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Optimize Your Immune System Naturally: Thymic Protein A

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What do the flu, chronic fatigue syndrome, rheumatoid arthritis, HIV, and cancer have in common? They all involve an immune system that is not functioning properly. 

The immune system is supposed to be our first line of defense, protecting us from the onslaught of bacteria, viruses and other foreign invaders seeking to attack our bodies. But for the estimated 65 million Americans who suffer from some type of immune system dysfunction, that defense system has broken down.

The two classic types of immune dysfunction are:

Underactive – a weakened or suppressed immune system that is unable to fight off infections, resulting in immunodeficiency.

Overactive – an immune system that misidentifies normal cells as antigens and attacks them, resulting in autoimmune diseases.

How the Immune System Works

The immune system is a complex network of cells, glands and organs that work together as an army to defend the body against disease. The two types of white blood cells that serve in this army are B-lymphocytes and T-lymphocytes, better known as B-cells and T-cells. B-cells mature in bone marrow (B for bone) and T-cells are matured by proteins from the thymus gland (T for thymus). B-cells serve as the body’s military intelligence division.

They seek out their targets, then send the infantry soldiers – the T-cells – in to attack. 

Of all the many different cells in the immune system, the T-4 helper cell is the most important because it acts as the general of the army – orchestrating the delicate balance of immune system functions.

T-4 cells have a role in regulating the total production of white blood cells, red blood cells and natural killer cells that attack and destroy invading pathogens. They also interact with B-cells, transforming them into antibody-producing cells and directing the reproduction of more B- and T-cells.

The thymus gland is key to effective T-4 cell and immune system function. Since T-4 cells are born immature, they need certain thymic proteins in order to function. However, the thymus, which is located just below the breastbone, begins to shrink after puberty. By age 40, the average human has only a small portion of the thymus gland left.

Therefore, it may become necessary to supplement the thymic proteins in order to maintain healthy T-4 cells.

The Story Behind Thymic Protein A

It wasn’t until the early 1960s that the immune system function of the thymus was first understood. By 1967 scientists had isolated a portion of calf thymus called “thymosin fraction 5” which contained a mixture of more than 30 peptides (small protein fragments). Due to its fragmented nature, this thymic fraction was only able to stimulate a very limited immune response.

But it did lay the groundwork for the later discovery of Thymic Protein A.

In the early 1970s, while still a doctoral student, Dr. Terry Beardsley became interested in immune deficiency. After completing his studies at Baylor College of Medicine, he moved to UCLA and began work with Professor Esther Hays, MD, one of the world’s leading experts in thymic function.

Dr. Beardsley explains the reasoning behind his research.

In the past, medicine has tried to either strengthen or decrease immune response by certain synthetic agents and drugs. I do not believe in forcing an immune response. I feel that the correct way to deal with these illnesses is by a well-regulated immune system. Since the T-4 cell is the key to regulation, we need to cooperate with nature by protecting and strengthening its activity, rather than interfering with or forcing it to behave in a certain manner.”(1)

In 1983, after many years of tedious and painstaking work separating and studying individual cells, Dr. Beardsley was finally able to identify one particular thymic fraction – fraction A – which contained 500 amino acids and comprised a complete protein. He named this fraction Thymic Protein A (TPA).

Further studies demonstrated that TPA acts as an immune regulator, activating the T-4 helper cells, and enhancing the development of specific cytotoxic T-killer cells that destroy infected cells.

As a result of his extensive research, Dr. Beardsley developed the product called ProBoost® Thymic Protein A, for which he currently holds the US and international patents for both composition of matter and use. His discovery was published in several scientific journals, including the Proceedings of the National Academy of Sciences.(2)

Thymic Protein A Research

Scientific studies, performed on in vitro cells, animals, and humans, have all shown significant benefits in supporting and strengthening the immune system by activating the T-4 helper cells using Thymic Protein A (TPA).

Two studies using TPA in a total of 22 cats with feline immunodeficiency virus (FIV) – a disease similar to human HIV – concluded that the protein enhanced immune response to infectious agents measured serologically, diminished disease symptoms, lengthened survival, and increased lymphocyte values.(3)

Stimulant or Modulator as Needed

Several human studies have further substantiated the scientific findings that this protein alone, in its purified state, has tremendous immune supporting capabilities as both a stimulant and a down-regulating agent, depending on the body’s requirements.

ME/CFS – In a 2001 study, 23 ME/CFS patients took three 4 mcg packets a day of ProBoost TPA for a total of 90 days. Sixteen of the 23 patients experienced normalization of immune function with a corresponding improvement in the clinical symptoms of ME/CFS.(4)

Chronic Epstein-Barr Virus – In a 1996 study, six patients with chronically elevated EBV early antigen antibody titers were treated for 60 days with TPA.  There was a significant reduction in antibody titers for four of the six participants.  Five of the participants, who also had an ME/CFS diagnosis, reported increased energy.(5)

HIV – The Division of AIDS of the U.S. National Institutes of Health (NIH) tested the protein in Thymic Protein A and noted that “contrary to the expectation of enhanced HIV expression as is observed with other immune modulators, Thymic Protein A actually suppressed HIV production as measured by P24 antigen.”(6)

Cancer – A University of California at San Diego study “demonstrates that mouse lymphoma cells undergo apoptosis (‘cell suicide’) in the presence of Thymic Protein A.”

