Immunology Lecture Notes PDF
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مالك العبوشي ، أسماء صرمة ، مرح حنجل ، عبد الحكيم أبو رجا
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This document is a lecture on immunology, focusing on antibody-antigen interactions. It covers key concepts including affinity and avidity, and their importance in binding strength. The document also provides detailed information on the interaction between these molecules, with a discussion on the relevant biological concepts and related diagrams.
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Immunology ﺗﻔﺮﯾﻎ :ﻣﺎﻟﻚ اﻟﻌﺒﻮﺷﻲ ،أﺳﻤﺎء ﺻﺮﻣﺔ ،ﻣﺮح ﺣﻨﺠﻞ ،ﻋﺒﺪ اﻟﺤﻜﯿﻢ أﺑﻮ رﺟﺎ ﺗﺪﻗﯿﻖ :ﻓﺘﺤﻲ ﻣﻠﺤﻢ Key Concepts in Ab-Ag interaction ...
Immunology ﺗﻔﺮﯾﻎ :ﻣﺎﻟﻚ اﻟﻌﺒﻮﺷﻲ ،أﺳﻤﺎء ﺻﺮﻣﺔ ،ﻣﺮح ﺣﻨﺠﻞ ،ﻋﺒﺪ اﻟﺤﻜﯿﻢ أﺑﻮ رﺟﺎ ﺗﺪﻗﯿﻖ :ﻓﺘﺤﻲ ﻣﻠﺤﻢ Key Concepts in Ab-Ag interaction ﺑدﻧﺎ ﻧﺣﻛﻲ ﻛم ﺷﻐﻠﺔ ال antibodyو اﻻﻧﺗﺟﯾن ﺑرﺗﺑطوا ب ) non-covalent bondsﺑﻧﻌرف ﻣن اﻟﻛﯾﻣﯾﺎ اﻧو ال covalentﻣن اﻗوى اﻟرواﺑط و اﻧﮭﺎ irreversibleف ﻛون اﻟرواﺑط non-covalentھﺎد ﺑﺧﻠﯾﮭﺎ (reversible ﺷﻛل ال paratopeﺑﻛون ﻣﻛﻣل ) (complementaryﻟل ) epitopeﺷوف ﺳﻼﯾد 8ﻋﺎﻟﺳرﯾﻊ( ال affinityو avidity Affinityھﻲ اﻟﻌﻼﻗﺔ ﺑﯾن paratopeو epitopeو ھﻲ ﻋﺑﺎرة ﻋن non-covalent bondsو ﺑﺗﺗﺣدد ﻗوﺗﮭﺎ ﺑﻘوة ھﺎي اﻟرواﺑط اﻟﻛﯾﻣﯾﺎﺋﯾﺔ.طﺑﻌﺎ ﺑﺗﻧﻘﺎس ﺑﺎل Kdو ھﺎد ﺑﻌﺑر ﻋن ﻗدرة ال epitopeو paratopeﻋﺎﻻﻧﻔﻛﺎك )ﻛل ﻣﺎ ﻗﻠت ﯾﻌﻧﻲ ﻗدرﺗﮭم ﻋﺎﻻﻧﻔﻛﺎك اﻗل ﯾﻌﻧﻲ ال affinityاﻛﺑر( Avidityﺑﺗﻌرب ﻋن اﻟﻌﻼﻗﺔ ﺑﯾن antibodyﻣﻊ اﻻﻧﺗﺟﯾن و ھﺎي ﺑﺗﻌﺗﻣد ﻋﻠﻰ : .1ال affinityﯾﻌﻧﻲ ﻛل ﻣﺎ زادت ﻗوة اﻻرﺗﺑﺎط ﺑﯾن ال epitopeو paratopeﻛﺎﻧت ال avidityاﻛﺑر .2ال valencyو ھﻲ ﺑﺎﺧﺗﺻﺎر )ﻛم paratopeارﺗﺑط ب (epitopeﻣﺛﻼ ﻟو ارﺗﺑط اﻧﺗﺟﯾن ب antibodyو ﻛﺎن اﻻرﺗﺑﺎط ﺑﯾﻧﮭم ھو paratopeواﺣد ﻣﻊ epitopeواﺣد رح ﺗﻛون ال avidityاﻗل ﻣن antibodyارﺗﺑط ﺑﺎﻧﺗﺟﯾن و ﻛﺎن اﻻرﺗﺑﺎط ﺑﯾﻧﮭم 10 epitopeﻣﻊ 10 paratope Key Concepts in Ab-Ag interaction 1. Antibody (Ab) form multiple non-covalent bonds with antigen=> Reversible - Attractive forces (H bonds, electrostatic bonds, van der Waals forces, & hydrophobic forces) => High affinity interaction 2. The Ag-binding sites of an Ab are complementary to the conformation of Ag determinants (epitopes) of an Ag. 3. Affinity vs. Avidity forA b ó A g Affinity => A measure of the strength of interaction between an Ag-binding site and its epitope => Kd, dissociation constant; small Kd => stronger affinity Avidity => The overall strength of A b ó A g => Affinity & the valency of interactions 3 Affinity and avidity راﺑط ب اﻛﺗرAB ھون ﻣش ﻣوﻧﻣر اﻧﻣﺎAB ھون ال ﺑﻧﺳﻣﯾﮫepitope ﻣن multivalent وﻋﻠﯾﮫ ﻛﺗﯾرpentamer - Can bind with 2 ﺑﺗﻘدر ﺗرﺗﺑطbindind sites epitopes up to 10 epitopes ﻛﺎﻣلAB ھون ﻋﻧﺎ ھون ﻋﻧﺎ ﺟزء ﻣن ال ﯾوﺟدfab ﺑسAB one binding ﺑس site اﻟﻣرﺗﺑطﯾنepitope ﻋدد ال binding ﻛل ﻣﺎ ﻛﺎن ﻋﻧدي اﻟﻛﻠﻲepitopes ﻋدد ال اﻛﺗر ﻛﺎن اﻟﺗﻔﺎﻋل ﺛﺎﺑتsites constant ﻛم ﺑﺿل اﻟرﯾﺎﻛﺷن اﻛﺗر one ﻻﻧﮫ ﻋﻧﺎAffinity epitope Avidity = more than one Multivalent binding between antibody and antigen (avidity or functional affinity) results in a considerable increase in stability as measured by the equilibrium constant, compared with simple monovalent binding. 