Different strains of donor parental lymphoid cells induce different models of chronic graft-versus-host disease in murine (Balb/c x A/J)F1 hybrid hosts

Advances in lupus stemming from the parent-into-F1 model

The parent-into-F1 model has led to important advances in our understanding of lupus. Here, we review the work in murine lupus that elucidated the role of T cells and supported the conclusion that the parent-into-F1 model of induced lupus compares favorably with de facto gold standard spontaneous models of lupus. Then we focus on recent work in parent-into-F1 mice, which has yielded novel insights into unresolved controversies, such as the role of apoptosis in the pathogenesis of lupus and lupus in patients receiving TNF blockade. Finally, the review considers the evidence that supports a potential role for CD8 T cells, both cytotoxic and memory cells, in mediating disease remission.

The IL-12 Role in Donor Cell Engraftment in a Murine Model of Semiallogenic GVH Disease with Signs of Autoimmune Disease

We analyzed the IL-12 effect in an autoimmune disease induced in a semiallogenic murine model of graft-vs-host disease (GVHD) Balb/c semiallogenic lymphoid cells i.v. infected in hybrid mice (Balb/c x A/J) F1 (CAF). IL-12 was administered 1 h before cell transplantation following two different protocols: (a) injecting 2 microg of mrIL-12 (murine recombinant IL-12) per mouse before the first semiallogenic cell injection; or (b) injecting the 2 microg of mrIL-12 fractionated in 5 days. ATh1 response was produced but an acute GVHD did not appear although differences in class I and II major histocompatibility complex (MHC) antigens were present. Four days after the semiallogenic cell transfer, IL-12 treated mice showed a marked reduction in the percent of spleen B cells compared with CAF1 control and CAF1 + Balb/c GVHD mice. After 5-6 months of follow-up, the donor cell chimerism increased significantly in spleen (70 +/- 31 vs. 43 +/- 31%) and in thymus. Flow cytometry of spleen lymphocytes demonstrated that donor chimerism was made up of TCD4, TCD8 and B lymphocytes and was higher in animals injected with IL-12. Moreover, CD8 T lymphocytes were 100% donor origin in the IL-12-injected group of GVHD animals and 50% origin in the IL-12-non-injected CAF1 + Balb/c group of animals. This paper shows that: (1) IL- 12 may play a role in the mechanisms of donor cell engraftment, probably produced by a CTL donor anti-host mechanism; (2) no acute GVHD was induced in spite of class I and II MHC differences; (3) IL-12 did not show any effect on the AR-like clinical signs of disease developed in this model of GVHD although histological subclinical signs were less frequent, and no glomerulonephritis was detected in the IL-12-treated GVHD mice.

HK-ATPase expression in the susceptible BALB/c and the resistant DBA/2 strains of mice to autoimmune gastritis

Neonatal thymectomy (NTx) in mice induces a group of alterations in the immune system homeostasis that results in the development of a variety of organ-specific autoimmune diseases such as gastritis, thyroiditis, oophoritis and orchitis. Given the importance of self-antigen expression in thymus for the control of autoreactive cells and generation of regulatory cells, we have compared the expression of parietal cell antigen in two strains of mice with the same H-2: BALB/c (susceptible to develop gastritis after NTx) and DBA/2 (resistant). We detected mRNA of HK-ATPase alpha and beta chains in day 1 thymi of both strains. Fifty percent of BALB/c mice presented mRNA levels similar to DBA/2. However, lower mRNA levels were found in the remaining BALB/c mice that may correspond to those that would develop AIG after NTx. Since the presence of the antigen in periphery is also necessary for the induction of regulatory cells, we have compared both strains observing in day 1 stomachs from resistant DBA/2 strain, a significantly higher content of positive cells for HK-ATPase subunits than stomachs from susceptible BALB/c strain. Also, the presence of antinuclear Abs in NTx BALB/c mice makes this model a useful experimental system for analyzing the responsible mechanisms breaking the non-specific self-tolerance.

Murine animal models of systemic sclerosis

Animal models of systemic connective tissue diseases have provided valuable insights into the causative mechanisms and the pathogenesis of these diseases, and have provided the means to test potentially useful therapeutic interventions. Although numerous animal models for systemic sclerosis (SSc) have been described, the most extensively studied are murine. One advantage of murine animal models is the large body of genetic information available for the mouse that is not available for other species. No animal model described to date reproduces precisely all manifestations of SSc. However, all animal models display tissue fibrotic changes similar to those present in SSc. The prudent interpretation of the results obtained from the study of animal models has provided substantial and valuable information about the pathogenesis of the human disease.

Animal models for scleroderma: an update

Scleroderma is a progressive debilitating fibrosing disease that may involve multiple organs. The pathogenesis of this disease remains unclear. Animal models for scleroderma are valuable for studying the pathogenesis of this complex disorder and for testing potential treatments for human scleroderma. There are several animal models available that exhibit important features of scleroderma, each with an emphasis on different aspects of the disease (tissue fibrosis, inflammation, vascular injury, or immunologic changes). These models can be separated into several categories in which fibrosis is induced by external agents (vinyl chloride, bleomycin), by breeding of mutant strain combinations (integrin alpha 1 null mouse, MRL/lpr gamma R-/- mouse), and by transplantation of disparate immune cells (sclerodermatous graft versus host disease). In addition, there are spontaneous mutations (UCD 200 chicken, tight skin mouse) in which fibrosis occurs. The tight skin mouse has been reviewed recently. This review discusses the other animal models and some interventions in each.

(SWR x SJL)F1 mice: a new model of lupus-like disease

During the study of autoimmune models we found that (SWR x SJL)F1 mice (both parental strains with the V beta a phenotype) spontaneously produced immunoglobulin G (IgG) antibodies directed against Sm/U1 small nuclear ribonucleoproteins (snRNPs). In some of these females, the presence of these autoantibodies was found as early as 10 wk of age. Their frequency increased with age i.e., 70% at 40 wk. At that time, only 10% of males developed anti-Sm/U1snRNP antibodies. Anti-Sm/U1snRNP antibodies from positive mice generally recognized the peptides BB', D, 70 kD, and A from RNPs. These polypeptides are known to bear the autoantigenic epitopes that are recognized by human sera containing anti-Sm and anti-U1snRNP antibodies. Reactivity of IgG antibodies with the octapeptide sequence PPPGMRPP was also found in 30% of anti-Sm/U1snRNP positive (SWR x SJL)F1 mice that precipitated BB' peptides. This octapeptide has been described as the most immunoreactive linear epitope in systemic lupus erythematosus (SLE) patients with anti-Sm and anti-U1snRNP antibodies. Approximately 30% of anti-Sn/U1snRNP positive females, later produced anti-dsDNA antibodies. This fact was accompanied by the development of proteinuria due to glomerulonephritis mediated by immunocomplexes. In addition to the specific autoimmune response, (SWR x SJL)F1 females also showed other immunologic abnormalities such as hypergammaglobulinemia, and an approximately twofold increase in spleen cell number compared with control mice. These results indicate that (SWR x SJL)F1 females develop clinical and serological abnormalities similar to those observed in human SLE and constitute a novel model for the study of the genetic mechanisms that result in autoimmunity.