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Biomedical subjects

H Rodt

Publications and source records attributed to H Rodt.

At least 37 records · Page 2Linked to original sources
PubMed1981

Cytochemistry and membrane markers in acute lymphatic leukaemia (ALL).

136 patients suffering from ALL were subdivided into 5 subtypes (C-ALL, C/T-ALL, pre-T-ALL, B-ALL) according to rosetting tests and using specific antisera directed against membrane antigens. In addition, leukaemic blasts of all patients were investigated according to morphological and cytochemical criteria. In APh and ANAE, indices and the percentages of cases showing a granular staining pattern were high in pre-T- and in T-ALL, but low in C/T- and in C-ALL. PAS-staining, conversely, was more pronounced in C/T- and C-ALL. APh proved to be more discriminative for recognition of the T- and pre-T-ALL subgroups than ANAE, but ANAE-cytochemistry may be useful to detect contaminating normal T-lymphocytes in ALL. Receptors for C3 were more frequent in C- and in T-ALL than in C/T- and in pre-T-ALL, receptors for Fc were distributed equally among all subtypes. Positively of C3- and Fc-receptors was not correlated with cytochemical results. Morphological criteria were not sufficient for subclassification of ALL; the combination of APh- and PAS-staining, however, is valuable to differentiate between C-subgroups and T-subgroups.

Acid Phosphatase↗
PubMed1980

Immunological conditioning of bone marrow for autotransplantation in childhood acute lymphoblastic leukaemia.

Samples of bone marrow from 32 leukaemic children were removed during remission and stored in liquid nitrogen for retransplantation during relapse. Subsequently two children in advanced stages of common acute lymphoblastic leukaemia (cALL) were transplanted with their own cryopreserved marrow cells, after intensive combination chemotherapy and high doses of radiation therapy. Before grafting, the marrow cells were treated with purified heterologous antibodies prepared against cALL antigens, to remove any residual tumour cells. The antibodies showed high cytotoxic activity against leukaemic cells of cALL type without interfering with normal haemopoietic stem cells. Evidence of take was obtained in one patient, who died on day 7 with cardiac failure. In the other patient the dose of nucleated marrow cells grafted was 1.9 x 10(8)/kg (86 000 CFU-C/kg). The patient achieved complete haematological recovery on day 27 and a normal platelet count after day 50 and is now in complete remission. Marrow cells collected during remission and treated with antileukaemic antibodies can repopulate bone marrow after conditioning of the recipient with high doses of radiation.

Antibodies, Neoplasm↗
PubMed1980

Classification of normal and malignant lymphatic cells using acid phosphatase and acid esterase.

UNLABELLED: The usefulness of cytochemical tests (APh and ANAE) to replace or to supplement membrane markers in subclassification of normal and malignant lymphatic cells was investigated. MATERIAL: normal lymphocytes subfractionated by rosetting and centrifugation, and in M. Hodgkin and CLL; lymphoblastoid cell lines; malignant lymphatic cells in different types of lymphatic leukemia. In normal human blood, T-lymphocytes are marked by a distinct "dot-like" ANAE-reactivity which is somewhat less pronounced in the small (11%) subgroup of Fc-IgG-receptor positive T-lymphocytes; B-lymphocytes are negative or finely granular positive. Lymphoblastoid cell lines of B- and of T-type are ANAE- and APh-positive. In some lymphatic malignancies, a characteristic pattern of activity of APh or of ANAE may support the diagnosis. The value of ANAE-cytochemistry is highly estimated for the quantitative determination of the percentage of normal T-lymphocytes lymphatic leukemias, immunological disorders, and during immunosuppressive therapy.

Acid Phosphatase↗
PubMed1980

Molecular identification of T cell-specific antigens on human T lymphocytes and thymocytes.

We have identified membrane glycoproteins which carry T cell-specific antigens on human T lymphocytes and thymocytes. Purified cells were surface-labeled with NaB3H4 after treatment with neuraminidase and galactose oxidase. Immunoprecipitations were performed with rabbit anti-human T cell-specific antibodies using coprecipitation with protein A-containing staphylococci strain Cowan I. The labeled membrane glycoproteins and the precipitates were subjected to polyacrylamide slab gel electrophoresis and visualized by fluorography. The antibodies specifically precipitated 4 proteins called GP 200, GP 180, GP 165 and GP 160 (mol. wts. = 200,000, 180,000, 165,000 and 160,000) from surface-labeled T lymphocytes and low-density (medullary) thymocytes. The GP 200 and GP 180 were not labeled on high-density (cortical) thymocytes. A protein with a mol. wt. of 45,000 was precipitated from thymocytes. Another glycoprotein on T lymphocytes and thymocytes with a mol. wt. similar to that of mouse and rat Thy-1 or theta antigen (mol. wt. 24,000) reacted with the antibodies.

Animals↗
PubMed1980

T cell-mediated cytotoxic immune responsiveness of chimeric mice bearing a thymus graft fully allogeneic to the graft of lymphoid stem cells.

Fully allogeneic, chimeric mice were established by adult thymectomy of (A x B) F1 animals, grafting parental A-type thymus under the kidney capsula, followed by lethal (900 rd) irradiation and reconstitution with B parental-type bone marrow cells treated with xenogeneic anti-T cell antiserum plus complement. Following in vivo sensitization with inactivated Sendai virus (SV) suspensions, no virus-specific T cells could be detected within the spleen cells of the mice. Upon stimulation with third-party allogenic cells in a primary mixed lymphocyte culture, spleen cells of all animals generated alloreactive cytotoxic T lymphocytes (CLT). More interestingly, upon secondary in vitro stimulation with inactivated SV-conjugated B-type stimulator cells, B-type-restricted, virus-specific CTL were inducible in each case. Upon restimulation with SV-conjugated A-type stimulator cells, A being the H-2 type of the grafted thymus, T cells of some but no all mice generated A-type-restricted, virus-specific CTL. The data suggest that in allogeneic, chimeric mice virus-specific CTL can be induced. Moreover, virus-specific CTL, restricted to the H-2 type of the lymphoid stem cell inoculum, are more readily inducible than those restricted to the H-2 type of the allogeneic thymus.

Animals↗
PubMed1980

T cell mediated cytotoxic immune reactivity of bone marrow reconstituted chimeric mice.

The capacity of bone marrow reconstituted chimeric mice to mount sendai virus specific H-2 restricted as well as alloreactive cytotoxic T-cell responses has been investigated. Chimeras of the type a leads to (a x b)F1 and (a x b)F1 leads to a were used. In addition chimeras produced with (a x b)F1 mice grafted under the kidney capsula with a type parental thymus, thymectomised, lethally irradiated and reconstituted with either a, (a x b)F1 or b type bone marrow cells were tested. In agreement with the data of Zinkernagel and Bevan it was noted that virus specific T cells of semi-allogeneic chimeric mice are able to recognise virus antigens in the context of the MHC of the thymus in which they have maturated. The unexpected finding was that fully allogeneic chimeras were able to mount both alloreactive CTL and H-2 restricted, virus specific CTL. The H-2 restricted CTL detected were preferentially restricted to their own MHC type. In some animals also virus specific CTL restricted to the allogeneic thymus MHC type were observed. Data are also presented to indicate that longterm cultured bone marrow cells have the potential to repopulate lethally irradiated mice.

Animals↗
PubMed1980

Influence of the recipient thymus on the maturation of T-lymphocytes in H-2 different radiation chimeras.

