Development of a Lymphoid Organ-Chip to Evaluate mRNA Vaccine-Boosting Strategies

In this webinar, Lisa Chakrabarti, PhD, from Institut Pasteur described how her team developed a lymphoid Organ-Chip (LO Chip) using the Emulate Chip-S1® Stretchable Chip to address the challenge of predicting vaccine immunogenicity in humans. Dr. Chakrabarti went into detail about how the LO chip recreated key lymphoid tissue features, including T cell/B cell interactions and emigration of matured plasmablasts, and demonstrated the capability to assess responses to mRNA vaccines. 

Key highlights from this webinar include how: 

  • The model recreates lymphoid tissue features, including CD4+ T cell/B cell cluster formation and emigration of matured plasmablasts. 
  • The LO Chip effectively mimics vaccine boosts, amplifying SARS-CoV-2 Spike protein-specific B cells and antibody production.
  • The dynamically perfused culture system outperforms traditional 2D and 3D static cultures in immune response simulation. 
  • The LO Chip is responsive to both protein and mRNA-encoded antigens, highlighting its potential for preclinical evaluation of vaccine boosting strategies. 

Read Dr. Chakrabarti’s full paper here.

Modeling memory B cell responses in a lymphoid organ-chip to evaluate mRNA vaccine boosting

Organ Model: Lymphoid Follicle

Application: Vaccine development

How Organ-Chips Were Used: Predicting the immunogenicity of candidate vaccines in humans remains a challenge. To address this issue, the authors developed a Lymphoid Organ-Chip (LO Chip) based on a microfluidic chip seeded with human PBMCs at high density within a 3D collagen matrix. The LO Chip represents a versatile platform suited to the preclinical evaluation of vaccine boosting strategies.

Key highlights:

  • The model recreates key lymphoid tissue features, including CD4+ T cell/B cell cluster formation and emigration of matured plasmablasts.
  • It effectively mimics vaccine boosts, amplifying SARS-CoV-2 Spike protein-specific B cells, plasmablast differentiation and antibody production.
  • The dynamically perfused culture system outperforms traditional 2D and 3D static cultures in immune response simulation.
  • The LO Chip is responsive to both protein and mRNA-encoded antigens, highlighting its potential for preclinical evaluation of vaccine boosting strategies.

Products Used In This Publication

DNA origami vaccine (DoriVac) nanoparticles improve both humoral and cellular immune responses to infectious diseases

Organ Model: Lymph Node

Application: Immunology, Vaccine Development

Abstract: Current SARS-CoV-2 vaccines have demonstrated robust induction of neutralizing antibodies and CD4+ T cell activation, however CD8+ responses are variable, and the duration of immunity and protection against variants are limited. Here we repurposed our DNA origami vaccine platform, DoriVac, for targeting infectious viruses, namely SARS-CoV-2, HIV, and Ebola. The DNA origami nanoparticle, conjugated with infectious-disease-specific HR2 peptides, which act as highly conserved antigens, and CpG adjuvant at precise nanoscale spacing, induced neutralizing antibodies, Th1 CD4+ T cells, and CD8+ T cells in naïve mice, with significant improvement over a bolus control. Pre-clinical studies using lymph-node-on-a-chip systems validated that DoriVac, when conjugated with antigenic peptides or proteins, induced promising cellular immune responses in human cells. These results suggest that DoriVac holds potential as a versatile, modular vaccine platform, capable of inducing both humoral and cellular immunities. The programmability of this platform underscores its potential utility in addressing future pandemics.

Lymph Node Chip for Vaccine Characterization

Featured session from Bethesda MPS Day, which took place on November 9, 2023.

Dr. Josie McAuliffe from GlaxoSmithKline (GSK) discusses her team’s efforts to employ a Lymph Node-Chip model to better understand and improve vaccine performance. Traditional vaccine development often relies on animal models and two-dimensional cell cultures that may not accurately predict clinical outcomes. The Lymph Node-Chip, a microphysiological system that recreates aspects of lymph node architecture and immune cell interactions, offers a more human-relevant environment for evaluating vaccine antigens and optimizing immune responses.

By collaborating with the Wyss Institute, Dr. McAuliffe’s team leveraged a Lymph Node-on-a-Chip platform capable of supporting T and B cells, as well as dendritic cells, under flow conditions. They demonstrated that this model could detect key immunological readouts, including cytokines/chemokines and antigen-specific antibody responses, after administration of a novel self-amplifying mRNA (SAM) vaccine formulation. The Lymph Node-Chip also showed follicle formation, an integral part of germinal center reactions critical for generating high-affinity antibodies.

Encouraged by these results, GSK decided to internalize the Lymph Node-Chip system. The goal is to evaluate proprietary vaccines more effectively in-house, reduce logistical complexities, and potentially correlate Lymph Node-Chip data with clinical results. Early in-house experiments have revealed promising markers, such as CXCL13, IP-10, and IL-15, known to be associated with effective vaccine-induced immune responses in humans. The team is now refining the model, looking into antibody detection methods, immunophenotyping, and single-cell sequencing to gain deeper insight into vaccine mechanisms of action and improve translation to clinical success.

Key learnings from this presentation include:

Enhanced translational relevance: The Lymph Node-Chip provides a more complex, physiological context than traditional 2D cultures or animal models, potentially improving predictions of human vaccine outcomes.

Robust immunological endpoints: The chip supports T and B cell interactions, follicle formation, and cytokine/chemokine production, enabling comprehensive analysis of germinal center reactions and antibody production.

