Development of host plasma cells during graft-versus-host reactions in mice

The bm12 Inducible Model of Systemic Lupus Erythematosus (SLE) in C57BL/6 Mice

Systemic lupus erythematosus (SLE) is an autoimmune disease with diverse clinical and immunological manifestations. Several spontaneous and inducible animal models mirror common components of human disease, including the bm12 transfer model. Upon transfer of bm12 splenocytes or purified CD4 T cells, C57BL/6 mice rapidly develop large frequencies of T follicular helper cells (Tfh), germinal center (GC) B cells, and plasma cells followed by high levels of circulating anti-nuclear antibodies. Since this model utilizes mice on a pure C57BL/6 background, researchers can quickly and easily study disease progression in transgenic or knockout mouse strains in a relatively short period of time. Here we describe protocols for the induction of the model and the quantitation Tfh, GC B cells, and plasma cells by multi-color flow cytometry. Importantly, these protocols can also be used to characterize disease in most mouse models of SLE and identify Tfh, GC B cells, and plasma cells in other disease models.

Selective thrombocytopenia and neutropenia occurring after bone marrow transplantation--evidence of an auto-immune basis

This study shows that hitherto unexplained thrombocytopenia and neutropenia occurring after bone marrow allografting and autografting may have an immune basis. In the case of autografts, such antibodies are, by definition, auto-antibodies, and it is suggested that similar antibodies occurring after allografting are also auto-immune.

Acute lethal graft-versus-host disease stimulates cellular proliferation in Peyer's Patches and follicle associated ileal epithelium of adult rats

In this study cell proliferation in Peyer's Patches (PP) and the crypts of Lieberkuhn of the follicle-associated ileal epithelium was analyzed during the development of acute lethal graft-versus-host disease (GVHD) in adult rats. In addition, the effect of thymectomy on GVHD-induced lymphoproliferation was determined by analyzing the 3H-thymidine labeling index in neonatally thymectomized-control and thymectomized-GVHD rats. A significant increase in the 3H-thymidine-labeling index was found in interfollicular (days 2-7), dome (days 5-10), and follicular (days 5-12) regions of PP as well as in associated ileal crypts (days 5-12) of GVHD rats as compared with controls. Thymectomy altered the proliferative response in PP of GVHD rats in that incorporation of 3H-thymidine by follicular and interfollicular cells was significantly lower than in sham-thymectomized GVHD controls during the later stages of the disease. The results suggest a possible role for host thymus-dependent cells in stimulation of or participation in cell proliferation within follicular and interfollicular areas of PP.

Are increased IgE-levels a signal of an acute graft-versus-host reaction?

IgE-levels are markedly elevated following bone-marrow transplantation in patients with and without GVHD. In patients with GVHD, there is a significant correlation between the timing of the IgE-increase and the appearance of clinical GVHD (p less than 0.01). The highest IgE-level (8000 kU/l) was noted in a recipient of a syngeneic graft. During the IgE-peak, the serum from this patient contained low concentrations of IgE reacting with several tested allergens as well as for the hapten TNP, which indicated polyclonal activation. In a patient with a known allergy to animal danders, RAST tests were positive against dog and cat both before and six weeks after total body irradiation and transplantation with marrow from a non-allergic donor. A slight increase in the amount of allergen-specific, IgE-antibodies was seen during the increase in total IgE. A non-allergic patient was transplanted with marrow from a donor allergic to timothy. Timothy-specific, IgE-antibodies were detected immediately after transplantation but they disappeared within a few days and could not be detected during the period of increase in total IgE. We believe that the IgE-elevation seen after conditioning with cytotoxic drugs and total body irradiation in BMT-patients is a polyclonal response in host B-cells induced during an acute, GVHR and influenced by disturbed regulatory T-cells. Lymphocytes from patients with acute GVHD had unusually large numbers of IgG/PFC in vitro after stimulation with staph. aureus Cowan 1 (p less than 0.001), which may reflect a clonal expansion of responsive B-cells.

