Suppression of type II collagen-induced arthritis by monoclonal antibodies

Water-soluble undenatured type II collagen ameliorates collagen-induced arthritis in mice

Earlier studies have reported the efficacy of type II collagen (C II) in treating rheumatoid arthritis (RA). However, a few studies have investigated the ability of the antigenic collagen to induce oral tolerance, which is defined as active nonresponse to an orally administered antigen. We hypothesized that water-soluble undenatured C II had a similar effect as C II in RA. The present study was designed to examine the oral administration of a novel, water-soluble, undenatured C II (commercially known as NEXT-II) on collagen-induced arthritis (CIA) in mice. In addition, the underlying mechanism of NEXT-II was also identified. After a booster dose (collagen-Freund's complete adjuvant), mice were assigned to control CIA group, or NEXT-II treatment group, to which saline and NEXT-II were administered, respectively. The arthritis index in the NEXT-II group was significantly lower compared with the CIA group. Serum IL-6 levels in the NEXT-II group were significantly lower compared with the CIA group, while serum IL-2 level was higher. Furthermore, oral administration of NEXT-II enhanced the proportion of CD4+CD25+T (Treg) cells, and gene expressions of stimulated dendritic cells induced markers for regulatory T cells such as forkhead box p3 (Foxp3), transforming growth factor (TGF)-β1, and CD25. These results demonstrated that orally administered water-soluble undenatured C II (NEXT-II) is highly efficacious in the suppression of CIA by inducing CD4+CD25+ Treg cells.

Sex hormones and pregnancy in rheumatoid arthritis and systemic lupus erythematosus

Rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE) are autoimmune disorders with a preponderance in females. RA and SLE differ in their response to sex hormones. Disease development of RA is mitigated by estrogen and pregnancy whereas SLE tends to flare during pregnancy and in response to estrogen. Pregnancy improves the symptoms of RA in about 75% of pregnant patients, but relapses within six months postpartum in 90% of cases. RA is regarded as a T cell-mediated and TH1 immune response-driven disease. Pregnancy induces a shift from TH1 to TH2 immune response, increasing the anti-inflammatory cytokines IL-4 and IL-10, which may contribute to gestational amelioration of RA. Prospective studies of SLE pregnancies indicate that about 50% of patients experience a flare, however, with no permanent aggravation of the disease. Lupus nephritis, presence of antiphospholipid antibodies, and a previous history of pregnancy loss increase the risk of complications during pregnancy and fetal loss. The marked increase of estrogen and progesterone during pregnancy seems to enhance some of the manifestations of SLE. The shift to a TH2 immune response may trigger SLE manifestations that are dependent on humoral immune responses such as lupus nephritis. Another factor stimulating immune responses is the pituitary hormone prolactin, which has been found elevated in SLE patients of both sexes and correlated to disease activity in several studies. The hyperprolactinemia of lactation seems to influence postpartum behavior of SLE as well as RA.

Collagen-induced arthritis in mice: synergistic effect of E. coli lipopolysaccharide bypasses epitope specificity in the induction of arthritis with monoclonal antibodies to type II collagen

DBA/1 mice develop a chronic peripheral arthritis after immunization with type II collagen termed collagen-induced arthritis. We have localized the main arthritogenic determinants of CB11, a CNBr-generated arthritogenic fragment of chick type II collagen (CII), using 3 smaller peptide fragments of CB11 generated by endoproteinase LysC, LysC1 (CII 124-290), LysC2 (CII 291-374) and LysC3 (CII 375-402) and a panel of monoclonal antibodies (mAb) specific to CB11. MAb specific to the arthritogenic region of CB11 were also used to study the synergistic effect of E. coli lipopolysaccharide (LPS) on antibody-mediated arthritis in naive DBA/1 mice. LysC2 contained a minimum essential arthritogenic fragment of type II collagen: LysC2 induced arthritis by active immunization, also, a combination of four mAb specific to LysC2 passively transferred arthritis to naive mice. A single i.p. injection of LPS (50 micrograms/mouse) reduced the threshold values of the arthritogenic dose of mAb from 1 mg to 50 micrograms/clone per mouse, and decreased the number of mAb required for inducing arthritis from 4 to 2 clones. These observations suggest that LysC2, an 84 amino acid residue fragment, contains the main arthritogenic determinants within chick CB11. Importantly, LPS, a strong inducer of pro-inflammatory cytokines, negates the required multiple epitope specificity of autoantibodies in the passive transfer model and acts synergistically in the induction of arthritis by autoantibody.

Therapeutic progress. I: Current treatment of rheumatoid arthritis

Over recent years the pharmacological treatment strategy for rheumatoid arthritis (RA) has changed. An early, aggressive approach has been adopted with a view to maintaining functional capacity. The changing role of nonsteroidal anti-inflammatory agents is discussed in the light of the potential toxicity of this class of drugs. The current use of second-line agents is dealt with in depth and includes guidelines to patient monitoring. Particular attention has been paid to the growing use of cyclosporin A in the treatment of RA as this drug represents the newest, most potent, nonexperimental form of treatment. The questions of when to introduce second-line agents, who should receive treatment and how many drugs should be prescribed are all addressed in this review. The relative efficacy and toxicity of these agents is discussed and a treatment protocol is proposed.

