B cell overexpression of FCRL5 and PD-1 is associated with low antibody titers in HCV infection

Antibodies targeting the hepatitis C virus (HCV) envelope glycoprotein E2 are associated with delayed disease progression, and these antibodies can also facilitate spontaneous clearance of infection in some individuals. However, many infected people demonstrate low titer and delayed anti-E2 antibody responses. Since a goal of HCV vaccine development is induction of high titers of anti-E2 antibodies, it is important to define the mechanisms underlying these suboptimal antibody responses. By staining lymphocytes with a cocktail of soluble E2 (sE2) glycoproteins, we detected HCV E2-specific (sE2+) B cells directly ex vivo at multiple acute infection timepoints in 29 HCV-infected subjects with a wide range of anti-E2 IgG titers, including 17 persistently infected subjects and 12 subjects with spontaneous clearance of infection. We performed multi-dimensional flow cytometric analysis of sE2+ and E2-nonspecific (sE2-) class-switched B cells (csBC). In sE2+ csBC from both persistence and clearance subjects, frequencies of resting memory B cells (rMBC) were reduced, frequencies of activated MBC (actMBC) and tissue-like MBC (tlMBC) were increased, and expression of FCRL5, an IgG receptor, was significantly upregulated. Across all subjects, plasma anti-E2 IgG levels were positively correlated with frequencies of sE2+ rMBC and sE2+ actMBC, while anti-E2 IgG levels were negatively correlated with levels of FCRL5 expression on sE2+ rMBC and PD-1 expression on sE2+ actMBC. Upregulation of FCRL5 on sE2+ rMBC and upregulation of PD-1 on sE2+ actMBC may limit anti-E2 antibody production in vivo. Strategies that limit upregulation of these molecules could potentially generate higher titers of protective antibodies against HCV or other pathogens.

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Insights into Antibody-Mediated Alphavirus Immunity and Vaccine Development Landscape

Microorganisms ◽

10.3390/microorganisms9050899 ◽

2021 ◽

Vol 9 (5) ◽

pp. 899

Author(s):

Anthony Torres-Ruesta ◽

Rhonda Sin-Ling Chee ◽

Lisa F.P. Ng

Keyword(s):

Diagnostic Tests ◽

Inflammatory Arthritis ◽

Chikungunya Virus ◽

Vaccine Development ◽

Antibody Responses ◽

Chikv Infection ◽

Wide Range ◽

Susceptible Populations ◽

Humoral Responses

Alphaviruses are mosquito-borne pathogens distributed worldwide in tropical and temperate areas causing a wide range of symptoms ranging from inflammatory arthritis-like manifestations to the induction of encephalitis in humans. Historically, large outbreaks in susceptible populations have been recorded followed by the development of protective long-lasting antibody responses suggesting a potential advantageous role for a vaccine. Although the current understanding of alphavirus antibody-mediated immunity has been mainly gathered in natural and experimental settings of chikungunya virus (CHIKV) infection, little is known about the humoral responses triggered by other emerging alphaviruses. This knowledge is needed to improve serology-based diagnostic tests and the development of highly effective cross-protective vaccines. Here, we review the role of antibody-mediated immunity upon arthritogenic and neurotropic alphavirus infections, and the current research efforts for the development of vaccines as a tool to control future alphavirus outbreaks.

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IMMU-29. B-CELL-BASED VACCINE PRODUCES GLIOBLASTOMA-REACTIVE ANTIBODIES THAT CONTRIBUTE TO TUMOR CLEARANCE

Neuro-Oncology ◽

10.1093/neuonc/noab196.388 ◽

2021 ◽

Vol 23 (Supplement_6) ◽

pp. vi98-vi98

Author(s):

Brandyn Castro ◽

Mark Dapash ◽

David Hou ◽

Aida Rashidi ◽

Deepak Kanojia ◽

...