Autoimmune lymphocytic thyroiditis in dogs

Primary diseases of the thyroid gland, especially lymphocytic thyroiditis and idiopathic follicular atrophy, were the most common lesions associated with clinical hypothyroidism in pet dogs. Lymphocytic thyroiditis resembled naturally occurring lymphocytic thyroiditis in the Obese-strain of White Leghorn chickens and Hashimoto's thyroiditis in man. The morphology of the thyroid lesion and frequent occurrence of circulating thyroglobulin autoantibodies suggested that lymphocytic thyroiditis was immune-mediated in pet dogs. Thyroid lesions similar to naturally occurring autoimmune thyroiditis in experimental dogs were induced by a local thyroidal graft-versus-host reaction. The lesions observed in the thyroid lobe which was not injected with immunocompetent cells appeared to develop from the formation of thyroid antibodies in the gland by migrating host lymphocytes. Autoimmune lymphocytic thyroiditis occurred secondary to an unrelated immune response occurring in target tissue.

Capacity of genetically different T lymphocytes to induce lethal graft-versus-host disease correlates with their capacity to generate suppression but not with their capacity to generate anti-F1 killer cells. A non-H-2 locus determines the inability to induce lethal graft-versus-host disease

When comparing, in a murine model, the kind of graft-versus-host (GVH) disease (GVHD) induced by the donor strain DBA/2 on the one hand and several H-2-congenic resistant B10 donor strains on the other, we found that strain DBA/2 was a universal nonkilling GVH donor for H-2-incompatible nonirradiated F1 hybrid recipients. In this respect, DBA/2 T cells differed from those of the H-2-identical donor strain B10.D2 as well as those of other b10 donor strains. The inability of strain DBA/2 to kill by GVH reaction was not limited to certain H-2 incompatibilities in the F1 recipients, but was nonspecific. The inability to kill is determined by a dominant locus not linked to H-2. DBA/2 T cells were also incapable of inducing the severe suppression of hematocrit values, bone marrow erythropoiesis, thymic cell proliferation, and splenic IgG production in the F1 recipients that was observed after the injection of T cell from the B10 strains. However, DBA/2 T cells, in contrast with those of the B10 donor strains, were vigorous stimulators of IgG production in H-2-incompatible F1 hybrid recipients. Surprisingly, strain DBA/2 as well as the B10 donor strains had good capacity to generate anti-F1 TK cells. Taken together, these findings raise the possibility that lethal GVHD disease is not caused, or not caused exclusively, by donor killer T cells, but by those donor T cells that directly or indirectly induce a suppression of cell proliferation in certain vital organs of the recipient.

Ultrastructural findings in the mouse exocrine pancreas during graft-versus host reaction

12- to 36-hours-old newborn CBA mice were intraperitoneally injected each with 10 X 10(6) allogeneic spleen cells of adult C57Bl mice. Control mice received syngeneic spleen cells of adult CBA mice either in the same way or remained untreated. The animals were killed 1, 3, 7, 14 or 21 days after the spleen cell injection. The pancreas was studied histologically and electron microscopically by common methods. Together with an interstitial lymphohistiocytic infiltration of the pancreas different acinar cell alterations were observed in the mice treated with allogeneic spleen cells: 1. Acute lethal pancreatic cell damages on the day after the intraperitoneal injection of allogeneic spleen cells. 2. Membrane-lined inclusion vacuoles between the 7th and 21st experimental day. 3. Atrophy of pancreatic acinar cells in the terminal stage of a severe graft-versus-host disease. The pathogenesis of the observed pancreatic changes seems to be due to nonimmunological and immunological processes. The membrane-lined inclusion vacuoles of the acinar cells could be the consequence of a cell-mediated immune process in the graft-versus-host reaction.

The host component of the popliteal lymph node graft-versus-host (GVH) reaction. Identification of cells in the node and kinetics of cell proliferation

The cellular composition of rat popliteal lymph nodes undergoing a GVH reaction was examined. The great majority of cells isolated from the nodes were lymphocytes, while the contribution of phagocytic cells was negligible (less than 5%). Both T and B cells were present in GVH nodes. However, the proportion of B cells was higher than in normal lymph nodes (40-50% vs 30%). Cells synthesizing DNA were enumerated autoradiographically in sections of GVH nodes up to day 7 of the response. A significant increase in the proportion of 3H thymidine labelled cells had already been found on the third day of the GVH response, before lymph node enlargement was apparent. Of the differnt days tested a maximum of 6% labelled cells was found on day 7. Liquid scintillation counting of cell suspension from such nodes showed an even higher increase in 3H thymidine incorporation in GVH vs normal nodes. These findings indicate that cell proliferation is a central mechanism behind the lymph node enlargement.

