In Vitro Bacterial Transinfection of T Cells via Immunological Synapse Formation
JoVE Encyclopedia of Experiments
Microbiology
0 views • 3:05 min • September 26th, 2025
Begin with wells containing CD4+ T cells expressing receptors specific to the ovoalbumin peptide or OVAp.
Into the negative control well, place a porous membrane insert.
In a tube, take dendritic cells infected with bacteria and loaded with OVAp for surface presentation.
Add dendritic cells directly into the test well and into the insert in the negative control well.
Add media to the wells and incubate.
In the test well, cells interact to form an immunological synapse, facilitating bacterial transfer from the dendritic cell to the T cell, a process known as transinfection.
In the negative control well, the membrane barrier prevents cell-cell interaction, thereby inhibiting transinfection.
Add the antibiotic gentamicin to the wells and incubate.
Gentamicin cannot penetrate eukaryotic cells, thus killing only non-internalized bacteria while internalized bacteria survive.
The test sample containing infected T cells and the control sample with uninfected T cells are now ready for T cell isolation and transinfection quantification.
To a 24-well culture plate, add two million CD4+ T cells in a volume of 0.5 milliliters to each of five wells.
Next, to control for physical contact, place polycarbonate trans-well barriers with a three micrometer pore size into the third and fourth wells. To the first well, add 0.1 milliliters of the infected overloaded dendritic cells. To the second well, add 0.1 milliliters of the infected non-loaded dendritic cells.
Add 0.1 milliliters of the infected overloaded dendritic cells to one well, and 0.1 milliliters of the infected non-loaded dendritic cells into the other well. Finally, as a negative control, directly infect the fifth well of CD4+ T cells at an MOI of 10. Then, bring the total volume of the well up to 0.6 milliliters with RPMI.
Incubate the plate for 30 minutes to allow immune synapses to form. After the incubation, add 100 micrograms of Gentamicin per milliliter of medium to each well, and incubate for one hour. Gentamicin is an aminoglycoside antibiotic that is not able to penetrate eukaryotic cells.
Therefore, in this step, aminoglycoside will kill extracellular bacteria but not intracellular bacteria.
Overview
This study investigates the process of transinfection between dendritic cells and CD4 + T cells using a specific peptide. The experimental setup includes both test and control wells to analyze the interactions and effects of bacterial infection on T cell activation.
Key Study Components
Area of Science
- Immunology
- Cell Biology
- Infectious Diseases
Background
- Transinfection is a process where dendritic cells transfer pathogens to T cells.
- Understanding this mechanism can provide insights into immune responses.
- CD4 + T cells play a crucial role in adaptive immunity.
- Dendritic cells are key antigen-presenting cells in the immune system.
Purpose of Study
- To elucidate the mechanism of bacterial transfer from dendritic cells to T cells.
- To assess the role of physical barriers in transinfection.
- To quantify the effects of antibiotic treatment on bacterial survival.
Methods Used
- CD4 + T cells were cultured in wells with dendritic cells.
- A porous membrane insert was used to create a negative control.
- Gentamicin was applied to differentiate between internalized and external bacteria.
- Incubation periods were established to allow for immune synapse formation.
Main Results
- Transinfection was successfully demonstrated in the test wells.
- The negative control wells showed inhibited bacterial transfer.
- Gentamicin effectively killed extracellular bacteria without affecting intracellular bacteria.
- Quantification of T cell activation was achieved post-experiment.
Conclusions
- The study confirms the role of dendritic cells in T cell transinfection.
- Physical barriers can significantly influence immune interactions.
- Antibiotic treatment is crucial for distinguishing bacterial infection states.
Frequently Asked Questions
Executive Industry Relevance
This method enables mechanistic interrogation of pathogen-immune cell interactions, supporting target validation in infectious disease and immunotherapy discovery. By quantifying transinfection efficiency, it provides predictive confidence in de-risking T cell-modulating candidates. The approach supports early discovery decisions by clarifying biological mechanisms of antigen-specific cell-cell communication.
