosome 15 peptide-binding cleft: 1+2 CD8 binding: 3 Function: recognize and present endogenous Ags to CD8+ T cells2) HLA

21、 class II molecules Genes: DR, DQ, DP Distribution: APC (B, DC, M) thymic epithelial cell, activated T cell Structure: chain (35kD) chain (28kD) peptide-binding cleft: 1+1 CD4 binding: 2 Function: recognize and present the exogenous Ags to CD4+ T cells 【简答】Biological function of MHC1、Participate in

22、the adaptive immune response serving as antigen presenting molecules(1)T cells recognize both the antigenic peptide and MHC molecules by TCR (double recognition)(2)MHC molecules can present both autoantigens and allogenic MHC molecules(3)MHC molecules participate in selection and differentiation of

23、T cells in the thymus.(4)MHC is the crucial determinant of disease susceptibility in different individuals；(5) MHC contributes to the genetic heterogeneity of the population2. Participate in the innate immunity serving as regulatory molecules(1)Classical MHC class III genes encode complement, hereby

24、 participating in complement reaction and the pathogenesis of some immune diseases.(2)Non-classical HLA class I molecules (HLA-E, G) regulate the activity of NK cells.(3)Inflammation related genes initiate and control inflammation. They also play a role in stress. (such as HSP).【简答】General propertie

25、s of CKsSmall proteins (MW: approx. 8-30 KD)Extremely potent, acting at 10-910-15MThe production is transient and tightly regulatedAutocrine, paracrine or endocrineCytokine actions: Pleiotropy, Redundancy, Synergy and Antagonism【简答】What are the differences between immature DC and mature DCInmature D

26、CPhenotype: high expression of receptors related to phagocytosis (FcR, CR, mannose receptor, DC-sign); low expression of CD54, CD40, CD80; CD86 and MHC II, CD14-Function: 1) strong capacity to ingest and process Ags, but weak ability to present Ags 2) induction of immune tolerance 3) sensing of infe

27、ctious agents by TLR (pattern recognition receptors) Mature DCPhenotype: low expression of receptors related to phagocytosis (FcR, CR, mannose receptor); high expression of CD54, CD40, CD80, CD86 and MHC II; CD83+ and CD25+ Function: weak ability to capture and process Ags, powerful ability to prese

28、nt Ags【简答】Effector functions of activated T cells（重点）1) CD4+ T cells Th1: secrete IFN-g, etc. express CD40L express FasL, kill Fas+ target cells effect on lymphocytes: IL-2 effect on neutrophil: TNF-a,b Th2: promote B cell growth and Ig production mediate hypersensitivity Th17: IL-17,IL-8,TNF-a: enh

29、ance leukocyte recruitment and inflammation 2). Effector functions of CD8+ T cellsCytotoxicity: kill target cells a. necrosis: perforin and granzyme b. apoptosis: granzyme, FasL 【简答】fuction of b cell1. Production of antibody Abs prevent microorganism from entry into cells and eliminate microorganisms by opsonization causing phagocytosis, complement activation and toxin neutralization.2. Ag presentation to T c