Engineering a multicellular vascular niche to model hematopoietic cell trafficking

Abstract

BackgroundThe marrow microenvironment and vasculature plays a critical role in regulating hematopoietic cell recruitment, residence, and maturation. Extensive in vitro and in vivo studies have aimed to understand the marrow cell types that contribute to hematopoiesis and the stem cell environment. Nonetheless, in vitro models are limited by a lack of complex multicellular interactions, and cellular interactions are not easily manipulated in vivo. Here, we develop an engineered human vascular marrow niche to examine the three-dimensional cell interactions that direct hematopoietic cell trafficking.MethodsUsing soft lithography and injection molding techniques, fully endothelialized vascular networks were fabricated in type I collagen matrix, and co-cultured under flow with embedded marrow fibroblast cells in the matrix. Marrow fibroblast (mesenchymal stem cells (MSCs), HS27a, or HS5) interactions with the endothelium were imaged via confocal microscopy and altered endothelial gene expression was analyzed with RT-PCR. Monocytes, hematopoietic progenitor cells, and leukemic cells were perfused through the network and their adhesion and migration was evaluated.ResultsHS27a cells and MSCs interact directly with the vessel wall more than HS5 cells, which are not seen to make contact with the endothelial cells. In both HS27a and HS5 co-cultures, endothelial expression of junctional markers was reduced. HS27a co-cultures promote perfused monocytes to adhere and migrate within the vessel network. Hematopoietic progenitors rely on monocyte-fibroblast crosstalk to facilitate preferential recruitment within HS27a co-cultured vessels. In contrast, leukemic cells sense fibroblast differences and are recruited preferentially to HS5 and HS27a co-cultures, but monocytes are able to block this sensitivity.ConclusionsWe demonstrate the use of a microvascular platform that incorporates a tunable, multicellular composition to examine differences in hematopoietic cell trafficking. Differential recruitment of hematopoietic cell types to distinct fibroblast microenvironments highlights the complexity of cell-cell interactions within the marrow. This system allows for step-wise incorporation of cellular components to reveal the dynamic spatial and temporal interactions between endothelial cells, marrow-derived fibroblasts, and hematopoietic cells that comprise the marrow vascular niche. Furthermore, this platform has potential for use in testing therapeutics and personalized medicine in both normal and disease contexts.Electronic supplementary materialThe online version of this article (10.1186/s13287-018-0808-2) contains supplementary material, which is available to authorized users.

Role of microvascular endothelial cells on proliferation, migration and adhesion of hematopoietic stem cells

“…Mesenchymal stem cells (MSCs) and endothelial cells (ECs) are the two major types of cells in bone marrow niche. It has been reported that ECs provide a nutrient-rich hematopoietic niche for HSC, which can effectively promote HSC proliferation and differentiation [4][5][6][7][8][9][10].…”

Binding Heterogeneity of Plasmodium falciparum to Engineered 3D Brain Microvessels Is Mediated by EPCR and ICAM-1

“…To better understand blood-brain barrier alterations on CM patients, future engineered 3D microvessel approaches toward a more physiological model could incorporate perivascular cells, such as pericytes and astrocytes in the collagen matrix, and add other blood components to the lumen to investigate the role that human factors play in CM complications. Additionally, as CM patients present a widespread sequestration in multiple vascular beds (17, 23, 52), future studies can take advantage of the versatility of our model (28, 34, 53–55) to study the avidity and consequences of IE binding to other vascular sites. In conclusion, our study reveals heterogeneity in parasite binding to resting and activated endothelial cells using a new flow-based 3D brain microvessel model in vitro platform that can be used to investigate host cell or pathogen interactions with brain endothelium.…”

Location First: Targeting Acute Myeloid Leukemia Within Its Niche

“…Bray et al generated a 3D co-culture with human umbilical vein endothelial cells (HUVEC), MSCs, and AML to investigate the impact of vascular niche in AML and they found that this scaffold supports the resistance of leukemic cells against chemotherapy [196]. Furthermore, Kotha and colleagues also developed an artificial in vitro vascular marrow and showed that patient-derived AML cells increase their adhesion and migration in response to distinct fibroblasts [197].…”