MHC Molecules on B Cell Microvilli Are Spatially Associated with IL-15Rα

Abstract

Interleukin-15 (IL-15) trans-presentation (TP) by B cells is an important mechanism of T-cell activation; however, the spatial organisation of interleukin-15 receptor (IL-15R) relative to major histocompatibility complex (MHC) molecules on B-cell microvilli remains poorly understood. As microvilli protrude from the B-cell surface and may serve as sites of initial B cell-T-cell contact, the distribution of IL-15R and MHC molecules within these structures may be important during the earliest stages of T-cell recognition and activation. Here, we investigated the spatial association and molecular proximity of IL-15R with MHC class I and class II molecules on B-cell microvilli before immunological synapse formation, using confocal microscopy, stimulated emission depletion (STED) microscopy, stochastic optical reconstruction microscopy (STORM), and fluorescence lifetime imaging microscopy-based Forster resonance energy transfer (FLIM-FRET). Both MHC class I and class II molecules showed significant spatial association with IL-15R; however, the extent of colocalisation decreased as spatial resolution increased. STED microscopy revealed significant colocalisation between IL-15R and MHC class I, whereas STORM did not detect this association. In contrast, IL-15R and MHC class II remained significantly colocalised at both resolutions. FLIM-FRET further demonstrated molecular proximity between IL-15R and both MHC class I and class II molecules, with higher FRET efficiency observed for MHC class II. Collectively, these findings indicate that IL-15R is spatially organised in proximity to both MHC class I and class II molecules on B-cell microvilli before immunological synapse formation. This arrangement at potential sites of initial B-cell-T-cell contact may facilitate the coordination of IL-15 trans-presentation and antigen presentation during the earliest stages of B-cell-T-cell interactions.

Spatially resolved single-cell atlas reveals cortical glial reactivity associated with regions of neuronal growth programs in both hemispheres after stroke
Matthew Kenwood, Dene Betz, Eduardo Guttierez-Kuri +5
bioRxiv26 Oct 2026PreprintCC BY-NCFull textNeurosciencebioRxivPMC
A Cell-based Screening Method Using an Intracellular Antibody for Discovering Small Molecules Targeting Hard-to-drug Proteins
Nicolas Bery, Terry H Rabbitts
Bio-protocol21 Sep 2026Peer-reviewedLicence not stated5 citedGeneral biochemistry General biologyHAL
Patterned alginate hydrogel spatially guides collagen fibrillogenesis, viscoelasticity and endothelial cell invasion
C. A. Garrido, D. S. Garske, B. Haessel +6
bioRxiv2 Sep 2026PreprintAll rights reservedFull textSystems & synthetic biologybioRxiv
The Role of the Immunoglobulin Superfamily of Cell Adhesion Molecules in Intellectual Disability
Nishat Zaman, Karina Bui, Vladimir Sytnyk
Cells2 Oct 2026Peer-reviewedCC BY 4.0Genetics & genomicsCrossref
PathwayFinder enables linked exploration of cell types and gene modules in spatially resolved transcriptomics data
Chang Li, Julian Thijssen, Thomas Kroes +4
iScience29 Oct 2026Peer-reviewedCC BY 4.0Full textSystems & synthetic biologyCell PressCrossrefEurope PMC

Cite

BibTeX RIS

BibTeX

@misc{rebenku2026molecules,
  title = {{MHC Molecules on B Cell Microvilli Are Spatially Associated with IL-15Rα}},
  author = {I. Rebenku and N. Bilakovics and L. Szolyka and L. Velas and T. Garda and G. J. Schütz and G. Vamosi},
  howpublished = {bioRxiv},
  year = {2026},
  month = sep,
  doi = {10.64898/2026.09.24.747988},
  url = {https://www.biorxiv.org/content/10.64898/2026.09.24.747988v1},
  note = {CC BY},
}

RIS

TY  - UNPB
TI  - MHC Molecules on B Cell Microvilli Are Spatially Associated with IL-15Rα
AU  - I. Rebenku
AU  - N. Bilakovics
AU  - L. Szolyka
AU  - L. Velas
AU  - T. Garda
AU  - G. J. Schütz
AU  - G. Vamosi
PY  - 2026
DA  - 2026/09/24
PB  - bioRxiv
DO  - 10.64898/2026.09.24.747988
UR  - https://www.biorxiv.org/content/10.64898/2026.09.24.747988v1
AB  - Interleukin-15 (IL-15) trans-presentation (TP) by B cells is an important mechanism of T-cell activation; however, the spatial organisation of interleukin-15 receptor (IL-15R) relative to major histocompatibility complex (MHC) molecules on B-cell microvilli remains poorly understood. As microvilli protrude from the B-cell surface and may serve as sites of initial B cell-T-cell contact, the distribution of IL-15R and MHC molecules within these structures may be important during the earliest stages of T-cell recognition and activation. Here, we investigated the spatial association and molecular proximity of IL-15R with MHC class I and class II molecules on B-cell microvilli before immunological synapse formation, using confocal microscopy, stimulated emission depletion (STED) microscopy, stochastic optical reconstruction microscopy (STORM), and fluorescence lifetime imaging microscopy-based Forster resonance energy transfer (FLIM-FRET). Both MHC class I and class II molecules showed significant spatial association with IL-15R; however, the extent of colocalisation decreased as spatial resolution increased. STED microscopy revealed significant colocalisation between IL-15R and MHC class I, whereas STORM did not detect this association. In contrast, IL-15R and MHC class II remained significantly colocalised at both resolutions. FLIM-FRET further demonstrated molecular proximity between IL-15R and both MHC class I and class II molecules, with higher FRET efficiency observed for MHC class II. Collectively, these findings indicate that IL-15R is spatially organised in proximity to both MHC class I and class II molecules on B-cell microvilli before immunological synapse formation. This arrangement at potential sites of initial B-cell-T-cell contact may facilitate the coordination of IL-15 trans-presentation and antigen presentation during the earliest stages of B-cell-T-cell interactions.
ER  -

Abstract

Related

Cite