Baseline Characteristics^*.

<p>*presented as median values.</p><p>**nucleosid/nucleotide analogs.</p><p>***not determined.</p

Effect of PD-L1/2 blockade on CD4⁺ T-cell expansion.

<p>Induction of CD4⁺ T-cell proliferation in chronic HBV (n = 23) from h0 (<i>left</i>) to antigenic stimulation (<i>middle</i>) and PD-L1/2 blockade (<i>right</i>) illustrated as point to point graphs from (<b>A</b>) PD-L1/2 responders (n = 9) and (<b>B</b>) Non-responders (n = 14). Contour plots are shown for each group. (<b>C</b>) Patients treated with nucleosid/nucleotid analogs (<i>black bars</i>) responded to PD-1 blockade using Chi²-test, indicating that viral control let enhance patients susceptibility as (<b>D</b>) treated patients are characterized by low viremia. (<b>E</b>) Decreased PD-1 expression in PD-L1/2 responders (R) (n = 6) versus non-responders (NR) (n = 6). (<b>F</b>) CD4⁺ T-cell frequencies upon antigenic stimulation (<i>black bars</i>) and PD-L1/2 inhibition (<i>grey bars</i>) in relation to PD-1 expression.</p

Inhibitory phenotype of HBV-specific CD4⁺ T-cells.

<p>(<b>A</b>) PD-1 (n = 29), CTLA-4 (n = 8), TIM-3 (n = 14), KLRG1 (n = 12) and CD244 (n = 8) expression is displayed on Tetramer⁺CD4⁺ T-cells during chronic HBV. (<b>B</b>) PD-1 expression in chronic (<i>black points</i>) (n = 29) and acute HBV (<i>black squares</i>) (n = 7), resolved HBV (<i>white squares</i>) (n = 5), EBV (<i>grey points</i>) (n = 15) and Flu (<i>white points</i>) (n = 21) infection. (<b>C</b>) Contour plots illustrate patterns of PD-1 expression during HBV, EBV and Flu infection. (<b>D</b>) CD127 expression on HBV-specific (<i>black points</i>) (n = 11) and Flu-specific CD4⁺ T-cells (<i>white points</i>) (n = 9). (<b>E</b>) Contour plots display CD127 expression on CD14⁻, CD19⁻, Via Probe⁻, Tetramer⁺ T-cells. (<b>F</b>) CD127 defines PD-1 expression as examined in HBV (<i>black bars</i>) and Flu infection (<i>white bar</i>). (<b>G</b>) Influence of viral load on CD127 expression.</p

Effect of PD-L1/2 blockade on cytokine release.

<p>Analysis of cytokine⁺CD4⁺ T-cells allows to differ (<b>A</b>) PD-L1/2 responders (n = 4) from (<b>B</b>) Non-responders (n = 9). Floating bars illustrate mean values ranging from minimun to maximum production of IFN-γ, IL-2 and TNF-α seperatly following antigen stimulation (<i>white bars</i>) and PD-1 blockade (<i>grey bars</i>). Contour plots are shown for IFN-γ (<i>top</i>), IL-2 (<i>middl</i>e) and TNF-α (<i>bottom</i>) secretion upon antigen stimulation (<i>left</i>) and PD-1 pathway neutralization (<i>right</i>) after gating on CD3⁺CD4⁺ T-cells.</p