Dietrich Götze

Identification and quantitation of human T-cell antigen by antisera purified from antibodies crossreacting with hemopoietic progenitors and other blood cells

Anti-T cell globulin (ATCG) prepared from antihuman thymocyte serum by absorption with kidney, cells from patients with chronic lymphatic leukemias, and several lymphoblastoid cell lines was shown to react specifically with human thymus-derived lymphocytes. While high activity against thymocytes and a T-lymphoblastoid cell line could be demonstrated, ATCG remained negative against several chronic lymphatic leukemias and B-lymphoblastoid cell lines. The ATCG was used in the cytotoxic test, electronmicroscopy, and immunoautoradiography for identification of T cells in thymus, tonsils, spleen, blood, bone marrow, lymphatic leukemias, and lymphoblastoid cell lines. A comparison of these results with the ability to form spontaneous SRBC-rosettes revealed remarkable deviations between both markers in leukemias. Absorption with human brain failed to remove specific activity of ATCG. Labeling experiments by immunoautoradiography and investigations by complement fixation permitted quantitation of relative T-cell antigen concentration on different cell populations. As further evidence for specificity it could be shown that ATCG was no longer toxic for hemopoietic progenitors, whereas unabsorbed globulin reduced the number of colonyforming cells considerably.

Models for recognition of virally modified cells by immune thymus-derived lymphocytes

Virus-immune effector T cells generated in vivo are specific for both the virus used and theH-2 type of the infected mouse. Genes mapping at H-2K or H-2D apparently serve as self markers. The mechanism underlying this function is, however, not understood. This paper summarizes models that seem, at present, to be feasible explanations for this phenomenon, and considers possible implications of the hypothesis that self-recognition may be mediated by way of the same V gene subset that codes for alloreactivity.

Classification of Leukemic Cells with T- and O-ALL-Specific Antisera

After the discovery of several surface markers on human lymphocyte populations many attempts have been made to classify leukemias and lymphomas on the basis of cell origin or cell characteristics. Although the biological implications of the various markers on leukemic cells are unknown, an exact characterization of these markers may lead to an early diagnosis of preleukemic stages or relapses and provide guidelines for more specific therapeutic regimens of these disorders. The panel of common surface markers was increased by recent reports on specific xenogeneic antisera identifying membrane antigens on different types of leukemia cells. The identification of the T-cell antigen by specific anti-T-cell sera on leukemias that formed spontaneous rosettes provided convincing evidence that these cells derived from the thymic pathway (3, 13, 16, 12). An antigen not present on normal mature lymphocytes was recently detected on cells of a subgroup of ALL cases by antisera which were produced against so-called O-ALL lymphoblasts lacking all the known markers (7). On the other hand, raising of diagnostic antisera against human lymphatic or leukemic tissues in other species is complicated by the fact that these sera are generally directed against xeno-specific determinants including many cells other than those used for immunization (25). Extensive absorption and purification procedures must therefore be performed to guarantee a definite specificity (22). In this report we describe the reaction pattern of an absorbed anti-T-cell-globulin (ATCG) and an anti-O-ALL-globulin (A-O-ALL-G) and their application to the classification of leukemias in several test systems.

Immunohistochemical localization of xenogeneic antibodies against Iak lymphocytes on B cells and reticular cells

Rabbit antiserum against B10.AQR mouse spleen and lymph node cells (RAQR), after appropriate absorption, reacted with Iak-positive spleen and lymph node cells in cytotoxic and complement-fixing indicator systems. It reacted neither with Iak-positive thymocytes nor Iak-negative thymocytes, spleen, and lymph node cells. Cryostat sections of tissue from Iak-positive and Iak-negative mice were incubated with RAQR and either rabbit anti-mouse Ig or rabbit anti-T cell globulin. With the unlabeled antibody enzyme method, RAQR-stained lymphocytes were concentrated in the B-cell regions of spleen and lymph nodes of Iak-positive CBA mice. The tissues of mice bearingI-region haplotypes different fromk were negative. Reticular cells of the T cell-supporting network were also positive in Iak mice, but liver, gall bladder, and testicular cells were not. Macrophages of both Iak-positive and -negative mice were stained by RAQR and also by heat-aggregated, peroxidase-labeled Ig. Iak-positive reticular cells survived 900 R total body irradiation and persisted after grafting with Iak-negative bone marrow. The reticular cells were also seen in a thymus which was depleted of cortisone-sensitive lymphocytes.

T(Iat)- and B(Iab)-cell alloantigens determined by theH-2 linkedI region in mice

The specificity of an antiserum directed againstI region associated (Ia) antigens is described. The serum was raised in (DBA/1×B10.D2)F1 mice against lymphocytes of AQR mice, differing from the responder for theI region only. The serum reacts with Ia antigens expressed on B cells (Iab) as well as with Ia antigens expressed on T cells (Iat). Absorption studies indicate that B cells possess at least two Ia antigens, and one of these is shared by T cells. However, this ‘shared antigen’ is not present on the surface of lymphocytes of thymectomized mice. Analysis of the strain distribution of Iab and Iat antigens revealed that the Iab antigens are present on lymphocytes of mice carrying theIAk subregion and that the Iat antigens are present on lymphocytes of mice carryingI region genes of theH-2k haplotype located between theIA andIB subregions. This conclusion is based on the analysis of the antiserums reactivity with T and B cells of the strains B10.A(2R), B10.A(4R) and B10.HTT: the serum reacts with B and T cells of B10.A(2R) but only with B cells of B10.A(4R) mice and only weakly with T cells of B10.HTT mice.

