Automated Multiplex Immunofluorescence Panel for Immuno-oncology Studies on Formalin-fixed Carcinoma Tissue Specimens

Summary

A detailed protocol for a six-marker multiplex immunofluorescence panel is optimized and performed, using an automated stainer for more consistent results and a shorter procedure time. This approach can be directly adapted by any laboratory for immuno-oncology studies.

Abstract

Continued developments in immuno-oncology require an increased understanding of the mechanisms of cancer immunology. The immunoprofiling analysis of tissue samples from formalin-fixed, paraffin-embedded (FFPE) biopsies has become a key tool for understanding the complexity of tumor immunology and discovering novel predictive biomarkers for cancer immunotherapy. Immunoprofiling analysis of tissues requires the evaluation of combined markers, including inflammatory cell subpopulations and immune checkpoints, in the tumor microenvironment. The advent of novel multiplex immunohistochemical methods allows for a more efficient multiparametric analysis of single tissue sections than does standard monoplex immunohistochemistry (IHC). One commercially available multiplex immunofluorescence (IF) method is based on tyramide-signal amplification and, combined with multispectral microscopic analysis, allows for a better signal separation of diverse markers in tissue. This methodology is compatible with the use of unconjugated primary antibodies that have been optimized for standard IHC on FFPE tissue samples. Herein we describe in detail an automated protocol that allows multiplex IF labeling of carcinoma tissue samples with a six-marker multiplex antibody panel comprising PD-L1, PD-1, CD68, CD8, Ki-67, and AE1/AE3 cytokeratins with 4′,6-diamidino-2-phenylindole as a nuclear cell counterstain. The multiplex panel protocol is optimized in an automated IHC stainer for a staining time that is shorter than that of the manual protocol and can be directly applied and adapted by any laboratory investigator for immuno-oncology studies on human FFPE tissue samples. Also described are several controls and tools, including a drop-control method for fine quality control of a new multiplex IF panel, that are useful for the optimization and validation of the technique.

Introduction

Immunoprofiling analysis of FFPE tumor tissue samples has become an essential component of immuno-oncology studies, particularly for the discovery and validation of novel predictive biomarkers for cancer immunotherapy in the context of clinical trials^1,2. Chromogenic IHC, using chemical chromogens such as diaminobenzidine, remains the standard technique in diagnostic pathology for the immunolabeling of biopsy tissue³. Standard IHC can also be used for cancer tissue immunoprofiling, including the quantitation of subpopulations of tumor-associated lymphocytes and the assessment of express....

Protocol

NOTE: The protocol presented here describes how to perform immunoprofiling of an mIF panel by using TSA for six antibodies (CD68, ki67, PD-L1, PD-1, CD8, and AE1/AE3) on an automated stainer (see Table of Materials). The protocol also describes how to perform the drop controls for a quality control of a new mIF panel (see Supplemental Materials). In this protocol, staining is performed with eight unstained FFPE slides from human tonsil (positive control) and eight unstai.......

Discussion

The ongoing cancer immunotherapy revolution is opening novel and promising therapeutic options for cancer patients¹³. Advances in the field of immuno-oncology will require increased knowledge of the inflammatory tumor microenvironment, not only to understand the biology of the immunological mechanisms involved in carcinogenesis but also to find predictive biomarkers for new immunotherapy-based treatments^1,2. Due to the complex biology of c.......

Materials

Name	Company	Catalog Number	Comments
"InForm 2.4.2" Software for Spectral Unmixing and Image Analysis	PerkinElmer	CLS151066	Called "spectral unmixing software" in text
"Phenochart 1.0.9" QPTIFF Software for Selection of MSI and Overall Slide Scan Viewing	PerkinElmer	CLS151067	Called "QPTIFF software" in text
#1.5 Coverslips	Sigma Aldrich	2975246
200 Proof Ethanol	Koptec	V1001
20x Tris-Buffered Saline	VWR	J640-4L
Antibody Diluent	DAKO	S2203
Anti-CD68 Mouse Monoclonal	DAKO	M087601-2	Clone PG-M1
Anti-CD8 Rabbit Monoclonal	Ventana	M5392	Clone SP239
Anti-CK Mouse Monoclonal	DAKO	M351501-2	Clone AE1/AE3
Anti-ki67 Mouse Monoclonal	DAKO	M724001-2	Clone MIB-1
Anti-PD-1 Rabbit Monoclonal	Cell Signaling	#86163	Clone D4W2J
Anti-PD-L1 Rabbit Monoclonal	Ventana	790-4905	Clone SP263
Bond Dewax Solution	Leica	AR9222	Called "dewax solution" in text
Bond Epitope Retrieval Solution 1	Leica	AR9961	Called "ER1" in text
Bond Epitope Retrieval Solution 2	Leica	AR9640	Called "ER2" in text
Bond Open Containers, 30 mL	Leica	OP309700	Called "30 mL open containers" in text
Bond Open Containers, 7 mL	Leica	OP79193	Called "7 mL open containers" in text
Bond Polymer Refine Detection	Leica	DS9800	Called "chromogenic detection kit" in text
Bond Research Detection Kit	Leica	DS9455	Called "research detection kit" in text
Bond Titration Kit	Leica	OPT9049	Called "titration kit" in text
Bond Universal Covertile Novocastra	Leica	S21.2001	Called "covertiles" in text
Bond Wash Solution 10X Concentrate	Leica	AR9590	Called "10x wash solution" in text
BondRX Autostainer	Leica		Called "automated stainer" in text
BondRX Software Version 5.2.1.204	Leica		Called "automated stainer software" in text
Opal 7-Color Automation IHC Kit	PerkinElmer	NEL801001KT	Called "multispectral staining kit" in text
Peroxidase Block	Leica	RE7101
ProLong Diamond Antifade Mountant	Thermo	P36965	Called "slide mountant" in text
Starfrost Slides	Fisher	15-183-51
Vectra Polaris Multispectral Microscope with "Vectra 3.0.5" Software for Multispectral Microscope Control	PerkinElmer	CLS143455	Called "microscope control software" in text