Dr. Fiona McCulloch ND, White Lotus Clinic
Thyroid Nation



Dr. McCulloch discusses T regulatory cells and autoimmune thyroid disease.

What-Are-The-T-Regulatory-Cells-Roles-In-Thyroid-DiseaseOur immune systems are complicated things, that is for certain. They contain a variety of different cells that can kill pathogens with a memory as sharp as a razor, keeping our bodies protected from disease. They are a small army, constantly patrolling our bodies for invaders and sending signals to other cells when a threat is detected. In some instances, however, something goes wrong with our immune system, and the immune system can attack our own “self” tissue, which is what happens in (AD).

T Cells – What Are They?

The T-cells are a type of white blood cell that matures in the thymus (a gland located behind the sternum) and tonsils. There are several different types of T cells including : T helper cells (these assist other cells by secreting cytokines that activate different killing mechanisms in the immune system), Cytotoxic T Cells (these cells do just what they sound like they do – they secrete toxic substances to destroy virally infected cells and cancer cells, Memory T Cells (these keep within them a memory of past infections so if reinfection occurs, the action of the immune system is swift), Natural Killer T Cells (these can perform actions similar to the T helper and the Cytotoxic T cells), and finally: Regulatory T Cells.

Regulatory T cells are the cells that keep everything in the immune system under control.

Regulatory T Cells shut off the immune response once it has finished its work, and are required for something known as immunological tolerance. Immunological tolerance is important for normal physiology, in that if our immune systems see our own tissues as a foreign substance to be attacked, we are in serious trouble.

Autoimmune Disease and T Regulatory Cells

In patients with autoimmune disease (AD), this function has gone awry. When the immune system attacks self-tissues,a variety of autoimmune diseases result, depending on the organ that is being targeted. It’s well known that patients with autoimmune disease have dysfunction of the regulatory T cells (Also known as CD4+ CD25% T Cells).

Typically, T regulatory cells that have a high surface expression of what is known as CD25+ (a special type of receptor on the surface of the cell) are known to be the most effective in regulating the immune response when it is needed.

A recent study looked at a group of patients with Hashimoto’s Thyroiditis, and Graves disease (these are two autoimmune thyroid diseases – where the immune system attacks the body’s own thyroid gland) and compared them to patients that had a non-autoimmune enlarged thyroid (goitre).

The study found that patients with Hashimoto’s Thyroiditis and Grave’s Disease had significantly lower levels of the T regulatory cells with CD25+ expression. Without these important cells, the autoimmune process goes unchecked, and precious thyroid cells are destroyed.

What can be done to improve T regulatory cell numbers?

  1. Astragalus – Astragalus is a herb that been found to substantially increase CD4+ CD25+ T cells.
  2. Vitamin D – Multiple studies have found that having good levels of Vitamin D will support healthy T regulatory cell function with good CD25+ expression. Autoimmune diseases such as multiple sclerosis have been associated with Vitamin D deficiencies. Taking Vitamin D and having levels checked is important for patients with Hashimoto’s or Grave’s Disease. A good target level for Vitamin D for patients with autoimmune disease is 70 ng/ml or 175 nmol/l.
  3. Grapeseed extract – A recent study investigating the effects of grapeseed extract on mice with Rheumatoid Arthritis found that grapeseed extract effectively upregulated the production of T regulatory cells and produced an anti-inflammatory response.
  4. Curcumin extract – Curcumin is an active component of the spice, turmeric. It has a remarkable anti-inflammatory profile and has been shown to significantly increase T reg populations. If you are trying to conceive however, it’s best to avoid curcumin since it’s a contraceptive. As curcumin is poorly absorbed from food sources, specific extracts may be most useful clinically. One absorbable form that I like is Theracurcumin.
  5. Specific Strains of Probiotics – This is a complicated topic and one I will likely address with its own blog post fairly soon. Different strains of probiotics appear to have different effects when it comes to stimulating the immune system. As you can imagine, a bacteria can be a profound stimulator of immune mechanisms and as such much research is being done into the use of probiotics in the regulation of the immune response. A highly detailed study recently found that S. thermophilus 1342, Lb. casei 290, Lb paracasei 292, S. thermophilus M5, Lb. delbrueckii ssp. bulgaricus 11842, B. lactis BB12, Lb. rhamnosus G5434, Lb. rhamnosus 5434, Lc. lactis , Bifidobacterium spp. (BL1941, BB12 and BB99), and Lb. salivarius 5248, all demonstrated a significant ability to induce CD25+ T regulatory cells, potentially beneficial for those with autoimmune diseases.
  6. Green Tea Extract – EGCG, an active component of Green Tea has been associated with increased Treg populations in lymphoid tissues and in the central nervous system. This may explain it’s beneficial anti-inflammatory effects for patients with autoimmune disease.

What to avoid if you have low T regulatory cells?

  1. Echinacea – A recent study found that echinacea works in part by reducing the action of T regulatory cells. This is one way in which it elicits an immune response against pathogens.
  2. DHA dominant fish oils – A recent study found that DHA reduces the suppressive and migratory functions of CD4CD25+ regulatory T cells. It’s important to note however that this is different from taking a whole food source of fish oil or fermented fish oil, which often is EPA dominant and can have the beneficial effect of increasing T regulatory cell function.

**This article originally featured on WhiteLotus.ca**

About the Author

Fiona McCulloch ND

Dr. Fiona is the Naturopathic Doctor advisor to IVF.ca: Canada’s premier online fertility community. Her research-based blog is featured by the American College for Advancement in Medicine. Her articles on the naturopathic treatment of autoimmune infertility and luteal phase defect were published in NDNR, one of the leading journals for naturopathic doctors and she has presented to other health care professionals on evidence-based acupuncture and fertility treatment. In the media, Dr. Fiona was featured in an hour long special on natural fertility on Wylde on Health, has appeared on A-Channel News, a CBC Documentary, and has been interviewed by FLARE and Wish magazines. Check out her Blog and follow her on Facebook and Twitter.

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