Minimally Invasive Preclinical Monitoring of the Peritoneal Cavity Tumor Microenvironment

Area of Science:

• Immunology
• Oncology
• Preclinical Research

Background:

• Intraperitoneal (i.p.) models in mice are crucial for studying abdominal cancer dissemination and the peritoneal cavity's immune microenvironment.
• Current methods for analyzing the peritoneal cavity involve terminal lavage, limiting continuous monitoring and increasing study costs and variability.
• The peritoneal cavity hosts diverse immune cells, including T, B, NK, and myeloid cells, vital for understanding various pathophysiological states.

Purpose of the Study:

• To introduce a novel, minimally invasive method for real-time monitoring of the peritoneal cavity in mice.
• To demonstrate the utility of this method for studying the i.p. tumor microenvironment (TME) in ovarian cancer models.
• To assess the potential of this technique for evaluating novel cancer therapies, such as CAR-T cell therapy.

Main Methods:

• Development and application of in vivo intraperitoneal lavage (IVIPL) for serial sampling of the peritoneal cavity.
• Utilizing IVIPL in a human high-grade serous ovarian cancer (HGSOC) xenograft mouse model to study CAR-T cell therapy.
• Applying IVIPL in a mouse HGSOC syngeneic model to analyze i.p. TME immune composition.

Main Results:

• IVIPL provides a simple, minimally invasive approach for continuous monitoring of peritoneal cavity cellularity.
• The method offers real-time insights into the i.p. tumor microenvironment, crucial for cancer therapy development.
• Proof-of-concept demonstrated IVIPL's effectiveness in tracking CAR-T cell therapy and characterizing immune cell populations in ovarian cancer models.

Conclusions:

• In vivo intraperitoneal lavage (IVIPL) is a valuable tool for advancing preclinical research in abdominal cancers and other peritoneal cavity-related conditions.
• This technique overcomes limitations of terminal lavage, enabling longitudinal studies and reducing animal usage.
• IVIPL facilitates real-time assessment of therapeutic responses and immune dynamics within the peritoneal microenvironment.