Imbalanced Th17 and Treg cells in Behcet's disease

Behcet's Disease: Unlocking the Immune Puzzle

Nico Varela in Health & Wellness December 2025 • 5 min read.

"New research reveals how imbalances in immune cells and related molecules may drive this complex inflammatory condition, paving the way for better diagnostics and treatments."

Behcet's disease (BD) is a chronic inflammatory disorder that can affect many parts of the body, including the eyes, skin, joints, blood vessels, and nervous system. Characterized by recurring oral and genital ulcers, eye inflammation (uveitis), and skin lesions, BD's unpredictable nature and diverse symptoms can make diagnosis challenging. While the exact cause remains elusive, genetic predisposition, environmental triggers, and immune system abnormalities are believed to play a role.

The immune system, which normally protects the body from infections, appears to go awry in BD, leading to inflammation and tissue damage. Researchers are particularly interested in the roles of specific immune cells, such as Th17 and regulatory T (Treg) cells, and the chemical messengers they produce (cytokines). These cells are critical for maintaining immune balance, and disruptions in their function may contribute to BD's development. Also of interest are microRNAs (miRNAs), small molecules that regulate gene expression and can influence immune cell behavior.

A recent study delved into the complex interplay of Th17 and Treg cells, cytokines, and miRNAs in patients with BD. By examining blood samples from BD patients and healthy individuals, the researchers aimed to identify key immune signatures that could shed light on the disease's underlying mechanisms and potentially lead to new diagnostic and therapeutic strategies. This article breaks down the study's findings, explaining how these immune components are altered in BD and what it could mean for those affected by this challenging condition.

Th17/Treg Imbalance: A Key Driver in Behcet's Disease?

Imbalanced Th17 and Treg cells in Behcet's disease

The study revealed significant imbalances in the proportions of Th17 and Treg cells in BD patients. Th17 cells, known for promoting inflammation, were found to be more abundant in the blood of BD patients compared to healthy controls. Conversely, Treg cells, which help to suppress excessive immune responses and maintain tolerance, were reduced in BD patients. This disrupted balance suggests that the immune system in BD is skewed towards inflammation.

To further investigate this imbalance, the researchers examined the expression levels of key transcription factors that govern the development and function of Th17 and Treg cells. Retinoic acid-related orphan receptor gamma t (RORyt) is essential for Th17 cell differentiation, while forkhead box P3 (FoxP3) is crucial for Treg cell development. The study found that RORyt expression was elevated in BD patients, whereas FoxP3 expression was decreased, further supporting the notion of a Th17/Treg imbalance.

Increased Th17 Cells: Contribute to inflammation.
Decreased Treg Cells: Reduce the ability to control inflammation.
Elevated RORyt: Transcription factor promoting Th17 development.
Reduced FoxP3: Transcription factor crucial for Treg cell development.

In addition to imbalances in immune cell populations and transcription factors, the study also found altered levels of certain cytokines in BD patients. Pro-inflammatory cytokines, such as IL-17 and IL-23, which are produced by Th17 cells, were elevated in BD patients. Conversely, anti-inflammatory cytokines, such as IL-10 and TGF-β, which are produced by Treg cells, were reduced. These findings further highlight the inflammatory nature of BD and the importance of the Th17/Treg balance in the disease.

miRNAs: Tiny Regulators with a Big Impact

MicroRNAs (miRNAs) are small, non-coding RNA molecules that regulate gene expression and can influence a variety of cellular processes, including immune cell development and function. The study found that the expression levels of several miRNAs were altered in BD patients. Some miRNAs, such as miR-25, miR-106b, miR-93, and miR-326, were upregulated, while others, such as miR-146a and miR-155, were downregulated. These changes in miRNA expression may contribute to the Th17/Treg imbalance and the overall inflammatory state in BD.

The altered miRNA expression patterns observed in BD patients may have important implications for disease pathogenesis. For example, miR-155 is known to target FoxP3, the master regulator of Treg cell development and function. The downregulation of miR-155 in BD patients may lead to reduced FoxP3 expression and impaired Treg cell activity. Similarly, miR-326 is known to regulate Th17 differentiation, and its upregulation in BD patients may contribute to the increased abundance of Th17 cells.

