A simple and enzyme-free method for processing infiltrating lymphocytes from small mouse tumors for ELISpot analysis

Area of Science:

• Immunology
• Cellular Biology
• Biotechnology

Background:

• ELISpot assays are crucial for detecting antigen-specific immune responses.
• Processing lymphocytes from solid tumors, especially small ones, is challenging due to low cell numbers and limitations of traditional enzymatic methods.
• Enzymatic dissociation can negatively impact lymphocyte viability and function.

Purpose of the Study:

• To develop and validate an enzyme-free protocol for efficient isolation of tumor-infiltrating lymphocytes (TILs) from small mouse tumors.
• To enable sensitive enumeration of antigen-specific effector lymphocytes via ELISpot analysis from limited tissue samples.
• To overcome the limitations of enzymatic dissociation methods for TIL preparation.

Main Methods:

• A novel enzyme-free protocol involving gentle agitation with a paddle blender for tumor dissociation.
• A short in vitro culture period post-dissociation to eliminate adherent cells and revive lymphocytes.
• Application of the protocol to small mouse tumors, including intracerebral and peripheral models.

Main Results:

• The enzyme-free method successfully isolates viable tumor-infiltrating lymphocytes (TILs) from small mouse tumors.
• The protocol enables effective ELISpot analysis for enumerating antigen-specific effector lymphocytes.
• The method demonstrates applicability to various tumor types and potentially other tissues with low lymphocyte populations.

Conclusions:

• The developed enzyme-free protocol provides a robust and sensitive method for processing small tumors for ELISpot analysis.
• This approach enhances lymphocyte recovery and preserves their functional integrity compared to enzymatic methods.
• The protocol is adaptable and holds promise for broader applications in immunological studies involving low-yield tissues.