Serum transfer of collagen-induced arthritis in mice.

Immunization of DBA/1 mice with native chick type II collagen resulted in development of polyarthritis 4-5 wk later. Sera of these mice contained high levels of anticollagen antibodies, and immunoglobulin concentrates of their sera transferred arthritis to unimmunized recipients. Histopathologically, this passively transferred arthritis resembled the early disease of immunized donors. Immunofluorescence studies demonstrated the deposition of IgG and C3 on the articular surface but not in synovial tissue of arthritic joints. Transferred, isotopically labeled anticollagen antibodies rapidly localized to the limbs and to other cartilage-containing tissues. When transfer concentrate was administered to arthritis-resistant strains, they also developed arthritis. Indeed, immunoglobulin concentrates from rats with collagen-induced arthritis transferred arthritis to naive mice. The amount of concentrate required for transfer to B10.D2 resistant mice was reduced by immunizing them with collagen 4 wk before transfer. Although susceptibility to arthritis from immunization is H-2 linked, these studies clearly demonstrate that passive transfer of arthritis depends upon injection of specific antibody and not on other host factors.

A spontaneous rheumatoid arthritis-like disease in MRL/l mice.

MRL/l mice spontaneously develop an arthritis very similar in many respects to human rheumatoid arthritis. A detailed morphologic and serologic analysis of this disease revealed the following: (a) a 75% incidence of synovial and periarticular inflammation, very similar to human rheumatoid arthritis, in 5-6 mo-old females, (b) close associations between presence of joint inflammation and subsynovial and/or periarticular vasculitis, and (c) a close correlation between presence of circulating IgM rheumatoid factor (RF) and demonstrable synovial and/or joint pathology, i.e., 95% of mice with significant levels of IgMRF had synovitis and/or arthritis.

Pathogenesis of the glomerulonephritis of NZB/W mice.

The development of glomerulonephritis in NZB/W mice is closely related to the formation of antinuclear, particularly anti-DNA, antibodies. The developing inflammatory glomerular lesions are characterized by the deposition of gammaG- and beta(1C)-globulins plus DNA and possibly other nuclear antigens, presumably as complexes, in a granular to lumpy pattern along the capillary walls and in the mesangia. Elution studies revealed the gammaG-globulin in the glomeruli to be largely gammaG(2A)-type antibody to soluble nuclear antigens. Enhancement of the antinuclear antibody response by active immunization of young NZB/W mice with DNA-methylated BSA hastens the development and increases the severity of the glomerulonephritis. Similarly, injections of soluble DNA into NZB/W mice with circulating anti-DNA antibodies but with as yet little nephritis causes rapid progression of nephritis.

Experimental allergic glomerulonephritis induced in the rabbit with heterologous renal antigens.

Rabbits immunized to different heterologous renal antigens developed antibodies some of which are fixed to their own glomeruli (autoantibodies). These autoantibodies, reacting with the host's kidneys, were directed to those antigenic determinants which were present in identical or cross-reactive form in both the immunizing antigen and the kidneys of the host. Glomerulonephritis developed in some of the rabbits immunized to heterologous mammalian kidneys, but in none of those immunized to nonmammalian kidneys. The development of glomerulonephritis in the immunized rabbits appears to depend upon two factors: (a) the amount of autoantikidney antibody made to the common renal antigens; and (b) the quantity of the common antigens available in the host's kidneys. An amount of common antigen sufficient to fix a nephritogenic amount of antibody is essential for the development of disease.

Transfer of ovine experimental allergic glomerulonephritis (EAG) with serum.

Serum globulin from donor sheep made nephritic by immunization with glomerular basement membrane and subsequently nephrectomized contained specific kidney-fixing antibody and was capable of inducing an immediate, although transient, glomerulonephritis when injected into unilaterally nephrectomized lambs. This nephritis was characterized by immediate proteinuria, PMN infiltration into the glomerulus, and localization of gammaG- and beta1C-globulins in a linear fashion along the recipients' glomerular capillary walls. The nephritogenic property of the serum could be absorbed in vitro with isolated sheep glomerular basement membranes.

Pathogenesis of chronic disease associated with persistent lymphocytic choriomeningitis viral infection. I. Relationship of antibody production to disease in neonatally infected mice.

