Hepatitis C infection affects approximately 3.9 million Americans and disproportionately impacts the health of veterans. Approximately one-third of infected individuals will develop progressive liver fibrosis culminating in cirrhosis. Bacterial infections and sepsis are prominent causes of morbidity and mortality in patients with cirrhosis. Susceptibility to infections in cirrhosis has largely been attributed to increased bacterial translocation across the gut in the setting of reduced innate immune protective mechanisms. Additionally, antibody responses to vaccines have been long established to be inefficient in cirrhotic patients, suggesting a defect in B-cell activation. However, the contribution of B-cell dysfunction to the cirrhotic immunocompromised state has largely remained unexplored. Our novel preliminary data demonstrate that cirrhosis is associated with the disappearance of CD27+ memory B-cells, leading to impaired B-cell activation and reduced capacity of B-cells to stimulate T-cells. Preliminary investigation suggests that soluble factors elevated in cirrhotic plasma may lead to B-cell hyperactivation, that Fas expression is markedly increased on CD27+ B-cells and expression of pro-survival receptors such as CD268/BAFF-R are reduced. We hypothesize that chronic hyperactivation due to gut translocation leads to either activation-induced apoptosis of memory B-cells or conversion to an exhausted CD27-CD21- memory B-cells population with weak effector capacity. The objectives of this proposal are to longitudinally confirm the association of B-cell dysfunction and cirrhosis identified in cross-sectional studies, to study the impact of cirrhosis o B-cell proliferation and apoptosis, and to explore approaches to reverse this dysfunction in vivo in translational studies. The research encompasses in vitro studies on B-lymphocyte function using blood and tissue samples donated by human subjects in addition to prospective studies of B-cell memory frequency with and without clinical interventions. First, we will examine if the loss of CD27+ B-cells in cirrhosis reflects specific deletion of innate B1-type B-cells critical for protection against bacterial sepsis. Second, we will examine activation of signal pathways such as NF B downstream of CD40, BAFF-R and TLR9 on the activation of CD27+ B-cells in cirrhosis relative to healthy donors. Lastly, we will longitudinally follow the phenotype and function of B-cells in after pharmacological reduction of bacterial translocation, cure of HCV viremia, and in the peritransplant setting to assess the impact of gut translocation, portal hypertension and viremia on maintenance of B-cell dysfunction in cirrhotic patients. The ultimate goal of these studies is to identify conditions under which cirrhotic patient B-cells function can be improved in vivo to reduce the morbidity and mortality of infectious complications of cirrhosis.

Public Health Relevance

Hepatitis C viral infection (HCV) increasingly contributes to morbidity, mortality and cost of healthcare in the U.S. due to time-dependent progression to cirrhosis and hepatocellular carcinoma. These complications disproportionately affect Veterans due to low cure rates and high rates of comorbid conditions that accelerate disease progression, specifically alcohol use, obesity, diabetes and HIV co-infection. We have identified a strong association of abnormalities of B-cell phenotype and function with the progression to cirrhosis. This proposal encompasses work to further define the role of viral infection and liver fibrotic stage in driving these abnormalities, to more precisely define how the phenotypic skewing alters B-cell proliferation and survival, and to rescue certain functionality of cirrhotic B-cells in vitro. We will further characterize the role of gut microbial translocation, portal hypertension and ongoing viremia in inducing and maintaining B-cell dysfunction in cirrhosis.

Agency
National Institute of Health (NIH)
Institute
Veterans Affairs (VA)
Type
Non-HHS Research Projects (I01)
Project #
5I01CX000981-02
Application #
8811013
Study Section
Infectious Diseases A (INFA)
Project Start
2014-01-01
Project End
2017-09-30
Budget Start
2014-10-01
Budget End
2015-09-30
Support Year
2
Fiscal Year
2015
Total Cost
Indirect Cost
Name
Philadelphia VA Medical Center
Department
Type
DUNS #
071609291
City
Philadelphia
State
PA
Country
United States
Zip Code
19104
Serper, M; Forde, K A; Kaplan, D E (2018) Rare clinically significant hepatic events and hepatitis B reactivation occur more frequently following rather than during direct-acting antiviral therapy for chronic hepatitis C: Data from a national US cohort. J Viral Hepat 25:187-197
Doi, Hiroyoshi; Hayashi, Eiichi; Arai, Jun et al. (2018) Enhanced B-cell differentiation driven by advanced cirrhosis resulting in hyperglobulinemia. J Gastroenterol Hepatol :
Serper, Marina; Taddei, Tamar H; Mehta, Rajni et al. (2017) Association of Provider Specialty and Multidisciplinary Care With Hepatocellular Carcinoma Treatment and Mortality. Gastroenterology 152:1954-1964
Knox, James J; Kaplan, David E; Betts, Michael R (2017) T-bet-expressing B cells during HIV and HCV infections. Cell Immunol 321:26-34
Chang, L-Y; Li, Y; Kaplan, D E (2017) Hepatitis C viraemia reversibly maintains subset of antigen-specific T-bet+ tissue-like memory B cells. J Viral Hepat 24:389-396
Chang, Li-Yuan; Li, Yonghai; Kaplan, David E (2016) Endotoxemia contributes to CD27+ memory B-cell apoptosis via enhanced sensitivity to Fas ligation in patients with Cirrhosis. Sci Rep 6:36862
Kaplan, David E (2015) Immunopathogenesis of Hepatitis C Virus Infection. Gastroenterol Clin North Am 44:735-60
Tanoue, Shiroh; Chang, Li-Yuan; Li, Yonghai et al. (2015) Monocyte-derived dendritic cells from cirrhotic patients retain similar capacity for maturation/activation and antigen presentation as those from healthy subjects. Cell Immunol 295:36-45
Doi, Hiroyoshi; Tanoue, Shiroh; Kaplan, David E (2014) Peripheral CD27-CD21- B-cells represent an exhausted lymphocyte population in hepatitis C cirrhosis. Clin Immunol 150:184-91