2019-2020 Immunology 7105306 23 Ab variability The hypervariable region (HV 1-3) are separated in the primary structure, but come together in the tertiary structure where they form antigen binding site. Alias Complementary Determining Region or CDR 1-3 -The HV regions form loops at the end of Ig domain - The intervening framework region (FR 1-4) make up the rest of the structure epitope ﻟلspecific وﺑﺗﻛونparatope ھﻲ اﻟﻠﻲ ﺑﺗﺷﻛل الvariable site ال 3 ﻋﻧﺎhypervariable region واﻟﺳﺑب ﺑذﻟك وﺟود ال, وھﻲ ﺳﺑﺳﻔك ﻻﻧﮭﺎ ﻣﺗﻐﯾرة و ﻣﺗل ﻣﺎ ﺷﺎﯾﻔﯾن ﺑﺎﻟرﺳﻣﮫ ﻋﺎﻟﯾﻣن ھﻣﺎ اﻟﻠﻲ ﻟوﻧﮭم اﺣﻣرHV1-2-3 ﻣﻧﺎطق ﺑﻧرﻣزﻟﮭم ب ter9ary ﺑﺎل, اﻣﺎ اﻻﺻﻔر ﻓﮭو ﻣش ﻣﺗﻐﯾر-ﻓﺑﻛوﻧو ﻣﻔﺻوﻟﯾن ﺑﺎﻟﺑراﯾﻣري ﺳﺗرﻛﺗﺷر اﻟﻠﻲ ﺑﻧﺳﻣﯾﮫan9gen binding site ﺑرﺗﺑطو ﻣﻊ ﺑﻌض وﺑﺷﻛﻠو الstructure (3D) alias complementary determining region CDR1-3 the اﻟﻠﻲ ﺑﺟﻣﻌﮭم طﯾب ؟ اﻟﻠﻲ ھو اﻻﺷﻲ اﻻﺻﻔر وﺑﻧﺳﻣﻲstructure ﺷو ال intervening framework region FR1-4 5 Antibody structural variation ﺑدﻧﺎ ﻧﺣﻛﻲ ﻋن اﺧﺗﻼﻓﺎت ﺑﺎل structuresﺗﺎﻋت ال antibodies :Isotypes.1ھون ﺑﺣﻛﻲ ﻋن اﻻﺧﺗﻼف ﺑﺎل classو ﺣﻛﯾﻧﺎﻋﻧﮭن زي IgM,IgG(1-4),IgD,IgA(1,2),IgEطﺑﻌﺎ اﻻﺧﺗﻼف ﺑﺎل heavy chains :allotypes.2ﺑدﻧﺎ ﻧﺣﻛﻲ ﻋن ﻧﻔس ال classﺑس ﻋﻧد اﺷﺧﺎص ﻣﺧﺗﻠﻔﯾن )ھﺎن ﺑﻛون ﻣﺛﻼ ال IgMﻋﻧدي ﺷﺑﮫ اﻟﻠﻲ ﻋﻧدك ﺑس ﻓﻲ ﻓروﻗﺎت immunologicalﺻﻐﯾرة )ﺣﺗﻰ ال v regionﺗﻘرﯾﺑﺎ ﻧﻔﺳﮭﺎ دﻻﻟﺔ اﻧﮭﺎ ﺑﺗﻘﺎوم ﻧﻔس اﻻﻧﺗﺟﯾن طﺑﻌﺎ ﻣﻊ ﺗﻐﯾرات ﺑﺳﯾطﺔ ( :Idiotypes.3ھﺎن ﺑﺣﻛﻲ ﻋن اﻧو ﻣن ﻧﻔس ال classﺑس ال v regionﻣﺗﻐﯾرة ﻻﻧو ﺑﻘﺎوم اﻧﺗﺟﯾﻧﺎت ﻣﺧﺗﻠﻔﺔ ﺑﺎﺧﺗﺻﺎر isotypesاﺧﺗﻼف ﺑﺎل Allotypes. classﻧﻔس ال class & v-regionﺑس اﺧﺗﻼﻓﺎت ﺑﺳﯾطﺔ ﻻﻧﮭﺎ ﻣش ﻣن ﻧﻔس اﻟﺷﺧص Idiotypes.ﻧﻔس ال classﺑس v regionاﺧﺗﻠﻔت Antibody structural variation Isotypes: have different heavy chains. They are represent classes ofAb. Allotypes: have the same constant regions with minor, but immunologic differences. Different individuals have different allotypes. Idiotypes: Abs that recognize different specific epitopes. Each idiotype is composed of several idiotypes or combining sites. Heavy chain isotypes are encoded by μ, δ, γ3, γ1,α1, γ2, γ4, α2, and ε genes on chromosome 14. The single κ and multiple λ isotypes are encoded by Cκ and Cλ genes on chromosomes 2 and 22, respectively. ھدول ﺑﻧﻔس اﻟﺷﺧصIgE IgD وﻛﻣﺎن الIgA 1-2 وIgM وﻛﻣﺎن الIgE1-2-3-4 ﻣﺗل ﻣﺎ ﻛﻧﺎ ﻧﺣﻛﻲ:isotypes -1 اﻟﻠﻲ ﺣﻛﯾﻧﺎھم9 الIgA –M-E واﻟﻔرق ازاindividual ﺑﻧﻔس الAB ھﻣﺎ ﺑﺎﺧﺗﺻﺎرisotopes ﺑﻧﺳﻣﯾﮭم , ﺗﻘرﯾﺑﺎ وCONSTANT R ھﻣﺎ ﻋﻧدھم ﻧﻔس الIgA 1 اﻟﻣوﺟود ﻋﻧدي وﻋﻧد زﻣﯾﻠﻲ الab الallotypes -2 immunologic difference Staph aureus ﺿﺪ الIgM أوE.coli ﺿﺪ الIgM ﻓﻤﻤﻜﻦAg ﺳﺒﺴﻔﻚ لAB ﻣﺶ اﺣﻨﺎ ﺑﻨﻨﺘﺞidiotype -3 Complementary interactions between Ag- binding sites and their epitopes Epitope binds to its binding site Each site is specific to its epitope ( its complementary to its Ag) ﺑرﺑط عepitope ﻣﺛل ﻣﺎ ﺷﺎﯾﻔﯾن ﻛﯾف ﻛل ﻣﻌﯾن و ﺑﻛون ﺧﺎص ﻓﯾﮫparatope 8 Specificity, Cross-reactivity & non-reactivity of AbóAg ﻋﻼﻗﺎت ﺑﺘﺨﺘﻠﻒ ﺣﺴﺐ ﻗﻮﺗﮭﺎ3 ﻓﻲantigen والantibody ﺑﯿﻦ ﺑﺎﻻﻧﺘﺠﯿﻦ ﯾﻌﻨﻲ الepitope ﻋﻠﻰ100% راﻛﺐ ﺑﺎﻟﺰﺑﻂantibody ﻋﺎلparatope و ھﺎد ﺑﻜﻮن ﻛﻞ: Specificity.1 100% ﺑﺘﻜﻮنavidity و ال100% ﺑﺘﻜﻮنparatope ﻋﻜﻞaffinity ﺑﺘﻨﻘﺴﻢ لantibody اﻟﻤﻮﺟﻮدات ﻋﺎلparatope ھﻮن ال:Cross-reaction.2 (anti Y )ﻣﺜﻞepitope ﻋﺎل100% ﺑﺮﺑﻂ ﺑﺸﻜﻞParatope (anti X )ﻣﺜﻞepitope ﺑﺮﺑﻂ ﺑﺸﻜﻞ ﺟﺰﺋﻲ ﻋﺎلParatope 100% اﻗﻞ ﻣﻦavidity ﻣﺘﻐﯿﺮة اﻣﺎ الaffinity ﺣﺘﻜﻮن الcross طﺒﻌﺎ ﺑﺎل.anti Z ﻣﺎ ﺑﺮﺑﻂ ﺑﺎﻟﻤﺮة ﻣﺜﻞParatope ﺑﺘﻜﻮنavidity وaffinity ف ﺑﺎﻟﺘﺎﻟﻲ ﺑﻨﻘﺪر ﻧﻘﻮل الparatope ﺑﻘﺪر ﯾﺮﺑﻂ ﻣﻊepitope ھﻮن ﺑﻜﻮن وﻻ:No reaction.3 0% 1 ﺣﺎﻟﺔ 2 ﺣﺎﻟﺔ 3 ﺣﺎﻟﺔ Specificity, Cross-reactivity & non-reactivity of AbóAg Antiserum specificity results from the action of a population of individual antibody molecules (anti-X, anti-Y, anti-Z) directed against different epitopes (X, Y, Z) on the same or different antigen molecules. Antigen A (AgA) and antigen B (AgB) have epitope Y in common. Antiserum raised against AgA (anti-XYZ) not only reacts specifically with AgA, but cross- reacts with AgB (through recognition of epitopes Y and X′). The antiserum gives no reaction with AgC because there are no shared epitopes. immunology 7105306 10 Q&As The figure shows two cases of ab/ag interaction, answer the following 1. Affinity is affected in every epitope/paratope except A. Anti X B. Anti Y C. Anti Z D. A+B 2. Which sentence is true (you can choose more than one) A. The avidity in case B is higher than in case A B. The avidity in case B is lower than in case A C. The valence in case A is 3 D. The plasma cell in case A is more likely to get clonal selection than in B Case A Case B Anti X Anti Y Anti Z 1. B 2. B&C&D The Nature of Ag determinants ھﺳﺎ اﻻﻧﺗﺟﯾن ﺑﺎﻟﻐﺎﻟب ﺑﻛون proteinو ﻣﻣﻛن ﯾﺗﻌرض ل denaturationﺳواء ﺑﺎﻟﺣرارة او phاو او ...و طﺑﻌﺎ ال denaturationﺑﺣول اﻻﻧﺗﺟﯾن ﻣن 3d structureل linear ﻓﻲ ﻋﻧﺎ ﻋدة أﻧواع ﻣن ال epitopesﻣن ھﺎي اﻟﻧﺎﺣﯾﺔ: : Conformational.1ھﺎد ﺑﺗﻌرف ﻋﻠﯾﮫ ال antibodyﻟﻣﺎ ﯾﻛون ال epitopeﺑﺎل 3d structureو ﻟو ﻋﻣﻠﺗﻠﮫ denaturationﺑﺑطل ﯾﺗﻌرف )ﻣﺛل اﻟﺣﺎﻟﺔ (A ) : Linear.2اﻟﺣﺎﻟﺔ (Bھﺎن ال antibodyﻣﺛﻼ ﻋرف ﯾﺗﻌرف ﻋﺎﻻزرق ﺑﺎﻟﺣﺎﻟﺗﯾن ) (linear & 3Dاﻣﺎ اﻟﺑرﺗﻘﺎﻟﻲ ﻣﺛﻼ ﻣﺎ ﻛﺎن ﻗﺎدر ﯾرﺑط ﻋﺎل 3Dﺑس ﻟﻣﺎ ﺻﺎر linearرﺑط :Neoantigenic.3ھﺎن ﻛﺎن ﺑﻠزم ال epitopeﻣﻌﺎﻟﺟﺔ ﻟﺣد ﻣﺎ ﻗدر ال antibodyﯾﺗﻌرف )ﺣﺎﻟﺔ (C The Nature of Ag determinants Antigenic determinants (shown in orange, red, and blue) may depend on protein folding (conformation) as well as on primary structure. Some determinants are accessible in native proteins and are lost on denaturation (A), whereas others are exposed only on protein unfolding (B). Neodeterminants arise from postsynthetic modifications such as peptide bond cleavage (C). immunology 7105306 14 Antibody & otherAntigen- Recognizing Molecules ھﺴﺎ ﻛﻞ ﺣﻜﯿﻨﺎ ﻛﺎن ﻋﻦ ال antibodiesاﻟﻠﻲ ھﻢ BCRھﺴﺎ ﺑﺪﻧﺎ ﻧﺤﻜﻲ ﺑﺸﻜﻞ ﺳﺮﯾﻊ ﻋﻦ ال TCRاﻟﻠﻲ ﻋﻠﻰ T cellsو ال ) MHCوﯾﻦ ھﺪول؟ ...