Influence of complement C5 and V beta T cell receptor mutations on susceptibility to collagen-induced arthritis in mice

SWR/J mice are resistant to collagen-induced arthritis (CIA) despite having a susceptible H-2q haplotype. We have earlier demonstrated the possible role of the V beta TCR mutation of SWR in the resistance to CIA. To investigate the influence of the C5 deficiency of SWR in this resistance, crosses were made between SWR and A/J (C5 deficient, TCRwild, H-2a), and between SWR and C3H.A (C5 sufficient, TCRwild, H-2a). Upon immunization with bovine type II collagen in adjuvant, there was a similar incidence and severity of arthritis in H-2q-bearing mice in the back-crosses A x (SWR x A) ad C3H.A x (SWR x C3H.A). The absence of hemolytic complement was confirmed in the arthritic A x (SWR x A) back-cross mice by standard SRBC hemolytic assays. In addition C57L (H-2b) mice, which were C5 sufficient but had a V beta TCR deletion mutation similar to SWR, could not complement for CIA susceptibility in H-2q-bearing C57L x (SWR x C57L) back-crosses and in (C57L x SWR)F2 hybrids. These studies show that complement C5 does not play a significant role in CIA susceptibility, and further implicate the V beta TCR mutation in the resistance to CIA in SWR mice.     

Type II collagen-induced arthritis in mice. III. Suppression of arthritis by using monoclonal and polyclonal anti-Ia antisera

Pretreatment of mice genetically susceptible to type II collagen-induced arthritis (CIA) with monoclonal or polyclonal antisera specific for I region gene products (Ia antigens) suppressed or delayed the onset of CIA, whereas pretreatment with anti-Ia to an irrelevant haplotype was without effect. The humoral response to type II collagen was transiently depressed 14 days after immunization but antibody levels did not differ significantly after 28 days. The peak delayed-type hypersensitivity to type II collagen was unaffected by anti-Ia treatment. Monoclonal antibody of one anti-Ia specificity enhanced both the antibody response and the arthritis incidence in one mouse strain.     

Complement deficiency ameliorates collagen-induced arthritis in mice

Collagen-induced arthritis (CIA) is an experimental animal model of human rheumatoid arthritis being characterized by synovitis and progressive destruction of cartilage and bone. CIA is induced by injection of heterologous or homologous collagen type II in a susceptible murine strain. DBA/1J mice deficient of complement factors C3 (C3(-/-)) and factor B (FB(-/-)) were generated to elucidate the role of the complement system in CIA. When immunized with bovine collagen type II emulsified in CFA, control mice developed severe arthritis and high CII-specific IgG Ab titers. In contrast, the C3(-/-) and FB(-/-) were highly resistant to CIA and displayed decreased CII-specific IgG Ab response. A repeated bovine collagen type II exposure 3 wk after the initial immunization led to an increase in the Ab response in all mice and triggered arthritis also in the complement-deficient mice. Although the arthritic score of the C3(-/-) mice was low, the arthritis in FB(-/-) mice ranked intermediate with regard to C3(-/-) and control mice. We conclude that complement activation by both the classical and the alternative pathway plays a deleterious role in CIA.     

Role of Mls-1 locus and clonal deletion of T cells in susceptibility to collagen-induced arthritis in mice

The role of T cell-mediated and humoral immunity to type II collagen has been well documented in collagen-induced arthritis (CIA). Previous work from our laboratory has indicated that genomic deletions of TCR V beta genes may play a role in CIA resistance in mice. This indicated a selectivity of TCR usage by autoreactive T cells in CIA in mice. Certain strains of mice, although having a normal genomic V beta TCR repertoire, can show clonal deletion of peripheral T cells that bear specific V beta gene products in their TCR. These clonally deleted T cells are reactive with self-Ag such as minor lymphocyte stimulation (Mls) Ag. An Mls-congenic strain, BALB.D2.Mlsa, which differs only at the Mls-1 a locus from BALB/c (Mls-1b), was used to examine the effect of clonal deletion of Mls-1a-reactive T cells in CIA. These two strains were crossed to three CIA-susceptible strains, B10.RIII (H-2r, Mls-1b), DBA/1 (H-2q, Mls-1a), and B10.Q (H-2q, Mls-1b), and the crosses were injected with type II collagen. A significantly decreased incidence of arthritis was observed in the (BALB.D2.Mlsa x B10.Q)F1 hybrids, compared with (BALB/c x B10.Q)F1 hybrids, upon immunization with chick type II collagen. The BALB.D2.Mlsa cross mice also had significantly lower levels of antimouse collagen antibodies. Flow cytometric analysis confirmed the clonal deletion of Mls-1a-reactive V beta 8.1, V beta 6, V beta 7, and V beta 9 subsets in the (BALB.D2.Mlsa x B10.Q)F1 hybrids. The study of H-2q/d mice in (BALB.D2.Mlsa x B10.Q) x B10.Q back-crosses demonstrated a significant correlation between CIA resistance and Mls-1a locus. On the other hand, B10.RIII crosses showed only a modest decrease in CIA incidence in the presence of Mls-1a. As expected, all the DBA/1 crosses had an equal incidence of CIA, which was somewhat less than that seen in DBA/1 mice themselves. These studies point out that the Mls-1a locus could play a role in decreasing CIA incidence by clonal deletion of T cells bearing specific V beta TCR, which may be involved in the pathogenesis of CIA. The influence of the clonal deletion of T cells on CIA, and hence the usage of specific V beta TCR by autoreactive anti-type II collagen T cells, however, depends not only on the source of the type II collagen and the MHC class II molecules involved but also on other background genes in mice.     

