laparoscopic-technique-for-serial-collection-liver-mesenteric-lymph

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

The mesenteric lymph nodes (MLN) and the liver are exposed to microbes and microbial products from the gastrointestinal (GI) tract, making them ...

Washington National Primate Research Center, University of Washington

Unlike peripheral lymph nodes (PLN), the mesenteric lymph nodes (MLN) draining the gastrointestinal (GI) tract are exposed to microbes and microbial products from the intestines and as such, are immunologically distinct. GI draining (MLN) have also been shown to be sites of early viral replication and likely impact early events that determine the course of HIV infection. They also are important reservoir sites that harbor latently-infected cells and from which the virus can emerge even after prolonged combination antiretroviral therapy (cART). Changes in the microbial flora and increased permeability of the GI epithelium associated with lentiviral infection can impact the gut associated lymphoid tissue (GALT) and induce changes to secondary lymphoid organs limiting immune reconstitution with cART. Nonhuman primate models for AIDS closely model HIV infection in humans and serial sampling of the GALT and associated secondary lymphoid organs in this model is crucial to gain a better understanding of the critical early events in infection, pathogenesis, and the role of immune responses or drugs in controlling virus at these sites. However, current techniques to sample GI draining (MLN) involve major surgery and/or necropsy, which have, to date, limited the ability to investigate mechanisms mediating the initiation, persistence and control of infection in this compartment. Here, we describe a minimally invasive laparoscopic technique for serial sampling of these sites that can be used with increased sampling frequency, yields greater cell numbers and immune cell subsets than current non-invasive techniques of the GALT and reduces the potential for surgical complications that could complicate interpretation of the results. This procedure has potential to facilitate studies of pathogenesis and evaluation of preventive and treatment interventions, reducing sampling variables that can influence experimental results, and improving animal welfare.

Laparoscopic Technique for Serial Collection of Para-Colonic, Left Colic, and Inferior Mesenteric Lymph Nodes in Macaques.

Biomedical translational research frequently incorporates collection of CSF from NHP, because CSF drug levels are used as a surrogate for CNS tissue penetration in pharmacokinetic and dynamic studies. Surgical placement of a CNS ventricular catheter reservoir for CSF collection is an intensive model to create and maintain and thus may not be feasible or practical for short-term studies. Furthermore, previous NHP lumbar port models require laminectomy for catheter placement. The new model uses a minimally invasive technique for percutaneous placement of a lumbar catheter to create a closed, subcutaneous system for effective, repeated CSF sample collection. None of the rhesus macaques (Macaca mulatta; n = 10) implanted with our minimally invasive lumbar port (MILP) system experienced neurologic deficits, postoperative infection of the surgical site, or skin erosion around the port throughout the 21.7-mo study. Functional MILP systems were maintained in 70% of the macaques, with multiple, high-quality, 0.5- to 1.0-mL samples of CSF collected for an average of 3 mo by using aspiration or gravitational flow. Among these macaques, 57% had continuous functionality for a mean of 19.2 mo; 50% of the cohort required surgical repair for port repositioning and replacement during the study. The MILP was unsuccessful in 2 macaques, at an average of 9.5 d after surgery. Nonpatency in these animals was attributed to the position of the lumbar catheter. The MILP system is an appropriate replacement for temporary catheterization and previous models requiring laminectomy and is a short-term alternative for ventricular CSF collection systems in NHP.

Solomon Wangari

Division of Primate Resources

Washington National Primate Research Center, University of Washington

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

Solomon Wangari

.css-o250i3{font-size:18px;font-family:Open Sans,sans-serif;line-height:21.6px;}Division of Primate Resources

Washington National Primate Research Center, University of Washington

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

Division of Primate Resources