What ProBoost Users Say

This powerful over-the-counter and natural immune stimulant is especially helpful for viral infections. In a study on Epstein-Barr virus antibody levels in CFS, ProBoost decreased levels by 70% – and many patients felt a lot better after taking it for three months… I recommend ProBoost not just for folks with CFS, but for everyone’s medicine cabinet. Taken at the first sign of a cold or flu, it can very quickly knock out the infection. For CFS, it takes about three months to have an effect.” – Dr. Jacob Teitelbaum, MD

I originally purchased this for my 81-year-old mother who has COPD. Whenever she caught a cold it would really linger and she would have breathing complications. Taking this immediately when she feels the cold coming on has shortened the duration and no complications. Since I have Fibromyalgia my immune system isn’t very strong and I caught everything. I now take it when Mom does or if I’ve been otherwise exposed to something and have not been sick since. I always have Proboost on hand now.” – Debra

This product does an outstanding job improving immunity. After 6 weeks of two packs per day, my natural killer cells went from 11 to 45!!! Dr. Teitlebaum recommends this product for Chronic Fatigue and Fibromyalgia, and now I know why.” – Sarah

What Makes ProBoost Thymic Protein A Different?

Thymic Protein A, the active ingredient in ProBoost, has the same biological activity as the natural thymic protein produced by the thymus gland. It has been examined by the NIH and described as an immune modulator and anti-viral agent.

Other thymic extracts on the market generally consist of ground whole thymus, which is then dried or strained into liquid and sold as capsules or sublingual drops. Because of the way these extracts are processed, the resulting product is a conglomeration of thymus tissue, cell debris, fragments of thymus proteins and thymus by-products. These thymic extracts have only been slightly effective in treating various immune deficiency illnesses.

By contrast, ProBoost TPA contains the only complete 500-amino acid chain which perfectly fits the receptor site on the T-4 cell. No other thymic extract known can compare because none of them contains this intact protein.

Another problem inherent with other oral thymic products is degradation by stomach acids. Since ProBoost TPA is a sublingual powder, it is absorbed directly into the system, maintaining its full potency.

Finally, one additional plus no other thymic product can claim – ProBoost TPA is made by cell culture in only one laboratory in the world, under the personal control and direct supervision of Dr. Beardsley himself.


How to Take:  ProBoost TPA comes as a powder in sealed individual dose packets. Empty the packet under your tongue and allow it to dissolve for 1-3 minutes. ProBoost powder has a pleasant, mildly sweet taste. ProBoost TPA should be taken 1 hour before or 1 hour after meals for optimal absorption.

Dosage:  The manufacturer’s suggested dosages are:

• For acute conditions, use three packets per day.

• To maintain immune function on a regular basis, use one packet daily, or every other day.

As with any supplement or medication, be sure to check with your healthcare provider before taking, particularly if you have a serious immune disorder.

Side Effects:  No serious side effects have been reported. In a few cases, people have experienced very mild flu-like symptoms when first starting ProBoost TPA, which subside shortly thereafter. These initial symptoms may occur because by taking ProBoost TPA, you are activating your immune system. This seemingly negative effect is actually evidence that your own immune system is starting to fight.

In Summary

ProBoost Thymic Protein A supports a healthy immune system – whether you’re just trying to prevent cold and flu viruses or facing a more serious immune dysfuction disease.

* Supplement research writer Karen Lee Richards is the Lead Expert specializing in Fibromyalgia and ME/CFS, for HealthCentral’s ChronicPainConnection. Karen is co-founder of the National Fibromyalgia Association and was Executive Editor of Fibromyalgia AWARE magazine for four years.


1.  Beardsley T. <a target=”_blank” href=”http://www.anapsid.org/cnd/drugs/beardsley2.html

“>”Thymic Protein A.” Melissa Kaplan’s Chronic Neuroimmune Diseases. December 18, 2009.

2.  Beardsley TR, et al. “Induction of T-cell maturation by a cloned line of thymic epithelium (TEPI).” PNAS 1983 80 (19) 6005-6009.
Abstract:  http://www.pnas.org/content/80/19/6005.abstract
Full Text:  http://www.pnas.org/content/80/19/6005.full.pdf+html

3.  Hale P.  “The FIV Connection – Why Cats May be the Purr-fect Model for HIV Infection.” Searchlight. Summer 1996.

4.  Rosenbaum ME, et al. “Improved Immune Activation Markers in Chronic Fatigue and Immune Dysfunction Syndrome (CFIDS) Patients Treated with Thymic Protein A.” Journal of Nutritional & Environmental Medicine. 2001, Vol. 11, No. 4, Pages 241-247.
Abstract:  http://informahealthcare.com/doi/abs/10.1080/13590840120103085
Full Text:  http://www.proboostmed.com/pdfs/white_blood_01.pdf

5.  Riordan NH, et al. “Pilot Study of the Effects of Thymus Protein on Elevated Epstein-Barr Virus Titers.” Townsend Letter for Doctors & Patients. February/March 1996. Pages 78-79.
Full Text:  http://www.proboostmed.com/pdfs/apoptosis_02.pdf

6.  Mamikonyan G, et al. “Detection of the active components of calf thymus nuclear proteins (TNP), histones that are binding with high affinity to HIV-1 envelope proteins and CD4 molecules.” Curr HIV Res. 2008 Jun;6(4):318-26.

Note: This information has not been evaluated by the FDA. It is general information and is not meant to prevent, diagnose, treat or cure any illness, condition or disease. It is very important that you make no change in your health support regimen or healthcare plan without researching and discussing it in collaboration with your professsional healthcare team.

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