Protective effect of cyclosporin A on immune abnormalities observed in the murine acquired immunodeficiency syndrome

The murine leukemia viruses (MuLV) designated LP-BM5 induce an immunodeficiency disease in susceptible strains of mice with many features in common to human acquired immunodeficiency syndrome (AIDS), including lymphadenopathy and profound immunodeficiency associated with enhanced susceptibility to infection and terminal B cell lymphomas. The disease, termed murine AIDS (MAIDS), crucially depends on the presence of B cells and CD4+ T cells, suggesting that mutual activation of these two cell types is central in the pathogenesis of the immunodeficiency syndrome. Cyclosporin A (CsA), whose immunosuppressive effect is attributed mainly to inhibition of interleukin 2 and interferon-gamma expression, interferes in T-B cell interactions. Here we show that chronic treatment with CsA (40 or 60 mg/kg/day) before and after infection with LP-BM5 MuLV protects against the development of immunodeficiency disease as assessed by functional, serological and histopathological criteria. The protection was not complete, suggesting both CsA-sensitive and CsA-resistant components to the pathogenesis of this syndrome, and was found to be independent of ecotropic MuLV expression. These results underline immunopathological mechanisms in the progression of immune abnormalities in MAIDS that are susceptible to inhibition of CsA and may serve as an experimental basis for developing a treatment of the human disorder with immunomodulators.

Cryoglobulinemia induced by a murine IgG3 rheumatoid factor: skin vasculitis and glomerulonephritis arise from distinct pathogenic mechanisms

MRL-lpr/lpr mice spontaneously develop a lupus-like syndrome characterized by immunopathological manifestations such as necrotizing vascular lesions of ear tips and severe glomerulonephritis. Similar skin vascular and glomerular lesions associated with cryoglobulinemia can be induced in normal mice by injection of a monoclonal antibody (mAb)--6-19 (gamma 3 heavy chain and kappa light chain), exhibiting both cryoglobulin and anti-IgG2a rheumatoid factor (RF) activities--derived from the MRL-lpr/lpr autoimmune mouse. To determine the role of RF and/or IgG3 Fc fragment-associated cryoglobulin activities in 6-19 mAb-induced tissue lesions, a 6-19-J558L hybrid mAb (gamma 3 heavy chain and lambda 1 light chain) was produced by fusion between the 6-19 hybridoma and the J558L myeloma. Here we report that the 6-19-J558L hybrid mAb, which loses the RF activity but retains the cryoglobulin activity, fails to induce skin vascular lesions. However, it is still able to provoke glomerular lesions identical to those caused by the 6-19 mAb. Further, we have observed that the depletion of the corresponding autoantigen, IgG2a, in mice by treatment with anti-IgM antisera from birth also prevents the development of skin but not glomerular lesions. Our results indicate that both RF and cryoglobulin activities of the 6-19 mAb are required for the development of skin vasculitis, but its cryoglobulin activity alone is sufficient to cause glomerular lesions. In addition, cDNA cloning and sequencing of the 6-19 mAb has revealed that the 6-19 kappa light chain variable region amino acid sequence is encoded in a germ-line configuration, suggesting that immunoglobulin variable region germ-line genes could contribute to the generation of pathogenic autoantibodies.

Spontaneous production of anti-mouse red blood cell autoantibodies is independent of the polyclonal activation in NZB mice

New Zealand Black (NZB) mice spontaneously develop an autoimmune hemolytic anemia together with a markedly increased production of polyclonal antibodies. The spontaneous generation of anti-mouse red blood cells (MRBC), anti-bromelain-treated MRBC (BrMRBC) and anti-DNA autoantibodies was compared to the polyclonal antibody formation in irradiated (800 rad) 2-month-old NZB mice reconstituted with bone marrow cells (BMC) from 2- or 10-month-old NZB mice. The injection of 10-month-old NZB BMC markedly accelerated the mortality rate in parallel with the progressive increase of anti-MRBC and anti-BrMRBC autoantibody production, but the spontaneous production of polyclonal IgM antibodies and anti-DNA autoantibodies was completely abolished down to the levels of non-autoimmune mice. In contrast, mice reconstituted with 2-month-old NZB BMC exhibited neither the acceleration of anemia nor the lack of polyclonal antibody production. These results strongly suggest that the spontaneous production of anti-MRBC autoantibodies, including anti-BrMRBC autoantibodies, in the NZB mouse occurs independently of the polyclonal B cell activation, and that they result from a specific immune stimulation, while the anti-DNA autoantibody production is a consequence of polyclonal antibody formation.

