Monoclonal antibody against a Burkitt lymphoma-associated antigen

A monoclonal antibody, referred to as 38.13, was obtained by fusing murine myeloma cells with Lewis rat splenocytes sensitized with Daudi cells (human Burkitt lymphoma containing Epstein--Barr virus genome but lacking HLA-A, -B, and -C and beta 2-microglobulin molecules at the cell surface). 38.13 antibody was demonstrated to be a rat IgM. By complement-dependent microcytotoxicity and indirect immunofluorescence assays, 38.13 antibody was shown to react specifically with cells derived from Burkitt tumors, including both Epstein--Barr virus genome-carrying and Epstein--Barr virus-negative Burkitt lymphoma. By contrast, Epstein--Barr virus-containing lymphoblastoid cell lines derived from normal B lymphocytes were not recognized by 38.13 antibody. Fresh malignant cells from patients affected with various lymphoproliferative disorders were negative, except 4/8 having abdominal Burkitt-like lymphomas. Normal lymphocytes from peripheral blood, spleen, lymph node, tonsil, and bone marrow and mitogen (phytohemagglutinin, pokeweed mitogen, and concanavalin A)-activated blasts were also negative. Thus, 38.13 antibody apparently recognized a Burkitt-associated antigen that is not related to Epstein--Barr virus. The pattern of reactivity of 38.13 antibody with various Burkitt lymphoma cells appeared quite heterogenous and some Burkitt cells were consistently negative. 38.13 antibody thus defines a subset of Burkitt lymphomas.

Interferon enhances the amount of membrane-bound beta2-microglobulin and its release from human Burkitt cells

Human leukocytes interferon (HuIFN-A) increased the amount of beta2-microglobulin on the surface of human Burkitt lymphoma cells (Ramos) and also increased the amount released into the culture medium. The effect was observed 1 h after addition of IFN. These results suggest that the increase in beta2-microglobulin on the cell surface of IFN-treated cells is not due to a decreased shedding of antigen from the cell surface, nor an "unmasking" of surface antigen, but rather to an increased synthesis of antigen.

[Production of monoclonal antibodies against HBs (author's transl)]

Two BALB/c mice were immunized 4 times with a mixture of adw2 and ayw4 subtypes of HBs antigens. Their spleens were then hybridized with mouse myeloma cell line NS1. Using three different radioimmunoassays (RIA), 264 independent hybridomas were screened for anti-HBs activity. By at last one of these techniques, 95% of the colonies were positive. Selected colonies were cloned and supernatants studied by RIA and immunodiffusion techniques for specificity characterisation. Some clones recognised the common "a" subtype, and other were directed to more restricted specificities. Ascites fluid was active on RIA up to 10(7) dilution (up to 29.000 UI/ml). These monoclonal antibodies may be powerful reagent for the diagnosis and understanding of viral hepatitis B.

Characterization of human teratoma cell lines for their in vitro developmental properties and expression of embryonic and major histocompatibility locus-associated antigens

Five human teratoma cell lines have been characterized for the presence of a certain number of marker antigens whose presence or absence has been shown to be characteristic of mouse embryonal carcinoma (EC) cells. Four out of the five lines have been shown to respond to at least some of the criteria associated with murine EC cells even though only limited in vitro differentiation could be demonstrated. The significance of certain unusual marker antigen combinations present on the cell line Tera I and its clones and so far unobserved for the murine model is discussed. The observation in Tera I populations of cells carrying simultaneously both the F9 and beta 2-microglobulin or HLA antigens, suggest that the human cell lines may represent a novel material for the study of mammalian differentiation.

Selective expression of blood group antigens on human teratocarcinoma cell lines

The presence of the blood group antigens H, P, Pk as well as the T-antigen of Thomsen-Friedenreich (detected by the PNA lectin) was investigated at the surface of human embryonal carcinoma cells and of normal or tumor cell lines from adult individuals by an indirect immunofluorescence method. The PNA lectin binds to all the teratoma cell lines investigated but only occasionally to the adult cell lines. The H antigen was detected by fluorescence only onto the embryonic carcinoma cell PA1, but the H enzyme (2-alpha-L-fucosyltransferase) was found catalytically active in all teratoma cells tested: PA1, Susa, Tera I and Tera Ii. Finally, it was also shown that P and Pk antigens are expressed very early during development, prior to HLA and H or ABO.

