Posts in Category: Immunobody

SCIB1 combined with PD-1 blockade induced efficient therapy of poorly immunogenic tumors (2016)

SCIB1 combined with PD-1 blockade induced efficient therapy of poorly immunogenic tumors (2016)

Wei Xue, Victoria A. Brentville, Peter Symonds, Katherine W. Cook, Hideo Yagita, Rachael L. Metheringham and Lindy G. Durrant

ABSTRACT:

Purpose: We have previously shown that supraoptimal signaling of high avidity T cells leads to high expression of PD-1 and inhibition of proliferation. This study was designed to see if this effect could be mitigated by combining a vaccine that stimulates high avidity T cells with PD-1 blockade.

Experimental Design: We investigated the anti-tumor effect of a huIgG1 antibody DNA vaccine (SCIB1) and PD-1 blockade.

Results: Vaccination of HLA-DR4 transgenic mice with SCIB1 induced high frequency and avidity T cell responses that resulted in survival (40%) of mice with established B16F1-DR4 tumors. SCIB1 vaccination was associated with increased infiltration of CD4 and CD8 T cells within the tumor but was also associated with upregulation of PD-L1 within the tumor environment. PD-1 blockade also resulted in increased CD8 T cell infiltration and an anti-tumor response with 50% of mice showing long term survival.In line with our hypothesis that PD-1/PD-L1 signaling results in inhibition of proliferation of high avidity T cells at the tumor site, the combination of PD-1 blockade with vaccination, enhanced the number and proliferation of the CD8 tumor infiltrate. This resulted in a potent anti-tumor response with 80% survival of the mice.

Conclusions: There is a benefit in combining PD-1 blockade with vaccines that induce high avidity T cell responses and in particular with SCIB1.

Progress in Vaccination against Cancer 2016

PIVAC 2016 SCIB1 Clinical Trial Poster

L.G. Durrant, C. Ottensmeier, C. Mulatero, P. Lorigan, R. Plummer, R. Metheringham, V.Brentville, S. Adams, L. Machado, I. Daniels, D. Hannaman and P.M. Patel 

PIVAC 2016 Adjuvants for Moditope Poster

Katherine Cook, Peter Symonds, Victoria Brentville, Rachael Metheringham,  Wei Xue and Lindy Durrant

PIVAC 2016 Citrullinated Alpha Enolase Poster

K. Cook, I. Daniels, V. Brentville, R. Metheringham, W. Xue, P. Symonds, T. Pitt, M.Gijon and L. Durrant

PIVAC 2016 Protein Arginine Deiminase Enzymes Poster

R. Metheringham, M. Gijon, I. Daniels, K. Cook, P. Symonds, T. Pitt, W. Xue, V. Brentville and L. Durrant

SCIB2, an antibody DNA vaccine encoding NY-ESO-1 epitopes (2016)

SCIB2, an antibody DNA vaccine encoding NY-ESO-1 epitopes (2016)

Wei Xue, Rachael L. Metheringham, Victoria A. Brentville, Barbara Gunn, Peter Symonds, Hideo Yagita, Judith M.  Ramage and Lindy G. Durrant

ABSTRACT: Checkpoint blockade has demonstrated promising antitumor responses in approximately 10–40% of patients. However, the majority of patients do not make a productive immune response to their tumors and do not respond to checkpoint blockade. These patients may benefit from an effective vaccine that stimulates high-avidity T cell responses in combination with checkpoint blockade. We have previously shown that incorporating TRP-2 and gp100 epitopes into the CDR regions of a human IgG1 DNA (ImmunoBody®: IB) results in significant tumor regression both in animal models and patients. This vaccination strategy is superior to others as it targets antigen to antigen-presenting cells and stimulates high-avidity T cell responses. To broaden the application of this vaccination strategy, 16 NY-ESO-1 epitopes, covering over 80% of HLA phenotypes, were incorporated into the IB (SCIB2). They produced higher frequency and avidity T cell responses than peptide vaccination. These T cells were of sufficient avidity to kill NY-ESO-1-expressing tumor cells, and in vivo controlled the growth of established B16-NYESO-1 tumors, resulting in long-term survival (35%). When SCIB2 was given in combination with Treg depletion, CTLA-4 blockade or PD-1 blockade, long-term survival from established tumors was significantly enhanced to 56, 67 and 100%, respectively. Translating these responses into the clinic by using a combination of SCIB2 vaccination and checkpoint blockade can only further improve clinical responses.