Mice infected shortly after birth with lymphocytic choriomeningitis (LCM) virus are not immunologically tolerant, although they carry the virus throughout life. These LCM carrier mice make anti-LCM antibody, which apparently complexes with viral antigen in the circulation and these complexes accumulate in the glomeruli. LCM carrier mice of different strains vary significantly as to concentration of detectable infectious virus in their tissue, amount and time of appearance of anti-LCM antibody, and development of an associated chronic disease. The chronic disease consists primarily of glomerulonephritis, focal hepatic necrosis, and disseminated lymphoid infiltrations. LCM carriers of the SWR/J strain contain high tissue concentrations of virus, considerable anti-LCM antibody detectable in the glomeruli by 3 wk to 2 months of age and develop chronic disease within the first 2-3 months of life. In contrast, C(3)H strain LCM carriers contain 1/1000 as much infectious virus, less detectable anti-LCM antibody, and have not, over a 24 month observation period, developed any detectable disease. B10D2 old and new carrier mice with intermediate amounts of virus develop chronic disease during the latter half of the first year of life. The pathogenesis of the glomerulonephritis of chronic LCM disease is apparently related to the formation of circulating virus-antibody complexes which are trapped in the glomerular filter. There is no evidence for direct glomerular injury by the virus nor for any autoimmune response by the host.

Immune complex disease in chronic viral infections.

Chronic viral infections of animals associated with immune complex disease resemble a number of human disorders. At present, on the basis of showing (a) virus, host antiviral antibody, and C3 deposited in a granular pattern along the glomerular capillary wall and in the mesangia and (b) virus-host Ig (presumably antiviral antibody) complexes in the circulation, immune complex disease occurs in chronic murine infections with LCM, LDV, MSV, and ADM. In addition, granular deposits in the glomeruli in Coxsachie B, polyoma, other leukemic viral infections in mice, equine anemia, and hog cholera suggest that immune complex disease also occurs in these infections. In transplacental LCM infections maternal antiviral antibody transferred in utero or via milk induces very early and severe immune complex disease. The severity of immune complex nephritis in mice neonatally or transplacentally infected with LCM virus is directly proportional to the amount of Ig elutable from the kidney and to the proportion of this Ig which reacts with the infecting virus.

Pathogenesis of immune complex glomerulonephritis of new zealand mice.

Observations based on elution of IgG from nephritic kidneys of NZ mice and absorption of the eluted IgG with selected antigens indicate that their immune complex nephritis involves at least two kinds of antigen-antibody complexes. Antibodies reactive with nuclear antigens account for nearly half of the IgG eluted from the kidneys while antibodies reactive with Gross viral antigens make up a significant but lesser amount. Superimposed chronic viral infections affect the nephritis of NZ mice in different ways. LCM and polyoma infections hasten and intensify the antinuclear antibody responses and glomerulonephritis of these mice while LDV infection appears to protect against both antinuclear antibody formation and development of nephritis.

Quantitation of acute and chronic serum sickness in the rabbit.

The amounts of BSA (immune complex) deposited in glomeruli of rabbits with acute and chronic serum sickness were determined using radio-labeled BSA and paired-label RSA. In animals with acute serum sickness and severe glomerulonephritis, about 18 microg of I*BSA were present in both kidneys after immune elimination (>99% of the circulating I*BSA). Visible with an immunofluorescent sensitivity of 0.25 microg per g of kidney, the I*BSA became rapidly undetectable and was presumably covered by deposits of circulating host anti-BSA and complement which increased demonstrably. In chronic serum sickness produced by daily injections of a quantity of BSA to balance antibody production, 0.04% of the daily dose of I*BSA was deposited in the glomeruli during the developmental stages of glomerulonephritis. Coincident with the onset of overt proteinuric glomerulonephritis, the daily I*BSA deposition, rate increased to about 0.5% of the daily dose. The half-disappearance rate of I*BSA from the kidney was about 5 days. Administration of huge excesses of BSA caused a fivefold increase in the half-disappearance rate. The accelerated I*BSA disappearance could be correlated with vanishing glomerular immunofluorescent deposits of BSA and immunoglobulin, as well as electron microscopic dense deposits; however, functional improvement of the disease was not observed. The roles of immune complex size, precipitating and nonprecipitating (total ABC) antibodies, and RES function in the development of chronic serum sickness glomerulonephritis are discussed.

