Influenza antibody profiling by protein microarray. Marion Koopmans, Professor of public health virology Head Viroscience department

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1 Influenza antibody profiling by protein microarray Marion Koopmans, Professor of public health virology Head Viroscience department

2 Influenza serology applications 1. Evaluation of vaccine response (functional antibodies) Hemagglutination inhibition, microneutralisation 2. Evaluation of influenza infection at population level (any antibodies) HI when specific viruses are known More difficult when studying human animal interface and unknown exposures 3. Emerging disease preparedness and ability to obtain serological data at BSL2 level (both) Level of immunity? Rate of asymptomatic infections Spread of infection in households Effect of control measures on spread of infection Assessment of immune response of candidate vaccines

3 Which antibodies? Many antibodies are produced upon exposure HA, NA, M, NP Functional antibodies: Binding blocking (HI, MNT) Targeting surface proteins Most specific, and considered dominant in seasonal influenza Insights from pandemic H1: Broadly reacting neutralising stem Ab Broadly reactive antibodies HA1 (ADCC?) Ikonen et al., 2010

4 Challenges for sero-epidemiology studies Current reference assays are difficult to standardise Require knowledge of virus persons are exposed to (which may be lacking in surveillance at human animal interface) Single mutations can affect ability to detect HI antibodies Need for testing to panels of viruses > costly, labor intensive and requiring a lot of serum > development of a more standardized method to assess exposure for population-based studies

5 117b signal :10 1:20 1:40 1:80 1:160 1:320 1:640 1:1280 1:2560 1:5120 H1.18 H1.33 H1.34 H1.99 H1.07 H1.09i H2.05 H3.03 H3.07 H5.04 H7.03 H9.99 Verdunning (log-scale) A/South Caroline/1/18 H1.18 A/WS/33 H1.33 A/Puerto Rico/8/34 H1.34 A/New Caledonia/20/99 H1.99 A/Brisbane/59/2007 H1.07 A/California/6/2009 H1.09 H2.57 A/Canada/720/05 H3.03 A/Wyoming/3/03 H3.07 A/Brisbane/10/2007 H5.04 A/Vietnam/1194/2004 H7.03 A/Chicken/Netherlands/1/03 H9.99 A/Guinea fowl/hong Kong/WF10/99 HA1 proteins expressed in HEK293 cells, HIS tag purified 16 or 64 wells / slide Quality control serum for slide-slide comparison and normalisation Quantitative signal (fluorescence) Calculation of titre from dilution curves

6 rabbit immunized with HA1 recombinant proteins Rabbit serum H H H H H H H anti-h anti-h anti-h anti-h anti-h anti-h anti-h1 2009* M. Koopmans et.al. 2011

7 Validation for use in humans Problem: true negative human sera do not exist Proxy is supernatants from differentiated plasma cells, and serum samples from children with primary infection PBMC culture to stimulate plasma-cell differentiation from individual specific memory B cells Testing of individual wells (human monoclonals) by proteinarray Children with few influenza exposures to assess ability to measure monospecific responses

8 Age stratified Ab profile prepandemic population sample (n = 122, 2008)

9 HI and PA profiles pandemic cases (n=18) Koopmans et al., 2011

10 HA1 A(H1N1)pdm09 responses in neonatal screening samples Rationale 13 countries 5 continents Convenience sample Standardized sampling material (blood spots) Profile of antibody responses based on women of childbearing age (maternal Ab) Validation Bloodspots collected before April 2009 used to set cutoff (30375 fluorescence) Standardization Single batch of antigens for total study Corrected for test-to-test variation to the mean value of positive control serum (09/194, NIBSC), for each slide separately

11 Other seroprevalence studies A(H1N1)pdm09 epidemic period Percentage positive/week (x100) Phase 5 alert Start vaccination De Bruin et al., 2014 Phase 6 alert Smoothed blood spot results with 95% CI intervals; Smoothing by generalized additive model (GAM) Woods et al. 2003, 2004, 2006, 2011

12 Percentage positive/week (x100) Europe, Lebanon, South Africa

13 What other information can be provided from the profiles of antibodies? Is it possible to distinguish Ab profiles within subtype? What is the effect of vaccination? Are the Ab measured for H9 Low level cross reactive antibodies or true exposures?

14 Patterns of (broad/cross reactivity) are very diverse, likely related to an individual s exposure history Koopmans et al., 2011

15 Patterns of (broad/cross reactivity) are very diverse, likely related to an individual s exposure history Koopmans et al., 2011

16 Patterns of (broad/cross reactivity) are very diverse, likely related to an individual s exposure history Koopmans et al., 2011

17 Patterns of (broad/cross reactivity) are very diverse, likely related to an individual s exposure history Koopmans et al., 2011

18 Potential applications: comparative analysis of vaccination and infection response Huijskens et al., 2013

19 Potential applications: avian influenza surveillance Guangdong H9 H7 Since 2012: enhanced surveillance Market environmental sampling and testing for AI by PCR Periodic serological sampling of poultry workers and blood donors > Analysis of seroresponses in relation to virus exposure Ke et al., 2014

20 Summary HA1 based profiling of immune response has potential for population studies of virus exposure in humans and animals Comparative evaluation against biological assays needed to fully leverage the potential (some studies planned in Flucop project, IMI)

21 Acknowledgements ErasmusMC Erwin de Bruin Gudrun Freidl Guus Rimmelzwaan Hendrik Jan van Ham Guandong CDC Ke Changwen Xin Zhang OUCRU Vietnam Maciej Boni Stacey Todd Nhat Nguyen Thi Duy Funding: FP7 project ANTIGONE