Keyword(s):

B Cells ◽

B Cell ◽

Humoral Immunity ◽

Ex Vivo ◽

Murine Models ◽

Effector Functions ◽

Tumor Bearing ◽

Tumor Clearance ◽

Cellular And Humoral Immunity

Abstract Glioblastomas (GBM) are characterized by a strong immunosuppressive environment, contributing to their poor prognosis and limited therapeutic response to immunotherapies. B-cells represent a unique opportunity to promote immunotherapy due to their potential to kill tumors by both cellular and humoral immunity. To generate our B-cell-based vaccine (BVax) platform, we activated 41BBL+ B cells from tumor bearing mice or GBM patient blood with BAFF, CD40, and IFNg. We have previously demonstrated that BVax potentiates radiation therapy, temozolomide and checkpoint blockade in murine models of GBM via enhancement of CD8+ T-cell based immunity. The aim of this current study is to evaluate the humoral effector functions of BVax. We examined the antibody (Ab) repertoire in vivo from serum of tumor-bearing B-cell knockout mice treated with BVax or by ex vivo stimulation of patient-derived BVax. Upon systemic administration, BVax infiltrates the tumor where it differentiates into plasmablasts. Murine BVax- and BNaive-derived serum immunoglobulin generated in vivo showed that the majority of murine BVax-derived Ab were IgG isotype, while BNaive mainly produced IgM isotype. Transfer of IgG from BVax treated mice directly into tumors of recipient animals significantly prolonged their survival, demonstrating anti-tumor cytotoxicity directly through humoral immunity. Patient-derived BVax activated ex vivo showed a plasmablast phenotype and the Ab repertoire supports the previous findings seen in our murine model. Our work suggests BVax-derived IgGs role in antibody-dependent cellular cytotoxicity and improved survival in murine models. This function, in addition to its role in cellular immunity against GBM, renders BVax a potentially effective alternative immunotherapeutic option for GBM patients.

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Constitutive expression of bcl-2 in B cells causes a lethal form of lupuslike autoimmune disease after induction of neonatal tolerance to H-2b alloantigens.

Journal of Experimental Medicine ◽

10.1084/jem.183.6.2523 ◽

1996 ◽

Vol 183 (6) ◽

pp. 2523-2531 ◽

Cited By ~ 29

Author(s):

M López-Hoyos ◽

R Carrió ◽

R Merino ◽

L Buelta ◽

S Izui ◽

...

Keyword(s):

B Cells ◽

Autoimmune Disease ◽

Constitutive Expression ◽

Systemic Autoimmune Disease ◽

Spleen Cells ◽

Term Survival ◽

F1 Hybrid ◽

Wide Range

The bcl-2 protooncogene has been shown to provide a survival signal to self-reactive B cells, but it fails to override their developmental arrest after encounter with antigen. Furthermore, constitutive expression of bcl-2 in B cells does not promote the development of autoimmune disease in most strains of mice, indicating that signals other than those conferred by bcl-2 are required for long-term survival and differentiation of self-reactive B cells in vivo. To further examine the factors that are required for the pathogenesis of autoimmune disease, we have assessed the effect of bcl-2 overexpression on the development of host-versus-graft disease, a self-limited model of systemic autoimmune disease. In this model, injection of spleen cells from (C57BL/6 x BALB/c)F1 hybrid mice into BALB/c newborn parental mice induces immunological tolerance to donor tissues and activation of autoreactive F1 donor B cells through interactions provided by allogeneic host CD4+ T cells. BALB/c newborns injected with spleen cells from (C57BL/6 x BALB/c)F1 mice expressing a bcl-2 transgene in B cells developed high levels of anti-single-stranded DNA and a wide range of pathogenic autoantibodies that were not or barely detectable in mice injected with nontransgenic spleen cells. In mice injected with transgenic B cells, the levels of pathogenic autoantibodies remained high during the course of the study and were associated with long-term persistence of donor B cells, development of a severe autoimmune disease, and accelerated mortality. These results demonstrate that bcl-2 can provide survival signals for the maintenance and differentiation of autoreactive B cells, and suggest that both increased B cell survival and T cell help play critical roles in the development of certain forms of systemic autoimmune disease.

