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January 19, 2024 BlogUlcerative Colitis

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The immune system is awesome, but overwhelming. It’s filled with billions of cells and quintillions of proteins. There are neutrophils, dendritic cells, antibodies, B cells, macrophages, lymphoid cells, lymphocytes, the complement system, and more! Instead of trying to understand the whole thing, let’s narrow our focus down to just one type of cell, the T cell, and just one variant, T-helper 17, or Th17.

T-cells are a type of white blood cell and are about the size of a red blood cell. They are adaptive, which means they change in response to threats. These cells start as virgin (or naïve) cells and transform into a specialized version when danger is detected. T-cells can be divided into two parts: killers and helpers. Killers are good at killing other (hopefully bad) cells, while helpers activate other cells and amplify immune responses. The cell we’re focusing on, Th17, is a type of helper cell, but a special one.

Th17 was first identified in 2005, but scientists have rapidly learned loads about it. It is particularly good at helping the body fight unusual attackers like fungi and certain bacteria. When activated, it releases a powerful signaling chemical that increases inflammation and recruits other white blood cells, telling them to come and fight. In addition, it can assist in tightening the spaces between our border cells to keep invaders out. When the body detects unknown particles, cells release signaling molecules. When a T-helper cell encounters the right mix of these molecules, it transforms into the rallying Th17 captain which sounds the alarm.

Unfortunately, all that shimmers is not silver. Th17 can certainly be useful in some circumstances, but it can be dangerous when activated by the wrong signals. In many of these cases, Th17 cells tell white blood cells to go nuts and attack anything that moves (or doesn’t move), but without a clear opponent, they just attack whatever’s around and cause an autoimmune response. Th17 has been implicated in diseases like experimental autoimmune encephalomyelitis (EAE), arthritis, and inflammatory bowel diseases (IBD) like Ulcerative Colitis. Let’s look at ulcerative colitis as an example.

Ulcerative colitis is an inflammatory bowel disease where the immune system attacks benign bacteria or food particles. The causes aren’t clear, but part of the problem is a thinning of the mucus and separation of border cells that line the intestines. Many signaling molecules called interleukins (abbreviated IL-) are released in the disease state, including three important ones for Th17. These are IL-1β, IL-6, and IL-23 (write this down for the quiz at the end). The first two activate Th17, and that’s when IL-23 can turn it into a problem. In the presence of IL-23, Th17 sends wild signals and can cause the autoimmune problems listed above, including ulcerative colitis. Also, remember how Th17 helps tighten the spaces between border cells? It turns out that in the presence of IL-23 this function doesn’t work properly and the borders stay open, letting in more particles that the body attacks with inflammation.

Scientists have been trying to find ways to solve the problems caused by Th17 since long before it was even known to exist. In the past, a treatment for something like ulcerative colitis might have been limited to restricting your diet. Currently, anti-inflammatory medications, steroids, and/or surgeries are used. Those are all big solutions bound to affect many other parts of the body and immune system. Now that Th17 has been identified as an occasional dirty traitor, researchers are instead targeting this specific cell to hopefully stop it from being activated incorrectly. With luck, we can help the T-helper cell to help us instead of unhelping us.

Staff Writer / Editor Benton Lowey-Ball, BS, BFA

Listen to the article here:


Kałużna, A., Olczyk, P., & Komosińska-Vassev, K. (2022). The role of innate and adaptive immune cells in the pathogenesis and development of the inflammatory response in ulcerative colitis. Journal of clinical medicine, 11(2), 400.

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Tesmer, L. A., Lundy, S. K., Sarkar, S., & Fox, D. A. (2008). Th17 cells in human disease. Immunological reviews, 223(1), 87-113.

Wu, B., & Wan, Y. (2020). Molecular control of pathogenic Th17 cells in autoimmune diseases. International immunopharmacology, 80, 106187.


Ulcerative colitis (UC) is a chronic and progressive autoimmune disorder that causes inflammation and ulcers to develop in the intestines, which can be very uncomfortable or debilitating. Ulcers are breaks or holes in the protective lining that can cause bloody diarrhea, with or without mucus. One of the significant symptoms of UC  is a high urgency of bowel movements. Other symptoms include abdominal pain, bowel inflammation, and constipation. UC is not a fun condition to experience, to say the least! It is usually experienced in cycles of remission and relapse with periods of terrible high and thankfully low (or no) symptoms. The high periods can even lead to hospitalization. 

UC can develop at any age but is more likely to develop in people 15 to 30 years old. Interestingly, there seems to be a lower chance of developing UC if your appendix has been removed or if you are a smoker. This disease doesn’t play favorites, so there is no difference between men and women developing UC. Racial differences may be minimal compared to differences in diet and lifestyle. For example, a diet that includes eating refined sugars and processed grains may increase the likelihood of developing the disease.

