Isolating Lymphocytes from the Mouse Small Intestinal Immune System

Summary

Here we describe a detailed protocol for the isolation of lymphocytes from the inductive sites including the gut-associated lymphoid tissue Peyer's patches and the draining mesenteric lymph nodes, and the effector sites including the lamina propria and the intestinal epithelium of the small intestinal immune system.

Abstract

The intestinal immune system plays an essential role in maintaining the barrier function of the gastrointestinal tract by generating tolerant responses to dietary antigens and commensal bacteria while mounting effective immune responses to enteropathogenic microbes. In addition, it has become clear that local intestinal immunity has a profound impact on distant and systemic immunity. Therefore, it is important to study how an intestinal immune response is induced and what the immunologic outcome of the response is. Here, a detailed protocol is described for the isolation of lymphocytes from small intestine inductive sites like the gut-associated lymphoid tissue Peyer's patches and the draining mesenteric lymph nodes and effector sites like the lamina propria and the intestinal epithelium. This technique ensures isolation of a large numbers of lymphocytes from small intestinal tissues with optimal purity and viability and minimal cross compartmental contamination within acceptable time constraints. The technical capability to isolate lymphocytes and other immune cells from intestinal tissues enables the understanding of immune responses to gastrointestinal infections, cancers, and inflammatory diseases.

Introduction

The gastrointestinal (GI) tract has many folds and protrusions that represents the largest interface separating the internal body and the external environment. The intestinal immune system plays an essential role in maintaining the barrier function of the GI tract. It is constantly exposed to dietary antigens, commensal bacteria, and pathogenic microbes. As such, it must remain tolerant to food antigens and commensal bacteria while preserving the capacity to rapidly generate an effective immune response to enteropathogenic microbes¹. The intestinal immune system can be anatomically divided into inductive sites, where naïve lymphocytes are ....

Protocol

All animal experiments were conducted in accordance with National Institute of Health guidelines and approved by the Stony Brook University Institutional Animal Care and Use Committee.

NOTE: Ensure that all approvals are granted prior to performing procedures.

1. Solution Preparation

1. HGPG (HEPES, L-glutamine, penicillin/streptomycin, and gentamycin), 100×
   1. Mix 59.6 g HEPES (500 mM final), 14.6 g L-glutamine (200 mM final), 1×10⁶ U penicillin (2,000 U/mL final), 1 g streptomycin (2 mg/mL final), and 2.5 mg gentamicin (5 µg/mL final). Add RPMI 1640 t....

Results

A schematic representation of the protocol is depicted (Figure 1). Lymphocytes within the intestinal mucosa inductive and effector sites are distinctly organized. Peyer's patches (PP) and mesenteric lymph nodes (MLN) contain lymphocytes in well-organized T-cell areas and B-cell follicles, whereas the intestinal epithelium contains lymphocytes that are more diffusely distributed. The lamina propria (LP) contains both diffusely distributed lymphocytes and lymph.......

Discussion

A detailed protocol is presented for the isolation of lymphocytes from the intestinal mucosal inductive (MLN and PP) and effector (LP and IEL compartment) sites. The protocol has been developed to balance input (time) and output (viability and yield) to maximize productivity and results. The protocol also ensures minimal cross compartmental contamination between LP and IEL compartments.

Several protocols for the isolation of immune cells from the mouse small intestine have been published

Materials

List of materials used in this article

Name	Company	Catalog Number	Comments
HEPES	Fisher Scientific	BP310-500
L-glutamine	Sigma-aldrich	G3126-100G
Penicillin-Streptomycin	Life Technologies	15140-122
Gentamicin	Life Technologies	15710-072
Sodium Hydroxide	Fisher Scientific	S318-500
RPMI 1640	Life Technologies	21870-076
Sodium bicarbonate	Fisher Scientific	S233-500
Fetal bovine serum	Life Technologies	26140-079
10x Hanks' balanced salt solution	Sigma-aldrich	H4641-500ML
1,4-Dithioerythritol	Sigma-aldrich	D9680-5G
0.5M EDTA, pH 8.0	Life Technologies	15575-020
Calsium chloride hexahydrate	Sigma-aldrich	21108-500G
Magnesium chloride hexahydrate	Sigma-aldrich	M2670-100G
Collagenase, Type I	Life Technologies	17100-017
DG gradient stock solution (Percoll)	GE Healthcare	17-0891-01
Red Blood Cell Lysis Buffer	Biolegend	420301
70-µm cell strainer	Corning	352350
14 mL Polypropylene Round-Bottom Tube	Corning	352059
Erlenmeyer flask	Kimble	26500R-50mL
Magnetic stirrer	Thermo Fisher	50094596
Stir bar	Fisher Scientific	14-512-148