Generation of Zika Virus-Specific T-Cells for Adoptive Immunotherapy
Year: 2019
Type: article
Abstract: Background Zika virus (ZIKV) infection during pregnancy can cause severe birth defects, with no effective treatment. Adoptive transfer of virus-specific T-cells has proven to be safe and effective for the prevention or treatment of many viral infections, and could represent a novel treatment approach for ZIKV infection. However, this approach for ZIKV infection has been hampered by limited data on immunogenic T-cell antigens within ZIKV. Hence, we have generated ZIKV-specific T-cells and characterized the cellular immune responses against ZIKV antigens. Methods T-cell products were generated from blood of ZIKV-exposed donors (n=3), ZIKV-naive adult donors (n=6), and umbilical cord blood (n=7) by stimulation with overlapping peptide libraries (15mers overlapping by 11 amino acids) spanning four ZIKV polyproteins (C, M, E, and NS1) using a GMP-compliant protocol. Results We successfully generated T-cells targeting ZIKV antigens with a mean 56.0-fold T cell expansion at 17 days for ZIKV-exposed donors and 21 days for ZIKV-naive donors and cord blood donors. The resultant products specifically recognized C, M, E, and NS1 proteins by IFN-γ ELISpot, with mean 142.5 spot forming cells (SFCs)/1 × 10 5 cells, 81.7 SFCs/1 × 10 5 cells, 132.1 SFCs/1 × 10 5 cells, and 180.7 SFCs/1 × 10 5 cells, respectively, compared to 5.4 SFCs/1 × 10 5 cells for irrelevant antigen (Fig 1). ZIKV-specific T-cells were polyclonal (16.2±2.8% CD3 + CD4 + and 32.4±2.4% CD3 + CD8 + T-cells) and expressed markers for both central and effector memory phenotype (3.5±0.6% CD45RO + CD62L + and 48.1±1.9% CD45RO + CD62L – ), with minimal expression of PD-1, Tim-3, Lag-3, and CTLA-4. Notably, both CD4 + and CD8 + subsets were polyfunctional comprising ZIKV-directed T-cell populations, which secreted multiple cytokines (16.7±0.6% CD4 + IFN-γ + TNF-α + and 7.4±0.4% CD8 + IFN-γ + TNF-α + ) as measured by intracellular cytokine staining. Moreover, multiplex cytokine assay demonstrated specific production of IFN-γ (928.7±239.8 pg/mL), TNF-α (1495.5±453.3 pg/mL), IL-2 (38.2±8.4 pg/mL), and GM-CSF (67.0±22.2 pg/mL) in response to ZIKV antigens. Importantly, ZIKV-specific T-cells selectively killed autologous monocytes infected with ZIKV confirming functionality of this unique T cell therapeutic. Epitope mapping using peptide arrays in IFN-γ ELISpot identified several novel HLA class I or class II-restricted epitopes within NS1, which is essential for viral replication and immune evasion. Conclusions Our findings demonstrate that it is feasible to generate potent ZIKV-specific T-cells from a variety of cell sources including virus naïve donors for future clinical use in an "off the shelf' setting.
Institutions: Children's National, Universidade de São Paulo
Language: English
Field: Medicine
Domain: Health Sciences
Open Access status: hybrid
Estimated APC paid: $3,650
OpenAlex ID: W2911601162