Serological characterization of ia antigens of the h-2k, h-2s, and h-2q haplotypes by antisera produced against skin, lymphocytes, and lymphoblasts. Strain distribution pattern of ia antigens and their relationship to ir genes.

Serological specificities of seven anti-Ia sera are described. Using five anti-Iak sera, six Ia specificities (Ia.1,2,17,W25,W26, and W28) could be defined. Three of the specificities were detected with antisera raised against skin, unstimulated, or allogeneic stimulated cells; the other three were detected by analyzing antisera raised against ConA-stimulated blasts. Four Ia specificities (Ia.4,12,W27, and W29) were defined by anti-Ias sera and two (Ia.10 and W30) by anti-Iaq sera. Antisera raised against ConA blasts exhibited the highest titer and almost total killing of spleen or lymph node lymphocytes, as well as of purified T lymphocytes; they crossreacted extensively with cells of strains carryingI haplotypes different from those against which the antibodies were induced. The strain distribution pattern of three of the Ia antigens was the same as that of the high response to the antigens (H,G)-A—L (Ia.2), IgA (Ia.17), and calf skin collagen type I (Ia.W29).

Immune response to calf collagen type I in mice: A combined control of Ir-1A and non H-2 linked genes

The genetically controlled immune response to calf skin collagen type I in mice could be demonstrated to be governed by at least two genes. One is linked to theH-2 complex and located within theIA subregion. High-responder alleles areH-2b,H-2f, andH-2s. The other gene(s) is not linked to theH-2 complex and high-responder allele(s) are found in the genome of B10 mice but not in the genome of DBA mice. There are strong indications that theIr-1A gene controls the response at the T-cell level, whereas it is assumed that the background gene(s) control the immune response at a different level.

The major histocompatibility complex of the rat,RT 1 : II. biochemical evidence for a complex genetic organization.

Recombinational analysis has shown that the rat MHC,RT1 is divided into two regions:RT1.A, which codes for class I (transplantation) antigens, andRT1.B, which controls the humoral immune response and proliferative response to allogeneic cells as well as the expression of class II (Ia) antigens. Serological and sequence studies suggest that there might be more than one antigen-coding locus within theRT1.A region. Results obtained by sequential immunoprecipitation reveal that both regions code for at least two gene products. By implication, theRT1 complex must therefore harbor at least four loci;RT1.A andD coding for class I glycoproteins (45,000 daltons); andRT1.B andE coding for class II (Ia) glycoproteins (35,000 and 28,000 daltons).

The major histocompatibility complex of the rat,RT1 : I. serological characterization of the MNR haplotype (RT1 ( m )) in regard to the cross-reacting haplotypesRT1 ( a ),RT1 ( c ), andRT1 ( b ).

The antigenic determinants expressed on RBC and lymphocytes and coded for by the MHC, RT1,of the MNR (RT1m) rat strain were compared to those of the BN.DA(RT1a), ALB (RT1b), and AUG (RT1c) strains by direct cytotoxicity and absorption analysis with RT1 typing sera, sera produced against MNR cells, and sera produced in MNR responders against cells carrying thea, b, andc haplotype determinants. The results indicate that MNR shares major class I (A) antigens with DA, and major class II (B) determinants with AUG, but that MNR differs from DA and AUG with respect to both classes of determinant. It appears, therefore, that the MNR haplotype does not represent a simple composite of the two other haplotypes,RT1a andRT1c, as reported earlier.

Genetic control and carrier and suppressor effects in the antibody response of mice to procollagen.

The response potential of inbred mouse strains against bovine type I procollagen and its separated structural domains, i.e., the globular procollagen peptide and the triple-helical collagen moiety, was compared by passive hemagglutination and radioimmune assays. Studies with congenic and recombinant lines and with backcross populations showed that the antibody response to procollagen peptide is under the control of a gene located in theIA, IB subregion of theH-2 complex. The strain distribution pattern of high response to the procollagen peptide is not identical to that of the high response to collagen. Both the procollagen peptide and procollagen are thymus-dependent antigens, since no response was observed in nude mice. Low response to procollagen peptide and/or collagen could be corrected in some, but not all mouse strains by using procollagen as immunogen. Strains which show low response against collagen but high response against procollagen were injected with collagen prior to a challenge with procollagen. This treatment reduced the antibody response to the procollagen peptide but not to collagen. Carrier and suppressor effects in the response to procollagen are apparently more complex than those observed in the response to synthetic peptides.