Rheumatoid factor, HLA-DR4, and allelic variants of DRB1 in women with recent-onset rheumatoid arthritis

OBJECTIVE

To examine the relationship of rheumatoid factor (RF) to HLA-DR4 and alleles of DRB1 in women with recent-onset rheumatoid arthritis (RA).

METHODS

Incident cases of RA were identified as part of a prospective, population-based case-control study. HLA typing was completed for 246 cases meeting criteria for definite or classic RA.

RESULTS

One hundred thirty-six patients (55%) were positive for DR4, and 130 (53%) were RF positive. DR4 was found to be strongly associated with seropositivity (odds ratio 4.1, P < 0.0001). Patients with a shorter interval from RA onset to RF testing had a higher frequency of seropositivity than those with a longer interval (< or = 18 months 60%, > 18 months 33%). Further analysis of patients who had RF testing within 18 months of RA onset showed that the frequency of seropositivity was significantly greater among DR4-positive patients who had the shared sequence stretch of DR beta 1 associated with RA susceptibility (76% RF positive) than among DR1-positive patients who had this sequence (45% RF positive) (odds ratio 3.8, P = 0.01). Moreover, the frequency of seropositivity among DR1-positive patients with the sequence did not differ from that among all patients without the shared sequence (47%) (odds ratio 0.9, P = 0.8).

CONCLUSION

HLA-DR4 is strongly associated with seropositivity in women with recent-onset RA. The amino acid sequence of DR beta 1 that is associated with susceptibility to RA and is shared between DR4 and DR1 appears not to be the primary determinant of seropositivity in these women.

T cell regulation of collagen-induced arthritis in mice. II. Immunomodulation of arthritis by cytotoxic T cell hybridomas specific for type II collagen

Injection of native type II collagen (CII) to susceptible strains of mice (H-2q) induces a rheumatoid arthritis-like disease. To study the role of CD8+ T cells in the collagen-induced arthritis (CIA), we generated CII-specific T cell hybridomas by fusion of cells from arthritic C3H. Q mice and an AKR thymoma. Two hybrid clones (P3G8 and P2D9) were selected for their ability to lyse syngeneic CII-pulsed macrophages and recognize different antigenic epitopes in association with Kq molecules. When these T cell clones were irradiated and inoculated into (C3H.Q x AKR)F1 mice 21 days prior to priming with native CII/complete Freund's adjuvant, the incidence and the duration of CIA were significantly reduced in comparison to groups receiving saline or control T cell hybridoma. Furthermore, both anti-CII T cell hybridomas were able to attenuate CIA in highly susceptible inbred strains of mice and this suppression was antigen and disease specific. The protective activity seems to require intact cells as neither membrane fractions nor cytosolic preparations of the hybridoma T cells retained the vaccinating activity. Most importantly, one of the hybrid clones (P3G8) had a therapeutic effect on CIA since its administration to arthritic DBA/1 mice on day 30 after priming down-regulated the ongoing disease. Taken together, these findings suggest that anti-CII cytotoxic T cell clones can vaccinate against CIA and even reverse the disease.

Modulation of type II collagen-induced arthritis in DBA/1 mice by intravenous application of a peptide from the C1q-A chain

In this report we are able to show that intravenous (i.v.) application (day 0) of a nonapeptide (residues 26-34) from the human C1q A-chain (designated peptide A-C1q) prior to intradermal (i.d.) administration of chicken type II collagen (CII) in arthritis-susceptible DBA/1 mice (H2q), leads to abrogation of polymorphonuclear neutrophil (PMN) invasion into the joints. This nonapeptide exhibits epitope characteristics and high homology to residues 137-147 of CB11 (a cyanogen bromide fragment of chicken CII, known to contain both arthritis inducing and suppressing determinants). Arthritis index was lowest in animals pretreated i.v. with CII (as internal control), though animals pretreated i.v. with peptide K (residues 137-147 with an additional glycine residue from CB11) or peptide A-C1q exhibited comparative arthritic indices. Only in the arthritis-positive control group (day 0: PBS i.v.) did i.d. application of CII lead to invasion of PMN into the synovial layer and the joint space. Analysis of antibody (Ab) responses at day 48 after i.v. immunization (day 0) and CII challenge (day 7) revealed IgE-Abs to native CII and also to native C1q. IgG titers to CII were highest in animals pretreated with peptide A-C1q. Abs from this group, exhibiting activity to peptide A-C1q (immunizing antigen), were of mainly IgG1 and IgG3 isotypes. Evaluation of the immune response following i.v. application of peptide A-C1q or CII, prior to i.d. CII administration, in DBA/1 mice, revealed IgM responses to peptide A-C1q and peptide K, but not to CII. Intravenous application of peptide A-C1q led to generation of IgG3-Abs reacting only with peptide A-C1q and peptide K, but not with native CII. Additionally, i.v. application of peptide A-C1q elicited IgG responses to a pentapeptide, resembling amino acid residues 26-30 (K-G-E-Q-G) of the C1q A-chain. This five residue antigenic determinant is present in peptide K, in chicken and human CII as well as in human C1q. No specific IgE response to any of the antigens tested could be detected. Since a peptide from the C1q A-chain is both capable of eliciting immune responses and modulating CII-induced arthritis in mice, we postulate that the collagen-like complement component C1q is involved in the development of CII-induced inflammatory arthritic lesions, and may represent, in vivo, the early antigen responsible for inducing anticollagen antibodies prior to CII in hyaline cartilage becoming available as antigen.