Immune cells protecting the colon.

Gut Guardians: How Special Immune Cells Fight Colorectal Cancer

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Beau Callahan in Health & Wellness December 2025 • 4 min read.

"Discover the role of CD19loCD27hi plasmablasts in suppressing harmful inflammation and improving outcomes in colorectal cancer patients."


Colorectal cancer (CRC) is a major health challenge, but our understanding of the immune system's role in fighting it is constantly evolving. Regulatory B (Breg) cells, in particular, have emerged as key players in controlling inflammation and influencing the course of the disease. These cells can dial down the immune response, preventing excessive damage to healthy tissues, but their precise function in CRC is still being unraveled.

Among the various types of Breg cells, a special group known as CD19loCD27hi plasmablasts has caught the attention of researchers. These cells produce interleukin-10 (IL-10), a powerful anti-inflammatory molecule. Scientists have observed that CRC tumors often contain a high concentration of these IL-10-producing plasmablasts, hinting at their potential to suppress harmful inflammation within the tumor.

A new study delves deeper into the role of these CD19loCD27hi plasmablasts in CRC. The researchers wanted to understand how these cells interact with other immune cells and whether they can be harnessed to improve cancer treatment. Their findings reveal a fascinating interplay between these plasmablasts and other components of the immune system, offering new hope for more effective CRC therapies.

What are CD19loCD27hi Plasmablasts and How Do They Fight Cancer?

Immune cells protecting the colon.

The researchers discovered that they could simulate tumor-infiltrating plasmablasts by co-culturing B cells from patient blood samples with colon cancer cells (Caco-2) and heat-killed bacteria. This approach allowed them to study the behavior of these specialized immune cells in a controlled environment. The plasmablasts generated in this way shared key characteristics with those found in actual tumors, including the production of IL-10.

The team then investigated how these CD19loCD27hi plasmablasts affected other immune cells, specifically T cells. T cells are critical for fighting cancer, but certain types, like Th17 cells, can promote inflammation and potentially fuel tumor growth. The researchers found that the CD19loCD27hi plasmablasts could effectively suppress the activity of these harmful Th17 cells.

  • IL-10 Production: The plasmablasts primarily mediated this suppression through the production of IL-10, highlighting the importance of this anti-inflammatory molecule.
  • RORγt Reduction: They also found that the plasmablasts reduced the expression of RORγt, a key protein involved in the development of Th17 cells.
  • No Foxp3 Increase: Interestingly, the plasmablasts did not appear to promote the development of regulatory T cells (Tregs), another type of immune cell that can suppress inflammation. This suggests that their primary mechanism of action is directly targeting Th17 cells.
To confirm the importance of IL-10, the researchers blocked IL-10 signaling and found that the suppressive effect of the plasmablasts was significantly reduced. This further emphasizes the critical role of IL-10 in mediating the beneficial effects of these cells. Furthermore, patients with a high frequency of IL-10-producing CD19loCD27hi plasmablasts in their tumors had lower levels of inflammatory Th17 cells and experienced better survival rates.

Hope for the Future: Harnessing Immune Power to Fight Cancer

This research sheds light on the complex interplay between immune cells in the fight against colorectal cancer. By understanding how CD19loCD27hi plasmablasts suppress harmful inflammation, scientists can explore new ways to harness their power and improve treatment outcomes. Future therapies might involve strategies to boost the activity of these beneficial plasmablasts or to deliver IL-10 directly to the tumor microenvironment, ultimately leading to more effective and less toxic treatments for CRC patients.

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.

Everything You Need To Know

1

What are CD19loCD27hi plasmablasts, and what role do they play in colorectal cancer (CRC)?

CD19loCD27hi plasmablasts are a specialized type of immune cell, a subgroup of regulatory B (Breg) cells, that have been found to play a crucial role in fighting colorectal cancer (CRC). They are found in CRC tumors and produce interleukin-10 (IL-10), an anti-inflammatory molecule. Their primary function is to suppress harmful inflammation within the tumor microenvironment, which is essential for improving outcomes in CRC patients.

2

How do CD19loCD27hi plasmablasts suppress inflammation within the tumor microenvironment?

CD19loCD27hi plasmablasts primarily suppress inflammation by producing interleukin-10 (IL-10). IL-10 reduces the activity of inflammatory T cells, such as Th17 cells. They also reduce the expression of RORγt, a protein that is involved in the development of Th17 cells. Interestingly, the plasmablasts do not promote the development of regulatory T cells (Tregs).

3

How do researchers study CD19loCD27hi plasmablasts?

Researchers can simulate tumor-infiltrating CD19loCD27hi plasmablasts by co-culturing B cells from patient blood samples with colon cancer cells (Caco-2) and heat-killed bacteria. This approach allows them to study the behavior of these specialized immune cells in a controlled environment. The plasmablasts generated in this way share key characteristics with those found in actual tumors, including the production of IL-10.

4

What is the significance of interleukin-10 (IL-10) in the context of CD19loCD27hi plasmablasts and CRC?

IL-10 is a critical molecule in the function of CD19loCD27hi plasmablasts. The plasmablasts use IL-10 to suppress inflammation by directly targeting Th17 cells. Patients with a high frequency of IL-10-producing CD19loCD27hi plasmablasts in their tumors experience better survival rates. Blocking IL-10 signaling significantly reduces the suppressive effect of the plasmablasts, highlighting IL-10's importance in their beneficial effects.

5

What are the potential implications of this research for future colorectal cancer (CRC) treatments?

This research opens new avenues for CRC treatment by highlighting the role of CD19loCD27hi plasmablasts. Future therapies might aim to boost the activity of these plasmablasts, or deliver IL-10 directly to the tumor microenvironment. This approach could potentially lead to more effective and less toxic treatments for CRC patients by harnessing the power of the immune system to fight cancer.

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