MUC1 Mucin: A Putative Regulatory (Checkpoint) Molecule of T Cells.

T lymphocytes are at the center of inducing an effective adaptive immune response and maintaining homeostasis. T cell responses are initiated through interactions between antigen presenting cells (APCs) and T cells. The type and strength of signals delivered through the T cell receptor (TCR) may modulate how the cells respond.

Modulation of weanling pig cellular immunity in response to diet supplementation with 25-hydroxyvitamin D(3).

There is still significant debate over the effects that vitamin D3 has on the immune system, as both pro-inflammatory and anti-inflammatory cellular responses have been described. The objective of this study was to use a weanling pig model of nutritional supplementation to provide a broad functional look at the immune cellular changes that occur as a result of vitamin D3 nutritional supplementation. We identified a significant impact on cellular immune parameters, particularly in pigs supplemented with a commercial hydroxylated version of vitamin D3, 25-hydroxyvitamin D3 [25(OH)D3; Hy·D].

A soluble form of the CSF-1 receptor contributes to the inhibition of inflammation in a teleost fish.

We previously reported on the identification of a novel soluble form of the CSF-1 receptor (sCSF-1R) in goldfish that induced dose-dependent down-regulation of macrophage proliferation. Herein, we report that sCSF-1R has a role beyond macrophage development, which extends into the control of cellular antimicrobial inflammatory responses in this lower vertebrate. Using an in vivo model of self-resolving peritonitis coupled to in vitro characterization of sCSF-1R activity, we show that sCSF-1R plays a role in the inhibition of inflammation which follows an initial acute phase of innate antimicrobial responses within an inflammatory site.

Fish and mammalian phagocytes differentially regulate pro-inflammatory and homeostatic responses in vivo.

Phagocytosis is a cellular mechanism that is important to the early induction of antimicrobial responses and the regulation of adaptive immunity. At an inflammatory site, phagocytes serve as central regulators for both pro-inflammatory and homeostatic anti-inflammatory processes. However, it remains unclear if this is a recent evolutionary development or whether the capacity to balance between these two seemingly contradictory processes is a feature already displayed in lower vertebrates.

MUC1 is a novel costimulatory molecule of human T cells and functions in an AP-1-dependent manner.

MUC1 mucin, primarily known as an epithelial antigen, has been demonstrated to be expressed on activated human T cells. In the present study, we first examined the expression of MUC1 on different subsets of T cells (naive, effector, effector/memory). MUC1 appears to be strongly upregulated on activated CD4(+) T cells in comparison with CD8(+) T cells.

MUC1 mucin is expressed on human T-regulatory cells: function in both co-stimulation and co-inhibition.

MUC1 mucin, an important protein of epithelial cells and epithelial-derived carcinomas, is also expressed on activated T cells, showing both positive and negative regulatory functions. It is currently unknown whether MUC1 is a true regulatory protein of T cells and what conditions lead to MUC1 co-stimulation versus co-inhibition. We have found that MUC1 is expressed on the majority of T-regulatory cells (CD4(+)/CD25(+)/FoxP3(+)) in humans (>90%) and that CD3/MUC1 co-stimulation leads to an increased number of T-regulatory cells.

Modified annexin V/propidium iodide apoptosis assay for accurate assessment of cell death.

Studies of cellular apoptosis have been significantly impacted since the introduction of flow cytometry-based methods. Propidium iodide (PI) is widely used in conjunction with Annexin V to determine if cells are viable, apoptotic, or necrotic through differences in plasma membrane integrity and permeability. The Annexin V/PI protocol is a commonly used approach for studying apoptotic cells.