Histoculture and Infection with HIV of Functional Human Lymphoid Tissue on Gelfoam®

Gelfoam^® histoculture provides a valuable tool for experimental studies of normal and pathological tissue physiology. It allows us to understand cell-cell interactions by mirroring their original spatial relationship within body tissues. Gelfoam^® histoculture can be employed to model host-pathogen interactions mimicking in vivo conditions in vitro. In the present chapter, we describe a protocol to process and infect lymphoid tissue explants with HIV and maintain them in Gelfoam^® histoculture at the liquid-air interface. The Gelfoam^® histocultures with human immunodeficiency virus (HIV) type 1-infected tissues have been used to further understand the biology of early HIV-1 pathogenesis, as well as a novel ex vivo platform to test the efficacy and toxicity of antiviral drugs.

Imaging DNA Repair After UV Irradiation Damage of Cancer Cells in Gelfoam® Histoculture

DNA damage repair in response to UVC irradiation was imaged in cancer cells growing in Gelfoam^® histoculture. UVC-induced DNA damage repair was imaged with green fluorescent protein (GFP) fused to the DNA damage response (DDR)-related binding protein 53BP1 in MiaPaCa-2 human pancreatic cancer cells. Three-dimensional Gelfoam^® histocultures and confocal imaging enabled 53BP1-GFP nuclear foci to be observed within 1 h after UVC irradiation, indicating the onset of DNA damage repair response. Induction of UV-induced 53BP1-GFP focus formation was limited up to a depth of 40 μm in Gelfoam^® histoculture of MiaPaCa-2 cells, indicating this was the depth limit of UVC irradiation.

Expression and Targeting of Tumor Markers in Gelfoam® Histoculture: Potential Individualized Assays for Immuno-Oncology

Tumor-specific antigens are important in the study of tumor biology, tumor diagnosis, and prognosis and as targets for tumor therapy. This chapter reviews patient colon, breast, and ovarian tumors in 3-dimensional Gelfoam^® histoculture maintaining in vivo-like expression of the important tumor antigens, for example TAG-72 and CEA. We have also reviewed that fluorescent antibodies can target tumors in Gelfoam^® histoculture, thereby providing an assay for individual patients for sensitivity to therapeutic antibodies which have become so important in immuno-oncology and other cancer therapies.

Imaging the Governing Step of Metastasis in Gelfoam® Histoculture

Distant organ colonization by cancer cells is the governing step of metastasis. We review in this chapter the modeling and imaging of organ colonization by cancer cells in Gelfoam^® histoculture. ANIP 973 lung cancer cells expressing green fluorescent protein (GFP) were injected intravenously into nude mice, whereby they formed brilliantly fluorescing metastatic colonies on the mouse lung. The seeded lung tissue was then excised and incubated in the three-dimensional Gelfoam^® histoculture that maintained the critical features of progressive in vivo organ colonization. Tumor progression was continuously visualized by GFP fluorescence of individual cultures over a 52-day period, during which tumor colonies spread throughout the lung. Organ colonization was selective in Gelfoam^® histoculture for lung cancer cells to grow on lung tissue, since no growth occurred on histocultured mouse liver tissue. The ability to support selective organ colonization in Gelfoam^® histoculture and visualize tumor progression by GFP fluorescence allows the in vitro study of the governing processes of metastasis.

Nestin-Expressing Hair-Follicle-Associated Pluripotent (HAP) Stem Cells Promote Whisker Sensory-Nerve Growth in Long-Term 3D-Gelfoam® Histoculture

Mouse whiskers containing hair-follicle-associated pluripotent (HAP) stem cells, from nestin-driven green fluorescent protein (ND-GFP) transgenic mice, were placed in 3D histoculture supported by Gelfoam(®). β-III tubulin-positive fibers, consisting of ND-GFP-expressing HAP stem cells, extended up to 500 mm from the whisker nerve stump in histoculture. The growing fibers had growth cones on their tips expressing F-actin indicating they were growing axons. The growing whisker sensory nerve was highly enriched in ND-GFP HAP stem cells which appeared to play a major role in its elongation and interaction with other nerves placed in 3D culture, including the sciatic nerve, the trigeminal nerve, and the trigeminal nerve ganglion. The results suggested that a major function of HAP stem cells in the hair follicle is for growth of the hair follicle sensory nerve.

3D Sponge-Matrix Histoculture: An Overview

Three-dimensional cell culture and tissue culture (histoculture) is much more in vivo-like than 2D culture on plastic. Three-dimensional culture allows investigation of crucial events in tumor biology such as drug response, proliferation and cell cycle progression, cancer cell migration, invasion, metastasis, immune response, and antigen expression that mimic in vivo conditions. Three-dimensional sponge-matrix histoculture maintains the in vivo phenotype, including the formation of differentiated structures of normal and malignant tissues, perhaps due to cells maintaining their natural shape in a sponge-gel matrix such as Gelfoam^®. Sponge-matrix histoculture can also support normal tissues and their function including antibody-producing lymphoid tissue that allows efficient HIV infection, hair-growing skin, excised hair follicles that grow hair, pluripotent stem cells that form nerves, and much more.

Human cytomegalovirus infection induces leukotriene B4 and 5-lipoxygenase expression in human placentae and umbilical vein endothelial cells

INTRODUCTION

Human cytomegalovirus (HCMV) can cause congenital infection with risk of neurological disability. Maternal-fetal transmission is associated with placental inflammation. 5-lipoxygenase (5-LO) is the key enzyme in the biosynthesis of Leukotrienes (LTs), which are proinflammatory mediators. This study investigated the effect of HCMV infection on 5-LO expression and Leukotriene-B4 (LTB4) induction in human placentae and umbilical vein endothelial cells (HUVEC).

METHODS

Seven placentae from fetuses with congenital HCMV infection and brain damage and six controls were stained with HCMV-immediate-early-antigen (HCMV-IEA) and 5-LO by immunohistochemistry. 5-hydroxyeicosatetraenoic acid (5-HETE) and LTB4 were measured in culture supernatant from ex vivo HCMV-infected placental histocultures by liquid chromatography. In vitro, HCMV infected HUVEC cells were analyzed for 5-LO mRNA and protein expression by real time PCR and immunofluorescence staining.

RESULTS

HCMV-IEA was abundant in all HCMV infected placentae but absent in control placentae. 5-LO expression was higher in endothelial and smooth muscle cells of HCMV-infected placentae, compared to control placentae. HCMV infection induced an up-regulation of LTB4 in ex vivo placental explants with higher levels of LTB4 at 72 h compared to controls (p = 0.002). In vitro, 5-LO transcript and protein expression were significantly induced in HCMV-infected HUVEC, compared to the control cultures (p = 0.036).

CONCLUSION

The presence of HCMV coincided with high 5-LO expression in cells of in vivo HCMV infected placentae. HCMV induced up-regulation of 5-LO in both ex vivo HCMV-infected placental explants and HUVEC. HCMV induced LT-biosynthesis in congenitally infected placentae may have a role in pathogenesis of congenital HCMV disease.