Suppression of collagen-induced arthritis in DBA/1J mice by preimmunization with house dust mite extract.

Collagen-induced arthritis (CIA) can be induced in DBA/1J mice by immunization with bovine type II collagen (bCII) and is a model of some types of human autoimmune rheumatoid arthritis. In this study we examined whether preimmunization of the mice with various antigens could inhibit the development of CIA. Preimmunization of the mice with an extract of the house dust mite Dermatophagoides farinae (mite antigen), chicken ovalbumin, or keyhole limpet hemocyanin strongly inhibited CIA development, but hen egg lysozyme, beta-lactoglobulin from bovine milk or myelin basic protein from guinea pig brain did not substantially affect CIA development. Splenic T cells and serum antibodies specific for mite antigen did not cross-react with bCII. Preimmunization of the mice with mite antigen did not affect the IFN-gamma and proliferative response of splenic T cells to bCII, nor serum antibody responses. The most inhibitory constituent had a molecular weight between 1,000 and 10,000.     

T cell regulation of collagen-induced arthritis in mice. I. Isolation of Type II collagen-reactive T cell hybridomas with specific cytotoxic function

After immunization with native type II collagen (CII), susceptible strains of mice (H-2q) develop a polyarthritis that mimics rheumatoid arthritis. Although the underlying mechanisms are still undefined, T cells and particularly CD4+ lymphocytes seem to play a crucial role in the initiation of collagen-induced arthritis. To investigate whether CD8+ cells may participate in the pathogenesis of the disease, we have generated lines and clones of cytotoxic T cell hybridomas reactive to CII by fusion of lymph node and spleen cells from bovine native CII-primed C3H.Q (H-2q) mice and the AKR-derived thymoma cell line BW 5147. Clones were selected for their ability to lyse syngeneic macrophages pulsed with bovine native CII in an Ag-dependent manner. The two hybrid clones that were characterized, exhibited cell surface phenotypes of cytotoxic cells and reacted with CII purified from various species. However, each of them recognized different determinants on the CII molecule. P3G8 clone was specific for an epitope shared by CII and type XI collagen, whereas P2D9 clone reacted with CII and type IX collagen. Both hybridomas recognized CII-pulsed targets in association with H-2Kq molecules. These data indicate that the two CII-specific cytotoxic clones recognize different epitopes that are shared by other articular collagens and will allow us to test their influence on the development of arthritis in vivo.     

HLA-DRB1*0402 (DW10) transgene protects collagen-induced arthritis-susceptible H2Aq and DRB1*0401 (DW4) transgenic mice from arthritis

To investigate the role of HLA-DR4 in predisposition to arthritis, we generated transgenic mice carrying DRB1*0401 and DRB1*0402 genes. We have previously shown that DRB1*0401 molecule renders B10.RQB3 (H2A(q)) mice susceptible to porcine and human type II collagen-induced arthritis. We report that the introduction of DRB1*0402 transgene does not lead to development of arthritis in mice when they are immunized with porcine and human type II collagen. In addition, DRB1*0402 protects B10.RQB3 mice against developing arthritis with bovine type II collagen. These data show that DRB1 can modulate the disease mediated by A(q). In vivo depletion of DRB1*0402 did not lead to induction of collagen-induced arthritis in transgenic mice. In vitro cytokine analysis shows that mice protected from collagen-induced arthritis produce lower amounts of Th1 and higher levels of Th2 type cytokines upon immunization with type II collagen. Protection of mice was also related to higher apoptosis in DW10 mice as indicated by higher amounts of BclII in response to type II collagen. On the basis of our observations in HLA transgenic mice, we hypothesize that DRB1 polymorphism can modulate disease by shaping the T cell repertoire in thymus and select autoreactive T cells.     