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hPSC-Derived Enteric Ganglioids Model Human ENS Development and Function

10.1101/2022.01.04.474746 ◽

2022 ◽

Author(s):

Homa Majd ◽

Ryan M Samuel ◽

Jonathan T Ramirez ◽

Ali Kalantari ◽

Kevin Barber ◽

...

Keyword(s):

Ex Vivo ◽

Xenograft Model ◽

Developmental Relationships ◽

Drug Candidates ◽

Effective Strategies ◽

Wide Range ◽

Functional Features ◽

And Function

The enteric nervous system (ENS) plays a central role in gut physiology and mediating the crosstalk between the gastrointestinal (GI) tract and other organs. The human ENS has remained elusive, highlighting the need for an in vitro modeling and mapping blueprint. Here we map out the developmental and functional features of the human ENS, by establishing robust and scalable 2D ENS cultures and 3D enteric ganglioids from human pluripotent stem cells (hPSCs). These models recapitulate the remarkable neuronal and glial diversity found in primary tissue and enable comprehensive molecular analyses that uncover functional and developmental relationships within these lineages. As a salient example of the power of this system, we performed in-depth characterization of enteric nitrergic neurons (NO neurons) which are implicated in a wide range of GI motility disorders. We conducted an unbiased screen and identified drug candidates that modulate the activity of NO neurons and demonstrated their potential in promoting motility in mouse colonic tissue ex vivo. We established a high-throughput strategy to define the developmental programs involved in NO neuron specification and discovered that PDGFR inhibition boosts the induction of NO neurons in enteric ganglioids. Transplantation of these ganglioids in the colon of NO neuron-deficient mice results in extensive tissue engraftment, providing a xenograft model for the study of human ENS in vivo and the development of cell-based therapies for neurodegenerative GI disorders. These studies provide a framework for deciphering fundamental features of the human ENS and designing effective strategies to treat enteric neuropathies.

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Abstract 1144: Successful Surface-Aminated Nanofiber Expansion of Human Umbilical Cord-Derived CD133+ Cells Leads to Augmentation of Angiogenic Functionality In Vitro and In Vivo

Circulation ◽

10.1161/circ.116.suppl_16.ii_231 ◽

2007 ◽

Vol 116 (suppl_16) ◽

Author(s):

Hiranmoy Das ◽

Matthew Joseph ◽

Nasreen Abdulhameed ◽

Hai-Quan Mao ◽

Vincent J Pompili

Keyword(s):

Umbilical Cord ◽

Hind Limb ◽

Ex Vivo ◽

Flow Cytometric Analysis ◽

Surface Expression ◽

Capillary Density ◽

Therapeutic Angiogenesis ◽

Human Umbilical Cord

Background: Umbilical cord blood (UCB) and marrow-derived CD133+ cells have been shown to mediate encouraging effects on therapeutic angiogenesis in both animal models and early clinical trials. Low numbers of CD133+ cells derived from a single donor have been a limitation of use of these cells in cardiovascular therapy. We hypothesized that an ex vivo aminated nanofiber system combined with cytokine supplementation would provide optimized topographical and biochemical signals to allow the expansion and potential functional augmentation of CD133+ cells without promoting terminal differentiation. Methods and Results: Human UCB derived CD133+ progenitor cells were isolated by MACS sorting and ex vivo expanded on aminated nanofiber plates with cytokine rich media. Cells harvested 10 days after expansion demonstrated a 225X increase in total number. Flow cytometric analysis demonstrated CD133–24%, CD34–93%, CXCR4–97%, LFA-97% surface expression. The expanded cells can uptake AcLDL efficiently and demonstrate a 2.3X increase in transwell migration to SDF-1 as compared to fresh UCB CD133+ cells. In vitro analysis revealed that expanded cells have potential to differentiate into endothelial or smooth muscle phenotype as demonstrated with CD31, vWF, VCAM-1 and F-pholloidin, α-actin, and SM myosin heavy chain immunocytochemistry when re-cultured for 14d in EGM2 or SMBM respectively. RT-QPCR analysis of 1% O 2 exposed (hypoxic) cells demonstrated a 2X increase in VEGF and 3X increase in IL-8 gene expression compared to normoxic control. In vivo functionality in a NOD/SCID mouse hind limb ischemic model demonstrated that mice treated with 5 x 10 6 expanded cells (n=7) augmented blood flow ratio (ischemic/control limb) as compared to mice treated with CD133+ cells (n=7) and control (n=7) at 28d. (control 0.32±.02 vs. UCB133+ 0.37±.02 vs. expanded cells 0.50±.04 p<0.01) Capillary density in ischemic hind-limb was increased at 28d (control 62.5±5.4 vs. expanded cell 97.6±2.5 p< 0.01) Conclusions: These studies demonstrate successful high level expansion of UCB derived CD133+ cells into functionally potent stem cells which have the capacity to differentiate into vascular cells and promote in vivo neovascularization.

