Can oligomeric T-cell receptor be used as a tool to detect viral peptide epitopes on infected cells?

Abstract

We have utilized soluble HIV Gag-specific T-cell receptor (TCR) D3 with low affinity and TCRlike antibody 25-D1.16 recognizing its natural peptide-MHC (pMHC) ligand with high affinity to determine how affinity and off-rate of the receptor-pMHC interactions affect the sensitivity of pMHC detection on the cell surface. We found that with soluble TCR cognate pMHCs can be detected only at relatively high cell surface densities when the TCR was oligomerized using either Strepavidin or quantum dots (QD) scaffolds. While the higher affinity probe led to a greater sensitivity of pMHC detection, monomers and oligomers of the probe showed essentially the same detection limit, which is restricted by the sensitivity of standard flow cytometry technique. We have also shown that imaging of QD/TCR specifically bound to cognate pMHC on the cell surface yielded a very bright fluorescent signal that can enhance the sensitivity of viral peptide detection on infected cells. Keywordssoluble TCR oligomers; detection of cognate pMHC on the cell surface; quantum dot/TCR conjugates

Kinetics of Early T Cell Receptor Signaling Regulate the Pathway of Lytic Granule Delivery to the Secretory Domain

“…The DHLA-capped QD-520 and QD-620 (emission wavelength 520 or 620 nm, respectively) were produced as previously described (Anikeeva et al, 2006; Anikeeva et al, 2009). For some experiments we utilized QDs encapsulated into lipid micelles (Evident Technology) as described elsewhere (Anikeeva et al, 2009).…”

“…For some experiments we utilized QDs encapsulated into lipid micelles (Evident Technology) as described elsewhere (Anikeeva et al, 2009). …”

Capsid antigen presentation flags human hepatocytes for destruction after transduction by adeno-associated viral vectors

“…Despite the high sensitivity of TCR multimers, no pMHC complexes were detectable by flow cytometry after staining hepatocytes transduced with AAV in culture (our unpublished observations). Others have shown that flow cytometry can limit the detection of low-density pMHC complexes by soluble TCR, as compared with more sensitive confocal imaging (16). We therefore investigated whether our TCR multimer could detect pMHC complexes by confocal microscopy.…”

Interaction of Streptavidin-Based Peptide–MHC Oligomers (Tetramers) with Cell-Surface TCRs

“…The complexes formed by streptavidin with biotinylated MHC, usually called tetramers, vary in the number of biotinylated MHC molecules per streptavidin (SA) molecule (33, 34). Figure 1A shows the distribution of oligomers when biotinylated class I MHC and SA were combined at different molar ratios.…”