HLA-DR2-associated Dw subtypes correlate with RFLP clusters: most DR2 IDDM patients belong to one of these clusters

The incidence of arthritis and the antibody response to mouse and to rat type 11 collagen after immunization with native rat type II collagen was studied in different mouse strains, including wild mouse-derived strains belonging to the H-2^p/H-2^q family. High serum levels of antibodies to mouse and rat type II collagen were seen only in H-2^q mice, whereas mice belonging to the p, w3, w5, and w17 haplotypes displayed low type II collagen-specific antibody responses. Mice from three different H-2^q-carrying strains (DBA/1, NFR/N, and B10.G) with different non-major histocompatibility complex genes were all susceptible to collagen arthritis, but they displayed a varying incidence of arthritis and varying clinical features. No arthritis was seen in non-H-2^q mice, except in the B10.CAS2 strain where a few mice developed arthritis despite very low serum levels of type II collagen-specific antibodies. We conclude that small differences in the A chain of class II transplantation antigens are of importance for the development of arthritis and for the stimulation of a high response after immunization with type 11 collagen.Abbreviations used in this paper ELISA enzyme-linked immunosorbent assay - PBS phosphate-buffered saline - Ig immunoglobulin - MHC major histocompatibility complex     

Production of murine collagen-induced arthritis using Klebsiella pneumoniae O3 lipopolysaccharide as a potent immunological adjuvant.

Collagen-induced arthritis (CIA) was produced in mice with non H-2q and H-2r haplotypes by repeated immunization of porcine type-II collagen (CII) together with Klebsiella O3 lipopolysaccharide (KO3 LPS) as an immunological adjuvant. Histological changes that appeared in joints of repeatedly immunized mice were characterized by destruction of normal joint structure, synovial hyperplasia with proliferation of synovial cells, and infiltration of inflammatory cells. No such lesions were produced in mice receiving repeated injections of CII alone or KO3 LPS alone. Development of the humoral antibody and the delayed-type hypersensitivity to CII was exclusively found in mice immunized with the mixture of CII and KO3 LPS. It was therefore suggested that arthritis lesions induced by repeated immunization with the mixture of CII and KO3 LPS might be caused by an autoimmune mechanism, and that the experimental model might be useful for characterization of human rheumatoid arthritis (RA).     

Importance of CD23 for collagen-induced arthritis: delayed onset and reduced severity in CD23-deficient mice

Increased expression of the low affinity receptor for IgE, FcepsilonRII/CD23 has been observed in rheumatoid arthritis. In view of this, we have investigated the expression and influence of CD23 in collagen-induced arthritis (CIA), an animal model for rheumatoid arthritis. CD23+ cells were analyzed in lymph nodes of DBA/1 mice immunized with bovine collagen type II (BCII) in CFA or with CFA only. The percentage of CD23+ lymph node cells was increased in both BCII/CFA- and CFA-immunized mice at 1, 3, and 7 wk after immunization compared with unimmunized mice, indicating a role for the adjuvant to trigger general inflammation and CD23 expression. To investigate the functional role of CD23 in CIA, CD23-deficient mice on the DBA/1 genetic background were studied. After immunization with BCII/CFA, these mice developed CIA with delayed onset and reduced severity compared with wild-type mice. These findings suggest that an increased number of CD23+ cells is part of an inflammatory response and that CD23 expression is of pathogenic importance in the arthritic process.     

Enforced Expression of Roquin Protein in T Cells Exacerbates the Incidence and Severity of Experimental Arthritis

To investigate the role of Roquin, a RING-type ubiquitin ligase family member, we used transgenic mice with enforced Roquin expression in T cells, with collagen-induced arthritis (CIA). Wild-type (WT) and Roquin transgenic (Tg) mice were immunized with bovine type II collagen (CII). Arthritis severity was evaluated by clinical score; histopathologic CIA severity; proinflammatory and anti-inflammatory cytokine levels; anti-CII antibody levels; and populations of Th1, Th2, germinal center B cells, and follicular helper T cells in CIA. T cell proliferation in vitro and cytokine levels were determined to assess the response to CII. Roquin Tg mice developed more severe CIA and joint destruction compared with WT mice. Production of TNF-α, IFN-γ, IL-6, and pathogenic anti-collagen CII-specific IgG and IgG2a antibodies was increased in Roquin Tg mice. In addition, in vitro T cell assays showed increased proliferation and proinflammatory cytokine production in response to CII as a result of enforced Roquin expression in T cells. Furthermore, the Th1/Th2 balance was altered by an increased Th1 and decreased Th2 population. These findings suggest that overexpression of Roquin exacerbates the development of CIA and that enforced expression of Roquin in T cells may promote autoimmune diseases such as CIA.     