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Polyinosinic: Polycytidylic Acid and Murine Cytomegalovirus Modulate Expression of Murine IL-10 and IL-21 in White Adipose Tissue

Viruses ◽

10.3390/v12050569 ◽

2020 ◽

Vol 12 (5) ◽

pp. 569

Author(s):

Pablo Garcia-Valtanen ◽

Ruth Marian Guzman-Genuino ◽

John D. Hayball ◽

Kerrilyn R. Diener

Keyword(s):

Adipose Tissue ◽

B Cells ◽

White Adipose Tissue ◽

Ex Vivo ◽

Interleukin 10 ◽

Poly I:C ◽

Murine Cytomegalovirus ◽

Polycytidylic Acid ◽

Polyinosinic Polycytidylic Acid

White adipose tissue (WAT) produces interleukin-10 and other immune suppressors in response to pathogen-associated molecular patterns (PAMPs). It also homes a subset of B-cells specialized in the production of IL-10, referred to as regulatory B-cells. We investigated whether viral stimuli, polyinosinic: polycytidylic acid (poly(I:C)) or whole replicative murine cytomegalovirus (MCMV), could stimulate the expression of IL-10 in murine WAT using in vivo and ex vivo approaches. Our results showed that in vivo responses to systemic administration of poly(I:C) resulted in high levels of endogenously-produced IL-10 and IL-21 in WAT. In ex vivo WAT explants, a subset of B-cells increased their endogenous IL-10 expression in response to poly(I:C). Finally, MCMV replication in WAT explants resulted in decreased IL-10 levels, opposite to the effect seen with poly(I:C). Moreover, downregulation of IL-10 correlated with relatively lower number of Bregs. To our knowledge, this is the first report of IL-10 expression by WAT and WAT-associated B-cells in response to viral stimuli.

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Towards Physiologically and Tightly Regulated Vectored Antibody Therapies

Cancers ◽

10.3390/cancers12040962 ◽

2020 ◽

Vol 12 (4) ◽

pp. 962 ◽

Cited By ~ 2

Author(s):

Audrey Page ◽

Floriane Fusil ◽

François-Loïc Cosset

Keyword(s):

B Cells ◽

Viral Vectors ◽

Checkpoint Inhibitors ◽

Ex Vivo ◽

Passive Immunization ◽

Cell Types ◽

Cell Receptor ◽

Short Period ◽

Antibody Secretion

Cancers represent highly significant health issues and the options for their treatment are often not efficient to cure the disease. Immunotherapy strategies have been developed to modulate the patient’s immune system in order to eradicate cancerous cells. For instance, passive immunization consists in the administration at high doses of exogenously produced monoclonal antibodies directed either against tumor antigen or against immune checkpoint inhibitors. Its main advantage is that it provides immediate immunity, though during a relatively short period, which consequently requires frequent injections. To circumvent this limitation, several approaches, reviewed here, have emerged to induce in vivo antibody secretion at physiological doses. Gene delivery vectors, such as adenoviral vectors or adeno-associated vectors, have been designed to induce antibody secretion in vivo after in situ cell modification, and have driven significant improvements in several cancer models. However, anti-idiotypic antibodies and escape mutants have been detected, probably because of both the continuous expression of antibodies and their expression by unspecialized cell types. To overcome these hurdles, adoptive transfer of genetically modified B cells that secrete antibodies either constitutively or in a regulated manner have been developed by ex vivo transgene insertion with viral vectors. Recently, with the emergence of gene editing technologies, the endogenous B cell receptor loci of B cells have been modified with the clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated endonuclease (Cas-9) system to change their specificity in order to target a given antigen. The expression of the modified BCR gene hence follows the endogenous regulation mechanisms, which may prevent or at least reduce side effects. Although these approaches seem promising for cancer treatments, major questions, such as the persistence and the re-activation potential of these engineered cells, remain to be addressed in clinically relevant animal models before translation to humans.

