Scientists have found a ‘brand new micro-organ’ in the human body

And it may hold the key to how vaccines work.
And it may hold the key to how vaccines work.

Scientists have identified what they say is a “brand new micro-organ” in the immune system that could provide clues as to how vaccines work.

The so-called organ is believed to be a place where immune cells gather to respond against an infection the body has seen before.

The structure was only discovered by the team at Australia’s Garvan Institute of Medical Research when they made videos of the immune system in action using a sophisticated 3D microscopy tool.

The researchers say the structures, which contains a variety of immune cells, are “strategically positioned to detect infection early, making it a one-stop shop for fighting a ‘remembered’ infection”.

Immune cells (pink and green) gathering at the SPF (Imogen Moran & Tri Phan/Garvan Institute)

Named SPFs or subcapsular proliferative foci, the structures only appear when they needed to fight an infection, which makes it hard to detect using traditional microscopy technology.

Tri Phan, an assistant professor at the institute, says the SPF structures “are perfectly placed” to fight infection in the quickest way possible, so “they can stop disease in its tracks before it takes hold”.

He added: “When you’re fighting bacteria that can double in number every 20 to 30 minutes, every moment matters.

“To put it bluntly, if your immune system takes too long to assemble the tools to fight the infection, you die.

“This is why vaccines are so important. Vaccination trains the immune system, so that it can make antibodies very rapidly when an infection reappears.

“Until now we didn’t know how and where this happened.”

The researchers say the reason why no-one had seen the structures before was because, until now, only traditional microscopy technology was used to analyse tissue samples that generated 2D images.

Dr Imogen Moran, a PhD student at the institute and first study author, said: “It was only when we did two-photon microscopy – which lets us look in three dimensions at immune cells moving in a living animal – that we were able to see these SPF structures forming.

“So this is a structure that’s been there all along, but no one’s actually seen it yet, because they haven’t had the right tools.”

The study is published in the journal Nature Communications.