The study's findings suggest that imbalances in Th17 and Treg cells, along with altered cytokine and miRNA expression, play a crucial role in the development of Behcet's disease. These immune signatures could potentially serve as diagnostic biomarkers to identify individuals at risk of developing BD or to monitor disease activity. Furthermore, targeting these immune pathways with novel therapies may offer new hope for patients with this challenging condition. Future research is needed to further elucidate the complex interplay of these immune components and to develop effective strategies to restore immune balance in BD.

About this Article -

This article was crafted using a human-AI hybrid and collaborative approach. AI assisted our team with initial drafting, research insights, identifying key questions, and image generation. Our human editors guided topic selection, defined the angle, structured the content, ensured factual accuracy and relevance, refined the tone, and conducted thorough editing to deliver helpful, high-quality information.See our About page for more information.

This article is based on research published under:

DOI-LINK: 10.1002/jcp.27207, Alternate LINK

Title: Disturbed Th17/Treg Balance, Cytokines, And Mirnas In Peripheral Blood Of Patients With Behcet’S Disease

Subject: Cell Biology

Journal: Journal of Cellular Physiology

Publisher: Wiley

Authors: Majid Ahmadi, Mehdi Yousefi, Sanaz Abbaspour‐Aghdam, Sanam Dolati, Leili Aghebati-Maleki, Shadi Eghbal‐Fard, Alireza Khabbazi, Davood Rostamzadeh, Shahriar Alipour, Mahdi Shabani, Mohammad Nouri, Zohreh Babaloo

Published: 2018-10-14

Everything You Need To Know

What is Behcet's Disease, and what are the primary factors believed to contribute to its development?

Behcet's Disease is a chronic inflammatory condition affecting various parts of the body. It's thought to arise from a combination of genetic factors, environmental triggers, and an overactive immune system. The body's defense mechanisms, instead of protecting, start attacking healthy tissues, leading to inflammation and the characteristic symptoms such as oral and genital ulcers, eye inflammation, and skin lesions. The exact mechanism is still under investigation.

How does the balance between Th17 cells and Treg cells affect the development of Behcet's Disease, and what are the roles of RORyt and FoxP3?

The balance between Th17 cells and Treg cells is crucial for immune regulation. In Behcet's Disease, there's an increase in Th17 cells, which promote inflammation, and a decrease in Treg cells, which suppress it. This imbalance leads to an overall inflammatory state in the body, contributing to the disease's symptoms and progression. The transcription factors RORyt and FoxP3 play a critical role. RORyt is elevated promoting Th17 development. FoxP3 is reduced, thus impacting Treg cell development.

What role do cytokines play in the inflammatory processes associated with Behcet's Disease, and which specific cytokines are most affected?

Cytokines are signaling molecules that mediate and regulate immunity and inflammation. Pro-inflammatory cytokines like IL-17 and IL-23, which are produced by Th17 cells, are elevated in Behcet's Disease, further driving inflammation. Conversely, anti-inflammatory cytokines like IL-10 and TGF-β, which are produced by Treg cells, are reduced, hindering the body's ability to dampen the inflammatory response. This creates a cycle of sustained inflammation.

How do microRNAs (miRNAs) contribute to the immune dysregulation seen in Behcet's Disease, and what are some examples of miRNAs that are affected?

MicroRNAs (miRNAs) are small molecules that regulate gene expression and can influence immune cell behavior. In Behcet's Disease, the expression levels of several miRNAs are altered. Some miRNAs, like miR-25, miR-106b, miR-93, and miR-326, are upregulated, while others, like miR-146a and miR-155, are downregulated. These changes contribute to the Th17/Treg imbalance and the overall inflammatory state, suggesting that miRNAs could be potential therapeutic targets.

How might a better understanding of immune cells, cytokines, and miRNAs lead to improved diagnostics and treatments for Behcet's Disease, particularly focusing on transcription factors RORyt and FoxP3?

Understanding the roles of immune cells like Th17 and Treg cells, cytokines, and miRNAs opens avenues for new diagnostic and therapeutic strategies. For example, identifying specific miRNA signatures could aid in early diagnosis, while targeting Th17 cells or modulating cytokine levels could help manage the disease. The interplay between RORyt and FoxP3 is key to understanding the role of transcription factors in the Behcet's Disease process. Future treatments may focus on restoring the balance between pro- and anti-inflammatory responses to alleviate symptoms and improve patients' quality of life.