HBV Biology a light(e)ning tour

Transcription

1 HBV Biology a light(e)ning tour

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3 J02203 X59795 X G mut BDM8 54 Q mut 265 M mut M32138 AF BDTF10 BD B2 BD B5 25 ARR mut BD B1 BDH3 BDH4 BDH7 BDH5 BDQ8 X65259 BDQ3 BDR5 BDM R mut BDQ15 BDM5 BDJ2 AF AF BDM2 BD R2 X BDJ 9 DM4 BDM AF AB B AF X75657 BD R1 L29017 X75664 BDQ6 BDBh4 X75658 X X D D23679 D23678 D00330 M54923 X51970 L13994 X70185 X75665 M26141 X01587 D BD PSH E F B A C D

4 A/D?F A/D? D B/C D/E? F B/C

5 B/C S.E. Asia C D Micronesia PNG C C/D Melanesia Australia C Polynesia

6 HBV Genotype C Diversity - Pacific and Eurasia CJ M AU PNG V TF

7 Ethnicity SE-Asian Subtype/ Genotype Amino Acid Variant Position Specific amino acid motifs found in a specific ethnic background. China adr/c S I N S E V adw2/b S I N S E V Korea adr/c S I N S E V Japan adr/c S I N S E V Vietnam ayw/1/b S I N S E V Pacific adrq-/c S I N S E V Caucasian USA adw2/a T V T N D T Italy adw2/a T V T N D T ayw2/d T V T V D T Scotland adw2/a T V T N D T ayw2/d T V T V D T

8 Receptor Mediated Endocytosis Nuclear Transport CCC DNA MINICHROMOSOME ER envelope proteins S,M,L HBV RNA transcripts pregenomic RNA Pol protein Release Golgi X core proteins pgrna Encapsidation of pgrna and Pol synthesis 5 Cap

9 Protein products of the surface gene PreS 1 PreS 2 S ATG ATG ATG TAA Small middle large Viral attachment region Hydrophilic region

10 Reactivation of hepatitis B during immunosuppressive lymphoma therapy Italian patient with B cell lymphoma since 1989, several therapies 1996 HBsAg neg., anti-hbc neg. anti-hbs 612 IU/L; no vaccination In cycles of chemotherapy July 2003 under chemotherapy HBsAg AxSym highly pos., not inhibitable HBsAg VIDAS neg. Anti-HBc neg., anti-hbs 93 IU/L No hepatitis HBV DNA 1.8x10 8 copies/ml Lamivudine therapy started Escape mutations: L109R, C137W, G145R Communicated by R. Kaiser and H. Pfister, University Cologne

11 Rituximab associated escape mutant W R R

12 Inhibition of HBsAg signals of a patient serum after neutralisation with anti-hbs sera from ahb-vaccinated donor ( IU/L) or from a Sheep immunised with wt HBsAg genotypes A, D, C ( IU) % Inhibition human sheep 1:10 1:100 1:1000 1:10000 Dilution of patient serum

13 Laurell Electrophoresis: detection of an HBsAg Escape* Variant Genotype D with a multivalent anti-hbs sheep antiserum raised with three genotypes Anti-wtA,D 2x10 6 IU/L Anti-wtA,D,C 4x10 4 IU/L HBsAg serum A Esc* D µg/ml 100 ca A Esc D 100 1:3 20 *Escape mutations: L109R, C137W, G145R Anti-HBs of the patient neutralised by HBsAg A or D, not C

14 Fingers Palm Fingers Palm Thumb HBV polymerase/rt rtt128n rtw153q rtl180m rtm204i st123n rtm204v sp120t si195m sw196s sm133l HBsAg sg145r a determinant

15 Protein products of the core gene Core promoter ATG Pre-C ATG C TAG Core protein HBeAg

16 HBeAg and immunotolerance HBeAg is: Not part of the virion A secreted protein Found in all hepadnaviruses Associated with high replication HBeAg? HBV birth infection Tolerant child In utero

17 Pre-core mutants Usually found in DNA+ anti-hbe+ patients Selected after seroconversion to anti-hbe In certain genotypes only Do not always correlate with progression Associated with fulminant hepatitis (see below) Do not directly predict response to interferon No effect on nucleoside analogue therapy

18 HBeAg+ HBeAg-?CTL?B cell?th HBeAg- WT core loss of immunomodulation B cell Th cell Cytopathic strains Ongoing Disease Disease mutations in other proteins further core mutations mutant core another immune response

19 Does sequence dictate cellular localisation? HBeAg Positive Anti-HBe Positive Mutagenesis No Mutation B cell Epitope/C-terminus Mutations B cell/c-terminus mutations Reversion to Wild type Nuclear Cytoplasmic Nuclear & Cytoplasmic Nuclear

20 Natural history of chronic HBV infection Serology HBeAg Anti-HBe DNA Pre-core variant HBsAg Anti-HBc HBV DNA Limit of HBsAg detection days years

21 Distribution of HBV DNA load and relation to HBe Ag/Ab in HBsAg+ Ghanaian blood donors (Allain et al. Blood 2003) <E1 E1 E2 E3 E4 E5 E6 E7 E8 >E8 HBV DNA load (IU/ml) 1 Anti-HBe HBe Antigen

22 Detection of HBV DNA in HBsAg positive samples Author Sensitivity DNA in HBsAg + IU/ml (%) Jardi /193 (66) Loeb /195 (84) Allain /159 (98)

23 Prevalence of anti-hbc only and HBV DNA frequency Author Country No screened Anti-HBc only (%) DNA+ (%) Hennig Germany 14, (0.14) 3 (15.0) Tseliou Greece 10, (4.8) 0 Zervou Greece (1.0) 0 Allain UK 103, (0.07) 0 Kleinman USA 387 4/107 (3.7) Almeida-Neto Brazil Ren China (0.3) Sato Japan 540, (0.2) 12 (1.1) Bernvil Saudi Arabia 6, (2.1) 4 (3.2) Allain Ghana (45.5) 14 (12.7)

24 Hidden HBV infection in pre and postvaccination sera in South Africa