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Aneja, J.

Publications and source records attributed to Aneja, J..

4 recordsLinked to original sources

CD8 T cells with classical and NK-like cytotoxic gene expression programs mediate control of HBV replication and functional cure

Chronic hepatitis B is characterized by a decades-long evolving engagement between host immunity and the hepatitis B virus (HBV). Understanding the molecular characteristics of HBV-specific CD8 T cells linked to control of viral replication and antigenemia is essential to design effective immunotherapeutic modalities. Here we show that HBV-specific CD8 T cells, even during infection stages with extremely high viral loads, lack the features of terminally exhausted CD8 T cells observed in chronic HCV and HIV infection or cancer. Instead, we observe emerging gene expression programs over disease stages that correlate with increasing HBV control, which include a bona fide cytotoxic and T-cell localization program associated with low levels of viral replication, and a second NK-like T-cell program that combines expression of classical NK markers (KIRs, KLRs, FCGR3A, TYROBP, IKZF2) with cytotoxic genes (GZMB, GNLY, PRF1), which emerges with complete control of HBV viremia and antigenemia. We also found enrichment of both CD8 T-cell programs in HIV-specific CD8 T cells from HIV elite controllers, supporting a conserved role in controlling persistent viral infections with viral reservoirs.

immunology↗

B cell transcriptomics reveals lasting dysregulation and rapid decline of protective memory after hepatitis C cure

O_FIG O_LINKSMALLFIG WIDTH=187 HEIGHT=200 SRC="FIGDIR/small/664545v1_ufig1.gif" ALT="Figure 1"> View larger version (59K): org.highwire.dtl.DTLVardef@d12426org.highwire.dtl.DTLVardef@9c54daorg.highwire.dtl.DTLVardef@186d559org.highwire.dtl.DTLVardef@120f2f3_HPS_FORMAT_FIGEXP M_FIG O_FLOATNOGraphical abstractC_FLOATNO C_FIG HighlightsO_LIB cells in CHC patients retained dysregulated transcriptional profiles despite successful DAA treatment C_LIO_LIB cell dysregulation is marked by global B cell hyperactivation and antigen-specific atypical MBC expansion C_LIO_LISustained upregulation of TNF- signaling via NF-{kappa}B (TNF-/NF-{kappa}B) is a central driver of persistent B cell dysregulation and chronic inflammation C_LIO_LIViral clearance leads to restoration of IFN responses and IFN-stimulated gene (ISG) signatures in B cells but not TNF-/NF-{kappa}B C_LIO_LIHCV IGHV1-69 bnAb-producing B cells are enriched within the CD86hi IgG MBC subset before treatment C_LIO_LICD86hi IgG MBC subset contracts rapidly post-cure in parallel with the rapid decline of cross-nAb responses and loss of protective immune memory against HCV reinfection C_LI Chronic hepatitis C (CHC) disrupts host humoral immune response by impairing the timely generation of neutralizing antibody (nAb) and durable immune memory. However, the underlying mechanisms and their reversibility after viral clearance remain poorly defined. Here, through integrated single-cell transcriptomics and antibody repertoire characterization, we show that B cells from CHC patients retain transcriptional dysregulation even after successful antiviral therapy. Sustained TNF- signaling emerged as a central driver of chronic B cell hyperactivation, persistent dysregulation and unresolved inflammation following cure. Furthermore, a CD86hi memory B cell subset, responsible for an IGHV1-69-encoded multi-donor class recall nAb response, declined rapidly following viral clearance, compromising immune memory against reinfection. Together, these findings reveal how CHC imprints lasting B cell dysregulation, impairs nAb memory, and sustains inflammation in the B cell compartment, after viral clearance. The insights underscore the need for strategies aimed at restoring B cell homeostasis to achieve durable immune protection.

immunology↗

Differentiation of exhausted CD8 T cells after termination of chronic antigen stimulation stops short of achieving functional T cell memory

T cell exhaustion is associated with failure to clear chronic infections and malignant cells. Defining the molecular mechanisms of T cell exhaustion and reinvigoration is essential to improving immunotherapeutic modalities. Analysis of antigen-specific CD8+ T cells before and after antigen removal in human hepatitis C virus (HCV) infection confirmed pervasive phenotypic, functional, and transcriptional differences between exhausted and memory CD8+ T cells. After viral cure, we observed broad phenotypic and transcriptional changes in clonally stable exhausted T-cell populations suggesting differentiation towards a memory-like profile. However, functionally, the cells showed little improvement and critical transcriptional regulators remained in the exhaustion state. Notably, T cells from chronic HCV infection that were exposed to antigen for shorter periods of time because of viral escape mutations were functionally and transcriptionally more similar to memory T cells from spontaneously resolved acute HCV infection. Thus, duration of T cell stimulation impacts the ability to recover from exhaustion, as antigen removal after long-term T cell exhaustion is insufficient for the development of key T cell memory characteristics.

immunology↗

Fine-mapping of genetic loci driving spontaneous clearance of hepatitis C virus infection

Approximately three quarters of acute HCV infections evolve to a chronic state, while one quarter are spontaneously cleared. Genetic predispositions strongly contribute to the development of chronicity. We have conducted a genome-wide association study to identify genomic variants underlying HCV spontaneous clearance using Immunochip in European and African ancestries. We confirmed two previously reported significant associations, in the IL28B/IFNL41,2 and MHC regions, with spontaneous clearance in the European population. We further fine-mapped the MHC association to a region of about 50 kilo base pairs, down from 1 mega base pairs in the previous study. Additional analyses suggested that the association in the MHC locus might be significantly stronger for virus subtype 1a than 1b, suggesting that viral subtype may have influenced the genetic mechanism underlying the clearance of HCV.

immunology↗