All Publications


  • Initiation of primary T cell-B cell interactions and extrafollicular antibody responses in an organized microphysiological model of the human lymph node. bioRxiv : the preprint server for biology Zatorski, J. M., Raskovic, D., Arneja, A., Kiridena, S., Ozulumba, T., Hammel, J. H., Anbaei, P., Ortiz-Cárdenas, J. E., Braciale, T. J., Munson, J. M., Luckey, C. J., Pompano, R. R. 2025

    Abstract

    Antibody production is central to protection against new pathogens and cancers, as well as to certain forms of autoimmunity. Antibodies often originate in the lymph node (LN), specifically at the extrafollicular border of B cell follicles, where T and B lymphocytes physically interact to drive B cell maturation into antibody-secreting plasmablasts. In vitro models of this process are sorely needed to predict aspects of the human immune response. Microphysiological systems (MPSs) offer the opportunity to approximate the lymphoid environment, but so far have focused primarily on memory recall responses to antigens previously encountered by donor cells. To date, no 3D culture system has replicated the engagement between T cells and B cells (T-B interaction) that leads to antibody production when starting with naïve cells. Here, we developed a LN-MPS to model early T-B interactions at the extrafollicular border built from primary, naïve human lymphocytes encapsulated within a collagen-based 3D matrix. Within the MPS, naïve T cells exhibited CCL21-dependent chemotaxis and chemokinesis as predicted. Naïve T and B cells were successfully skewed on chip to an early T follicular helper (pre-Tfh) and activated state, respectively, and co-culture of the latter cells led to CD38+ plasmablast cells and T cell dependent production of IgM. These responses required differentiation of the T cells into pre-Tfhs, physical cell-cell contact, and were sensitive to the ratio at which pre-Tfh and activated B cells were seeded on-chip. Dependence on T cell engagement was greatest at a 1:5 T:B ratio, while cell proliferation and CD38+ signal was greatest at a 1:1 T:B ratio. Furthermore, plasmablast formation was established starting from naïve T and B cells on-chip. We envision that this MPS model of primary lymphocyte physiology will enable new mechanistic analyses of human humoral immunity in vitro.

    View details for DOI 10.1101/2025.01.12.632545

    View details for PubMedID 39868310

    View details for PubMedCentralID PMC11761657

  • Measurement of Covalent Bond Formation in Light-Curing Hydrogels Predicts Physical Stability under Flow. Analytical chemistry Zatorski, J. M., Lee, I. L., Ortiz-Cárdenas, J. E., Ellena, J. F., Pompano, R. R. 2024

    Abstract

    Photo-crosslinking hydrogels are promising for tissue engineering and regenerative medicine, but challenges in reaction monitoring often leave their optimization subject to trial and error. The stability of crosslinked gels under fluid flow, as in the case of a microfluidic device, is particularly challenging to predict, both because of obstacles inherent to solid-state macromolecular analysis that prevent accurate chemical monitoring and because stability is dependent on size of the patterned features. To solve both problems, we obtained 1H NMR spectra of cured hydrogels which were enzymatically degraded. This allowed us to take advantage of the high-resolution that solution NMR provides. This unique approach enabled the measurement of degree of cross-linking (DoC) and prediction of material stability under physiological fluid flow. We showed that NMR spectra of enzyme-digested gels successfully reported on DoC as a function of light exposure and wavelength within two classes of photo-cross-linkable hydrogels: methacryloyl-modified gelatin and a composite of thiol-modified gelatin and norbornene-terminated polyethylene glycol. This approach revealed that a threshold DoC was required for patterned features in each material to become stable and that smaller features required a higher DoC for stability. Finally, we demonstrated that DoC was predictive of the stability of architecturally complex features when photopatterning, underscoring the value of monitoring DoC when using light-reactive gels. We anticipate that the ability to quantify chemical cross-links will accelerate the design of advanced hydrogel materials for structurally demanding applications such as photopatterning and bioprinting.

    View details for DOI 10.1021/acs.analchem.4c03482

    View details for PubMedID 39625220

  • Measurement of covalent bond formation in light-curing hydrogels predicts physical stability under flow. bioRxiv : the preprint server for biology Zatorski, J. M., Lee, I. L., Ortiz-Cardenas, J. E., Ellena, J. F., Pompano, R. R. 2024

    Abstract

    Photocrosslinking hydrogels are promising for tissue engineering and regenerative medicine, but challenges in reaction monitoring often leave their optimization subject to trial and error. The stability of crosslinked gels under fluid flow, as in the case of a microfluidic device, is particularly challenging to predict, both because of obstacles inherent to solid-state macromolecular analysis that prevent accurate chemical monitoring, and because stability is dependent on size of the patterned features. To solve both problems, we obtained 1H NMR spectra of cured hydrogels which were enzymatically degraded. This allowed us to take advantage of the high-resolution that solution NMR provides. This unique approach enabled the measurement of degree of crosslinking (DoC) and prediction of material stability under physiological fluid flow. We showed that NMR spectra of enzyme-digested gels successfully reported on DoC as a function of light exposure and wavelength within two classes of photocrosslinkable hydrogels: methacryloyl-modified gelatin and a composite of thiol-modified gelatin and norbornene-terminated polyethylene glycol. This approach revealed that a threshold DoC was required for patterned features in each material to become stable, and that smaller features required a higher DoC for stability. Finally, we demonstrated that DoC was predictive of the stability of architecturally complex features when photopatterning, underscoring the value of monitoring DoC when using light-reactive gels. We anticipate that the ability to quantify chemical crosslinks will accelerate the design of advanced hydrogel materials for structurally demanding applications such as photopatterning and bioprinting.

    View details for DOI 10.1101/2024.06.30.601353

    View details for PubMedID 39005331

  • New tools for immunologists: models of lymph node function from cells to tissues. Frontiers in immunology Ozulumba, T., Montalbine, A. N., Ortiz-Cardenas, J. E., Pompano, R. R. 2023; 14: 1183286

    Abstract

    The lymph node is a highly structured organ that mediates the body's adaptive immune response to antigens and other foreign particles. Central to its function is the distinct spatial assortment of lymphocytes and stromal cells, as well as chemokines that drive the signaling cascades which underpin immune responses. Investigations of lymph node biology were historically explored in vivo in animal models, using technologies that were breakthroughs in their time such as immunofluorescence with monoclonal antibodies, genetic reporters, in vivo two-photon imaging, and, more recently spatial biology techniques. However, new approaches are needed to enable tests of cell behavior and spatiotemporal dynamics under well controlled experimental perturbation, particularly for human immunity. This review presents a suite of technologies, comprising in vitro, ex vivo and in silico models, developed to study the lymph node or its components. We discuss the use of these tools to model cell behaviors in increasing order of complexity, from cell motility, to cell-cell interactions, to organ-level functions such as vaccination. Next, we identify current challenges regarding cell sourcing and culture, real time measurements of lymph node behavior in vivo and tool development for analysis and control of engineered cultures. Finally, we propose new research directions and offer our perspective on the future of this rapidly growing field. We anticipate that this review will be especially beneficial to immunologists looking to expand their toolkit for probing lymph node structure and function.

    View details for DOI 10.3389/fimmu.2023.1183286

    View details for PubMedID 37234163