In VitroCytotoxic Effects of Stabilizing Sugars within Human Intravenous Immunoglobulin Preparations against the Human Macrophage THP-1 Cell-line

BMP4 micro-immunotherapy increases collagen deposition and reduces PGE2 release in human gingival fibroblasts and increases tissue viability of engineered 3D gingiva under inflammatory conditions

Background

We aimed to evaluate the effect of low doses (LD) bone morphogenetic protein‐2 (BMP2) and BMP4 micro‐immunotherapy (MI) in two in vitro models of periodontal wound healing/regeneration.

Methods

We first evaluated the effect of LD of BMP2 and BMP4 MI on a 2D cell culture using human gingival fibroblasts (hGF) under inflammatory conditions induced by IL1β. Biocompatibility, inflammatory response (Prostaglandin E2 (PGE2) release), collagen deposition and release of extracellular matrix (ECM) organization‐related enzymes (matrix metalloproteinase‐1 (MMP1) and metalloproteinase inhibitor 1 (TIMP1)) were evaluated after short (3 days) and long‐term (24 days) treatment with BMP2 or BMP4 MI. Then, given the results obtained in the 2D cell culture, LD BMP4 MI treatment was evaluated in a 3D cell culture model of human tissue equivalent of gingiva (GTE) under the same inflammatory stimulus, evaluating the biocompatibility, inflammatory response and effect on MMP1 and TIMP1 release.

Results

LD BMP4 was able to decrease the release of the inflammatory mediator PGE2 and completely re‐establish the impaired collagen metabolism induced by IL1β treatment. In the 3D model, LD BMP4 treatment improved tissue viability compared with the vehicle, with similar levels to 3D tissues without inflammation. No significant effects were observed on PGE2 levels nor MMP1/TIMP1 ratio after LD BMP4 treatment, although a tendency to decrease PGE2 levels was observed after 3 days.

Conclusions

LD BMP4 MI treatment shows anti‐inflammatory and regenerative properties on hGF, and improved viability of 3D gingiva under inflammatory conditions. LD BMP4 MI treatment could be used on primary prevention or maintenance care of periodontitis.

Differential modulation of cord blood and peripheral blood monocytes by intravenous immunoglobulin

BACKGROUND

Immunoglobulins (IVIG) have been shown to be useful in adults suffering from sepsis. In contrast, prophylactic and curative IVIG trials failed to show beneficial effects in neonates. We tested the hypothesis that IVIG, have different effects on monocytes from cord blood (CBMO) and peripheral blood monocytes from adults (PBMO) with respect to survival, phenotype, and function.

METHODS

Mononuclear cells, or purified monocytes, were cultured in 5% human serum, incubated with polyvalent IVIG (1 mg/ml), stimulated with green fluorescent protein (GFP)-labeled Escherichia coli (E. Coli-GFP), Interferon-γ (IFN-γ, 50 U/ml), or the T cell mitogen anti-CD3 monoclonal antibody, αCD3-mAb, (5 μg/ml). Phagocytosis, phenotype, T cell proliferation, and apoptosis were assessed by flow cytometry.

RESULTS

IVIG enhanced phagocytosis in PBMO or CBMO when infected directly after isolation, while IVIG had no effect on monocytes cultured 48 h prior to infection. In contrast to PBMO, IVIG inhibited the IFN-γ mediated up-regulation of CD80, CD86, and HLA-DR on CBMO. In the presence of IVIG, stimulation with αCD3 in cord blood enhanced deletion, inhibited blast formation and CD28 up-regulation of T cells (P < 0.05 vs. T cells from adults). IVIG induced monocyte apoptosis, associated with up-regulation of Annexin V and loss of nuclear DNA, which was more pronounced in CBMO. Although phagocytosis induced cell death (PICD) was lower in CBMO (P < 0.05 vs. PBMO), the addition of IVIG enhanced PICD levels of CBMO to the extent of PBMO.

CONCLUSIONS

IVIG inhibits co-stimulatory receptors and functions of CBMO and induces apoptosis. These findings may be of clinical relevance for the failure of IVIG benefit in neonatal sepsis.