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In vitro-transcribed antigen receptor mRNA nanocarriers for transient expression in circulating T cells in vivo

Nature Communications ◽

10.1038/s41467-020-19486-2 ◽

2020 ◽

Vol 11 (1) ◽

Author(s):

N. N. Parayath ◽

S. B. Stephan ◽

A. L. Koehne ◽

P. S. Nelson ◽

M. T. Stephan

Keyword(s):

T Cells ◽

Ex Vivo ◽

Human Leukemia ◽

Antigen Receptors ◽

Wide Range ◽

Engineered T Cells ◽

Circulating T Cells ◽

The Cost

AbstractEngineering chimeric antigen receptors (CAR) or T cell receptors (TCR) helps create disease-specific T cells for targeted therapy, but the cost and rigor associated with manufacturing engineered T cells ex vivo can be prohibitive, so programing T cells in vivo may be a viable alternative. Here we report an injectable nanocarrier that delivers in vitro-transcribed (IVT) CAR or TCR mRNA for transiently reprograming of circulating T cells to recognize disease-relevant antigens. In mouse models of human leukemia, prostate cancer and hepatitis B-induced hepatocellular carcinoma, repeated infusions of these polymer nanocarriers induce sufficient host T cells expressing tumor-specific CARs or virus-specific TCRs to cause disease regression at levels similar to bolus infusions of ex vivo engineered lymphocytes. Given their ease of manufacturing, distribution and administration, these nanocarriers, and the associated platforms, could become a therapeutic for a wide range of diseases.

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Recombinant Antigen-Enterotoxin A2/B Chimeric Mucosal Immunogens Differentially Enhance Antibody Responses and B7-Dependent Costimulation of CD4+ T Cells

Infection and Immunity ◽

10.1128/iai.69.1.252-261.2001 ◽

2001 ◽

Vol 69 (1) ◽

pp. 252-261 ◽

Cited By ~ 25

Author(s):

Michael Martin ◽

George Hajishengallis ◽

Daniel J. Metzger ◽

Suzanne M. Michalek ◽

Terry D. Connell ◽

...

Keyword(s):

T Cells ◽

B Cells ◽

Ex Vivo ◽

Immunoglobulin A ◽

Chimeric Protein ◽

Antibody Responses ◽

Chimeric Proteins ◽

Binding Region ◽

Cervical Lymph Nodes

ABSTRACT The ADP-ribosylating enterotoxins, cholera toxin (CT) and theEscherichia coli heat-labile toxin (LT-IIa), have been shown to enhance mucosal and systemic antibody (Ab) responses to coadministered antigens. The purpose of the present study was to compare the ability of the nontoxic A2/B subunits of these toxins, which have distinct targeting properties, to augment the immunogenicity of a genetically coupled protein antigen. Structurally similar chimeric proteins were generated by genetically replacing the toxic A1 subunit of CT or LT-IIa with the saliva-binding region (SBR) from the streptococcal adhesin AgI/II. Intranasal immunization of BALB/c mice with either chimeric protein induced significantly higher plasma and mucosal anti-SBR immunoglobulin A (IgA) and IgG Ab responses than SBR alone. Moreover, compared to SBR–LT-IIaA2/B, SBR-CTA2/B elicited significantly higher levels of plasma IgG1 and salivary IgA anti-SBR Ab responses. Ex vivo and in vitro experiments revealed that SBR-CTA2/B selectively up-regulated B7-2 expression on murine B cells isolated from both the nasal associated lymphoid tissue, cervical lymph nodes, and spleen. In contrast, SBR–LT-IIaA2/B had little effect on B7-1 or B7-2 expression on B220+, CD11b+, or CD11c+ cells. Analysis of the functional costimulatory activity of SBR-CTA2/B-treated B cells revealed a significant enhancement in anti-CD3-stimulated CD4+ T-cell proliferative responses, and this proliferation was significantly reduced by treatment with anti-B7-2 but not with anti-B7-1 or isotype control Abs. Thus, SBR-CTA2/B and SBR–LT-IIaA2/B exhibit distinct patterns of antibody responses associated with differential effects on B7-2 expression and subsequent costimulatory effects on CD4+ T cells.

