Administration of group A streptococcal cell walls to rats induces an interleukin 2 deficiency.

Intraperitoneal administration of group A streptococcal cell walls to Lewis rats induces a chronic arthritis, whereas the Fischer strain is resistant to the development of the lesion. Spleen cells from cell wall-treated rats (Lewis and Fischer) are deficient in the synthesis of IL-2. Using an mAb directed against the rat IL-2-R, the present studies indicate that the expression of IL-2-R on spleens of cell wall-treated rats is normal. However, the addition of exogenous IL-2 to spleen cells cultured with Con A does not stimulate the mitogenic response.

Properties of a collagenase inhibitor partially purified from cultures of smooth muscle cells.

An inhibitor of mammalian collagenase has been partially purified from the spent medium of smooth muscle cells grown in culture. The inhibitor is a glycoprotein with an apparent molecular weight of 25,000. It is stable to heat, acid, and mercurials, but is destroyed by trypsin treatment and by reductive alkylation. The inhibitor interacts with active mammalian collagenase and this interaction results in the loss of enzymatic activity. This presumptive collagenase-inhibitor complex is stable to the treatment with mercurials and to trypsin. These latter observations suggest that this inhibitor is different from other collagenase inhibitors that are thought to be responsible for the latency of the enzyme.

Purification and properties of a collagenase inhibitor from cultures of bovine aorta.

Bovine medial explants in culture synthesize a potent inhibitor of mammalian collagenase but not of bacterial collagenase. This inhibitor has been partially purified and has an apparent molecular weight of 45,000. It is a glycoprotein and is stable to heat, trypsin, acid and mercurials. Inhibitory activity is destroyed on reductive alkylation. The inhibitor interacts with collagenase and this interaction leads to the loss of enzymatic activity. This inhibitor may play a physiological role in the control of collagen degradation in blood vessels.

In vitro synthesis of anticollagen IgG by sensitized lymph node cells derived from type II collagen-induced polyarthritic rats.

Using lymph node cells from Type II collagen-induced polyarthritic rats, the present studies describe an in vitro system that is active in the synthesis of anticollagen IgG. Synthesis of anticollagen IgG by these cells is blocked by the addition of cycloheximide, indicating a requirement for de novo protein synthesis. The predominant anticollagen IgG synthesized is IgG2a; this subclass also represents the major anticollagen IgG present in the serum and the cartilage of polyarthritic rats. Synthesis of anticollagen IgG is inhibited by a mixture of D-penicillamine and copper sulfate. These latter observations suggest that the in vitro system described is responsive to pharmacologic intervention.

Streptococcal cell wall arthritis: studies with nude (athymic) inbred Lewis rats.

Group A streptococcal cell walls, upon intraperitoneal administration, fail to induce a chronic arthritis in athymic inbred Lewis rats (mu/mu). In contrast, heterozygous euthymic littermates (+/mu) develop a chronic arthritis upon administration of the cell wall material. Chronic arthritis can be readily induced in athymic rats if they are reconstituted intravenously with spleen cells derived from normal heterozygous euthymic littermates. Both athymic and euthymic rats develop the acute arthritis elicited by cell walls. These studies indicate that the requirements in the host for the induction of acute and chronic arthritis are different. Induction of acute arthritis is not dependent on functional T lymphocytes whereas the induction of chronic arthritis is dependent on functional T cells.

Studies on the effect of D-penicillamine, gold thioglucose and methotrexate on streptococcal cell wall arthritis.

Intraperitoneal administration of group A streptococcal cell walls to rats induces an acute arthritis that resolves and is followed by a chronic lesion. The effect of low dose methotrexate, D-penicillamine and gold thioglucose has been investigated in this model. Whereas D-penicillamine and gold thioglucose had no effect on the hind paw inflammation and joint destruction (radiological assessment) associated with the lesion, methotrexate treatment suppressed both of these variables. Spleen cells derived from cell wall treated arthritic rats were hyporesponsive to concanavalin A (Con-A) and were deficient in the synthesis of interleukin 2 (IL-2). Spleen cells derived from methotrexate treated rats exhibited an improved response to Con-A and their ability to synthesize IL-2 was significantly enhanced.