Application to novel vaccines: By integrating SAM mRNA vaccines into the Lymph Node-Chip, the team observed antigen-specific antibody responses and immune markers reminiscent of those seen in human vaccine recipients.

In-house implementation: Bringing the Lymph Node-Chip technology internally allows GSK to test proprietary formulations, streamline logistics, and refine experimental parameters without external dependencies.

Future directions: Ongoing optimization focuses on strengthening endpoint assays (e.g., sensitive antibody detection), correlating Lymph Node-Chip data with clinical efficacy, and potentially exploring other lymphoid tissues or different species (like nonhuman primates) for enhanced translational insights.

Human vascularised synovium-on-a-chip: a mechanically stimulated, microfluidic model to investigate synovial inflammation and monocyte recruitment

Organ Model: Synovium

Application: Inflammation

Abstract: Healthy synovium is critical for joint homeostasis. Synovial inflammation (synovitis) is implicated in the onset, progression and symptomatic presentation of arthritic joint diseases such as rheumatoid arthritis and osteoarthritis. Thus, the synovium is a promising target for the development of novel, disease-modifying therapeutics. However, target exploration is hampered by a lack of good pre-clinical models that accurately replicate human physiology and that are developed in a way that allows for widespread uptake. The current study presents a multi-channel, microfluidic, organ-on-a-chip (OOAC) model, comprising a 3D configuration of the human synovium and its associated vasculature, with biomechanical and inflammatory stimulation, built upon a commercially available OOAC platform. Healthy human fibroblast-like synoviocytes (hFLS) were co-cultured with human umbilical vein endothelial cells (HUVECs) with appropriate matrix proteins, separated by a flexible, porous membrane. The model was developed within the Emulate organ-chip platform enabling the application of physiological biomechanical stimulation in the form of fluid shear and cyclic tensile strain. The hFLS exhibited characteristic morphology, cytoskeletal architecture and matrix protein deposition. Synovial inflammation was initiated through the addition of interleukin-1?(IL-1?) into the synovium channel resulting in the increased secretion of inflammatory and catabolic mediators, interleukin-6 (IL-6), prostaglandin E2 (PGE2), matrix metalloproteinase 1 (MMP-1), as well as the synovial fluid constituent protein, hyaluronan. Enhanced expression of the inflammatory marker, intercellular adhesion molecule-1 (ICAM-1), was observed in HUVECs in the vascular channel, accompanied by increased attachment of circulating monocytes. This vascularised human synovium-on-a-chip model recapitulates a number of the functional characteristics of both healthy and inflamed human synovium. Thus, this model offers the first human synovium organ-chip suitable for widespread adoption to understand synovial joint disease mechanisms, permit the identification of novel therapeutic targets and support pre-clinical testing of therapies.

Ectopic Lymphoid Follicle Formation and Human Seasonal Influenza Vaccination Responses Recapitulated in an Organ-on-a-Chip

Organ Model: Lymphoid Follicle

Application: Immunology

Abstract: Lymphoid follicles (LFs) are responsible for generation of adaptive immune responses in secondary lymphoid organs and form ectopically during chronic inflammation. A human model of ectopic LF formation will provide a tool to understand LF development and an alternative to non-human primates for preclinical evaluation of vaccines. Here, it is shown that primary human blood B- and T-lymphocytes autonomously assemble into ectopic LFs when cultured in a 3D extracellular matrix gel within one channel of a two-channel organ-on-a-chip microfluidic device. Superfusion via a parallel channel separated by a microporous membrane is required for LF formation and prevents lymphocyte autoactivation. These germinal center-like LFs contain B cells expressing Activation-Induced Cytidine Deaminase and exhibit plasma cell differentiation upon activation. To explore their utility for seasonal vaccine testing, autologous monocyte-derived dendritic cells are integrated into LF Chips. The human LF chips demonstrate improved antibody responses to split virion influenza vaccination compared to 2D cultures, which are enhanced by a squalene-in-water emulsion adjuvant, and this is accompanied by increases in LF size and number. When inoculated with commercial influenza vaccine, plasma cell formation and production of anti-hemagglutinin IgG are observed, as well as secretion of cytokines similar to vaccinated humans over clinically relevant timescales.

On-chip recapitulation of clinical bone marrow toxicities and patient-specific pathophysiology

Organ Model: Bone Marrow

Application: ADME-Tox

Abstract: The inaccessibility of living bone marrow (BM) hampers the study of its pathophysiology under myelotoxic stress induced by drugs, radiation or genetic mutations. Here, we show that a vascularized human BM-on-a-chip (BM chip) supports the differentiation and maturation of multiple blood cell lineages over 4 weeks while improving CD34+ cell maintenance, and that it recapitulates aspects of BM injury, including myeloerythroid toxicity after clinically relevant exposures to chemotherapeutic drugs and ionizing radiation, as well as BM recovery after drug-induced myelosuppression. The chip comprises a fluidic channel filled with a fibrin gel in which CD34+ cells and BM-derived stromal cells are co-cultured, a parallel channel lined by human vascular endothelium and perfused with culture medium, and a porous membrane separating the two channels. We also show that BM chips containing cells from patients with the rare genetic disorder Shwachman-Diamond syndrome reproduced key haematopoietic defects and led to the discovery of a neutrophil maturation abnormality. As an in vitro model of haematopoietic dysfunction, the BM chip may serve as a human-specific alternative to animal testing for the study of BM pathophysiology.