اﻟﻠﻲ ﺑﻌﻤﻠﻮا antigen presentingﻟﻞ (TCRو ﺑﺪﻧﺎ ﻧﺤﻜﻲ ﻋﻦ أوﺟﮫ اﻟﻤﻘﺎرﻧﺔ 1. Antigen binding site :Antibodyﻣﺜﻞ ﻣﺎ ﺑﻨﻌﺮف اﻧﻮ ال paratopeﻣﻮﺟﻮد ﺑﺎل V regionو ھﺎي اﻟﻤﻨﻄﻘﺔ ﻓﯿﮭﺎ 3CDRsﻋﻠﻰ Vhو 3CDRsﻋﻠﻰ ) VLارﺟﻌﻮا ﻛﻢ ﺳﻼﯾﺪ ورا ﻟﺘﺘﺬﻛﺮوا ال (CDR :TCRذاﻛﺮﯾﻦ ﻟﻤﺎ ﺣﻜﯿﻨﺎ ﺑﺘﺸﺎﺑﺘﺮ 2ﺳﻼﯾﺪ 47ﻋﻦ ال T delta gammaو T alpha betaھﺴﺎ اﻟﺘﺴﻤﯿﺔ اﺟﺖ ﻣﻦ أﺳﻤﺎء اﻟﺴﻼﺳﻞ ﺑﺎل) TCRرﻛﺰ ﺑﺎﻟﺼﻮرة( ھﺴﺎ ﻟﻮ اﺧﺬﻧﺎ ال TCRاﻟﻤﻮﺟﻮد ﻋﻠﻰ T alpha betaرح ﻧﻼﻗﻲ اﻧﻮ ﻓﻲ 3CDRs ﻋﻠﻰ ال V alphaو 3CDRsﻋﻠﻰ V beta :MHCھﺎن ﺑﻜﻮن ال binding siteزي ﺟﯿﺒﺔ ﻣﺘﻜﻮﻧﺔ ﻣﻦ ﺳﻠﺴﻠﺘﯿﻦ ) alpha1 & alpha2ﺑﺎل MHCIو alpha1 beta1ﺑﺎل (MHCII AB Antibody & otherAntigen- Recognizing Molecules 2. Nature of antigen processing ھﯿﻚ ﺟﺎي ﻣﻦ ﺑﺮا ﻋﻄﻮل ﺑﺘﻌﺮف ﻋﻠﯿﮫ دون اﻟﺤﺎﺟﺔ لmacromolecule ﺑﻜﻮن أي:Antibody (intact )ﺑﻨﺴﻤﯿﮫ MHC ﺻﻐﯿﺮة و ﺑﻌﺪھﺎ ﯾﻘﺪﻣﻠﻮ ﯾﺎه الpeptides ھﺎد ﻣﺪﻟﻊ ﺑﺪو اﻟﺒﺮوﺗﯿﻦ ﯾﺘﻘﻄﻊ ل: TCR TCR اﻟﻠﻲ ﺣﺘﺸﻮﻓﮭﺎ الpeptides ﺑﺤﻤﻞ ال:MHC 3. Antigenic determinant recognized (conformational) 3D اوlinear ﻣﺜﻞ ﻣﺎ ﻗﻠﻨﺎ ﺑﻘﺪر ﯾﺮﺑﻂ ب:Antibody 2-3 amino acids و أﻗﺼﺎهlinear ﺑﻜﻮن ﺑﺲ:TCR peptides ف ﺣﯿﻜﻮن ﻗﻄﻊ ﺻﻐﯿﺮة ﻣﻦTCR ﺑﺤﻤﻞ ﻧﻔﺲ اﻻﻧﺘﺠﯿﻦ اﻟﻠﻲ ﺑﺪو ﯾﻔﺮﺟﯿﮫ ل: MHC 4. Affinity of antigen binding secondary lymph ﻻﻧﻮ ﺑﺎلimmune response و ﺑﺘﺰﯾﺪ وﻗﺖ ال10^-11 اﻟﻰ10^-7 ﺑﻜﻮن: Antibody affinity ھﺎد ﺑﺰﯾﺪ الgerminal center ﺑﺘﺼﯿﺮ ﺑﺎلaffinity maturation ﺑﻨﻌﺮف اﻧﻮ ﺑﺼﯿﺮ اﺷﻲ اﺳﻤﻮorgans 10^-7 اﻟﻰ10^-5 :TCR extremely stable binding و ﺑﻤﺘﺎز ب10^-9 اﻟﻰ10^-6 :MHC ﻛﻠو ﻣﻠﺧص ﺑﺎﻟﺟدول اﻟﻠﻲ ﺑﺎﻟﺳﻼﯾد اﻟﺑﻌد Antibody & other Antigen- Recognizing Molecules immunology 7105306 17 Flexibility of A b ó A g interactions ھﺎن ﺑﺣﻛﻲ ﻋن ﻣﻧطﻘﺔ اﺳﻣﮭﺎ ال hingeو ھﺎي ﺑﺗﻛون ﺷﺑﮫ اﻟزﻣﺑرك ﺣرة اﻟﺣرﻛﺔ ف ﺑﺗﻣﻛن ﻣن ﺧﻼﻟﮭﺎ ال antibodyاﻧو ﯾﻣﺳك epitopesﺑﻌﯾدة ﻋن ﺑﻌﺿﮭﺎ )ﻟدرﺟﺔ اﻧو antibodyواﺣد ﺑﻘدر ﯾرﺑط ع epitopeﻣن ﺧﻠﯾﺔ و ﻛﻣﺎن epitopeﻣن ﺧﻠﯾﺔ ﺛﺎﻧﯾﺔ و ھﺎد ﺑﻔﯾدﻧﺎ ﺑﻌﻠم اﻻﻣﺻﺎل( طﺑﻌﺎ ھﺎي اﻟﺧﺎﺻﯾﺔ )اﻧو ال antibodyﯾﻘدر ﯾﻣﺳك ﺑﺄﻛﺛر ﻣن ﺧﻠﯾﺔ( ﺑﺳﺗﺧدﻣوھﺎ ﺑﺎل : blood test )ﻣﺛﻼ ﻋﻧﺎ ﻋﯾﻧﺔ دم ﺣطﯾﻧﺎ ﻋﻠﯾﮭﺎ antiAﺻﺎرت ﺗﺗﻛﺗل و ﺣطﯾﻧﺎ antiBﻣﺎﺻﺎر اﺷﻲ ﻓﺑﻔﮭم اﻧو ال antiAﻗدر ﯾرﺑط ﻣﻊ اﻛﺛر ﻣن ﺧﻠﯾﺔ ﻋﺷﺎن ھﯾك ﺗﻛﺗ ّل ف ﻣوﺟود اﻧﺗﺟﯾن Aاﻣﺎ اﻧﺗﺟﯾن Bﻣش ﻣوﺟود ﻓﺑﻌرف اﻧو زﻣرة دﻣو (A 18 The Development of monoclonal Ab : ﺑدﻧﺎ ﻧﺣﻛﻲ ﻋن ﻣﺻطﻠﺣﯾن ﻣﺧﺗﻠﻔﺔ ﻗﺎدرة ﻋﻠﻰ اﻟرﺑط ﺑﻧﻔس اﻻﻧﺗﺟﯾن )ھﺳﺎ ﻻﻧوB cells ﻣنan9bodies ھو ﻋﺑﺎرة ﻋن ﻋدة: Polyclonal an9bodies ﺛﺎﻧﻲ ﯾرﺑط عan9body ﻣﻌﯾن وepitope ﯾرﺑط ﻋﻠﻰan9body ﻋدﯾدة و ﻣﺧﺗﻠﻔﺔ ف ﻣﻣﻛن اﻧوepitopes اﻻﻧﺗﺟﯾن ﻋﻠﯾﮫ (epitope ﺑرﺑطوا ﻋﺎﻧﺗﺟﯾن واﺣد ﺑس ﻣش ﻋﻧﻔس الan9bodies ﺛﺎﻧﻲ ﻋﻧﻔس اﻻﻧﺗﺟﯾن( )ﺑﺎﺧﺗﺻﺎر ﻋدةepitope plasma cell ﺷو ﯾﻌﻧﻲ ؟ ﯾﻌﻧﻲ ﻣن ﻧﻔس الepitope ﺑرﺑطوا ﻋﻧﻔس الan9bodies ھون ﻋدة:Monoclonal an9body ھﺳﺎ ھﺎد اﻻﻛﺗﺷﺎف اﻟو ﻋدة ﺗطﺑﯾﻘﺎت Unlimited production of unique Ab for a specificAg => Revolutionize Immunology & other fields Its Applications: - Identification of phenotypic markers - Immunodiagnosis & Immunotherapy 19 - Tumor diagnosis & therapy The Development of monoclonal Ab-II ﺑدﻧﺎ ﻧﺣﻛﻲ ﻋن طرﯾﻘﺔ اﻟﺗﺻﻧﯾﻊ : .1ﺑﻧزرع اﻻﻧﺗﺟﯾن ﻓﻲ ﻛﺎﺋن ﺣﻲ )ﺑﺗﻧﺷط ال APCﺑﻌدھﺎ T cells اﻟﻠﻲ ﺑﺗﻧﺷط (B cellﻧﺗﺞ ﻋﻧﺎ plasma cellﺑﺗﻧﺗﺞ الantibody .2اﺣﻧﺎ ﺑدﻧﺎ ﯾﺎھﺎ ﺗﺿل ﻛﻣﺻدر ﺧﺎرج ﺟﺳم اﻟﺣﯾوان