Virtual Infection Cues Trigger Early Immune Response

A team led by researchers from the University of Geneva and École Polytechnique Fédérale de Lausanne have discovered that anticipating a virtual infection can stimulate an immune response through the activation of innate lymphoid cells (ILCs).

Innate lymphoid cells are vital for quick immune responses. Unlike adaptive immune cells, they don't require antigen recognition but promptly react to inflammation and pathogen signals.

Typically, the body's defense against pathogens involves a variety of responses after actual contact. Until now, an anticipatory immune reaction hadn't been demonstrated. However, in their study published in Nature Neuroscience, "Neural anticipation of virtual infection triggers an immune response," researchers created a multisensory experiment to test if human brains could predict potential infections through VR and initiate early immune responses.

Sixty healthy adults were divided into four groups (n=15) and exposed to infectious, neutral, or threatening avatars in immersive VR or received an influenza vaccine. The team used psychophysical testing, EEG, fMRI, mass spectrometry, and flow cytometry to measure neural and immune responses.

Participants interacted with infectious avatars exhibited increased peripersonal space (PPS) effects, measurable as quicker reaction times to tactile stimuli even from distant avatars. EEG analyses on an additional 32 participants revealed anticipatory neural activity in multisensory-motor regions and activation within the salience network, particularly in the anterior insula and medial prefrontal cortex.

ILCs showed notable changes in frequency and activation due to virtual infections, similar to reactions seen with actual pathogens as evidenced by a comparison with an influenza vaccine group. Both types of infections induced decreases in ILC1s and increases in ILC2s and precursors, indicating active immune mobilization.

fMRI findings pinpointed anticipatory responses to critical brain regions including the intraparietal sulcus, premotor cortex, anterior cingulate cortex, and medial prefrontal cortex. Dynamic causal modeling showed altered connectivity between these areas and the hypothalamus during encounters with infectious avatars, linking neural anticipation to immune regulation via the hypothalamic-pituitary-adrenal axis.

The researchers concluded that human immune systems activate not just after physical contact but also when confronted by potential infection threats within peripersonal space. This anticipatory neuro-immune mechanism could allow for rapid responses to virtual or real infections.

This article was written by our author Justin Jackson, edited by Lisa Lock, and verified by Robert Egan through rigorous human efforts. Your support sustains independent science journalism. Consider a donation (especially monthly) to keep this work alive, and enjoy an ad-free experience in return.