Systems affected

Immune system, Digestive system, Circulatory system, Muscular system, possible Lymphatic system, if pass blood crain barier

The principal cell sources of TGF-β include monocytes, macrophages, T cells (primarily regulatory T cells), chondrocytes, and intestinal epithelial cells, involving both innate and adaptive immune responses.

For instance, in patients with active IBD, TGF-β has been found at increased levels in the inflamed gut compared with mucosa unaffected by the disease (<a id="xref-ref-25-2" class="xref-bibr" href="http://www.pnas.org/content/114/34/E7150#ref-25">25</a>). Thus, elevated levels of TGF-β in ME/CFS patients may actually be detrimental and may be a major factor in promoting relentless inflammation and a “fibrotic” milieu resistant to therapeutic interventions in some ME/CFS patients.

Resistin is a cytokine produced primarily by peripheral blood mononuclear cells (PBMCs) in humans and by adipocytes (i.e., as an adipocytokine) in rodents (<a id="xref-ref-30-1" class="xref-bibr" href="http://www.pnas.org/content/114/34/E7150#ref-30">30</a>). Resistin in humans appears to have a significant proinflammatory role by targeting PBMCs, endothelial cells, smooth muscle cells, platelets (<a id="xref-ref-30-2" class="xref-bibr" href="http://www.pnas.org/content/114/34/E7150#ref-30">30</a>), and chondrocytes (<a id="xref-ref-31-1" class="xref-bibr" href="http://www.pnas.org/content/114/34/E7150#ref-31">31</a>) and by increasing the release of IL-1β, IL-6, and TNF-α via the NF-κB pathway (<a id="xref-ref-32-1" class="xref-bibr" href="http://www.pnas.org/content/114/34/E7150#ref-32">32</a>).

Endothelium refers to cells that line the interior surface of blood vessels and lymphatic vessels, forming an interface between circulating blood or lymph in the lumen and the rest of the vessel wall. It is a thin layer of simple, or single-layered, squamous cells called endothelial cells.

The intestinal epithelium is the layer of cells that forms the <a title="Lumen (anatomy)" href="https://en.wikipedia.org/wiki/Lumen_(anatomy)">luminal</a> surface or lining of both the <a title="Small intestine" href="https://en.wikipedia.org/wiki/Small_intestine">small</a> and <a title="Large intestine" href="https://en.wikipedia.org/wiki/Large_intestine">large intestine</a> (colon) of the <a class="mw-redirect" title="Human gastrointestinal tract" href="https://en.wikipedia.org/wiki/Human_gastrointestinal_tract">gastrointestinal tract</a>. It is composed of <a title="Simple columnar epithelium" href="https://en.wikipedia.org/wiki/Simple_columnar_epithelium">simple columnar epithelium</a>. It has two important functions: absorbing helpful substances and providing a barrier against harmful substances.