Rapid GMP-Compliant Expansion of SARS-CoV-2–Specific T Cells From Convalescent Donors for Use as an Allogeneic Cell Therapy for COVID-19

Abstract

COVID-19 disease caused by the SARS-CoV-2 virus is characterized by dysregulation of effector T cells and accumulation of exhausted T cells. T cell responses to viruses can be corrected by adoptive cellular therapy using donor-derived virus-specific T cells. One approach is the establishment of banks of HLA-typed virus-specific T cells for rapid deployment to patients. Here we show that SARS-CoV-2–exposed blood donations contain CD4 and CD8 memory T cells which recognize SARS-CoV-2 spike, nucleocapsid and membrane antigens. Peptides of these antigens can be used to isolate virus-specific T cells in a GMP-compliant process. The isolated T cells can be rapidly expanded using GMP-compliant reagents for use as an allogeneic therapy. Memory and effector phenotypes are present in the selected virus-specific T cells, but our method rapidly expands the desirable central memory phenotype. A manufacturing yield ranging from 1010 to 1011 T cells can be obtained within 21 days culture. Thus, multiple therapeutic doses of virus-specific T cells can be rapidly generated from convalescent donors for potential treatment of COVID-19 patients.

SARS‐CoV‐2 spike glycoprotein‐reactive T cells can be readily expanded from COVID‐19 vaccinated donors

“… 24 The infection also induces a cellular response to these proteins, 25 and these responses can be ex vivo enhanced. 9 , 10 We confirmed reactivity to these proteins by analyzing samples from two control donors (patients). Samples from these control donors (patients) were first collected before they contracted the virus and became sick with COVID‐19, and then 2 weeks after their recovery from the disease.…”

“…These data were in line with our recent study where samples from SARS‐CoV‐2‐unexposed donors or prostate cancer patients were also largely not enriched with SARS‐CoV‐2 spike glycoprotein‐specific CD8 + T cells. 31 Even though we cannot entirely exclude that after so many months of the raging pandemic, some of the healthy donors in this study had contracted SARS‐CoV‐2 unnoticed, then having COVID‐19 with no or mild symptoms, 9 , 10 the donors showed no detectable trances of the virus‐specific immunity before the COVID‐19 vaccination. Unlike the two control donors (patients) analyzed in this study, the healthy donors of this study had no detectable SARS‐CoV‐2 spike glycoprotein‐, NCP‐, or membrane protein‐specific antibodies in their sera, nor their PBMCs had the potential to become enriched with neither of the virus protein‐reactive T cells.…”

“…Previous studies have shown that SARS‐CoV‐2 T cell‐based immunity could be enhanced and used for T cell‐based therapy of COVID‐19 after ex vivo large scale expansion of SARS‐CoV‐2‐specific T cells from COVID‐19 convalescent donors. 9 , 10 Whether this enhancement could also be attained and therapeutically harvested after COVID‐19 vaccination of donors with no previous history of COVID‐19 and/or no detectable SARS‐CoV‐2‐specific immunity is unknown.…”

Interplay between Neutrophils, NETs and T-Cells in SARS-CoV-2 Infection—A Missing Piece of the Puzzle in the COVID-19 Pathogenesis?

“…In addition, the dysregulation of effector T cells and accumulation of exhausted T cells is one of the key features of COVID-19 disease [134]. The phenomenon of the exhaustion of memory T cells is visible by overall lymphopenia and increased levels of T ex [134]; however, the exhaustion of cytotoxic lymphocytes in the course of COVID-19 has not been reported, although functional exhaustion of cytotoxic lymphocytes (CTL) is often correlated with disease progression [135].…”

“…In addition, the dysregulation of effector T cells and accumulation of exhausted T cells is one of the key features of COVID-19 disease [134]. The phenomenon of the exhaustion of memory T cells is visible by overall lymphopenia and increased levels of T ex [134]; however, the exhaustion of cytotoxic lymphocytes in the course of COVID-19 has not been reported, although functional exhaustion of cytotoxic lymphocytes (CTL) is often correlated with disease progression [135]. Nevertheless, it has been shown that the total number of CTLs significantly decreases in patients infected with SARS-CoV-2 and the level returns to normal after the infection, but with a reduced expression of NKG2A [135], which is known to be a novel inhibitory molecule on the immune-checkpoint blockade [136].…”