Strategic Applications in Biopharma R&D
Early Discovery & Target Validation
- Scientific Value: Interrogates therapeutic hypotheses regarding dendritic cell-mediated pathogen transfer to T cells.
- Operational Value: Enables functional validation of targets involved in immunological synapse formation.
- Predictive Value: Supports portfolio triage by distinguishing compounds that modulate transinfection versus those affecting general T cell activation.
Screening & Assay Development
- Scientific Value: Generates quantitative readouts of bacterial transfer dependent on antigen-specific cell contact.
- Operational Value: Establishes a reproducible co-culture system with built-in negative controls via membrane separation.
- Assay Readiness: Outputs are compatible with downstream T cell isolation and infection quantification for hit validation.
Translational & Preclinical Research
- Translational Value: Uses disease-relevant antigen presentation (OVA peptide) to model pathogen-specific T cell engagement.
- Mechanistic De-risking: Clarifies whether observed T cell effects stem from direct transinfection versus bystander activation.
- Preclinical Continuity: Supports risk-adjusted advancement by isolating the contribution of antigen-specific synapse formation to immune outcomes.
Pipeline & Workflow Integration
The method fits within the discovery continuum from target engagement screening to mechanistic validation in immunology-focused pipelines.
- Discovery Biology: Tests hypotheses about antigen-dependent pathogen transfer mechanisms in adaptive immunity.
- Screening: Delivers standardized, quantitative transinfection readouts amenable to compound library screening.
- Analytics: Enables comparison of intracellular versus extracellular bacterial survival via gentamicin protection assay.
- Translational Research: Links antigen-specific synapse formation to functional T cell readouts for biomarker alignment.
- Enterprise Reuse: Platform can be adapted to other antigen-pathogen pairs to study cross-reactive immune evasion mechanisms.
Operational & Enterprise Impact
- Scientific Value: Reduces mechanistic ambiguity in T cell-pathogen interaction studies.
- Operational Value: Employs gentamicin protection assay to distinguish internalized from surface-bound bacteria with high specificity.
- Strategic Value: Informs go/no-go decisions by quantifying the dependence of transinfection on antigen-specific recognition.
- Portfolio Impact: Enables risk-adjusted prioritization of immunomodulators based on transinhibition potency.
Implementation Considerations
- Requires expertise in primary T cell and dendritic cell co-culture techniques.
- Dependent on access to antigen-loaded, pathogen-infected dendritic cells.
- Necessitates standardized gentamicin dosing to avoid eukaryotic toxicity while ensuring extracellular bacterial clearance.
- Adaptation to alternative models requires validation of membrane pore size for selective cell contact inhibition.
- Limited to pathogens that survive gentamicin exposure and can be tracked post-transfer.
Biopharma FAQs
Establishment of an In vitro System to Study Intracellular Behavior of Candida glabrata in Human THP-1 Macrophages
Related Videos
0 Views
Quantification of Intracellular Growth Inside Macrophages is a Fast and Reliable Method for Assessing the Virulence of Leishmania Parasites
Related Videos
0 Views
A High-throughput Shigella-specific Bactericidal Assay
Related Videos
0 Views
Retroviral Transduction of T-cell Receptors in Mouse T-cells
Related Videos
0 Views
A TIRF Microscopy Technique for Real-time, Simultaneous Imaging of the TCR and its Associated Signaling Proteins
Related Videos
0 Views
Immunological Synapse Formation Between Helper T Cells and Antigen-Presenting Cells
Related Videos
0 Views
An In Vitro Technique to Stimulate Lymphocytes via Pathogenic Bacteria
Related Videos
0 Views
An In Vitro Technique to Study T Cell Interaction with Supported Planar Lipid Bilayers
Related Videos
0 Views
Real-time Live Imaging of T-cell Signaling Complex Formation
Related Videos
0 Views
T Cells Capture Bacteria by Transinfection from Dendritic Cells
Related Videos
0 Views
Last updated: 22 August 2026