The role of dendritic cells in the immunomodulation to implanted biomaterials

Abstract

Considering the substantial role played by dendritic cells (DCs) in the immune system to bridge innate and adaptive immunity, studies on DC-mediated immunity toward biomaterials principally center on their adjuvant effects in facilitating the adaptive immunity of codelivered antigens. However, the effect of the intrinsic properties of biomaterials on dendritic cells has not been clarified. Recently, researchers have begun to investigate and found that biomaterials that are nonadjuvant could also regulate the immune function of DCs and thus affect subsequent tissue regeneration. In the case of proteins adsorbed onto biomaterial surfaces, their intrinsic properties can direct their orientation and conformation, forming “biomaterial-associated molecular patterns (BAMPs)”. Thus, in this review, we focused on the intrinsic physiochemical properties of biomaterials in the absence of antigens that affect DC immune function and summarized the underlying signaling pathways. Moreover, we preliminarily clarified the specific composition of BAMPs and the interplay between some key molecules and DCs, such as heat shock proteins (HSPs) and high mobility group box 1 (HMGB1). This review provides a new direction for future biomaterial design, through which modulation of host immune responses is applicable to tissue engineering and immunotherapy.

The HDAC inhibitor zabadinostat is a systemic regulator of adaptive immunity

“…We were interested to explore the effect of zabadinostat treatment on antigen-presenting cells and for this part of the study used bone marrow-derived DCs taken from C57BL/6 and Balb/c mice. We measured CD11c as the DC marker, and CD86 for the DC maturation and activation marker 14 , 15 . Upon zabadinostat treatment, there was a highly significant increase in the size of the CD11c and CD86 DC populations, which coincided with increased H3K14 acetylation (Fig.…”

Fn‐HMGB1 Adsorption Behavior Initiates Early Immune Recognition and Subsequent Osteoinduction of Biomaterials

“…[ 41 ] A recent review suggests that the proteomic spectra of biomaterials adsorbed on their surfaces form complexes with immune activation effects, known as BAMP, similar to DAMP/PAMP. [ 13 ] To demonstrate whether the substances adsorbed onto the imp‐BCP surface are immunogenic, Mφs and DCs were stimulated with extracted pure BCP and imp‐BCP, and the activation ratio of immune recognition cells was detected using flow cytometry. The experiment was based on a single‐species cell culture system in vitro, that is, the materials acted on Mφs and DCs separately.…”

“…Therefore, they activate immune cells predominantly through early adsorption of proteins on their surfaces, which are known as BAMPs. [ 13 ] In addition, the physicochemical properties of most CaP ceramic scaffold surfaces were similar, which determines that their patterns of protein adsorption are similar. [ 59 ] Although there are physicochemical differences between CaP ceramic scaffolds prepared by different processes, such differences are still insignificant compared to other biomaterials.…”

“…[11,12] However, the research on BAMPs is still in its Early-phase, and its internal structure is still unclear. [13] Therefore, the analysis and evaluation of the adsorption hierarchy of immune activation-related proteins on the surface of materials using molecular and structural dynamics methods can help to determine potential factors regarding the biomaterial to initiate immune recognition.…”

Potential effects of biomaterials on macrophage function and their signalling pathways

“…TLRs constitute a family of receptors within the innate immune system that detect and identify PAMPs, DAMPs and biomaterial-associated molecular patterns (BAMPs) in the host. 119,120 The involvement of TLR signalling in the biomaterial-macrophage interaction has been reported in several studies. In a study, the absence of TLR2 resulted in the complete cessation of TNF production in mouse macrophages stimulated with intermediate chitin in vivo.…”