Identification of Tick-Borne Encephalitis Virus CD4+ and CD8+ T-Cell Epitopes in Vaccinated or Naturally Infected Humans

Transcription

1 Identification of Tick-Borne Encephalitis Virus CD4+ and CD8+ T-Cell Epitopes in Vaccinated or Naturally Infected Humans Schwaiger Julia Clinical Institute of Virology

2 Thank you! Franz X. Heinz Judith Aberle all my colleagues: 2

3 Background 3

4 Flaviviruses - Serocomplexes 4 Fields Virology 4th ed.

5 Flaviviruses - Genome 5 Fields Virology 5th ed.

6 TBE - occurence 6

7 Antigen presentation 7

8 MHC restriction and epitope immunodominance Association between HLA haplotype and disease expression (DEN, Hep B, CMV) 8

9 MHC restriction and epitope immunodominance Association between HLA haplotype and disease expression (DEN, Hep B, CMV) Only very few of theoretical possible peptides lead to an immune response 9

10 MHC restriction and epitope immunodominance Association between HLA haplotype and disease expression (DEN, Hep B, CMV) Only very few of theoretical possible peptides lead to an immune response Immunodominance 10

11 MHC restriction and epitope immunodominance Association between HLA haplotype and disease expression (DEN, Hep B, CMV) Only very few of theoretical possible peptides lead to an immune response Immunodominance T-cell specificity is important for the course of illness (HCV, HIV) CD4 epitope pattern is important in the immune response to viral infection 11

12 T-cell response to flaviviruses Dengue virus West Nile virus Japanese encephalitis virus Kunjin virus Murray valley encephalitis virus 12 Fields Virology 5th ed.

13 Objectives Aims 13

14 Objectives Comparison of TBEV epitope specificity, functionality and breadth in TBEV infection versus TBE vaccination in humans. 14

15 4 aims: Establish a sensitive IFN-γ ELISpot assay Identify TBEV-specific T-cell targets in natural TBEV infection and TBEV vaccination Effector phase Memory phase Characterization of phenotype and function of TBEV eptiope-specific T-cells Analyse whether age is associated with a decline in the T-cell response pattern 15

16 Patients Methods 16

17 Patients 80 patients 40 TBEV infected patients * 40 TBE vaccinated patients 20 >50 years 20 <30 years 20 >50 years 20 <30 years * patients with acute TBEV infection (recruited in Budweis) probands with regular TBE vaccination after booster vaccination (recruited in Vienna) 17

18 Patients TBEV infected patients TBE vaccinated patients 18

19 IFN-γ ELISpot Isolation of monocytes from PBMC by MACS Preparation of immature dendritic cells (idc) IFN-γ ELISpot 19

20 FACS CD4+ CD3 gated cells: (to exclude NK cells) CD4 CD8+ IFN-γ 20

21 Identification of Tick-Borne Encephalitis Virus CD4+ and CD8+ T-Cell Epitopes in Vaccinated or Naturally Infected Humans Establishing a highly sensitive IFN-γ ELISpot assay 9 8 E-50 number of responders E-4 E-12 2 E-3 E-37E-41 E E-1 E-6 E-11 E-16 E-21 E-26 E-31 E-36 E-41 E-46 E-51 E-56 E-61 E-66 E-71 E-76 E-81 E-86 E-91 overlapping peptides Identifying TBEV-specific T-cell targets after infection and vaccination Characterizing the phenotypical and functional properties of TBEV epitope-specific T-cells Age => decline in the T-cell response pattern? 21

22 22

23 References (1) Paradoa Perez ML, Trujillo Y, Basanta P. Association of dengue hemorrhagic fever with the HLA system. Haematologia (Budap) 1987; 20(2):83-7. (2) Lan NT, Kikuchi M, Huong VT, et al. Protective and Enhancing HLA Alleles, HLA-DRB1*0901 and HLA-A*24, for Severe Forms of Dengue Virus Infection, Dengue Hemorrhagic Fever and Dengue Shock Syndrome. PLoS Negl Trop Dis 2008; 2(10):e304. (3) Huang YW, Hu CY, Chen CL, et al. Human leukocyte antigen-drb1*1101 correlates with less severe hepatitis in Taiwanese male carriers of hepatitis B virus. J Med Virol 2009; 81(4): (4) Varga M, Rajczy K, Telkes G, et al. HLA-DQ3 is a probable risk factor for CMV infection in high-risk kidney transplant patients. Nephrol Dial Transplant 2008; 23(8): (5) Addo MM, Yu XG, Rathod A, et al. Comprehensive epitope analysis of human immunodeficiency virus type 1 (HIV-1)-specific T-cell responses directed against the entire expressed HIV-1 genome demonstrate broadly directed responses, but no correlation to viral load. J Virol 2003; 77(3): (6) Schulze zur Wiesch J, Lauer GM, Day CL, et al. Broad repertoire of the CD4+ Th cell response in spontaneously controlled hepatitis C virus infection includes dominant and highly promiscuous epitopes. J Immunol 2005; 175(6): (7) Thimme R, Oldach D, Chang KM, Steiger C, Ray SC, Chisari FV. Determinants of viral clearance and persistence during acute hepatitis C virus infection. J Exp Med 2001; 194(10): (8) Parsons R, Lelic A, Hayes L, et al. The memory T cell response to West Nile virus in symptomatic humans following natural infection is not influenced by age and is dominated by a restricted set of CD8+ T cell epitopes. J Immunol 2008; 181(2): (9) Simmons CP, Dong T, Chau NV, et al. Early T-cell responses to dengue virus epitopes in Vietnamese adults with secondary dengue virus infections. J Virol 2005; 79(9): (10) Kumar P, Krishna VD, Sulochana P, Nirmala G, Haridattatreya M, Satchidanandam V. Cell-mediated immune responses in healthy children with a history of subclinical infection with Japanese encephalitis virus: analysis of CD4+ and CD8+ T cell target specificities by intracellular delivery of viral proteins using the human immunodeficiency virus Tat protein transduction domain. J Gen Virol 2004; 85(Pt 2): (11) Hill AB, Mullbacher A, Parrish C, Coia G, Westaway EG, Blanden RV. Broad cross-reactivity with marked fine specificity in the cytotoxic T cell response to flaviviruses. J Gen Virol 1992; 73 ( Pt 5): (12) Lobigs M, Arthur CE, Mullbacher A, Blanden RV. The flavivirus nonstructural protein NS3 is a dominant source of cytotoxic T cell peptide determinants. Virology 1994; 202(1):

24 IFN-γ ELISpot 24 Sigma-Aldrich, online

25 IFN-γ ELISpot 25