ف ﺑﻧطﻠﻊ ﻋﯾﻧﺔ ﻣﻧﮫ و ﺑﻧﻌزل ال ) B cellsﺳﻼﯾد 56ﺗﺷﺎﺑﺗر(2 .3اذا ﺿﻠت ﺑرا اﻟﺟﺳم اﺣﺗﻣﺎل ﺗﻣوت ﺑﺳرﻋﺔ ف ﺑﻧدﻣﺟﮭﺎ) (fusionﻣﻊ ) cancerous cellﺑﻣﺗﺎزوا ﺑﺎﻧﻘﺳﺎﻣﺎت ﺳرﯾﻌﺔ و ﺣﯾﺎة طوﯾﻠﺔ( .4ھﺳﺎ ﻓﻲ ﺧﻼﯾﺎ ﻣﺎ ﺻرﻟﮭﺎ fusionف ﺑدﻧﺎ ﻧﻘﺗﻠﮭﺎ ﻋن طرﯾق زرع ال mixtureﺟوا وﺳط ﺑﺳﻣﺢ ﺑﺣﯾﺎة ال fused cells only .5ھﺳﺎ ﺑﻧﻌزل اﻟﺧﻼﯾﺎ اﻟﻠﻲ ﺿﻠت ﻣﻌﻧﺎ ﺣﺳب اي اﻧﺗﺟﯾن ﺑﺗﻌﺎﻟﺞ )ﺳﻼﯾد 56ﺗﺷﺎﺑﺗر (2 .6ﺑﻧﻣﻲ ﻛل ﺧﻠﯾﺔ ﺑﺗﻧﺗﺞ antibodyﻣﻌﯾن و ﺑﺳﺣب اﻓرازاﺗﮭﺎ )ﻣن ﺑﯾﻧﮭﺎ (antibodyو ﻣن ھون ﺑﻛون ﺟﺑت monoclonal antibody Immunodiagnosis- ELISA طب ھﺳﺎ ﺷﻔﻧﺎ ﻛم ﺻﻌب ﻧطﻠﻊ ال monoclonal antibodiesھﺳﺎ ﺑدﻧﺎ ﻧﻌطﯾﮭم ﻟﻠﻧﺎس ..ھل ﻣﻌﻘول اﻋطﻲ ال serumﻟواﺣد ﻋﻧدو antibodyاﺻﻼ؟ ﻻ .طب ﻛﯾف ﺑدﻧﺎ ﻧﻌرف اذا ﻋﻧدو antibodiesﻻﻧﺗﺟﯾن ﻣﻌﯾن ؟ ﻋن طرﯾق immunodiagnosis ﺑﺎﺳﺗﺧدام ELISAو ھﺎد ﺑﻣﺷﻲ ﻋﺎﻟﻣﺑدأ اﻟﺗﺎﻟﻲ : .1ﺑﻌﻣل ﻟوﻋﺎء coatingﺑﺎﻻﻧﺗﺟﯾن اﻟﻠﻲ ﺑدي اﻋرف ھل ﻋﻧدو antibodyاو ﻻ .2ﺑﺟﯾب ﻋﯾﻧﺔ ﻣن اﻟﺷﺧص و ﺑﺣﻠل ﻣرﻛﺑﺎت اﻟدم ﻟﺣد ﻣﺎ اﺣﺻل ﻋﺎل ) antibodiesھﺎي ﻛﻠﻠل اﻟﻠﻲ ﺑﺎﻟﺟﺳم ﻣش ﻻﻧﺗﺟﯾن ﻣﻌﯾن( .3ﺑﺣط ﻋﯾﻧﺔ ال antibodiesﺑﺎﻟوﻋﺎء اﻟﻠﻲ ﻋﻣﻠﻧﺎﻟو ) coatingطﺑﻌﺎ اﻟﻠﻲ ﺑرﺑط ھو ال antibodyاﻟﻠﻲ ﺑرﻛب ﻋﺎﻻﻧﺗﺟﯾن( .4ﺑﻌﻣل washingف أي اﺷﻲ ﻣش راﺑط ﺑﺎﻻﻧﺗﺟﯾن ﺑروح .5ﺑﺟﯾب ﺟزيء ﻣﻛون ﻣن ﺟزيء ﺑرﺑط ﻋﺎل )antibodyزي antibodyﻟل (antibodyو ھﺎد اﻟﺟزيء ﻋﻠﯾﮫ اﻧزﯾم ھﺎد ﻛﻠو ﺑﺳﻣﯾﮫ ligand .6ﺑﻌﻣل washingف أي ligandﻣﺎ رﺑط ب antibodyﺑروح .7ﺑﺣط chromogenوھﺎد زي ﻣﺎدة ﻟﻣﺎ ﺗﺗﻌرض ﻟﻼﻧزﯾم ﺑﺗﻐﯾر ﻟوﻧﮭﺎ .8طﺑﻌﺎ اذا ﻣﺎ ﺗﻐﯾر اﻟﻠون ﻣﻌﻧﺎھﺎ ﻣﺎ ﻓﻲ antibodyاذا ﺗﻐﯾر ﺷوي ﺻﻐﯾرة ﻓﻲ antibodiesﺑﺗراﻛﯾز ﻗﻠﯾﻠﺔ و ﻛل ﻣﺎ زاد اﻟﺗﻐﯾﯾرﺑﻛون ﺗرﻛﯾز ال antibodies Immunodiagnosis- ELISA ﺣطﯾﻧﺎ chromogenو ھﺎد ﺑﺗﻐﯾر ﻟوﻧﮫ ﻟﻣﺎ ﯾﺗﻌرض ﻻﻧزﯾم ﺣطﯾﻧﺎ ﻋﯾﻧﺔ اﻟدم و ﺑس ال ﺑﻧﻼﺣظ اﻧو ﺑﻧﻘدر ﻧﻼﻗﻲ ال concentra6on antibodyاﻟﻠﻲ ﺑدﻧﺎ ﯾﺎه رﺑط ﺣﺳب ﻛﻣﯾﺔ اﻟﺗﻐﯾر ﻓﻲ اﻟﻠون Enzyme Ligand Absorption Wash Wash Antibody concentration .1ﺑﻧﻌﻣل coatingﺑﺎﻻﻧﺗﺟﯾن ﻋﻣﻠﻧﺎ washingﻋﺷﺎن أي ﻣواد ھون ﺣطﯾﻧﺎ ال ligandو ﺛﺎﻧﯾﺔ ﺗروح و ﯾﺿل اﻟراﺑط ﺑس ﺑﻌدھﺎ washingﻋﺷﺎن أي اﻧزﯾﻣﺎت ﻣﺎ رﺑطت ﺗروح Immunodiagnosis- ELISA immunology 7105306 23 Immunoprecipitation ھﺎن ﺑدﻧﺎ ﻧﻌﻣل detectionﻻﻧﺗﺟﯾن ﻣﻌﯾن)ﻧﻘول اﻻﻧﺗﺟﯾن اﻟﻣرﺑﻊ( .1رح ﻧﺿﯾف antibodyﻣﻧﺎﺳب ﻟﻼﻧﺗﺟﯾن .2ﺑﻧﺣط اﺷﻲ اﺳﻣو co-precipitating reagents ﺑﺗﺳﺎﻋد اﻧو ﯾﺗرﺳب .3ﻟﻣﺎ ﯾرﺗﺑطوا رح ﯾﻛون ﺣﺟﻣﮭم و ﻛﺗﻠﺗﮭم اﻛﺑر ف ﺑﻧﻘدر ﻧﻌزﻟﮭم ﺑﺎﻟطرد اﻟﻣرﻛزي centrifugationو ﺑﻧطوﻟﮭم ﻣن اﻟﻌﯾﻧﺔ .4ﺑﻧﺣطﮭم ع SDS gelو ھﺎد ﺑﻌﻣل ﻋﻔﺻل اﻟﺑروﺗﯾﻧﺎت ﻋن ﺑﻌض .5ﺑﻛﺷف ﻋن اﻟﺑروﺗﯾﻧﺎت ﺑﺎﺷﻲ اﺳﻣو immunoblottingﺑﺎﻟﺳﻼﯾد اﻟﺑﻌد ﺣﻧوﺧذو 24 Immunoblotting ﻣﻧﺳﻣﯾﮭﺎ autoradiographو SDS gel sampleاﻟﻌﻣﻠﯾﺔ ﺑﯾن separationﯾﻌﻧﻲ ﺑﻌد ﻣﺎ ﻋﻣﻠﻧﺎ ﺑﻌد ﻣﺎ ﻧﻘﻠﻧﺎھﺎ ﻋﻠﻰ اﻟورﻗﺔ ھﺎي ﻣﻧﺣط ﻣﺎدة ﺑﺗﻛون regulativeأو immunoflourscent ﻣﺷﺎن ﻧﻌﻣل ﺑﯾﮭﺎ visualiziation وﻧﺷوف اﻟﺑروﺗﯾﻧﺎت اﻟﻣوﺟودة أو ال Antigensاﻟﻣوﺟودة ﻋﻧﺎ immunology 7105306 25 Fc receptors اﻟﻣوﺟودات ﻋﻠﻰ اﻟﺧﻼﯾﺎ وھمFC receptors ھون ﺑﺣﻛﻲ ﻋن Phosphorylation of the ITAM motif وﻣﻧﺳﺗﻔﯾد ﻣن ارﺗﺑﺎطﮭم اﻧﮫAn/bodiesاﻟﻲ ﯾرﺗﺑطوا ﺑﯾﮭم ال triggers activities such as:. signaling ﻟﻠﺧﯾﻠﺔ ﻣن ﺧﻼلac/va/on ﺑﺻﯾر ﻋﻧﺎ ﺑﺻﯾر ﻋﻧﺎsignaling molecules ﺑﺎﻟﻧﺳﺑﺔ ﻟل molecules وأﻧﺎ )اﻟدﻛﺗور( ﺑﺣﻛﻲphosphorylation of ITAM motif وﻟﻣﺎActivation اﺧﺗﺻﺎر لITAM ﻓﻲA أﺣﻔظوا اﻧﮫ ال ﺑﺗﺣﻔز اﻟﺧﻠﯾﺔ وﺑﺗﺟﻌﻠﮭﺎ ﺗﺻﯾرITAM ﻟلactivation ﯾﺻﯾر -:وﺣدة ﻣن اﻷﺗﯾﺎت phagocytosis; antibody-dependent cell-mediated cytotoxicity (ADCC); apoptosis; mediator release; cytokines زي ال enhancement of antigen presentation ﺑﺻﯾر ﻣن ﺧﻼلinhibition ﻓﻲ ﻋﻧﺎactivation طﺑﻌﺎ ً زي ﻣﺎ ﻓﻲ ﻋﻧﺎ ﻋﻛسITIM وطﺑﻌﺎ ﺑﻛونFC gamma 2 receptor اﻟﻣﺳﺗﻘﺑﻼت ﻣﺛل.negative feedback ﺑﻌﻣلITIM وITAM ﻻزم ﯾﺻﯾر إﻟﮫimmune response ﻛﻠﻧﺎ ﻣﻧﻌرف إﻧﮫ أي ﺗﺑﻌتmechanism ﺑﺎﻵﺧر وﺑﺻﯾر ﺑﻧﻔس الtermination ﺑﺗﺻﯾر ﻣن ﺧﻼلinhibiton ﺗﺑﻌت الmechanism والactivation FC gamma بantibody ﻟﻠﺧﻠﯾﺔ إﻧﮭﺎ ﺗوﻗف ﻣن ﺧﻼل ارﺗﺑﺎطsignals وﺑﺻﯾر ﻋﻛس اﻟﻲnegative Feedback واﻟﻣﺳﺗﻘﺑل ﺑﻌﻣل2 Receptor. activation ﺻﺎر ﺑﺎل immunoreceptor tyrosine-based activation (ITAM) or immunoreceptor tyrosine-based inhibitory (ITIM) FcγRI is involved in phagocytosis of immune complexes and mediator release FcγRI (CD64) binds: monomeric IgG1 and IgG3 with high affinity; relative to IgG4, low affinity; ﻣﺧﺗﻠﻔﺔreceptors ھون ﺑس أﻣﺛﻠﺔ ﻋﻠﻰ IgG2 does not have detectable binding affinity. ﻛﺎﻧو ﻣﺣطوطﺎت ﺑﺟداول ﻗﺑل ﺑس ھدول ﯾﻠﻲ receptor ھﺎن ﺑدﻧﺎ ﻧﺣﻔظﮭم وﻧﻌرف ﻛل ﯾﻠﻲ ﺑرﺑط وﺷو وظﯾﻔﺗﮫantibody ﻣﯾن ال FcγRII is expressed in two forms وﻛﻣﺎنFCyRII والFCyRI ﺑﺣﻛﯾﻠﻧﺎ ﻋن ال وأﻧواﻋﮭﺎFCyRIII ﺑﺎﻟﺳﻼﯾد ﯾﻠﻲ ﺑﻌدھﺎ ﻋﻧﺎ ال اﻟﻣﺧﺗﻠﻔﺔ FcγRII (CD32a; CD32b) is expressed as structurally and اﻟدﻛﺗور ﺣﻛﻰ ﺑﺗﻘرأوا ھﺎي اﻟﺳﻼﯾدات ﻗراءة وﺑﺗﺣﻔظو اﻷﻣﺛﻠﺔ functionally distinct FcγRIIa and FcγRIIb forms with wide but differing cellular distribution. The α chain of FcγRIIa: has moderate affinity for monomeric IgG1 and IgG3; binds complexed (multivalent, aggregated) IgG with high avidity; expresses an ITAM motif within its cytoplasmic tail; and may be produced as a polymorphic form which can bind monomeric IgG2. immunology 7105306 37 FcγRIII is expressed as FcγRIIIa and FcγRIIIb FcγRIIIa (CD16a) is structurally and functionally distinct from FcγRIII (CD16b) and they have different cellular distributions. Both are extensively glycosylated. FcγRIIIa is a transmembrane protein (like FcγRI, FcγRIIa, and FcγRIIb), whereas FcγRIIIb is GPI (glycosyl phosphatidyl inositol) anchored The α chains of FcγRIIIa: have a moderate affinity for monomeric IgG; and may be associated with γ/ξ and/or β chains bearing ITAM motifs. FcγRIIIa is expressed on monocytes, macrophages, NK cells, and a fraction of T cells. The FcγRIIIb form: is selectively expressed on neutrophils and basophils; and has a low affinity for monomeric IgG. immunology 7105306 38 The FcR for IgA is FcαRI FCaRI ﯾﻠﻲ ﺑرﺑط ﻋﻠﻰ الIgA ھون ﻛﻣﺎن ﻋﻧﺎ ال low واﺣد ﺑرﺑط بreceptors 2 ﯾﻠﻲ اﻟﮫIgE وﻋﻧﺎ ال The receptor for IgA is FcαRI (CD89): رح ﻧﯾﺟﻲ وﻧﺣﻛﻲhigh affinity وواﺣد بaffinity it is comprised of two Ig superfamily domains; R1 ﻋﻧﺎ ﻟﺑﻌدﯾن وأھﻣﯾﺗﮭم وﻣﯾن اﻟﺧﻼﯾﺎ ﯾﻠﻲ ﻣوﺟود ﻋﻠﯾﮭﺎ it is associated with a γ chain; ٣ وﺣﻛﻰ أﻧﮫ ﻧﺣﻔظ اﻷﻣﺛﻠﺔ ﻣﻧﯾﺢ ﯾﻠﻲ ﺑﮭدول الR2 او it is expressed on myeloid cells; ﺳﻼﯾدات can trigger phagocytosis, cell lysis and the release