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Virus-Encoded MicroRNAs Facilitate Gammaherpesvirus Latency and Pathogenesis In Vivo

mBio ◽

10.1128/mbio.00981-14 ◽

2014 ◽

Vol 5 (3) ◽

Cited By ~ 52

Author(s):

Emily R. Feldman ◽

Mehmet Kara ◽

Carrie B. Coleman ◽

Katrina R. Grau ◽

Lauren M. Oko ◽

...

Keyword(s):

B Cells ◽

Memory B Cells ◽

Mutant Virus ◽

Murine Gammaherpesvirus ◽

Wide Range ◽

Cellular Pathways ◽

Regulatory Rnas ◽

Host Target

ABSTRACTGammaherpesviruses, including Epstein-Barr virus (EBV), Kaposi sarcoma-associated herpesvirus (KSHV, or HHV-8), and murine gammaherpesvirus 68 (MHV68, γHV68, or MuHV-4), are B cell-tropic pathogens that each encode at least 12 microRNAs (miRNAs). It is predicted that these regulatory RNAs facilitate infection by suppressing host target genes involved in a wide range of key cellular pathways. However, the precise contribution that gammaherpesvirus miRNAs make to viral life cycle and pathogenesisin vivois unknown. MHV68 infection of mice provides a highly useful system to dissect the function of specific viral elements in the context of both asymptomatic infection and disease. Here, we report (i) analysis ofin vitroandin vivoMHV68 miRNA expression, (ii) generation of an MHV68 miRNA mutant with reduced expression of all 14 pre-miRNA stem-loops, and (iii) comprehensive phenotypic characterization of the miRNA mutant virusin vivo. The profile of MHV68 miRNAs detected in infected cell lines varied with cell type and did not fully recapitulate the profile from cells latently infectedin vivo. The miRNA mutant virus, MHV68.Zt6, underwent normal lytic replicationin vitroandin vivo, demonstrating that the MHV68 miRNAs are dispensable for acute replication. During chronic infection, MHV68.Zt6 was attenuated for latency establishment, including a specific defect in memory B cells. Finally, MHV68.Zt6 displayed a striking attenuation in the development of lethal pneumonia in mice deficient in IFN-γ. These data indicate that the MHV68 miRNAs may facilitate virus-driven maturation of infected B cells and implicate the miRNAs as a critical determinant of gammaherpesvirus-associated disease.IMPORTANCEGammaherpesviruses such as EBV and KSHV are widespread pathogens that establish lifelong infections and are associated with the development of numerous types of diseases, including cancer. Gammaherpesviruses encode many small noncoding RNAs called microRNAs (miRNAs). It is predicted that gammaherpesvirus miRNAs facilitate infection and disease by suppressing host target transcripts involved in a wide range of key cellular pathways; however, the precise contribution that these regulatory RNAs make toin vivovirus infection and pathogenesis is unknown. Here, we generated a mutated form of murine gammaherpesvirus (MHV68) to dissect the function of gammaherpesvirus miRNAsin vivo. We demonstrate that the MHV68 miRNAs were dispensable for short-term virus replication but were important for establishment of lifelong infection in the key virus reservoir of memory B cells. Moreover, the MHV68 miRNAs were essential for the development of virus-associated pneumonia, implicating them as a critical component of gammaherpesvirus-associated disease.

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