Absence of endogeneous interleukin-10 enhances the evolution of murine type-II collagen-induced arthritis.

Interleukin-10 (IL-10) exerts a wide spectrum of regulatory activities in the immune and inflammatory response. The aim of this study was to investigate the role of endogenous IL-10 in the modulation of the inflammatory response in mice subjected to collagen-induced arthritis. Collagen-induced arthritis (CIA) was induced in mice lacking the gene for IL-10 (IL-10 "knock-out", IL-10KO) and in wild-type control (IL-10WT) mice by an intradermal injection of 100 mul of the emulsion (containing 100 mug of bovine type II collagen) (CII) and complete Freund's adjuvant (CFA) at the base of the tail. On day 21, a second injection of CII in CFA was administered. IL-10 wild type (WT) mice developed an erosive, hind paw arthritis when immunised with CII in CFA. Macroscopic clinical evidence of CIA first appeared as peri-articular erythema and oedema in the hind paws. The incidence of CIA was 100% by day 27 in the CII-challenged IL-10WT. The severity of CIA progressed over a 35-day period, with radiographic evaluation revealing focal resorption of bone. The histopathology of CIA included erosion of the cartilage at the joint margins. IL-10KO mice experienced higher rates of clinical signs and more severe knee and paw injury as compared to IL-10WT. The degree of oxidative and nitrosative damage was significantly higher in IL-10KO mice than in wild-type littermates, as indicated by elevated malondialdehyde levels and formation of nitrotyrosine and poly (ADP-ribose) synthetase (PARS). Plasma levels of the proinflammatory cytokines, tumour necrosis factor, interleukin-1beta and interleukin-6 were also greatly enhanced in comparison to wild-type mice. These data demonstrate that endogenous IL-10 exerts an anti-inflammatory role during chronic inflammation and tissue damage associated with collagen-induced arthritis, possibly by regulating neutrophil recruitment, and the subsequent cytokine and oxidant generation.     

Murine T cells reactive to type II collagen. I. Isolation of lines and clones and characterization of their antigen-induced proliferative responses

Mice of the DBA/1 strain develop arthritis after immunization with native chick type II collagen. Although both a humoral and a cell-mediated response specific to type II collagen are associated with the disease, the underlying immunologic basis remains to be established. As an initial step to analyzing the involvement of cellular immunity in collagen-induced arthritis, we isolated and characterized T cell lines and clones specific to type II collagen. Two sets of T cell lines were obtained by limiting dilution. One set was found to react exclusively with denatured type II collagen, whereas the other set responded to both native and denatured type II collagen. The specificity of such T cells was demonstrated by their inability to respond to other soluble proteins such as type I collagen, HGG, KLH, or OVA. Cells from these lines recognized type II collagen only in an MHC (H-2q)-restricted fashion. Furthermore, the collagen-specific T cells were found to respond to type II collagens obtained from various species, including chick, bovine, and rat. Finally, each set of cells displayed a phenotype characteristic of T helper cells, namely Thy-1+, L3T4+, Lyt-2-.     

THR0921, a novel peroxisome proliferator-activated receptor gamma agonist, reduces the severity of collagen-induced arthritis