of inflammatory mediators; and can bind both IgA1 and IgA2. The two types of Fc receptor for IgE are FcεRI and FcεRII Two types of Fc receptor for IgE (FcεR) are defined in humans : the high-affinity FcεRI which is expressed on mast cells and basophils and is the ‘classical’ IgE receptor; and the low-affinity FcεRII (CD23), which is expressed on leukocytes and lymphocytes. immunology 7105306 39 Development of the antibody repertoire by gene recombination Heavy chain VDJ recombination in humans The heavy chain gene loci recombine three segments to produce a VDJ gene, which encodes the VH domain. Of some 80 V genes, about 50 are functional and the others are pseudogenes. The V gene segment recombines with one of 23 DH segments and one of six JH segments to produce a functional VDJ gene in the B cell. immunology 7105306 40 Development of the antibody repertoire by gene recombination ﻣﻧﺳﺄل ﺣﺎﻟﻧﺎ ﻛﯾف ﻣﻧطﻘﺔ ﻣﺣددة ﻣن ال DNA,ﻗﺎدرة أﻧﮭﺎ ﺗﻧﺗﺞ ﻛل ﻣرة antigen binding siteﻣﺧﺗﻠف ﺑﻧﺎﺳب ال antigensاﻟﻣﺧﺗﻠﻔﺔ ﯾﻠﻲ ﻣﻣﻛن ﺗدﺧل ﻋﺎﻟﺟﺳم ،ھﺎذ اﻟﻣوﺿوع اﻻﺷﻲ اﻟرﺋﯾﺳﻲ ﯾﻠﻲ ﺑﻌﻣﻠﮫ ھو ال VDJ recombination,ﻓﺑﺣﻛﯾﻠﻧﺎ أﻧﮫ ﺑﺻﯾر development of antibody repertoire by gene recombination, طﺑﻌﺎ ً ال gene recombinationﻣﻣﻛن ﺗﺻﯾر ﺑﻣﻧطﻘﺔ ال heavy chainوﻣﻣﻛن ﺗﺻﯾر ﺑﺎلlight chain. ھون ﺑﮭﺎي اﻟﺻورة ﺑﺣﻛﯾﻠﻧﺎ ﻋن ال variationﺑﺎل heavy chain أول اﺷﻲ ﻓﻲ ﻋﻧﺎ ﻣﻧطﻘﺔ اﺳﻣﮭﺎ ال V geneوﻣﻧطﻘﺔ اﺳﻣﮭﺎ ال D geneوﻣﻧطﻘﺔ ال J gene ،ھدول اﻟﻣﻧﺎطق ﻓﯾﮭم زي ﻗطﻊ أو fragmentsﻣﺛﻼً ال Vﺑﺣﻛﯾﻠﻧﺎ ﻓﯾﮭﺎ ، genes 80وال Dﻓﯾﮭﺎ ﻣﺛﻼً ، genes 23وال Jﻋﻧﺎ ﻣﻧﮭﺎ ,6ھدول ﺑﺻﯾرﻟﮭم recombinationﺑطرﯾﻘﺔ ﻋﺷواﺋﯾﺔ ،ﯾﻌﻧﻲ ﺑﺧﺗﺎر وﺣدة ﻣن ال V genesوﺑﻌدﯾن وﺣدة ﻣن ال D genesوآﺧر اﺷﻲ وﺣدة ﻣن ال J genes,وﺑﻧدﻣﺟو ﻣﻊ ﺑﻌض وﺑﺻﯾر ﻋﻧﺎ ، recombinationﻓﻌﻧﺎ ﺳﺑب ال variabilityاﻟﻌﺎﻟﯾﺔ ھو وﺟود ال fragmentsاو ال segmentsﯾﻠﻲ ﺑﺗﻌﻣل . variation اذا ً ھﺎي ﺑﺳﻣوھﺎ ال VDJ recombinationأﻧﮫ أﻛﺛر ﻣن ﺟﯾن ﺑﺷﻛﻠﻠﻧﺎ ال . variable heavy domain k chain production in humans During differentiation of the pre-B cell, one of several Vk genes on the germline DNA (V1–Vn) is recombined and apposed to a Jk segment (Jk1–Jk5). The B cell transcribes a segment of DNA into a primary RNA transcript that contains a long intervening sequence of additional J segments and introns. This transcript is processed into mRNA by splicing the exons together, and is translated by ribosomes into k chains. The rearrangement illustrated is only one of the many possible recombinations. (B cell DNA is colored light brown; RNA is colored green; and immunoglobulin peptides are colored yellow.) 