Adjuvant induced arthritis

Adjuvant Arthritis in the Rat
Adjuvant arthritis (AA) is an induced form of (sub)chronic arthritis. Strains of rats have a varying genetic susceptibility to AA, whereas mice generally are notsusceptible. AA is most easily induced with mycobacteria suspended in oil, although in some strains of rats it can be induced with oily adjuvants in the absence of mycobacteria. The disease is a Tcell–mediated autoimmune arthritis that is frequently used to study immunological aspects of rheumatoid arthritis (RA) and other arthritic or inflammatory diseases in humans. Furthermore, it is used as a modelfor developing and testing antiinflammatory drugs. There are no particularly well-defined autoantigens in AA; in this respect, the model resembles spontaneous arthritic diseases in humans. In allsusceptible rat strains, the inflammatory process of AA is self remitting, although usually the disease is severe and leads to permanent joint malformations, including ankylosis; a time line for AAdevelopment is presented in Figure 15.4.1. This unit describes the induction and evaluation of AA (see Basic Protocol) and the preparation of adjuvant used to induce AA (see Support Protocol). INDUCTION OFADJUVANT ARTHRITIS In this protocol, adjuvant arthritis (AA) is induced in Lewis rats in the classical manner using ground, heat-killed Mycobacterium tuberculosis H37Ra suspended in incomplete Freund’sadjuvant (IFA; see Support Protocol). Disease development is monitored daily during the critical period (days 10 to 35 post immunization) using one or more possible techniques. The success rate ofthe procedure should approach 100%. Materials 10 mg/ml heat-killed Mycobacterium tuberculosis (strain H37Ra) suspended in incomplete Freund’s adjuvant (IFA; see Support Protocol) Lewis rats, 6 to 12weeks old and pathogen free 1-ml glass syringe 20- and 25-G needles Scale Restraining device for rats Wet cotton Additional reagents and equipment for animal care, handling, and restraint (UNITS...