Graft-versus-host reactions in mice can be suppressed by incubation of the donor cells with T-cell-specific antibodies prior to transplanting them into lethally irradiated recipients. Since reconstitution of the immune functions in these recipients requires the formation of a new T-lymphocyte population, we investigated whether H-2 differences between recipient thymus and donor stem cells as well as an age dependent thymic involution impaired the maturation of immunocompetent T-lymphocytes. For this purpose the immune response of different chimeric mice against SRBC and third party skin grafts as well as the repopulation of the lymphatic organs with T-lymphocytes was evaluated. Chimeras of the type CBL leads to CBL/CBA and CBL/CBA leads to CBA were used for the experiments. In addition chimeras which had been thymectomized, transplanted with the thymus of one parent strain, lethally irradiated and transfused with bone marrow from other parent strain were analyzed. In all chimeric combinations, even in the case of complete H-2 difference between donor cells and recipient thymus, a normal or almost normal reconstitution of the immune response against SRBC and incompatible skin grafts were detected. Furthermore age-involuted thymi returned to normal morphologically and functionally after bone marrow transplantation. The repopulation of the lymphatic organs in the investigated chimeric mice was remarkably similar to normal controls. This indicates that hemopoietic stem cells and/or lymphopoietic progenitors may differentiate in a thymus in spite of H-2 differences to functional T-lymphocytes able to respond against SRBC and incompatible skin grafts.

Animals↗
PubMed1980

Bone marrow transplantation into recipients sensitized against donor-type T cells.

Immunization of prospective bone marrow recipients with thymocytes of the marrow donor strain prevented subsequent hemopoietic engraftment of the marrow. Immunization with thymocytes of a third party strain sharing the marrow donor's theta alloantigen but not his histocompatibility antigens permitted chimaerism and suppressed GVH in mice. Bone marrow of rat strains of the Th-1.1 group did not take in mice sensitized against mouse Th-1.1 thymocytes. This observation lead to the conclusion that hemopoietic stem cells of rats but not of mice express an early thymic and even prethymic antigen. This antigen is not restricted to the Th-1.1 specificity: rabbit anti-rat thymocyte globulin absorbed in a way which removed stem cell toxicity from a rabbit anti-mouse thymocyte globulin prevented hemopoietic engraftment when incubated with rat bone marrow before transfer to irradiated mice. Serologically this antiserum reacted with thymocytes as well as lymphocytes in the rat bone marrow but less with lymph node cells. An antiserum against rat lymph node cells was rendered T cell specific by absorption. It defined a postthymic T antigen lacking on stem cells, bone marrow lymphocytes and thymus. It labeled lymphocytes in the interfollicular T dependent area of lymph nodes by an immunohistochemical method. T cells in rats were thus found to express a prethymic and/or a postthymic antigen. Implications of theta alloantigens for the suppression of GVH in polytransfused bone marrow grafted patients are discussed.

Animals↗
PubMed1980

Antibody incubation of human marrow graft for prevention graft versus host disease.

An in vitro incubation of incompatible donor bone marrow by xenogenic anti-T-cell globulin (ATG) suppressed an otherwise lethal GvH reaction in animal models. An application of this principle to clinical bone marrow transplantation was successfully tried in three patients with acute lymphoblastic leukemia. Preparation of the specific anti-human T-cell globulin (ATCG-H) was carried out by absorption of anti-human thymocyte globulin with liver-kidney homogenate, chronic lymphocytic leukemia cells of B-cell type, and erythrocytes. Subsequent testing revealed that the serum still reacted with human T-cells but no longer reduced the number of colony-forming units in culture (CFU-C). All three bone marrow recipients were treated by chemotherapeutic conditioning and total body irradiation followed by grafting of in vitro treated bone marrow from HLA-identical siblings. The transplantation of the bone marrow was well tolerated and no major side effects were encountered. No patient so far (24, 7, 6 months) has shown any signs of GvHD. The in vitro pretransplantation treatment of bone marrow with anti T-globulin may be a new approach to the prevention for GvHD in man.

Adolescent↗
PubMed1980

Specific anti-marmoset T-cell globulin: cytotoxic and mitogenic properties.