THR0921 is a novel peroxisome proliferator-activated receptor gamma (PPARgamma) agonist with potent anti-diabetic properties. Because of the proposed role of PPARgamma in inflammation, we investigated the potential of orally active THR0921 to inhibit the pathogenesis of collagen-induced arthritis (CIA). CIA was induced in DBA/1J mice by the injection of bovine type II collagen in complete Freund's adjuvant on days 0 and 21. Mice were treated with THR0921 (50 mg/kg/day) starting on the day of the booster injection and throughout the remaining study period. Both clinical disease activity scores as well as histological scores of joint destruction were significantly reduced in mice treated with THR0921 compared to untreated mice. Proliferation of isolated spleen cells, as well as circulating levels of IgG antibody to type II collagen, was decreased by THR0921. Moreover, spleen cell production of IFN-gamma, tumor necrosis factor (TNF)-alpha and IL-1beta in response to exposure to lipopolysaccharide or type II collagen was reduced by in vivo treatment with THR0921. Steady state mRNA levels of TNF-alpha, IL-1beta, monocyte chemotactic protein-1 and receptor activator of nuclear factor kappaB ligand (RANKL) in isolated joints were all decreased in mice treated with THR0921. Finally, THR0921 inhibited osteoclast differentiation of bone marrow-derived cells stimulated with macrophage colony-stimulating factor and RANKL. In conclusion, THR0921 attenuates collagen-induced arthritis in part by reducing the immune response. As such, PPARgamma may be an important therapeutic target for rheumatoid arthritis.     

A monoclonal anti-type II collagen antibody with cross-reactive anti-Ig activity specific for the F(ab')2 fragment

An IgG2a hybridoma antibody (BC-10) was obtained by a myeloma fusion with lymphocytes from B10.RIII mice immunized against native bovine type II collagen. This anti-collagen monoclonal exhibited extensive cross-reactivity with several type II collagen species. BC-10 was found to have self-associating properties, but not the specificity of a typical IgG rheumatoid factor, inasmuch as this mAb bound to F(ab')2 fragments of itself and of normal mouse IgG. Self binding was inhibited by the association of BC-10 with type II collagen, and inhibition assays indicated that antibodies with the capacity to inhibit BC-10 binding to collagen were present in the sera from B10.RIII arthritic mice, but not from DBA/1 LacJ arthritic mice. Joint inflammation and histopathologic features consistent with arthritis were observed in mice injected with the BC-10 hybridoma.     

Collagen-induced arthritis in mice. Relationship of collagen-specific and total IgE synthesis to disease.

The relationship between production of IgE and collagen-induced arthritis in mice was examined. Collagen-specific IgE was produced as a consequence of immunization of DBA/1 mice with chicken type II collagen emulsified in CFA. We observed a rise in collagen-specific IgE antibody levels at the onset of CIA clinical and histologic signs in DBA/1 mice. This rise in IgE paralleled that of IgG2a anticollagen antibodies, an isotype implicated in the pathogenesis of CIA by other laboratories. The collagen-specific IgE contained in the plasma of mice with CIA could arm basophils for Ag- (collagen) dependent degranulation. Collagen-specific IgE may thus contribute to CIA by promoting mast cell degranulation in the synovia of susceptible mice immunized with chick type II collagen; but, further work is required to establish such a role for IgE in CIA. However, genetic differences in disease susceptibility could not be accounted for by quantitative differences in collagen-specific IgE production. Further, comparable levels of IgE anticollagen antibodies were observed in animals with active CIA and after spontaneous remission, thereby confirming that the presence of such antibodies is insufficient for disease. Total IgE levels peaked just before spontaneous remission indicating active production of IL-4. IL-4 was administered to animals with CIA to determine if this lymphokine could be involved in the remission process. IL-4 facilitated remission of CIA. Enhanced total IgE production may thus be a marker for activation of Th2 cells that produce lymphokines such as IL-4 and IL-10, factors that may be involved in the spontaneous remission process.     

THR0921, a novel peroxisome proliferator-activated receptor gamma agonist,reduces the severity of collagen-induced arthritis

THR0921 is a novel peroxisome proliferator-activated receptor gamma (PPARγ) agonist with potent anti-diabetic properties. Because of the proposed role of PPARγ in inflammation, we investigated the potential of orally active THR0921 to inhibit the pathogenesis of collagen-induced arthritis (CIA). CIA was induced in DBA/1J mice by the injection of bovine type II collagen in complete Freund's adjuvant on days 0 and 21. Mice were treated with THR0921 (50 mg/kg/day) starting on the day of the booster injection and throughout the remaining study period. Both clinical disease activity scores as well as histological scores of joint destruction were significantly reduced in mice treated with THR0921 compared to untreated mice. Proliferation of isolated spleen cells, as well as circulating levels of IgG antibody to type II collagen, was decreased by THR0921. Moreover, spleen cell production of IFN-γ, tumor necrosis factor (TNF)-α and IL-1β in response to exposure to lipopolysaccharide or type II collagen was reduced by in vivo treatment with THR0921. Steady state mRNA levels of TNF-α, IL-1β, monocyte chemotactic protein-1 and receptor activator of nuclear factor κB ligand (RANKL) in isolated joints were all decreased in mice treated with THR0921. Finally, THR0921 inhibited osteoclast differentiation of bone marrow-derived cells stimulated with macrophage colony-stimulating factor and RANKL. In conclusion, THR0921 attenuates collagen-induced arthritis in part by reducing the immune response. As such, PPARγ may be an important therapeutic target for rheumatoid arthritis.     

