Validation of an Immunohistochemistry Assay for Detection of CD155, the Poliovirus Receptor, in Malignant Gliomas

Abstract

Context. The oncolytic polio-rhinovirus recombinant (PVSRIPO) has demonstrated promise in currently ongoing phase I/II clinical trials against recurrent glioblastoma and was granted breakthrough therapy designation by the Food and Drug Administration/Center for Biologics Evaluation and Research. A reliable clinical assay to document expression of the poliovirus receptor, CD155, in routinely available patient tumor samples is needed for continued clinical development of PVSRIPO oncolytic immunotherapy in primary brain tumors and beyond. Objectives. To validate a novel anti-CD155 antibody for immunohistochemistry and develop a robust, reliable, and specific protocol for detecting CD155 expression in glioblastoma formalin-fixed, paraffin-embedded (FFPE) tissue samples. To characterize the expression of CD155 in human glioblastoma cells as well as to evaluate the influence of CD155 expression levels on tumor cell susceptibility to PVSRIPO infection and killing. Design. Immunohistochemical staining on glioblastoma FFPE tissue sections and immunoblot of corresponding frozen tissues were performed. Positive controls were confirmed sites of poliovirus propagation, spinal cord anterior horn, and tonsils; negative controls were vascular smooth muscle in patient samples and FFPE sections from a confirmed CD155-negative Burkitt lymphoma line (Raji). Results. We succeeded in developing a reliable assay to specifically detect CD155 by immunohistochemistry in glioblastoma FFPE sections. Our data suggest widespread, virtually universal expression of CD155 in glioblastoma cells at levels commensurate with susceptibility to PVSRIPO infection and killing. Conclusions. Anti-CD155 antibody D3G7H achieves monospecific detection of CD155 in immunoblots of tumor homogenates and immunohistochemistry of tumor FFPE sections. Our assay has utility in defining appropriate use of PVSRIPO in oncolytic immunotherapy against malignant glioma and other cancer histotypes.

Recombinant Poliovirus for Cancer Immunotherapy

“…These reservoirs for poliovirus propagation coincide with CD155 expression (9, 10). Poliovirus propagation in the gastrointestinal tract does not produce overt enteric pathology and is generally clinically silent; tropism for lower motor neurons is the reason for the pathognomonic signature of poliovirus -paralytic poliomyelitis- and an obvious grave concern for biosafety considerations.…”

“…CD155 expression is high in virtually all solid neoplasias (4), except Burkitt lymphoma, where CD155 is transcriptionally silenced, possibly due to Epstein Barr virus infection (43). We recently described validation of an immunohistochemistry protocol for reliable detection of CD155 expression in formaldehyde-fixed, paraffin-embedded tumor tissue sections [in glioblastoma; (9)]. Utilization of this assay in 19 samples of triple-negative breast cancer is shown in Figure 1.…”

“…Broadly upregulated CD155 expression in solid neoplasia means that neoplastic cells in such lesions are susceptible to PVSRIPO infection. While CD155 expression is categorically required for mediating tumor cell susceptibility to PVSRIPO, CD155 expression levels may not influence targeting by PVSRIPO (9), as the number of receptors required for productive infection of host cells likely is extremely low (51). …”

Recurrent Glioblastoma Treated with Recombinant Poliovirus

“…10 PVSRIPO tropism is determined by CD155, 11 a high-affinity ligand for the T-cell immunoreceptor with immunoglobulin and immunoreceptor tyrosine-based inhibition motif domains. 12 In solid tumors, CD155 is broadly up-regulated on malignant cells 13,14 and expressed in antigen-presenting cells. PVSRIPO infection of neoplastic cells in vitro results in lethal cytotoxic effects and activates innate antiviral interferon responses.…”

Potential Therapeutic Effect of Zika Virus in Glioblastoma Treatment

“…It should be reported that once recurrent, the median survival is only 4-7 months. 15,16 As cancer cells evolve to a totally malignant pattern and metastatic phenotype, they acquire multiple mutations and epigenetic modifications, creating a heterogeneous environment, resistant to standard treatment and frequently induce development in treatment refractory disease. Therefore, one of the challenges facing the cancer research community is to develop strategies that can combine and overcome the resistance mechanisms of the tumor.…”