5-Azacytidine inhibits the lpr gene-induced lymphadenopathy and acceleration of lupus-like syndrome in MRL/MpJ-lpr/lpr mice

MRL/MpJ-lpr/lpr mice spontaneously develop a lupus-like autoimmune disorder characterized by massive proliferation of T cells and rapidly fatal immune complex glomerulonephritis. We evaluated the therapeutic effect of 5-azacytidine (5AC), a cytidine analogue known as an inhibitor of DNA methylation, in MRL/MpJ-lpr/lpr mice. Intraperitoneal injection of 5AC (50 micrograms, twice a week) starting from 6 weeks of age retarded the development of lymphadenopathy and autoimmune syndrome. Its beneficial effects included: (a) increased life-span, (b) diminution of lymphadenopathy and splenomegaly, (c) reduction in circulating levels of autoantibodies such as anti-DNA and rheumatoid factors, and (d) suppression of lupus glomerulonephritis. However, similar treatment in BALB/c mice did not affect the development of IgG anti-human IgG antibody responses. These results suggest that the protective effect of 5AC is related to the inhibition of the lpr gene-induced T cell proliferation, thereby suppressing the autoimmunity-accelerating effect mediated by the lpr gene.

Differential effect of the autoimmune Yaa and lpr genes on the acceleration of lupus-like syndrome in MRL/MpJ mice

The Yaa gene (Y chromosome-linked autoimmune acceleration), linked to the BXSB/MpJ Y chromosome, and the autosomal recessive lpr (lymphoproliferation) gene have been shown to accelerate the progression of the lupus-like autoimmune syndrome in the BXSB and MRL strains, respectively. To compare more directly the role of the Yaa and lpr genes in the development of the autoimmune syndrome, the Y chromosome of BXSB mice was transferred to MRL mice by backcross procedures, and the effect of the Yaa gene on the autoantibody formation and the development of lupus-like nephritis in MRL mice was investigated in comparison with those bearing the lpr mutation. The Yaa gene as well as the lpr gene were able to shorten the life span of MRL mice as a result of the accelerated development of lethal lupus-like nephritis. However, the acceleration promoted by the Yaa gene (50% mortality rate: 12 months) was less severe than that induced by the lpr gene (50% mortality rate: 7 months). This may be related to the finding that the lpr gene enhanced the production of a large spectrum of autoantibodies, including anti-DNA, rheumatoid factors and anti-gp70, and of cryoglobulins, whereas only anti-gp70 production among the autoantibodies studies was markedly enhanced by the Yaa gene. The selective autoimmune accelerating effect of the Yaa gene was similarly observed in (NZW X MRL)F1 hybrid mice. Our results suggest that the Yaa gene, unlike the lpr gene, exhibits selective autoimmune accelerating activity, but as a result of increased formation of certain nephritogenic autoantibodies such as anti-gp70 antibodies, the Yaa gene is able to accelerate the progression of lupus-like nephritis in lupus-prone mice.

Anti-IgM treatment of C57BL/6-1pr/1pr mice: depletion of B cells reduces 1pr gene-induced lymphoproliferation and mononuclear cell vasculitis

In order to study the role of B cells in autoimmune abnormalities observed in C57BL/6 mice bearing the autosomal mutant gene 1pr (lymphoproliferation), we treated mice from birth continuously with rabbit anti-IgM antiserum. Anti-IgM treatment resulted in the complete suppression of B cell development, documented by the absence of surface Ig-positive cells, the lack of lipopolysacchride-induced mitogenic responses, and the lack of autoantibody production. Although, anti-IgM-treated C57BL/6-1pr/1pr mice developed 1pr gene-associated lymphoproliferation due to the accumulation of Thy-1+, CD4-, CD8-, B220+ T lymphocytes in spleen and lymph nodes, the size of their spleen and lymph nodes was considerably smaller than that of normal rabbit serum-treated C57BL/6-1pr/1pr mice. Systemic vascular lesions associated with mononuclear cell infiltration were a little affected by anti-IgM treatment. This indicates that the development of mononuclear cell vasculitis in mice bearing the 1pr gene may be associated with the 1pr gene-induced lymphoproliferation and is independent of B cells and autoantibody production.

Resistance to tolerance induction to human gammaglobulin (HGG) in autoimmune BXSB/MpJ mice: functional analysis of antigen-presenting cells and HGG-specific T helper cells

Autoimmune male, but not female, BXSB/MpJ mice resist the induction of tolerance to human gammaglobulin (HGG). To better define the cellular basis for this abnormality, we have compared in vitro the functional activity of antigen-presenting cells between tolerant-resistant male and susceptible female mice, and evaluated in vivo the immunological status of HGG-specific T helper cells in male BXSB mice after the treatment with monomeric deaggregated HGG (DHGG). Our results indicated that there were no significant differences in the ability of male and female antigen-presenting cells to present HGG to either male or female HGG-specific immune T blasts. Further, thymic cells from DHGG-treated male BXSB mice failed to support anti-HGG antibody responses when adoptively transferred with non-treated bone marrow cells, and that draining lymph node cells from male as well as female BXSB mice treated with DHGG prior to the challenge of immunogenic aggregated HGG (AHGG) were unable to exhibit the proliferation upon in vitro restimulation with AHGG. This indicates that HGG-specific T helper cells were indeed tolerized in tolerant-resistant male BXSB mice by the treatment with DHGG. In contrast, when the tolerance induction was inhibited by bacterial lipopolysaccharides, HGG-specific T helper cells from such mice exhibited a marked proliferation upon in vitro restimulation with AHGG. These results suggest that the cellular defect in the abnormal resistance to tolerance induction to HGG in male BXSB mice resides neither in the antigen-presenting cells nor in the HGG-specific T helper cells, and that the mechanism responsible for this abnormality in male BXSB mice is basically different from that involved when tolerance is overcome by lipopolysaccharide.

