The secret cancer weapon in oats, barley and mushrooms

We depend upon our immune system to protect us from illness. Like an internal army, our immune cells operate independently of any organ, traveling where needed to destroy and eliminate invading pathogens.

Scientists at the University of Pennsylvania have done some important work, proving that certain types of immune cells can be trained to go after malignant tumors.

By using a natural substance that’s already known to prevent cancer, these scientists have shown that we can improve the “memory” of our immune cells so that they can fight cancer.

But before we get into that, it’s essential to understand the two types of immunity in your body and how they differ.

Innate vs. adaptive immunity

Innate and adaptive immunity are the two main types of immunity operating in your body.

Innate immunity, as the name implies, is present at birth. It is a kind of global, non-specific ability to search out and eliminate a broad range of pathogens.

What innate immunity doesn’t do is make fine distinctions between pathogens. For example, it doesn’t treat a cancerous cell any differently than it would treat a virus or a chemical toxin.

Innate immunity is fast-acting. It’s our first line of defense. It uses both physical and chemical barriers to defend us. These include phagocytes, natural killer (NK) cells, mast cells and plasma protein that lives in the blood.

Innate immune cells also have no memory. The battle starts from scratch if you’re exposed to the same pathogen again.

In contrast, adaptive immunity only develops after exposure to a pathogen, and adaptive immune cells (B cells and T cells) can create an immunological memory of a particular pathogen. It’s these cells that form the basis of vaccines.

Adaptive immunity is highly potent and specific. However, it is slow-moving. We’re talking as much as a week or two before their full potency is available to the body.

The immune system can be trained

This brings us to the critical questions that the University of Pennsylvania study sought to answer:

Is there a way to “train” fast-acting innate immune cells to respond more specifically, for example, to help treat cancer?
Can innate immune cells develop any sort of specific immunological memory?

Before the present study, the University of Pennsylvania team had already found that exposure to beta-glucans, a soluble fiber found in foods like oatmeal, mushrooms, barley and seaweed, could improve immune recovery after chemotherapy in a mouse model.

They also found that this “memory” was held within the bone marrow, in stem cells that later developed into macrophages and other cells that are active in the adaptive immune system.

But the researchers weren’t satisfied to stop there.

“The fact that β-glucan helps you fight tumors doesn’t necessarily mean it was through trained immunity,” said George Hajishengallis of the University of Pennsylvania School of Dental Medicine, who co-led the study.

To confirm that link, the researchers took neutrophils (innate immune cells) from mice exposed to beta-glucan and transferred them to mice that had not received beta-glucan. At the same time, they injected cells that grow into melanoma tumors.

Tumor growth was significantly slower in the mice who received the transplanted cells.

Just to be sure, the researchers performed bone marrow transplants, transferring bone marrow cells from “trained “mice into mice that had lost much of their own bone marrow.

The recipients fought tumors much more effectively than mice that received “untrained” bone marrow.

“This is innate immune memory at work,” said Triantafyllos Chavakis, a long-term collaborator of Hajishengallis and co-senior author of the study.