B-cell characteristics define HCV reinfection outcome.

Background & Aims: In individuals highly exposed to HCV, reinfection is common, suggesting that natural development of sterilising immunity is difficult. In those that are reinfected, some will develop a persistent infection, while a small proportion repeatedly clear the virus, suggesting natural protection is possible. The aim of this study was to characterise immune responses associated with rapid natural clearance of HCV reinfection.

Optimisation and validation of a new method for antibody dependent cellular phagocytosis in hepatitis C virus infection.

Lack of a simple, high throughput antibody-dependent cellular phagocytosis (ADCP) assay has limited our understanding of its potential role of in hepatitis C (HCV) infection. Here, we optimised a flow-cytometry based ADCP assay using HCV envelope (E2)-protein coated microbeads that were opsonised with anti-E2 monoclonal IgG antibody (αE2 mAb) and the THP-1 monocyte cell line as effector cells. We found 1.

Atypical B cells are part of an alternative lineage of B cells that participates in responses to vaccination and infection in humans.

The diversity of circulating human B cells is unknown. We use single-cell RNA sequencing (RNA-seq) to examine the diversity of both antigen-specific and total B cells in healthy subjects and malaria-exposed individuals. This reveals two B cell lineages: a classical lineage of activated and resting memory B cells and an alternative lineage, which includes previously described atypical B cells.

Anti-envelope antibody responses in highly exposed seronegative individuals may be associated with protection from HCV infection.

In rare cases, individuals with a history of long-term injecting drug use remain seronegative and aviraemic, despite prolonged and likely repeated exposure to Hepatitis C virus (HCV) through high-risk behaviour. We describe anti-HCV Envelope (E) antibody responses in a prospective cohort of carefully defined highly exposed but uninfected subjects (HESN) and comparison subjects who were also high risk and uninfected, but rapidly became HCV infected (Incident). Longitudinally collected samples from HESN cases (n = 22) were compared to Incident controls (n = 22).