3H-deoxythymidine incorporation in graft-versus-host disease in the Norway rat. II. Autoradiographic studies

A sequential analysis was made of various areas within the lymph nodes and spleen of newborn Brown Norway (BN) rats suffering from graft-versus-host disease (GVHD) subsequent to an allogeneic injection of adult Lewis (L) lymph node cells (experimental). One micron thick autoradiographs were compared between such experimental and control littermates having received the same number of syngeneic adult BN cells. Both experimental and control animals received tritiated deoxythymidine (3HdT) one hour before killing. The autoradiographs revealed a 2.25 and 2.50 times higher thymidine labeling index of lymphocytes in the deep cortex of mesenteric lymph nodes and white pulp of the spleen, respectively, for experimental animals. The experimental effect occurred within one day. The majority of the labeled cells in experimental animals were large lymphoblasts with prominent nucleoli. The labeling index within these areas remained significantly higher than control values until day 8 in the spleen and through day 14 within the lymph nodes. However, differences in labeled cells present in high powered microscopic fields reached a peak on day 3 within compartments in experimental animals but fell significantly below control values by day 9 owing to a pronounced disappearance of both small and large lymphocytes from these areas, and a decreased intensity of individual cell labeling as the reaction progressed. In contradistinction the concentration of labeled cells present in high powered microscopic fields of lymph nodes' medulla became 3.13 times controls by day 4. Most of these labeled cells contained a more basophilic cytoplasm than those found in the deep cortex and some were distinctly plasma cell precursors. In contrast to the deep cortex their concentration remained approximately three times control values until death. The data indicates that the major proliferative events within the spleen and lymph nodes in neonatal rat GVHD are initially restricted to donor cell localization areas of these tissue compartments. Subsequently the GVHD-related events may be attributed to other areas and possibly cell types. Thus any proliferation contributing to splenomegaly in the latter stages of GVHD appears to occur in the red pulp and that contributing to lymph node enlargement a medullary response.

Graft-versus-host reaction: a pathogenetic principle for the development of drug allergy, autoimmunity, and malignant lymphoma in non-chimeric individuals. Hypothesis

It is proposed that the same diseases as those induced by the graft-versus-host reaction (GVHR) will arise in nonchimeric individuals, if structures of the major histocompatibility complex (MHC) on lymphocytes are altered, either by viral infection or by chemicals, in such a way that autologous T lymphocytes react against them as the react in the GVHR to semiallogeneic (F1) lymphocytes differing at the MHC. Diseases in which a GVHR-like pathogenesis is suspected will be discussed.

Shared idiotypic determinants on B and T lymphocytes reactive against the same antigenic determinants. IV. Isolation of two groups of naturally occurring, idiotypic molecules with specific antigen-binding activity in the serum and urine of normal rats

In the rat the major histocompatibility locus antigens are determined by the Ag-B locus. In the present article evidence is presented that the sera and urine of normal adult rats contain naturally occurring antibody-like molcules with reactivity to allogeneic Ag-B antigens. Such molecules can be shown to contain both antigen-binding capacity for the relevant antigens and the idiotypic markers signifying such specific reactivity. The molecules could be shown to be composed of two groups of molecules, one around 7S IgG in size and the other around 35,000 in molecular weight. Only the smaller molecules were found in the urine. From other data we know that the 7S molecules are produced by B lymphocytes and the 35,000-molecular-weight molecules by T cells. Purified natural anti-Ag-B factors, when inoculated into rabbits or chickens, lead to the production of specific anti-idiotypic antibodies that will selectively inactivate rat T lymphocytes with the capacity to react against the relevant Ag-B antigens while leaving other reactivity intact. We thus conclude that the present system allows the purification of naturally occurring idiotypic B- and T-cell products with antigen-binding specificity for further biochemical and functional analysis.