Life and death within germinal centres: a double-edged sword.

摘要: LILIANA GUZMAN-ROJAS, JENNIFER C. SIMS-MOURTADA, ROBERTO RANGEL &HECTOR MARTINEZ-VALDEZ Department of Immunology, The University TexasMD Anderson Cancer Center, Houston, Texas, USASUMMARYWithin germinal centres, B lymphocytes are destined to die by apoptosis via Fas signalling, unlessthey positively rescued antigen and signals initiated CD40–CD154 interactions. Thus,while the centre microenvironment can become a virtual graveyard for most lympho-cytes that fail bind with high affinity, it concomitantly provides necessary stimuli forthe survival cells successfully accomplish affinity maturation. Such dichotomy in thephysiology reaction results functional B-cell repertoire andthe elimination abnormal cells, dictates fate towards homeostasis or disease.Consequently, death survival-signalling arms within centres predominantlyreside on timely controlled expression its ligand (FasL), CD40 andCD154, respectively. In keeping this notion, lymphoproliferation deficient immunity aredocumented landmarks inactivation either Fas/FasL CD40/CD154 signalling pathways.The present review considers two different scenarios control deathwithin germinalcentres. Thefirst is anidealistic scenario, inwhicha discriminatory andco-ordinatesignalling pairs, respectively, leads rescue thefunctional phenotype. second gloomyscenario which both lack hyperexpression receptor/ligand seen asequally deleterious.INTRODUCTIONJust like good education prestigious university campus,the acquisition memory from nai¨ve takes placewithin highly specialized microenvironment, namely thegerminal (GC) secondary lymphoid organs.The screening process recruitment GC candidates isinitiated induction immunoglobulin (Ig)M