41 immunology 7105306 l chain production in humans k chain production in humans ﺑﺎﻟﻣﻘﺎﺑل ﻓﻲ ﻋﻧﺎ ال light chainوﻛﻣﺎن ﻓﻲ ﻋﻧﺎ ﻧوﻋﯾن ﻣﻧﮭﺎ ال kapa chainوال lamda chain ،اذا ﻣﻧﺗذﻛر ﺷﻛل ال antibodiesﻋﻧﺎ ال heavy chains اﻟطوال وﻋﻧﺎ ال light chainﯾﻠﻲ ﻣﻣﻛن ﺗﻛون kapaاو ، lamdaھﺎد ﻋﻔﻛرة ﻛﻣﺎن ﻧوع ﻣن ال variationsوﻛﻣﺎن داﺧل ﻛل وﺣدة ﻓﯾﮭم kapaاو lamda ﺑﻛون ﻧﻔس اﻟﻣﺑدأ ﯾﻠﻲ ﺣﻛﯾﻧﺎ ﻋﻧﮫ ﺑﺎﻟﺳﻼﯾد ﯾﻠﻲ ﻗﺑل ،ﯾﻌﻧﻲ genesﺑﺻﯾرﻟﮭم recombinationﻣﻊ ﺑﻌض ﺑس ﺑﻛوﻧو Vﻣﻊ Jﺑدون Dﻓﮭﺎي اﻟﺟﯾﻧﺎت ﺑﺗطﻠﻌﻠﻲ ﻛﻣﺎن ﺳﻼﺳل light chainsﻣﺧﺗﻠﻔﺔ ،طﺑﻌﺎ ً ھﺎد اﻟﺣﻛﻲ ﺑﻧطﺑق ﻋﻠﻰ kapaوﻛﻣﺎن ﻋﻠﻰ lamdaﯾﻠﻲ ﺑﺎﻟﺳﻼﯾد ﯾﻠﻲ ﺑﻌدھﺎ l chain production in humans During B cell differentiation, one of the germline Vl genes recombines with a J segment to form a VJ combination. The rearranged gene is transcribed into a primary RNA transcript complete with introns (noncoding segments occurring between the genes), exons (which code for protein), and a poly A tail. This is spliced to form mRNA with loss of the introns, and then translated into protein. 2019-2020 Immunology 7105306 42 Recombination sequences in immunoglobulin genes light chain and heavy chain ﺑﯾن الrecombination وﻛﻣﺎن ھون ﺑﺣﻛﯾﻠﻧﺎ أﻧﮫ ﺑﺻﯾر ﻋﻧدي. variation ﻟلsource ھﺎي ﺑرﺿو ﻛﻣﺎن The recombination sequences in the light chain genes (top) and heavy chain genes (bottom) consist of heptamers (7), 12 or 23 unconserved bases, and nonamers (9). The sequences of heptamers and nonamers are complementary and the nonamers act as signals for the recombination activating genes to form a synapsis between the adjoining exons. Similar recombination sequences are present in the T cell receptor V, D, and J gene segments (see Chapter 5). immunology 7105306 43 Diversity is generated at several different levels Multiple V genes recombining with D and J segments VJ and VDJ recombination Recombinational inaccuracies and N-nucleotide addition Gene conversion Combination of different heavy and light chains Somatic point mutation. 2019-2020 Immunology 7105306 44 Diversity is generated at several different levels ﺑﺎﻟﻣﺧﺗﺻر ﺣﺎﻛﯾﮭم ھون ﺳﺑﺑﮭﺎantibody ﯾﻠﻲ ﺑﺗﺻﯾر ﺑﺎلdiversity ﺑﺣﻛﯾﻠﻧﺎ ال J segments والD ﻣﻊ الmultiple V genes recombining ﺑﻛون.1 recombination ﺑﺻﯾرheavy chain ﺗﺑﻌت الVDJ ﻣﻊ الlight chain ﺗﺑﻌت الVJ ﻛﻣﺎن ال.2 ﺟدﯾدةvariations وﺑﺗﻌﻣل variation ﻟلsource ﺑرﺿو ھﺎيgenes ﯾﻌﻧﻲ ﺑﺻﯾر ﻗﻠب ﻟلgene conversion ﺑﻌدﯾن ال.3 light ﻻن زي ﻣﺎ ﺣﻛﯾﻧﺎ ﻋﻧﺎ الcombination of different heavy and light chains ﻋﻧﺎ ال.4 ﻋﻧﺎ ﻣﻧﮭم اﻧواع ﻛﻣﺎن ﯾﻠﻲ ھمheavy chains وﺑﺎﻟﻧﺳﺑﺔ ﻟلlamda اوkapa ﺑﺗﻛون اﻣﺎchain اوﻏﯾرھمIgM والIgG ال ﻣن ﺧﻼل اﻟطﻔرات ﯾﻠﻲimprove for affinity ﯾﻠﻲ ﺑﺗﻌﻣلsomatic hypermutation ﻋﻧﺎ.5 affinityﺑﺗﺻﯾر وﻣﻣﻛن اﻧﮭﺎ ﺗﻛون ﻧﺎﻓﻌﺔ وﺗزﯾد ال اﻟﻧﻘطﺔ اﻟﺳﺎدﺳﺔ ﺷرﺣﮭﺎ ﺑﺎﻟﺳﻼﯾد ﯾﻠﻲ ﺑﻌده.6 Diversity is generated at several different levels وﻓﻲ ﻋﻧﺎ ال recombinational inaccuracies ، N-nucleotide addition andﻟو ﻧﺗذﻛر ﺷو ﺷرﺣﻧﺎ ﺑﺳﻼﯾد 40ﻟﻣﺎ ﺣﻛﯾﻧﺎ اﻧﮫ ﺑﺻﯾر recombinationوﺑﻛون ﻋﻧﺎ nucleotide sequencesطﯾب ﻛﯾف ھذول ﺑﺗرﺑطو ﻣﻊ ﺑﻌض ؟ ﻓﻲ ﻋﻧﺎ اﺷﻲ اﺳﻣﮫ ال RAGﯾﻠﻲ ﺑﺎﻟﺻورة ،ھو ﯾﻠﻲ ﺑﯾﺟﻲ ﺑﻛﺳر ﻗطﻊ ال Vوال Dوال Jﻋن اﻟﺳﻠﺳﻠﺔ ﻋﺷﺎن ﯾرﺑطﮭم ﻣﻊ ﺑﻌض ،ﺑس ھون ﻟﻣﺎ ﻛﺳرھم واﺟﺎ ﯾرﺑطﮭم ﻟﻘﻰ ﻋﻧدي ﻣﺷﻛﻠﺔ أﻧﮭم ﻣش ﻣﺗﻣﻣﺎت ﻟﺑﻌض ، طﯾب ﻛﯾف ﺑدﻧﺎ ﻧرﺑطﮭم ؟ ﺑﯾﺟﻲ وﺑﺿﯾف ﻧﯾوﻛﻠﯾوﺗﯾدات ﻣﻌﯾﻧﺔ ﻋﻠﯾﮭم ،ﻋﺷﺎن ﺗﺻﯾر ﻋﻧﺎ ﻋﻣﻠﯾﺔ ال recombinationﺑﯾﻧﮭم ﺗﺻﯾر ﻣﻼﺋﻣﺔ ،وﺑﻌدﯾن ﺑﯾﺟﻲ ﺑﻌﺑﻲ اﻟﻔراﻏﺎت اﻟﻣوﺟودة ﻟﺣﺗﻰ ﺗﻛﺗﻣل وھﺎذ ﻧوع ﻛﻣﺎن ﻣن اﻧواع ال sources of variation