Progress in Vaccination against Cancer 2015

PIVAC 2015 SCIB2 Poster

Wei Xue, Rachael Metheringham, Victoria Brentville, Katherine Cook, Peter Symonds, Ian Daniel and Lindy Durrant

PIVAC 2015 Moditope poster 2

V. Brentville, W. Xue, P. Symonds, K. Cook, B. Gunn, R. Metheringham and L.G. Durrant

PIVAC 2015 SCIB1 resected disease

L.G. Durrant, C. Ottensmeier, C. Mulatero, P. Lorigan, R. Plummer, R. Metheringham, V. Brentville, L. Machado, I. Daniels, D. Hannaman and P.M. Patel

PIVAC 2015 SCIB1 plus checkpoint inhibition

Wei Xue, Victoria Brentville, Rachael Metheringham, Katherine Cook, Peter, Symonds, Ian Daniels and Lindy Durrant

High avidity cytotoxic T lymphocytes can be selected into the memory pool but they are exquisitely sensitive to functional impairment (2012)

High avidity cytotoxic T lymphocytes can be selected into the memory pool but they are exquisitely sensitive to functional impairment (2012) 

Victoria A. Brentville, Rachael L. Metheringham, Barbara Gunn and Lindy G. Durrant

ABSTRACT: High avidity cytotoxic T lymphocytes (CTL) are important in viral clearance and anti-tumor immunity, however, mechanisms for their optimal generation and maintenance in vivo remain unclear. Immunizing mice with an antibody-DNA vaccine encoding a single CTL epitope, induces a 100 fold higher avidity response than peptide vaccination with the identical epitope. The high avidity response is retained into memory and can be efficiently reactivated with an antibody-DNA boost. In contrast, reactivation of high avidity CTL with peptide, stimulated responses with a significant drop in avidity, suggesting loss or conversion of the high avidity CTL to lower avidity. Similarly, high avidity T cells maintained ex vivo were exquisitely sensitive to signaling with low doses of peptide (1 ng/ml) giving optimal TCR stimulation and resulting in retained avidity, proliferation and ability to kill specific targets. In contrast, high avidity T cells maintained ex vivo with supraoptimal TCR stimulation (10 μg/ml peptide) resulted in reduced avidity and failure to kill tumor cells. They also failed to proliferate, showed a significant increase in apoptosis and expressed high levels of the exhaustion marker programmed death-1 (PD-1) and low levels of the lymphocyte-activation gene 3 (LAG-3). This suggests high avidity T cells are recruited to the memory pool but can be lost by supraoptimal stimulation in vitro and in vivo. This is characterized by loss of function and an increase in cell death. The remaining CTL, exhibit low functional avidity that is reflected in reduced anti-tumor activity. This could contribute to failure of the immune system to control the growth of tumors and has implications for vaccination strategies and adoptive transfer of T cells.

Vaccines as early therapeutic interventions for cancer therapy: neutralising the immunosuppressive tumour environment and increasing T cell avidity may lead to improved responses (2010)

DNA vaccination with T-cell epitopes encoded within Ab molecules induces high-avidity anti-tumor CD8 T cells (2009)

DNA vaccination with T-cell epitopes encoded within Ab molecules induces high-avidity anti-tumor CD8 T cells (2009)

Victoria A. Pudney, Rachael L. Metheringham, Barbara Gunn, Ian Spendlove, Judith M. Ramage and Lindy G. Durrant

ABSTRACT: Stimulation of high-avidity CTL responses is essential for effective anti-tumor and antiviral vaccines. In this study we have demonstrated that a DNA vaccine incorporating CTL epitopes within an Ab molecule results in high-avidity T-cell responses to both foreign and self epitopes. The avidity and frequency was superior to peptide, peptide-pulsed DC vaccines or a DNA vaccine incorporating the epitope within the native Ag. The DNA Ab vaccine was superior to an identical proteinvaccine that can only cross-present, indicating a role for direct presentation by the DNA vaccine. However, the avidity of CTL responses was significantly reduced in Fc receptor γ knockout mice or if the Fc region was removed suggesting that cross presentation of Ag via Fc receptor was also important in the induction of high-avidity CTL. These results suggest that generation of high-avidity CTL responses by the DNA vaccine is related to its ability to both directly present and crosspresent the epitope. High-avidity responses were capable of efficient anti-tumor activity in vitro and in vivo. This study demonstrates a vaccine strategy to generate high-avidity CTL responses that can be used in anti-tumor and anti-viral vaccine settings