Reactivity of human lymphoid and lymphoblastoid cells with peanut agglutinin: detection of a blood cell subset which lacks detectable membrane HLA

The number of cells reacting with fluorescein-labelled peanut agglutinin varies widely among human lymphoid organs. By separation techniques, reactive cells from tonsils were characterized as E-negative, non-immunoglobulin-bearing lymphocytes. In peripheral blood, the lectin reacted with a small percentage of lymphoid and monocytoid cells which lacked HLA membrane determinants but expressed the beta 2-microglobulin antigens. The latter phenotype was also found on human lymphoblastoid cell lines. Lectin binding thus provides an effective means of characterizing these cell subsets.

Clinical, cytogenetical, histological, immunological and hormonal studies in a case of true hermaphroditism

A true hermaphrodite with ambiguous genitalia and 46XX karyotype was studied from 18 months of age to 17 years. At 13 years, he developed an ambiguous puberty, with marked bilateral gynaecomastia and public hair score three. A relatively high testosterone level (21 nmol/l), not increased by hCG stimulation, was associated with a high LH level (6 UI/l). In the venous blood of the right ovotestis, the steroid concentrations were in the adult male range, especially testosterone (1400 nmol/l). After removal of the right gonad, large fluctuations of oestradiol levels were observed (150-810 pmol/l). The testosterone secretion of the left ovotestis was low, concentrations begin 4.2 and 130 nmol/l in peripheral and gonadal blood respectively at 16 years. A significant LH surge was induced by oral ethinyl-oestradiol before removal of the left gonad. The 5 alpha-reductase activity was normal in pubic skin. In the left gonad the concentrations of cytosol receptors for testosterone and 5 alpha-dihydrotestosterone (DHT) were significant: 14.5 and 65.5 fmol/mg protein respectively. However the plasma DHT level was not increased by hCG. Finally, the presence of H-Y antigen was demonstrated on lymphocytes. This accords with the presence of testicular tissue in an XX subject, and with significant testosterone production. The high testosterone production did not prevent the appearance of a positive oestrogen-LH feedback. The relative peripheral insensitivity to testosterone, is, in some ways, inconsistent with the presence of receptors for androgens.

Functional study and detection of HLA-D products on fractionated human bone marrow cells

Bone marrow cells from nine normal human volunteers obtained from the Iliac crest, were used in this work for antigen determination and functional studies. The bone marrow aspirated cells were sequentially separated: elimination of erythrocyte, granulocytes and monocytes achieved by Ficoll-Isopaque centrifugation followed by plastic adherence. Purified bone marrow cells were finally separated by size using velocity sedimentation. The slow sedimenting small cells were shown to be mainly T lymphocytes, probably of blood origin. The medium sized bone marrow cells were shown to contain myeloid precursors (CFu-c). Large immature cells were in cycle actively synthesizing DNA molecules. HLA-D and HLA-DR detections on the fractionated cells were performed using three techniques: fluorescence with specific anti HLA-DR allo and xeno antisera; primed lymphocyte typing (PLT) with anti HLA-DR monospecific in vitro primed lymphocytes and detection of the HLA-D stimulating product using the bone marrow fractionated cells as stimulators in a mixed leukocyte culture. Concordant results were obtained with the three techniques. Lymphocytes in the bone marrow express HLA-D products a peripheral lymphocytes. Bone marrow fractions depleted of lymphocytes and monocytes also contain approximately 20% of cells expressing HLA-D products The meaning of the expression of HLA-D products on immature precursors non-lymphoid cells is discussed.