Immunogenetics of collagen-induced arthritis in rats. Both MHC and non-MHC gene products determine the epitope specificity of immune response to bovine and chick type II collagens.

Seven inbred, RT1-congenic rat strains were immunized with native bovine (BII), porcine (PII), or chick (CII) type II collagen and observed for onset, incidence, and severity of arthritis. Clinical results were compared with IgG reactive with native rat type II collagen (RII) and the purified, renatured cyanogen-bromide peptides of BII, CII, or RII. Immunodominant responses to CB11, CB9,7, and CB12 of RII were identified. Secondary responses to CB8 and CB10 also occurred. Reproducible patterns of peptide reactivity were defined in each strain and reflected both RT1 and non-RT1 genotypes plus the species of immunizing collagen. BN non-RT1 gene products moderated clinical arthritis but increased the levels of reactivity to CB11 in three strains carrying RT1l,n,av1 haplotypes. WF (RT1u) rats were susceptible to collagen-induced arthritis (CIA) and developed very high levels of autoantibodies with dominant responses to rat CB11 after CII injections and to rat CB11 and CB9,7 after BII injections. DA (RT1av1) rats developed the most severe arthritis but had only moderate (total) levels of anti-RII IgG: a broad response to CB11, CB10, and CB9,7 after CII injections but predominantly to CB12 and CB9,7 after BII injections. Three RT1n strains--DA.1N(BN), WF.1N(MAXX), and BN--were resistant to BII-induced CIA but developed mild arthritis after immunization with CII. After BII: BN IgG reacted with CB9-7, CB11, and CB12; DA.1N and WF.1N IgG reacted with CB9,7 and CB12. After CII: BN IgG reacted broadly with CB11, CB9-7, CB12, and CB8; WF.1N IgG reacted to CB9-7, CB11, CB8, and CB12; DA.1N IgG reacted with CB8, CB11, and CB9-7. Thus, selective induction of CIA in BN, WF.1N, and DA.1N rats by CII correlated with serum IgG reactivity to rat CB11, but overall strain results identified no single cyanogen-bromide peptide as expressing the sole "arthritogenic" epitope in CIA.     

Bacterial lipopolysaccharide potentiates type II collagen-induced arthritis in mice

Collagen-induced arthritis (CIA) is an immunologically relevant animal model of human rheumatoid arthritis. Studies comparing the disease incidence in genetically susceptible male and female DBA/1LacJ mice demonstrated that under low density/low stress housing conditions, female mice had earlier onset (day 35) and higher disease incidence (25%) than the male mice (17% at day 49) when immunized with bovine type II collagen. A single subcutaneous or intraperitoneal injection of bacterial lipopolysaccharide (LPS) 17-24 days after collagen immunization greatly potentiated this standard CIA model in a dose related manner. 20-40 mug of LPS accelerated the onset of disease from day 35 to day 21 and exacerbated the clinical severity score from 0.27 to 2.00 at day 42. A similar administration of 6 mug of recombinant interleukin-beta produced a comparable potentiated CIA model. The acute phase protein, serum amyloid P (SAP), was elevated in the serum at day 26 to 440 mug ml(-1) for the LPS potentiated CIA mice compared to 65 mug ml(-1) in the non-potentiated immunized CIA mice. There was a significant correlation (r = 0.78) between SAP levels and disease expression in the LPS treated CIA mice. The rapidity and uniformity of disease expression in this LPS potentiated CIA model will allow more and different drugs to be evaluated with a smaller number of animals.     

The effect of anti-adhesion molecule antibody on the development of collagen-induced arthritis.

In order to study how inflammatory cells including autoimmune lymphocytes interact with each other to develop collagen-induced arthritis (CIA), we injected monoclonal antibodies against mouse LFA-1 and ICAM-1 into DBA/1 mice immunized with type II collagen (CII). Both antibodies suppressed the development of CIA. These antibodies showed no effect on anti-CII antibody response, although they both significantly suppressed DTH response. It was suggested that anti-adhesion molecule antibodies suppress CIA mainly through their effect on cell-mediated immunity, without affecting humoral immunity under the conditions used.