Janine André-Schwartz

Polyspecificity of Monoclonal Lupus Autoantibodies Produced by Human-Human Hybridomas

We studied the serologic properties of monoclonal autoantibodies that were produced by hybridomas derived from lymphocytes of patients with systemic lupus erythematosus. The hybridomas were made by fusion of a human lymphoblastoid cell line, GM 4672 (derived from a patient with multiple myeloma), with peripheral-blood or splenic lymphocytes from six patients with lupus. Thirty monoclonal autoantibodies, selected for their ability to react with denatured DNA, were analyzed. Eighteen of them reacted with three or more additional polynucleotides, including native DNA, left-handed double-helical DNA (Z-DNA), poly(l), and poly(dT). Ten reacted both with nucleic acids and the phospholipid cardiolipin. The multiple binding reactions of the monoclonal autoantibodies may be explained by the presence of appropriately spaced phosphodiester groups in both the polynucleotides and the phospholipid. The sharing of antigenic groups by polymers of different natures may contribute to the apparent diversity of serologic reactions in systemic lupus erythematosus. These findings suggest that DNA itself need not be the immunogenic stimulus for autoantibody formation in this disease.

Termination of the Respiratory Burst in Human Neutrophils

Recent evidence has suggested that a particulate O(2) (-)-forming system is responsible for the respiratory burst in activated neutrophils. The respiratory burst is normally a transient event, lasting only 30-60 min. To investigate the mechanism by which the burst is terminated, we examined the O(2) (-)-forming activity of neutrophil particles as a function of time in the presence and absence of agents known to affect the function of intact cells. Measurements of the O(2) (-)-forming capacity of the particles against time of exposure of neutrophils to opsonized zymosan, a potent stimulating agent, revealed a rapid fall in activity when exposure was continued beyond 3 min. Exposure to zymosan under conditions in which the myeloperoxidase system was inactive (i.e., in the presence of myeloperoxidase inhibitors, or in the absence of oxygen) resulted in a substantial increase in the initial O(2) (-)-forming activity of particles from the zymosan-treated cells, but did not prevent the sharp fall in activity seen when zymosan exposure exceeded 10 min. The fall in activity was, however, prevented when activation took place in the presence of cytochalasin B (1.5 mug/ml), an agent thought to act largely by paralyzing the neutrophil through an interaction with its microfilament network.We conclude from these findings that the termination of the respiratory burst results at least in part from the inactivation of the particulate O(2) (-)-forming system. This inactivation involves at least two processes which probably act simultaneously. One is the destruction of the system through the action of myeloperoxidase. The other appears to require active cell motility and is independent of oxygen. The current view holds that the O(2) (-)-forming system of the neutrophil is located in the plasma membrane. It may be that the second process involves the internalization and degradation of this membrane-bound system.

Canine Systemic Lupus Erythematosus. TRANSMISSION OF SEROLOGIC ABNORMALITIES BY CELL-FREE FILTRATES

The presence of viruses was sought in a colony of dogs bred from parents with systemic lupus crythematosus (SLE). Cell-free filtrates prepared from the spleens of these animals were injected into newborn dogs, mice, and rats. The canine recipients developed antinuclear antibody (ANA) and positive lupus erythematosus (LE) cell tests: ANA and, in some cases, antinative DNA antibodies were produced by the murine recipients: no abnormalities were detected in the rats. Serial passage of spleen cells or cell-free filtrates of spleen tissue in syngeneic mice reduced the time required for appearance of ANA from 9 to 4 mo. Some murine recipients of the canine filtrate developed malignant lymphomas. Murine leukemia viruses were identified in these tumors by electron microscopic, virologic, and serologic technics. These neoplasms, but not other tumors known to contain murine leukemia viruses, were associated with the production of ANA. Puppies inoculated with the canine filtrate-induced mouse lymphoma developed ANA and positive LE cell tests within 4 mo. THE RESULTS WERE INTERPRETED TO INDICATE THE PRESENCE IN CANINE SLE OF A VIRUS CAPABLE OF: (a) inducing the serologic abnormalities of SLE in normal dogs and mice: (b) activating latent murine leukemia viruses: and (c) spreading by both horizonal and vertical routes.

Gaucher's disease and chronic lymphocytic leukemia. Possible pathogenetic link between Gaucher's disease and b‐cell proliferations?

The authors report a case of Gauchers disease with chronic lymphocytic leukemia. The diagnosis of Gauchers disease was confirmed by electron microscopy and glucocerebrosidase assay. There may be a pathogenetic link between Gauchers disease and B‐cell proliferation.