As mentioned above, diet can be a risk factor; this may be because of an immune response to the food. Research continues to show that the food you eat can affect all parts of the body. People with genetic factors have an immune system that attacks non-harmful gut bacteria, and low gut microbiota diversity may also be a risk factor.

Ulcerative colitis often presents with other diseases. Data suggests that there is a relationship between UC and rheumatoid arthritis. Some experts think joint pain and swelling may be part of the same immune response responsible for ulcerative colitis. Other comorbidities include acute hepatitis (liver inflammation) and occasional skin conditions.

Treatments for UC aim at inducing a period of remission. All of them come with side effects, so your doctors, specialist and primary care, should all be informed about the medications that you are taking. A particularly unpleasant and severe treatment is a colectomy or bowel resection, which removes part of the affected colon. 20-30% of people with UC  may have to undergo this procedure. 

The good news is that researchers continue to look for better ways to treat UC. With your help, we can make a difference!  Visit our enrolling studies page to get involved in the latest clinical research.

Written by: Benton Lowey-Ball, B.S. Behavioral Neuroscience


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Lee, S. H., eun Kwon, J., & Cho, M. L. (2018). Immunological pathogenesis of inflammatory bowel disease. Intestinal research, 16(1), 26.

Attalla MG, Singh SB, Khalid R, Umair M, Epenge E. Relationship between Ulcerative Colitis and Rheumatoid Arthritis: A Review. Cureus. 2019;11(9):e5695. Published 2019 Sep 18. doi:10.7759/cureus.5695


Ulcerative Colitis is a rare inflammatory bowel disease (IBD) with less than 200,000 cases per year. Ulcerative colitis can cause long-term effects on the body including inflammation and ulcers in the digestive tract. This can affect the innermost lining of the large intestine as well as the rectum.

The symptoms of ulcerative colitis can range from mild to severe. Symptoms include rectal bleeding, bloody diarrhea, abdominal cramps and pain. Those who have Ulcerative Colitis are also at a greater risk of developing colon cancer.

Doctors usually diagnose the different types of ulcerative colitis according to its location in the large intestine. The different types of ulcerative colitis include:

Ulcerative Proctitis

This is when the inflammation is in the area closest to the rectum. Rectal bleeding may be a sign of this disease, and it tends to be the mildest form.


This type of ulcerative colitis is confined to the rectum as well as the lower end of the colon (sigmoid colon). Symptoms include abdominal cramps, bloody diarrhea, and the inability to move bowels, even though you feel as though you need to.

Left-sided colitis

If you have sharp pain on your left side, bloody diarrhea, abdominal cramping or weight loss, you may be experiencing left-sided colitis. This happens when inflammation extends from the rectum through the sigmoid and descending colon.


Pancolitis often affects the entire colon. This can cause severe bloody diarrhea, abdominal cramps and pain, fatigue and weight loss.

Acute severe ulcerative colitis

This form of colitis is rare. It is a severe form and it affects the entire colon. It can cause severe pain, profuse bloody diarrhea, fever and complete loss of appetite.

Although rare, ulcerative colitis can cause an abundance of health problems. It is imperative to participate in clinical trials in order to move medicine forward and help find effective treatments for ulcerative colitis sufferers. 

Resources: Cleveland Clinic, Crohn’s and Colitis


More than just diarrhea…


Inflammatory Bowel Diseases include Crohn’s Disease and Ulcerative Colitis. These diseases cause inflammation in the digestive tract.  Both diseases can have similar symptoms such as diarrhea, urgency, abdominal pain and cramping, fatigue, and rectal bleeding.


What’s the difference between Crohn’s and Ulcerative Colitis?

Crohn’s Disease can cause inflammation anywhere in the digestive tract, from the mouth to the anus.  Ulcerative Colitis (UC) affects only the colon (also known as large intestine or large bowel). UC causes ulcers along with the inflammation and puts those affected at a higher risk of developing colon cancer.


What causes Ulcerative Colitis?

Physicians used to believe that stress and diet choices caused ulcerative colitis. Physicians now believe that UC was already present, and can be aggravated by these factors.

Research has shown that the immune system plays a role in developing Ulcerative Colitis.


My own immune system is giving me this disease?

There is no clear cause of UC.  Medical science shows that an overactive immune system may be to blame. This can lead to continuous inflammation of the colon, and Ulcerative Colitis.

Many of the medicines currently prescribed to treat UC suppress (decrease the activity of) the immune system.


Is there a cure?

There is currently no medical cure for UC.  Medical treatment is available to help manage it. American hospitals experience 500,000 visits per year and 46,000 hospitalizations for Ulcerative Colitis. In severe cases, surgical removal of the colon does cure ulcerative colitis.


The Good News

New medicines are now being studied with ENCORE Research to find a cure for UC.  Please call for more information, or to schedule an evaluation to see if this is an option for you.


We look forward to talking with you!

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