Laparoscopic Technique for Serial Collection of Liver and Mesenteric Lymph Nodes in Macaques

Abstract

The mesenteric lymph nodes (MLN) and the liver are exposed to microbes and microbial products from the gastrointestinal (GI) tract, making them immunologically unique. The GI tract and associated MLN are sites of early viral replication in human immunodeficiency virus (HIV) infection and the MLN are likely important reservoir sites that harbor latently-infected cells even after prolonged antiretroviral therapy (ART). The liver has been shown to play a significant role in immune responses to lentiviruses and appears to play a significant role in clearance of virus from circulation. Nonhuman primate (NHP) models for HIV and Acquired Immunodeficiency Syndrome (AIDS) closely mimic these aspects of HIV infection and serial longitudinal sampling of primary sites of viral replication and the associated immune responses in this model will help to elucidate critical events in infection, pathogenesis, and the impact of various intervention strategies on these events. Current published techniques to sample liver and MLN together involve major surgery and/or necropsy, which limits the ability to investigate these important sites in a serial fashion in the same animal. We have previously described a laparoscopic technique for collection of MLN. Here, we describe a minimally invasive laparoscopic technique for serial longitudinal sampling of liver and MLN through the same two port locations required for the collection of MLN. The use of the same two ports minimizes the impact to the animals as no additional incisions are required. This technique can be used with increased sampling frequency compared to major abdominal surgery and reduces the potential for surgical complications and associated local and systemic inflammatory responses that could complicate interpretation of results. This procedure has potential to facilitate studies involving NHP models while improving animal welfare.

Mitigation of endemic GI-tract pathogen-mediated inflammation through development of multimodal treatment regimen and its impact on SIV acquisition in rhesus macaques

“…All animals had three rounds of negative culture and parasitology results prior to declaration of GPF status and post-treatment sampling. All enrolled study animals had baseline samples of spleen, mesenteric lymph nodes (MLN), and liver by a minimally invasive laparoscopic surgery [ 43 ], scopeless bronchoalveolar lavage (BAL) [ 44 ], microbiome fecal collection, axillary lymph node (ALN), bone marrow, and distal descending colonic mucosal pinch biopsies taken prior to administration of the treatment. These samplings were repeated 6 weeks post-administration of the last dose of the additional round of fenbendazole.…”

The human IL-15 superagonist N-803 promotes migration of virus-specific CD8+ T and NK cells to B cell follicles but does not reverse latency in ART-suppressed, SHIV-infected macaques

“…All N-803 injections were given as subcutaneous doses of 100 μg/kg. Axillary and inguinal lymph node biopsies, colon biopsies and laparoscopic collection of mesenteric lymph node and spleen were collected in accordance with the procedures outlined [35]. The Oregon Health & Science University Institutional Animal Care and Use Committee reviewed and approved all study protocols, which were in accordance with the U.S. Department of Health and Human Services' Guide for the Care and Use of Laboratory Animals.…”

Antimicrobial prophylaxis does not improve post-surgical outcomes in SIV/SHIV-uninfected or SIV/SHIV-infected macaques (Macaca mulatta and Macaca fascicularis) based on a retrospective analysis

“…Once prepared for surgery, the patient was draped with sterile towels and cloth drapes, and all procedures were performed using aseptic technique. Laparoscopic MLN and liver biopsies were otherwise collected as described by Zevin et al [ 9 ]. If the spleen was biopsied, the cannula and endoscope were relocated to the paraumbilical port site, and the spleen was visualized.…”

“…SIV-infected animals commonly undergo serial surgical biopsies throughout the course of their study to sample primary and secondary lymphoid and mucosal sites. Common surgical procedures include peripheral lymph node biopsy, laparoscopic biopsies (mesenteric lymph node, liver, and spleen), and mucosal pinch biopsies [ 7 – 9 ]. Unfortunately, antimicrobial prophylaxis for these procedures is frequently unreported in the literature, despite their common use for the reasons previously discussed and due to the perceived increased risk of SSIs from presumed SIV related immunosuppression [ 10 ].…”