High-specificity in-situ hybridization. Methods and application.

We describe a technique of in-situ hybridization using oligonucleotide probes employing the expression of immunoglobulin VH genes as a model. Optimal conditions for hybridization with the 35S-labeled oligonucleotide probes were established with monoclonal B-cell lines that express VH genes of known nucleic acid sequence. The range of sensitivity and specificity achieved with this technique is documented. Under conditions of high stringency. this method can detect the expression of highly related VH hypervariable regions.

Cellular immunity in the mouse. V. Further studies on leukemia virus activation in allogeneic reactions of mice: stimulatory parameters.

Abstract The relationship between activation of thymic (T)-derived lymphocytes and mouse leukemia virus (MuLV) induction were studied in vivo and in vitro . The results indicate that there is no simple relationship between the severity of GVH, assayed by splenomegaly, alteration of T-cell reactivity in vitro , the activation of mouse leukemia viruses, and the subsequent development of lymphoma. Allogeneic stimulation either in vivo or in vitro is a potent activator of MuLV, as is the drug iododeoxyuridine. However, nonspecific T-cell mitogens such as PHA or Con-A, the drug cyclophosphamide, or specific antigenic stimulus such as sheep red blood cells after in vivo sensitization are not effective virus activators. The source of the cell supporting MuLV replication in vitro appears to be a theta-positive (T) lymphoblast.

Self-reactive repertoire of tight skin (TSK/+) mouse: Immunochemical and molecular characterization of anti-cellular autoantibodies

The tight skin (TSK/+) mouse has been proposed as an experimental model for progressive systemic sclerosis because of the biochemical alterations in collagen synthesis and pathological similarities to the human disease. Here, we report the analysis of tight skin mice sera for the presence of anti-cytoplasmic and anti-nuclear autoantibodies and determination of the frequency of hybridomas producing anti-cellular autoantibodies. The binding specificity of TSK mAbs to nuclear and cytoplasmic antigens such as keratin, actin, vimentin, and mitochondria was determined. Of 71 monoclonal antibodies that we have studied, only 3 appear to bind to foreign as well as self-antigens, indicating that the majority of these antibodies do not belong to the class of natural autoantibodies. Our results also showed that the frequency of hybridomas producing anti-nuclear and anti-cytoplasmic antibodies was higher in TSK mice than in C57BL/6 pa/pa, the control mouse strain, used in these studies. The results of the analysis of V gene usage showed that the majority of anti-cytoplasmic and anti-nuclear antibodies are encoded by genes from a restricted number of VH and VK genes families. In the sera of TSK mice we have detected the presence autoantibodies specific for cytoplasmic antigens in addition to anti-nuclear and anti-topoisomerase I antibodies which are characteristic of scleroderma. Since the presence of anti-cytoplasmic antibodies has not been described in scleroderma, the significance of their production in tight skin mice is not clear. However, the presence of such autoantibodies in the animal model provides a basis for investigation of this type of antibodies in human disease.

Acute Leukaemia with Eosinophilia or Acute Eosinophilic Leukaemia: A Dilemma

Summary. A young male patient is described with acute leukaemia whose bone marrow and peripheral blood contained abundant cells of the eosinophilic series in all stages of maturation. These cells, proven histochemically to be true eosinophils, were abnormal in both maturation and proliferation. Upon electron microscopic study of bone marrow and peripheral blood, abnormalities in the eosinophilic series were identified as early as the promyelocytic stage as well as in the most mature eosinophil seen. The clinical and morphologic picture of this patients disease raises the possibility of this being an acute eosinophilic leukaemia.

Characterization of a retrovirus that cross-reacts serologically with canine and human systemic lupus erythematosus (SLE)☆

Abstract This report characterizes the SP104 virus, which was previously shown to contain an antigen that cross-reacts with an antigen present on surfaces of blood lymphocytes of human and canine patients with systemic lupus erythematosus (SLE). Morphologically, the virus was a Type C particle. By physicochemical characterization it was a typical retrovirus with a bouyant density of 1.15–1.17 g/cm 3 , high molecular weight RNA and RNA-dependent DNA polymerase. The virus had antigens that cross-reacted with p30, gp71, p12, and p15 of other murine retroviruses. Biologically, SP104 was characterized as a murine B-tropic virus that was only weakly oncogenic but highly efficient in eliciting the production of antinuclear antibody in mice. Nucleic acid hybridization experiments indicated that the RNA of SP104 virus had only partial identity with the other murine leukemia viruses tested. There was no evidence that the genetic sequences found in the SP104 virus were present in tissues from canine or human patients with SLE.