基础医学院医学免疫学-chapter21课件.ppt

1、Chapter 21Topics on medical immunology Endoscopic imaging of the duodenum shows multiple prominent nodules 35 mm in size,consistent with nodular lymphoid hyperplasiaA child with severe combined immunodeficiency showing skin lesions due to infection with vaccinia gangrenosum resulting from smallpox i

2、mmunization.Lesions were widespread over the whole body.Mutation of TAP geneEndogenous Ag cant be transported on endoplasmic reticulumGene derangement in C II TA,RFX5,or RFXAPChronic viral infection in respiratory tractDTH,little Ab to TD-Ag,susceptibility to virusBreak in TCR&Ig heavy chain genesDe

3、fective DNA repair mechanismGene derangement in PI3-K Immune defects Reduced T cell-numbers and functions(PHA,con-A responses)Low IgG and IgA Non immune defects Lack of coordination TelangiectasisIg levels in Ataxia-telangiectasia4C1-INH deficiencyPig-GPICD55CD59MACImmune hemolysis5Immunodecifiency

4、caused by infectious agentsMany bacterial,viral and parasitic agents compromise the host immune functions,most prominent among theses is HIV infectionImmunodeficiency resulting from aging and malnutritionA number of immune functions become less efficient with agingImmunodeficiency during malignancy

5、and other diseasesIatrogenic causesOverview of the HIV replication cycleThe necessity for CD4 antigen expression for entry of HIV into a human cell.HeLa cells do not have CD4 antigen and are not infected.HeLa cells transfected with CD4 gene are infected Chemokine receptors are involved,in associatio

6、n with CD4 antigen,in infection by HIV(left).The chemokine can block attachment of the virus to its receptors(middle).Mutations in the chemokine receptor can lead to resistence to HIV infection(right)Virus titer,CD4 cell number and anti-gp120 titer during the course of HIV infection 1.Budding causes

7、 cell lysis Some possible mechanism for the loss of T4 cells after HIV infectionuninfected CD4 cellGp120 negativeCells FuseInfected CD4 cellGp120 positive2.Killing of CD4 cells-Syncytia formationCytotoxic T cell3.Killing of CD4 cells -Cytotoxic T cell-mediated lysisA Binding of cytokine induces TNF

8、alpha expression in macrophage and receptor expression in CD8+T cell Induction of apoptosis in T8 cells B.The cells contact one-another and TNF-alpha and the receptor interact.Apoptosis ensuesC.Macrophages internalize T cellHAART:highly active antiretroviraldrug therapyFactors affecting HIV progression.Therapeutic strategies for controlling AIDSighlyctiventi-etroviralherapyHAART:两种脱氧核苷类似物逆转录酶抑制剂和一种蛋白酶抑制剂Now also:两种脱氧核苷类似物逆转录酶抑制剂和一种非核苷