Ulrich Hämmerling

Cytomegalovirus Pneumonia after Bone Marrow Transplantation Successfully Treated with the Combination of Ganciclovir and High-Dose Intravenous Immune Globulin

STUDY OBJECTIVE To assess the efficacy of the combination of the antiviral agent ganciclovir (9-1,3 dihydroxy-2-propoxymethylguanine) and high-dose intravenous immune globulin for treating cytomegalovirus interstitial pneumonitis after allogeneic bone marrow transplantation. DESIGN Nonrandomized prospective trial of combined treatment with two drugs; findings in these patients were compared with those in control patients treated with either of the two drugs alone. SETTING Medical, pediatric, and intensive care units of a tertiary-care cancer treatment center. PATIENTS Consecutive cases of 10 patients in the study group and of 11 patients in a historical control group with evidence of cytomegalovirus pneumonia after bone marrow transplantation for treatment of leukemia or congenital immune deficiency. INTERVENTIONS Study Group (10 patients): ganciclovir, 2.5 mg/kg body weight, three times daily for 20 days, plus intravenous immune globulin, 500 mg/kg every other day for ten doses. Patients were then given ganciclovir, 5 mg/kg.d three to five times a week for 20 more doses, and intravenous immune globulin, 500 mg/kg twice a week for 8 more doses. Control Group (11 patients): ganciclovir alone (2 patients), 5 mg/kg twice a day for 14 to 21 days; cytomegalovirus hyperimmune globulin (5 patients), 400 mg/kg.d for 10 days; and intravenous immune globulin (4 patients), 400 mg/kg.d for 10 days. MEASUREMENTS AND MAIN RESULTS Responses were observed in all patients treated with combination therapy; 7 of 10 patients were alive and well, and had no recurrence of disease at a median of 10 months after therapy. No therapeutic benefit was observed, and none of the 11 patients treated with either ganciclovir or intravenous immune globulin alone survived (P = 0.001 by Fisher exact test). CONCLUSIONS Ganciclovir, when combined with high-dose intravenous immune globulin, appears to have significantly altered the outcome of patients with cytomegalovirus pneumonia after allogeneic bone marrow transplantation.

Isolation of twelve monoclonal antibodies against Ia and H-2 antigens. Serological characterization and reactivity with B and T lymphocytes

The cell hybridization technique was used for the production of 12 monoclonal antibodies against H-2Kk, H-2Db, I-Ak and I-Ek antigens. The strain distribution pattern indicated that three antibodies reacted with new H-2 and Ia determinants, respectively, while the majority of determinants defined by the monoclonal antibodies showed good correlation with H-2 and Ia determinants described by conventional alloantisera.Monoclonal Ia antibodies showed strong reactivity with about 90% of surface IgM positive B cells, but not with T cells. In double fluorescence studies, both I-A and I-E determinants were always found to be coexpressed on the same B cells. When the high sensitivity of the fluorescence activated cell sorter was utilized, about 30 to 40% of purified lymph node T cells were found to carry both I-A and I-E antigens, although in a much lower density than B cells. In conclusion, monoclonal Ia antibodies appear to display the same serological and cellular reactivity pattern as do conventional antisera.

Description of the Reference Panel of B-Lymphoblastoid Cell Lines for Factors of the HLA System: The B-Cell Line Panel Designed for the Tenth International Histocompatibility Workshop

The major objective for the collaborative studies within the Tenth International Histocompatibility Workshop was to compare biochemical and molecular genetic techniques for characterization of polymorphic HLA determinants with HLA specificities defined by conventional serological and cellular techniques. It was, for this purpose, attractive to develop an experimental design that would focus on the in-depth characterization of a limited number of target cells common for all Workshop components and shared by the participating laboratories.

Rapid Immunodiagnosis of Cytomegalovirus Pneumonia by Bronchoalveolar Lavage Using Human and Murine Monoclonal Antibodies

Bronchoalveolar lavage material from 54 immunocompromised patients with interstitial pneumonia was examined by immunofluorescence with cytomegalovirus-specific monoclonal antibodies. Twelve patients (22%) had cytomegalovirus detected in their lavaged cells, and 9 of these patients (17%) had proven cytomegalovirus pneumonitis. This assay detected all samples with cytomegalovirus when the virus was detected by established methods either at the time of lavage or after any other procedure in the subsequent 2 months; that is, it had a sensitivity of 100%. Cytomegalovirus could be detected within 3 hours of the lavage, and a clear correlation was seen between the number of fluorescent cells and the presence of cytomegalovirus pneumonia. All 9 patients with pneumonitis had more than 0.5% fluorescent cells, whereas the 3 patients in whom cytomegalovirus was detected without pneumonia had significantly fewer fluorescent cells. This method provides a sensitive, rapid, and quantifiable system for detection of cytomegalovirus, facilitating the early diagnosis and treatment of cytomegalovirus pneumonia.

Lymphocyte differentiation from precursor cells in vitro.

Much of the recent work in our laboratory has centered about an induction assay developed by Komuro and Boyse in which one of the early maturational steps in the T-cell development, the differentiation from prothymocyte to early thymocyte, can be induced in vitro within two hours. This assay is based on a decade of work concerned with the characterization of cell-surface markers, especially the cytotypic differentiation alloantigens of murine T-cells. As a result of this work on the cell-surface composition of murine lymphocytes, we can summarize the antigenic phenotype of the cortical thymocyte as shown in FIGURE 1. The maturational step in the pathway of T-cell differentiation that can be induced in vitro involves the appearance of this characteristic antigen profile on the surface of the precursor cell; it can be seen that in this differentiation event the products of at least six unlinked genes are expressed. This rapid in vitro T-cell induction assay clearly had potential as a possible bioassay for the identification of the thymic hormone responsible for inducing T-cell differentiation in vivo. Our further studies were designed to answer pertinent questions with respect to this possible application of the assay.

