Finding immune system solutions so often necessitates stoking an immune response. Scientists unfortunately have to carry out tests for treatment for the immune system on live organisms, such as mice and non-human primates.

What if there were a way to do this without animal testing?

An organ-like chip

A group at Harvard University designed a microfluidic organ chip that could replace the need for animal models in this field. Here, human B and T cells (types of immune cells) were grown and transformed into different parts of the human body that mediate the immune response. One of the most important of these structures is the lymphoid nodes which control immune cell production, inspiring the device’s name: the lymphoid follicle (LF) chip.

Different chambers in the LF chip allow for different conditions for scientists to study the chain of events that occur when the immune response is triggered. These micro-environments allow for the modeling of a whole complex system in just a tiny chip. Further details were recently published in Advanced Science.

How can the chip reduce animal testing?

This technology can be used to predict immune responses to vaccinations, helping select which variety may perform best. This is a huge step up in efficiency, cost, accuracy, and speed compared to current preclinical testing methods including dishes of cells or non-human primates.

“Animals have been the gold-standard research models for developing and testing new vaccines, but their immune systems differ significantly from our own and do not accurately predict how humans will respond to them,” stated Goyal. “Our LF Chip offers a way to model the complex choreography of human immune responses to infection and vaccination, and could significantly speed up the pace and quality of vaccine creation in the future.”

A chance discovery

Like many important scientific findings, serendipity played a huge role in the LF chip’s development. To the group’s surprise, the immune cells spontaneously organized into these complex organ structures when placed in the device, opening up a whole new avenue of science that could be carried out using it. “It was so unexpected that we completely pivoted from the original experiment and focused on trying to figure out what they were,” said first author Girija Goyal.

The future of the LF chip looks bright, with the team currently testing out various vaccines in collaboration with pharmaceutical companies. It also comes at the right time, with traditional animal testing models becoming scarcer after the high demand during the pandemic. Hopefully, the invention could streamline and improve vaccine development in the future.

Source study: Advanced Science – Ectopic Lymphoid Follicle Formation and Human Seasonal Influenza Vaccination Responses Recapitulated in an Organ-on-a-Chip