PD-1 blockade partially recovers dysfunctional virus–specific B cells in chronic hepatitis B infection
Loghman Salimzadeh, … , Patrick T.F. Kennedy, Antonio Bertoletti
Loghman Salimzadeh, … , Patrick T.F. Kennedy, Antonio Bertoletti
Published August 7, 2018
Citation Information: J Clin Invest. 2018;128(10):4573-4587. https://doi.org/10.1172/JCI121957.
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Research Article Hepatology Infectious disease

PD-1 blockade partially recovers dysfunctional virus–specific B cells in chronic hepatitis B infection

Abstract

Chronic HBV (CHB) infection suppresses virus-specific T cells, but its impact on humoral immunity has been poorly analyzed. Here, we developed a dual-staining method that utilizes hepatitis B virus (HBV) surface antigens (HBsAg) labeled with fluorochromes as “baits” for specific ex vivo detection of HBsAg-specific B cells and analysis of their quantity, function, and phenotype. We studied healthy vaccinated subjects (n = 18) and patients with resolved (n = 21), acute (n = 11), or chronic (n = 96) HBV infection and observed that frequencies of circulating HBsAg-specific B cells were independent of HBV infection status. In contrast, the presence of serum HBsAg affected function and phenotype of HBsAg-specific B cells that were unable to mature in vitro into Ab-secreting cells and displayed an increased expression of markers linked to hyperactivation (CD21lo) and exhaustion (PD-1). Importantly, B cell alterations were not limited to HBsAg-specific B cells, but affected the global B cell population. HBsAg-specific B cell maturation could be partially restored by a method involving the combination of the cytokines IL-2 and IL-21 and CD40L-expressing feeder cells and was further boosted by the addition of anti–PD-1 Abs. In conclusion, HBV infection has a marked impact on global and HBV-specific humoral immunity, yet HBsAg-specific B cells are amenable to a partial rescue by B cell–maturing cytokines and PD-1 blockade.

Authors

Loghman Salimzadeh, Nina Le Bert, Charles-A. Dutertre, Upkar S. Gill, Evan W. Newell, Christian Frey, Magdeleine Hung, Nikolai Novikov, Simon Fletcher, Patrick T.F. Kennedy, Antonio Bertoletti

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Figure 6

HBsAg-specific and global B cells of CHB patients are enriched for an AtM phenotype.

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HBsAg-specific and global B cells of CHB patients are enriched for an At...
(A) Flow cytometric data of MBCs from 15 healthy vaccinated, 11 early acute, 20 late acute, 19 resolved, and 76 CHB patients were analyzed by the dimensionality reduction algorithm UMAP and concatenated. Four different MBC subsets were delineated (left panel) based on the expression heatmaps of 13 markers (right panels). (B) HBsAg-specific B cells from 15 healthy vaccinated, 20 HBeAg+ chronic infection, 15 HBeAg+ chronic hepatitis, 18 HBeAg– chronic hepatitis, and 23 HBeAg– chronic infection patients were concatenated, normalized to their correct frequency, and overlaid onto the UMAP plot of global concatenated MBCs. (C) Frequency of AtM B cells among HBsAg-specific B cells within the different cohorts. (D) Frequency of global AtM B cells among total B cells (CD19+) present in the subjects of the different cohorts. (E) Correlation of frequency of global AtM among total B cells with serum HBsAg (left), HBV DNA (middle), and ALT (right) levels. (F) Overlay of HBsAg-specific B cells on global MBCs of 11 concatenated acute (left) and 19 resolved (right) HBV patients. (G) Percentage of HBsAg-specific B cells with an AtM phenotype in 6 acute HBV patients at different time points from disease onset. Each symbol represents a single patient. (H) Percentage of global AtM B cells among total B cells (CD19+) of healthy vaccinated, acute, and resolved HBV patients. (I) Percentage of global AtM B cells in 6 acute HBV patients at different time points from disease onset. Bar graphs present median, and statistical analysis was performed by the Kruskal-Wallis test followed by Dunn’s multiple comparisons test (C, D, and H) and Spearman’s rank correlation (E). *P < 0.05; **P < 0.01.