Retinoids as ligands and coactivators of protein kinase C alpha

Whereas retinoic acids control nuclear events, a second class of retinol metabolites, that is, the hydroxylated forms exemplified by 14‐hydroxy‐retro‐retinol (HRR), operate primarily in the cytoplasm. They function as regulatory cofactors for cell survival/cell death decisions. In accordance with these biological aspects, we demonstrate that these retinoids bound protein kinase C (PKC) alpha with nanomolar affinity and markedly enhance the activation of PKC alpha and the entire downstream MAP kinase pathway by reactive oxygen species. HRR was 10 times more efficient than retinol, and the optimum doses are 10–7 and 10–6 M, respectively. PKC alpha activation was reversed rapidly by imposition of reducing conditions. The retinoid binding site was mapped to the first cysteine‐rich region in the regulatory domain, C1A, yet was distinct from the binding sites of diacylglycerol and phorbol esters. The C1B domain bound retinoids poorly. The emerging theme is that retinoids serve as redox regulators of protein kinase C.

Studies of the mouse Ly-6 alloantigen system

The discovery of several monoclonal antibodies provided the impetus to revisit the Ly-6 group of antigens. Our serological data point to the existence of at least five separate Ly-6 antigens. They are distinguished by the patterns of their tissue expression as (1) the classical Ly-6 alloantigen of peripheral lymphocytes (Ly-m6.2A), (2) a bone marrow cell-restricted antigen (Ly-m6.2B), (3) an antigen shared by bone marrow cells and peripheral lymphocytes (Lym6.2C, possibly identical with H9/25),(4) an antigen expressed on bone marrow cells, thymocytes, and peripheral lymphocytes (Ly-m6.2D), and (5) an antigen occurring exclusively on lymphoblasts (Ly-m6.IE, similar to Ala-1). ThB is a sixth distinct antigen of the group. The assumption that separate antigens exist is supported by distinctive distribution patterns in normal and neoplastic tissues. The genes controlling Ly-6 antigens are closely linked, as they are transmitted as two haplotypes only. One incidence of a crossover within the Ly-6 region was observed: the Ly-6B.2 alloantigen was expressed in NZB mice, which type Ly-6.1 for other Ly-6 specificities.

Structural domains of endogenous murine leukemia virus gp70s containing specific antigenic determinants defined by monoclonal antibodies

Abstract Eight distinct antigenic determinants, or epitopes (labeled a-h) were identified on endogenous ecotropic murine leukemia virus (MuLV) gp70s using a series of murine and rat monoclonal antibodies. These epitopes were characterized by their distribution patterns in a panel of cloned MuLVs, and by their localization in fragments of gp70 generated either by spontaneous breakdown of purified gp70, or by controlled proteolysis of gp70 in solubilized virions. A major 32K carboxy terminal fragment was formed which contained epitopes b, c, and f. This fragment also possessed the p15(E) disulfide linkage site, and contained approximately four complex (type 1) carbohydrate chains. An amino terminal 35K fragment contained epitopes a, d, g, and h, and possessed two glycosylated sites, including a site which occasionally retained an endoglycosidase H-sensitive oligosaccharide chain. A related 49K fragment was also obtained which included the entire 35K region and contained an additional sequence bearing epitope e. In a series of dual-tropic MCF-type viruses studied, only those epitopes located in the 32K fragment were ever retained, indicating that for these recombinant viruses at least a portion of that domain was derived from the ecotropic parent. A model is presented indicating the likely orientation of these fragments and their structural characteristics.

A new mouse cell-surface antigen (Ly-m20) controlled by a gene linked to Mls locus and defined by monoclonal antibodies

Five monoclonal antibodies were established by the fusion of mouse myeloma cells (NS.1) with spleen cells from A and (A x C3H/An)F1 mice hyperimmunized with 70Z/3 tumor cells. These antibodies recognized a new antigenic specificity provisionally called Ly-m20.2. In direct cytotoxicity assays, 60 percent of cells in spleen, 40 percent in lymph node, 50 percent in bone marrow and less than 5 percent in thymus were found to react with three of the five antibodies, whereas the two others yielded somewhat lower cytotoxicity indices. The Ly-m20.2 antigen was also expressed on cells derived from liver and kidney but not on cells derived from brain. As judged from cytotoxicity assays with separated T and B cells, Ly-m20.2 antigen is carried preferentially on B lymphocytes. Direct plaque-forming cells (PFC) were completely eliminated by Ly-m20.2-specific antibody and complement. Linkage tests by analysis in 20 (CBA/J x C3H/An) x C3H/An backcross mice and by segregation analysis of BXH and SWXL recombinant inbred strains indicate close association of the loci controlling Ly-m20.2 and Mls antigens on chromosome 1.

Monoclonal antibodies against murine cell surface antigens: anti-H-2, anti-Ia and anti-T cell antibodies.

During the course of antibody responses many different lymphocyte clones are activated. This results in the appearance of a mixture of different antibody species in the serum. Moreoever, different immunizations with the same antigen may yield different antibody populations. Recently, cell hybridization of myeloma cells with immune lymphocytes has been proven to be a powerful tool for the immortalization of individual antibody producing cells (1). These hybrid cell lines (hybridomas) which continuously secrete antibody of a desired specificity can be grown as tumors in mice and allow the isolation of large amounts of monoclonal antibodies.