Murine serum glycoprotein gp70 behaves as an acute phase reactant.

A single intraperitoneal injection of bacterial lipopolysaccharide (LPS) or its lipid A component induced high levels of glycoprotein, gp70, in sera of several strains of mice within 24 h. This serum gp70 response induced by LPS was independent of the activation of B cells and the presence of T cells. However, serological and immunohistochemical studies demonstrated the production of gp70 by hepatic parenchymal cells and its subsequent release into the circulating blood. The expression of gp70 in the serum was enhanced not only by LPS but also other inducers of acute phase reactants (APR) such as turpentine oil or polyriboinosinic-polyribocytidylic acid. Further, the serum gp70 response was kinetically identical to those of APR. These results strongly suggest that (a) the liver may be the major source for serum gp70, (b) serum gp70 behaves like an APR, (c) its expression may be controlled by a mechanism similar to that for other APR, and (d) this glycoprotein apparently behaves as a normal host constituent and not a product of a viral genome.

Subclass-restricted IgG polyclonal antibody production in mice injected with lipid A-rich lipopolysaccharides.

The effects of five distinct bacterial lipopolysaccharides (LPS) on the induction of polyclonal IgM and IgG antibodies, including polyclonal autoantibody formation, were investigated in several strains of mice. Injections of most LPS preparations that contained polysaccharide transiently induced only IgM polyclonal antibodies. However, LPS from Salmonella minnesota R595 (R595 LPS), which had a particularly high content of lipid A but lacked O-antigen polysaccharide, induced a markedly prolonged IgM and IgG polyclonal antibody response in mice, including athymic nude mice, but not in LPS-unresponsive C3H/HeJ mice. Polyclonal IgM and IgG production peaked in sera on day 8 and day 15, respectively, and remained higher than control values 2 mo after the injection. The IgG induced by R595 LPS was strictly restricted to IgG2b and Igg3 subclasses in normal mice. In contrast, in athymic nude mice which have normally lower levels of IgG1 and IgG2a than normal mice, R595 LPS stimulated the production of all the IgG subclasses and reconstituted serum levels of IgG1 and IgG2a up to, but not higher than, control values of normal mice. These findings suggest that different mechanisms regulate production of each IgG subclass after stimulation with LPS.

(NZW x BXSB)F1 hybrid. A model of acute lupus and coronary vascular disease with myocardial infarction.

Both sexes of the (NZW x BXSB)F1 mice developed an early systemic lupus erythematosus-like disease. In males, the disease resembled that in the BXSB male parent and was not affected by sex hormonal manipulation. In females, the disease duplicated that of (NZB x NZW)F1 females by virtue of a delayed onset and estrogen dependence. Autoantibody production, circulating Ig-bound gp 70 immune complexes, and deposition of Ig and gp 70 in the affected glomeruli were demonstrated in both males and females. The abnormally high incidence of degenerative coronary vascular disease with myocardial infarction, particularly in these F1 males, provides a useful model for the investigation of a possible immunologic component in coronary vascular disease.

Pathogenesis of chronic disease associated with persistent lymphocytic choriomeningitis viral infection. II. Relationship of the anti-lymphocytic choriomeningitis immune response to tissue injury in chronic lymphocytic choriomeningitis disease.

Tissue injury (chronic disease) associated with persistent LCM infection is apparently caused by the host immune response to the virus. Employing parabiosis or cell transfer from hyperimmune donors to isologous virus carriers, the tissue injury of chronic disease could be initiated and/or intensified. Furthermore, the transfer of anti-LCM antibody to SWR/J carrier mice results in acute necrotizing inflammatory lesions in regions of viral persistence, followed by chronic mononuclear infiltrates quite similar to those seen after the transfer of immune cells. The pathogenesis of the nonglomerular tissue injury of chronic LCM disease is apparently at least in part related to the interaction of circulating anti-LCM antibody with viral antigen at the tissue site. Trapping of circulating virus-antibody complexes in the glomerular filter is apparently the major cause of the glomerulonephritis.