A virus-transformed marmoset lymphoblastoid cell line (LCL) with T-cell characteristics was used for the production of rabbit anti-marmoset T-cell globulin (RAMTG). Exhaustive absorption of the crude antiserum with kidney-liver homogenate and pooled marmoset B-LCL yielded a T-cell-specific antibody. Specificity of the absorbed RAMTG was evidenced by plateau formation in the cytotoxic activity on marmoset peripheral blood lymphocytes (PBL) and clear discrimination between marmoset T-LCL and B-LCL. Unexpectedly, the absorbed RAMTG was not cytotoxic for human PBL. Assays for mitogenic activity showed that unabsorbed RAMTG exhibited mitogenic activity on marmoset, but not on human or baboon PBL. Unabsorbed rabbit anti-human T-cell globulin (RAHTG) induced cellular proliferation in human and baboon PBL, whereas marmoset or Saimiri sciureus PBL showed no response. Absorbed RAMTG did not stimulate DNA synthesis of marmoset PBL. In conclusion, the specific RAMTG may be useful for studies on the functional role of T-lymphocytes in the marmoset immune response to organ allografts or infectious agents.

Animals↗
PubMed1980

H-2 restriction as a consequence of intentional priming: T cells of fully allogeneic chimeric mice as well as of normal mice respond to foreign antigens in the context of H-2 determinants not encountered on thymic epithelial cells.

Fully allogeneic chimeras were able to develop in vitro alloantigen-specific, as well as H-2-restricted, Sendai virus-specific cytotoxic T-lymphocyte (CTL) response. Depending on the immunization regimen used, Sendai virus-specific CTL responses were restricted to the H-2 antigens of either the stem cell donor or the thymus. Similarly, unprimed splenic T cells of normal mice were found to contain CTL-precursor cells that specifically reacted against Sendai virus or trinitrophenyl derivatives in the context of allogeneic major histocompatibility complex determinants that had not been encountered during their thymic differentiation. A frequency analysis of allogeneically versus syngeneically restricted virus-specific CTL precursors present in splenic T cells showed a ratio of about 1 to 6. These results provide evidence that H-2 restriction of trinitrophenyl- or Sendai virus-specific T cells is dictated by the complex type of the antigen-presenting cell and thus appears to be independent of the type of thymus in which the T cells have undergone maturation.

Animals↗
PubMed1980

Immunohistologic analysis of the organization of normal lymphoid tissue and non-Hodgkin's lymphomas.

Hoping to improve the systems for identifying and classifying normal and malignant lymphoid subpopulations, frozen and paraffin sections of nonmalignant lymphoid tissue and of malignant lymphomas were immunostained for surface (S) and cytoplasmic antigens using the peroxidase-antiperoxidase method. Primary follicle cells and follicle mantle cells known to be part of the recirculating B-cell pool were found to be constantly Ia and C3 receptor (C3R) positive, mostly SIgM and SIgD positive and cytoplasmic immunoglobulin (CIg) negative. The light zone of germinal centers (GC), which is rich in centrocytes, contained a large number of T cells and showed the well-known intercellular Ig network pattern; the dark zone, containing densely packed centroblasts, was usually free of T cells, but was bordered ay a mantle-like accumulation of T cells. Usually only some of the GC cells were definitely positive for SIg and CIg of different classes. All cells reacted positively for Ia and C3R. In areas described by other authors as containing marginal zone cells, cells densely bearing SIgM and deficient in SIgD were detected. The immunoblasts of the hyperplastic plasma cell reaction usually contained CIg. Cells from chronic lymphoid leukemia sections that immunostained for SIgM and SIgD were interpreted as representing a neoplasm of recirculating B cells expressing SIgM and SIgD. The immunohistologic architecture of follicular centroblastic/centrocytic lymphoma showed a more or less close similarity to the organization of secondary follicles. Lymphomas whose cells resembled reactive centrocytes were strongly SIgM positive and SIgD negative or only weakly SIgD positive. CIg was demonstrable in nearly 90% of the lymphomas whose cells resembled centroblasts and in 70% of the lymphomas whose cells resembled immunoblasts of the plasma cell reaction. Finally, immunohistologic staining results from a T-zone lymphoma are presented, which confirm that this lymphoma was composed of a neoplastic T zone and a non-malignant B zone.

Antigens↗