Suppression of experimental allergic encephalomyelitis by mitoxantrone.

Treatment of rats with a developing or an established lesion of experimental allergic encephalomyelitis (EAE) with mitoxantrone (Novantrone) suppressed the hind limb paralysis associated with the disease. Histopathological examination of the spinal cords of these rats showed that mitoxantrone-treated rats had reduced vascular lesions that are associated with EAE. Spleen cells derived from immunized rats that had been treated in vivo with mitoxantrone did not transfer disease when these cells were administered to naive syngenic recipients. In addition, spleen cells from diseased rats did not transfer EAE lesions when these cells were administered to recipients that had been treated with mitoxantrone. Recipients treated with mitoxantrone were resistant to EAE lesions induced by sensitized cells in a rapid passive transfer system. Finally, when spleen cells from rats with EAE were incubated, in vitro, with mitoxantrone, these cells did not transfer disease to recipients. Thus the present studies indicate that treatment with mitoxantrone can suppress the lesions associated with both the active and passive forms of EAE.

Passive transfer of collagen arthritis: studies with affinity-purified anticollagen IgG prepared in rabbits.

Affinity-purified rabbit anticollagen IgG failed to transfer arthritis to rats when it was injected intravenously. Immunofluorescence examination of the joints of the hind paws of recipient rats showed the deposition of rabbit IgG on the articular surfaces; however, C4 or C3 deposition was not detected. In recipient rats injected intravenously with equivalent amounts of rat anticollagen IgG, arthritis occurred within 48 hr; IgG, C4, and C3 could be detected on the articular surface. Rats given Type II collagen intravenously accumulated inflammatory cells in the pleural cavity in response to a subsequent challenge with intrapleural rat anticollagen IgG; with rabbit anticollagen IgG significantly fewer cells accumulated. Rabbit anticollagen IgG did not promote the lysis of Type II collagen coated sheep red blood cells that were incubated with rat serum. In parallel control experiments, lysis of cells occurred when rat serum was added to either sheep cells coated with Type II collagen and incubated with rat anticollagen IgG or sheep cells coated with bovine serum albumin and incubated with rabbit anti-bovine serum albumin. These observations suggest that the failure of rabbit anticollagen IgG to transfer arthritis to rats is, at least in part, due to its inability to activate rat complement.

Induction of collagenase synthesis in chondrocytes by a factor synthesized by inflamed synovial tissue.

Rabbit inflamed synovial tissue grown in culture synthesizes a factor that induces collagenase synthesis in chondrocytes and in cartilage. Synthesis of this factor by the synovial tissue is inhibited by cycloheximide but not by indomethacin. The factor has an apparent molecular weight of 30,000, is stable to heat and to trypsin treatment but is inactivated by acid. Induction of collagenase synthesis in chondrocytes occurs after a lag period of 6 hours.

Methotrexate suppresses passive adjuvant arthritis: studies on the metabolism of methotrexate in mononuclear cells derived from normal and adjuvant arthritic rats.

Passive transfer of adjuvant arthritis by spleen cells is suppressed by methotrexate. Mononuclear cells derived from spleens of normal and adjuvant arthritic Lewis rats were incubated with [3H]-methotrexate and harvested at various periods of time. The amount of methotrexate and its various polyglutamates were quantitated. The results of these studies indicate that the kinetics of uptake of methotrexate by mononuclear cells from normal and adjuvant arthritic rats are similar. However, the amount of methotrexate polyglutamates accumulating in the mononuclear cells of adjuvant arthritic rats was significantly lower than that observed in mononuclear cells derived from normal rats.