Immunoreactive basement membrane antigens in normal human urine and serum.

Using a sheep antiserum to human glomerular basement membrane (GBM), studies of urine from healthy adults showed the presence of two cross-reactive antigens. These antigens were purified partially by preparative electrophoresis and electrofocusing, and separated on G-200; both appeared to be acidic, of high molecular weight, and carbohydrate rich. Their immunologic relationship to human GBM solubilized by several techniques was deduced from lines of identity with the native GBM digests in double diffusion analyses. These antigens will combine with homologous anti-GBM antibodies and block their fixation to human kidney sections, and will evoke heterologous anti-GBM antibody production in the rabbit. Fractionation studies of normal human serum indicated the presence of trace amounts of basement membrane antigens in the circulation. Although the serum antigens appear immunologically identical to the urinary antigens, the precise anatomic structures from which both are derived is not certain. Demonstration of immunoreactive basement membrane antigens in the circulation provides a plausible source of immunogen for the potential development of anti-GBM antibody-mediated glomerulonephritis as well as a clue to a mode for reestablishment of tolerance in such an autoimmune disorder.

The effect of induced chronic viral infections on the immunologic diseases of New Zealand mice.

Chronic infections induced at birth with either LCM, an RNA virus, or polyoma, a DNA virus, in NZB, NZW, and NZB x W mice enhance ANA formation, aggravate the immune complex glomerulonephritis, and increase the associated mortality. The ANA titer was increased without apparent change in specificity of the antibodies involved in all three types of mice. Glomerulonephritis, while more severe in infected mice, was of the same type as occurred spontaneously and was characterized by a granular to lumpy accumulation of host IgG and C3 in the mesangia and along the capillary walls of the glomeruli. Of the LCM infected mice of all three types over 50% had died of glomerulonephritis by 6 months and over 85% by 9 months. Of the polyoma infected mice of all three types approximately 20% had died of glomerulonephritis by 6 months and over 40% by 9 months. Of the uninfected controls of all three types less than 10% had died by 6 months and less than 20% at 9 months except for the NZB x W females which had a 67% mortality at 9 months as a result of their spontaneous glomerulonephritis. The two viral infections had significant effect on the incidence of anti-red cell antibodies or the severity of autoimmune hemolytic anemia in any of the three NZ mice.

Disease accompanying in utero viral infection. The role of maternal antibody in tissue injury after transplacental infection with lymphocytic choriomeningitis virus.

Early, after in utero infection with LCM virus, SWR/J and HA/ICR mice developed manifestations of immune complex disease. Observations based on nursing such mice with virus-infected, immune, or noninfected mouse mothers indicated that maternal antiviral antibody was responsible for the early immune complex glomerulonephritis. Despite comparable viral persistance, in utero-infected offspring failed to develop glomerulonephritis when nursed by noninfected mouse mothers, but did when suckled by virus-infected mouse mothers. Nursing by mouse mothers carrying high titers of anti-LCM viral antibody markedly enhanced the Ig glomerular deposits and the resultant nephritis.

Effect of immunosuppression on chronic LCM virus infection of mice.

C3H mice chronically infected with LCM virus were found to be lethally affected by small doses of immunosuppression which caused bone marrow aplasia but had no effect on the amount of virus carried by the mouse. Humoral immune response of SWR/J mice to acute LCM infection was found to be totally suppressed by repeated single doses of 300 R/wk with no alteration in the level of virus carried by the mouse. In contrast, the established anti-LCM humoral immune response encountered in mice chronically infected with LCM virus was not suppressed by the same irradiation procedure. Over half of the chronic LCM carrier SWR/J mice treated with cyclophosphamide for 6 mo had total anti-LCM humoral immunosuppression, but showed no change in the level of virus carried. The glomerulonephritis which occurs in chronic LCM carrier mice was prevented by cyclophosphamide treatment in 90% of the mice. The humoral immune response which occurs in chronic LCM carrier mice appears to play no role in controlling the amount of virus carried by the mouse. Suppression of the LCM immune response by cyclophosphamide does prevent the development of glomerulonephritis in these mice.

Lack of relationship between serum gp70 levels and the severity of systemic lupus erythematosus in MRL/l mice.