The Y chromosome from autoimmune BXSB/MpJ mice induces a lupus-like syndrome in (NZW x C57BL/6)F1 male mice, but not in C57BL/6 male mice

The Y chromosome of the BXSB mouse has been shown to be responsible for the acceleration of lupus-like autoimmune syndrome in inbred BXSB mice and in their F1 hybrids with NZB or NZW mice. To further define the role of this as yet unidentified gene linked to the BXSB Y chromosome, designated Yaa (Y chromosome-linked autoimmune acceleration), the Y chromosome was transferred from the BXSB strain to nonautoimmune C57BL/6 (B6) mice. The effect of the Yaa gene on the autoantibody formation and the development of glomerulonephritis was investigated in B6 mice and in their F1 hybrids with NZW mice. The presence of the BXSB Y chromosome was not able to induce significant autoimmune responses in B6 mice. However, (NZW x B6)F1 males bearing the BXSB Y chromosome developed a severe lupus-like autoimmune syndrome, as documented by the production of anti-DNA antibodies and gp70-anti-gp70 immune complexes and the development of lethal lupus nephritis. Both sexes of (NZW x B6)F1 hybrids without the BXSB Y chromosome were essentially normal. Our results suggest that (a) the BXSB Y chromosome by itself is not sufficient to initiate autoimmune responses in nonautoimmune B6 mice, and (b) it is able to induce autoimmune responses in mice potentially capable of developing the disease, but whose autosomal abnormality by itself is not sufficient to develop autoimmune diseases.

Community participation in New York City: success or failure?

This paper describes the planning efforts of a community agency that was ultimately unsuccessful in converting two primary care centers from the traditional fee-for-service Medicaid reimbursement system to a per-capita prepaid Medicaid reimbursement system. We analyze how the community agency prepared its plan, the barriers it encountered in trying to implement a demonstration project, the ambiguous messages community organizations receive from policy-makers, and the role the Mount Sinai School of Medicine played in the conversion effort.

The international role of a U.S. medical school in developing health services

This paper discusses the educational approach taken by the Department of Community Medicine of the Mount Sinai School of Medicine in providing technical assistance in foreign countries. Using a specific project in the Dominican Republic as an example, the paper describes the role and different functions assumed by the department in planning and developing a health care system in the eastern region of that country.

Technical assistance offered to community health programs through a resource model

A multidisciplinary unit in the Department of Community Medicine, Mount Sinai School of Medicine, consists of a core group of specialists who plan, develop, and evaluate community health care programs. The primary tools used by the staff of the Services Coordination Unit, epidemiology and behavioral and management sciences, result in improved organization and coordination of health services and community resources. The small unit of specialists functions as a resource group, helping community groups address the complex problems of planning, organization, delivery, and financing of health services. By offering technical assistance rather than day-to-day health care services, the unit has established an education and training program in New York's East Harlem, which surrounds the medical school. Over the last 10 years, that approach has enhanced the administrative and financial viability of existing health programs in East Harlem. Since the unit's establishment, it has collaborated with a broad variety of community groups. More than 20 programs have resulted. The income generated by the unit completely covers the expenses and has done so since 1976; "seed money" was used for startup and the first 3 years of operation. The unit is paid for long-term services and for most consultations.

A medical school's involvement in the development of a community-based health center

This paper presents a planning model developed by the Department of Community Medicine of the Mount Sinai School of Medicine to facilitate the interactions between the medical school and the community. The planning process involved application of the model, exemplified through the growth and development of a neighborhood health center governed by a community agency. The main characteristics of the medical school, of the community, and of the community agency are presented briefly and the seven-year history of the development of the neighborhood health center is summarized. In recapitulating that history three distinct phases are identified in the planning process: how the planning was planned, how the plan was prepared, and how the services program was implemented. The role of the Department of Community Medicine in each phase is analyzed.

A proposed network to improve access to high-quality health care for Medicaid-eligible families

There is today both a need and an opportunity to develop and test a variety of models--organizational and financial--for improving the delivery of health care services. This article describes the structure and functioning of one such model and highlights the organizational problems expected to arise during its implementation. The proposed health plan is intended to facilitate the access of Medicaid-eligible, inner-city families to already available health services. The central hypothesis is that in low-income urban areas the elementary schools offer an organizational focus for the development of a health plan. As a prepaid, community-based model, this plan is designed to address the issues of accessibility, equity, accountability, continuity of care, and consumer participation, primarily through the development of a coordinating agency, the health plan office (HPO), which assures the linking of consumers and providers of health care. Adapted from the Kaiser-Permanente model, the HPO also assumes responsibility for marketing, enrollment, coordination of services, consumer advocacy, and quality surveillance.

Training of a community board to increase the effectiveness of a health center

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