Quantitation of retroviral gp70 antigen, autoantibodies, and immune complexes in extravascular space in arthritic mrl‐lpr/lpr mice. use of a subcutaneously implanted tissue cage model

Abstract

MRL‐lpr/lpr (MRL/1) mice spontaneously develop a disease that is characterized by glomerulonephritis, diffuse vasculitis, and arthritis associated with high levels of autoantibodies that include IgG rheumatoid factor (RF). To define the immunopathogenic mechanisms that lead to the development of extravascular lesions such as arthritis, we implanted a tissue cage subcutaneously in arthritic MRL/1 mice and compared components of the tissue cage fluid, which resembles the extravascular fluid, with those of sera. When compared with those of sera, tissue cage fluids from arthritic MRL/1 mice had similar levels of RF and one‐third the amount of Clq immune complexes. In contrast, anti‐DNA activities in tissue cage fluids corresponded to only 10% of the serum activities and, most strikingly, nephritogenic retroviral gp70‐anti‐gp70 immune complexes were almost undetectable in tissue cage fluids. This was also the case for another strain of autoimmune mice, (New Zealand black x New Zealand white)F1 mice, although they did not produce RF. The absence of gp70 immune complexes in tissue cage fluids could be due to markedly limited diffusion of gp70 antigen in these fluids. These results strongly suggest that serum proteins, including autoantigen and autoantibodies, appear in extravascular fluid in a selective manner, depending on their size and charge. Their specific properties in sera or extravascular fluid could partly account for the different manifestations of vascular and extravascular lesions observed in autoimmune mice.

Alanylation of Teichoic Acids ProtectsStaphylococcus aureusagainst Toll‐like Receptor 2–Dependent Host Defense in a Mouse Tissue Cage Infection Model

“…We kept 12-16-week-old female C57BL/6 wt mice (purchased from RCC) and TLR2 Ϫ/Ϫ mice, which had been backcrossed for 6 generations on a C57BL/6 background, under specific pathogen-free conditions in the Animal House of the Department of Research, University Hospitals Basel, according to the regulations of the Swiss veterinary law. Mice were anesthetized via intraperitoneal injection of 100 mg/kg ketamine (Ketalar; Warner-Lambert) and 20 mg/ kg xylazinum (Xylapan; Graeub), and a sterile tissue cage was implanted subcutaneously in the back [29,30]. The cages (internal and external diameters, 8 and 10 mm, respectively; length, 30 mm; internal volume, 1.84 mL) were identical to those used in the guinea pig foreign body infection model, as described elsewhere [15], and consisted of closed polytetrafluoroethylene Teflon cylinders with 130 regularly spaced 0.2-mm holes and contained 8-sinter glass beads.…”

Weak effect of metal type and ica genes on staphylococcal infection of titanium and stainless steel implants

“…Mice were anaesthetized via intraperitoneal injection of ketamine (100 mg/kg) (Ketalar; Pfizer AG, Zürich, Switzerland) and xylazinum (20 mg/kg) (Xylasol; Graeub AG, Bern, Switzerland). Sterile cages were subcutaneously implanted under aseptic conditions into an air pouch in the back of the mouse [25,28,29]. Inocula (200 μL) containing 10 2 –10 4 CFUs S. aureus and 10 4 –10 6 CFUs S. epidermidis were injected with a 25‐gauge needle percutaneously, either perioperatively or postoperatively (14 days after cage implantation).…”