In the MRL/l mouse, gp70 apparently plays a role as an autoantigen in the development of SLE. However, while gp70 may be an important pathogenetic element, it is not essential to MRL SLE, since elimination of most of the serum gp70 and virtually all of the immune complex gp70 from MRL/l-low gp70 congenic lines had no observable effect on the course or nature of the disease. Thus, while gp70 in the MRL/l mouse appears to be a convenient autoantigenic target when present in significant levels, in its absence the host appears capable of directing its aberrant immunologic responsiveness elsewhere with undiminished pathogenicity.

Monoclonal IgM rheumatoid factors derived from arthritic MRL/Mp-lpr/lpr mice.

MRL/lpr/lpr (MRL/l) mice develop a lupus-like syndrome and a disease histologically and serologically similar to human rheumatoid arthritis. Their sera contain polyclonal IgM rheumatoid factors (RF) reactive with all murine IgG subclasses (frequently strongest with IgG2a) and several heterologous IgG. To examine the repertoire and epitopic specificities of these RF, we fused splenocytes from 3.5-mo-old seropositive MRL/l mice with appropriate myeloma partners and derived 1,723 hybridomas of which 23 secreted IgMRF. These monoclonal IgMRF bound to murine IgG only, not to other murine isotypes. Eight murine IgG subclass-specific clonotypes were identified. Most clones reacted with either multiple IgG subclasses or with IgG2a alone. A few clones reacted solely with IgG2b but none reacted exclusively with IgG1 or IgG3. Monoclonal IgMRF with exclusively anti-IgG2a activity exhibited allotypic specificity, reacting, with few exceptions, with a, c, and e, but not b, d, or j IgG2a allotypes. Four clonotypes could be distinguished by cross-reactivity with IgG from species other than mice. Monoclonals possessing activity against several murine subclasses cross-reacted extensively with heterologous IgG, including all human IgG subclasses without allotypic restrictions. Monoclonal IgMRF specific for murine IgG2a or 2b did not cross-react with heterologous IgG. Based on the absence of cross-reactions by IgG2a-specific monoclonal autoantibodies, certain peptides of the IgG CH2 and CH3 domains appear to generate the antigenic determinants of the anti-IgG2a RF in MRL/l mice. All of the monoclonal RF bound to Fc and, with one exception, not to Fab fragments of murine IgG. Binding of the monoclonal RF to substrate IgG was not inhibited by Clq, thus excluding the Clq-binding site at the CH2 domain as one of the responsible epitopes in the induction of MRL/l RF. mIgMRF could be categorized as strongly, weakly, or noninhibitable by protein A, which interacts with IgG molecules at or near the CH2-CH3 junction. Inhibition appears to be caused by conformational changes and/or steric shielding of certain IgG areas distant from this junction and not by identical binding sites between protein A and RF. Certain of the mIgMRF that were weakly or not at all inhibitable by protein A were found to cross-react equally well with human Fc (CH2-CH3 domains) and pFc' (CH3 domain) fragments, indicating that the binding site for these monoclonals is at the CH3 domain. Monoclonal RF were devoid of anti-double-strand DNA, anticollagen, or antipeptidoglycan pentapeptide cross-reactivity, but one of the monoclonals cross-reacted with histones, four with single-strand DNA, and one with both histones and single-strand DNA.

Association of circulating retroviral gp70-anti-gp70 immune complexes with murine systemic lupus erythematosus.

Endogenous retroviral gp70 was investigated as a participant in the pathogenesis of a lupus-like disease that spontaneously develops in four kinds of mice (NZB, NZB x W MRL/1, and male BXSB). Sera from these strains contain a heavy form of gp 70 that varies in sedimentation rates from 9S to 19S in sucrose density gradient analysis and appears with the onset of disease and persists throughout its course. Immunologically normal strains of mice do not develop rapidly sedimenting gp70 by 8-10 mo of life. The fact that the heavy gp70 is selectively absorbed with anti-IgG antibodies or with Staphylococcus aureus protein A suggests that it is complexed with antibodies. The incidence and quantities of these gp70 ICs rise with the progression of disease in all strains with lupus. These findings suggest that Ig-complexed heavy gp70 may be involved in the pathogenesis of glomerulonephritis of mice with SLE.