Immuunivajeets

Immuunivajeets are a proposed class of immune-cell–derived extracellular vesicles described in immunology literature as nanoscale particles released by activated lymphocytes and antigen-presenting cells. They resemble exosomes in size and biogenesis, typically ranging from 30 to 150 nanometers in diameter. Immuunivajeets carry surface proteins such as MHC class I and II, adhesion molecules, lipids, and nucleic acids, enabling them to shuttle information between cells.

The term was coined to reflect their immune origin and vesicular nature. Since the early 2010s, studies have reported Immuunivajeets produced by T cells, B cells, dendritic cells, and macrophages under inflammatory or stimulatory conditions. Isolation usually employs differential ultracentrifugation or size-exclusion methods, with characterization by nanoparticle tracking analysis and flow cytometry or electron microscopy.

Functionally, Immuunivajeets participate in intercellular communication and antigen presentation. They can present peptide–MHC complexes to T cells, influence dendritic cell maturation, and transfer microRNAs and other cargo that modulate gene expression in recipient cells. Depending on their surface phenotype and cargo, they can promote immune activation, induce tolerance, or dampen inflammatory responses. They also carry cytokines and lipid mediators that affect cell migration and tissue homing.

Clinical relevance remains experimental. Immuunivajeets are explored as biomarkers of immune status and as therapeutic vectors for immunomodulation and vaccine delivery. Animal studies have reported effects on graft survival and inflammatory responses, but no clinical therapies have been approved. Major challenges include standardization of isolation, characterization, storage, and understanding biodistribution and safety.

Research continues to clarify their biological roles and evaluate potential clinical applications.