Characterization of a human ovarian teratocarcinoma-derived cell line

A cell line (PA I), derived from human ovarian teratocarcinoma cells, was obtained by culturing ascitic fluid cells from a patient with recurrence of malignant ovarian teratoma. During early passages the cultured cells showed a variable morphology, a long doubling time, and a low plating efficiency (2%). After about 50 passages in vitro, a cell population which was more homogeneous and resembled embryonal carcinoma cells were obtained. These cells had a shorter doubling time (26 h), and increased plating efficiency (77%). The early-passage cells were aneuploid (P 24) whereas the late-passage cells had a normal diploid karyotype with one balanced translocation between chromosomes No. 15 and No. 20 (P 224). Details of the karyotype suggest that the cells are heterozygous, i.e. derived from a stage before the first meiotic division. One of the two X chromosomes were inactive, and the cells expressed HLA antigens (A28 and B12), and beta 2-microglobulin. Expression of F9 antigen, characteristic of two-cell and later preimplantation embryos, was absent, while expression of PCC4 antigen, expressed also by blastocysts, was present. This finding suggests that the line might express some embryonic characteristics. The PA I cell line maintained in monolayer cultures showed several characteristics of malignant cells. The proportion of malignant cells increased with successive passages in vitro. The late-passage cells represented a fairly homogenous population of malignant cells similar to embryonal carcinoma cells. Late-passage PA I cells, when seeded under conditions that prevented attachment of cells to the substratum, formed embryoid bodies consisting of an inner core of cells similar to embryonal carcinoma cells, surrounded by a rind of endoderm-like cells. These two cell layers were separated by a basement membrane-like structure containing fibronectin. The core embryonal carcinoma cells expressed high alkaline phosphatase activity whereas the endoderm-like cells had low alkaline phosphatase activity. Embryoid bodies seeded on an adhesive substratum formed polycystic structures divided by layers of epithelial-like cells and containing extracellular fibrils similar to collagen type I or III. In these cultures, further limited differentiation into endoderm-like, epithelial-like cells and pigmented cells was observed. Morphological differenciation of undifferentiated PA I cells into endoderm-like cells in monolayer cultures could be obtained by treatment with BrdUrd or by plating in low serum concentration and at low density. Cells with characteristic fibrillar distribution of fibronectin and actin microfilament bundles were then observed, indicating formation of cells lacking properties of malignant cells. As indicated by these results, the PA I cell line, in spite of a limited capacity to differentiate in vitro, shares some of the properties of mouse teratocarcinoma cell lines and might therefore serve as a useful model for studies on some developmental mechanisms in human cells.

[Clinical, cytogenetical, histological, immunological and hormonal studies in a case of true hermaphroditism (author's transl)]

A true hermaphrodite with ambiguous genitalia and 46 XX caryotype was investigated during adolescence. At 13 years testosterone concentrations (ng/ml) were 6 and 390 respectively in peripheral and right ovotestis venous blood. After removal of the right gonad, large fluctuations of estradiol levels (40 to 220 pg/ml) were observed. But the testosterone secretion by the left ovotestis was low, although responsive to hCG. A significant LH surge was induced by ethinyl-estradiol load before removal of the left gonad. The 5 alpha-reductase activity was normal in the pubic skin and the levels of cytosolic receptors of testosterone and DHT were high in the left gonad. The presence of H-Y antigen was demonstrated on lymphocytes.

Absence of allogeneic restriction in human T-cell-mediated cytotoxicity to Epstein-Barr virus-infected target cells. Demonstration of an HLA-linked control at the effector level

Peripheral T lymphocytes from patients with infectious mononucleosis (IM) are sensitized in vivo against the Epstein-Barr virus (EBV). The expression of HLA-A, B, or C molecules at the target cell surface is necessary for the cytotoxic reaction because (a) EBV-positive Daudi cells lacking HLA-A, B, and C determinants are resistant to anti-EBV T-cell lysis, (b) cytolysis of EBV-positive target cells can be consistently inhibited by anti-HLA-A, B, and C and anti-beta 2 microglobulin antibodies. However, no evidence for allogeneic restriction in this system was apparent as (a) cytotoxic T lymphocytes (CTL) from one given individual could exert a cytotoxicity of a similar magnitude on different EBV-positive target cells, regardless of the number of HLA-A or B specificities shared by the effectors and targets; (b) CTL from IM patients were able to kill target cells without any HLA-A or B antigen in common; and (c) T5-1 variants lacking one or two HLA antigens at the A, B, or D locus are killed to the same extent as the parental cells. 7 of the 9 IM patients with detectable circulating anti-EBV CTL carried the HLA-A1 antigen, whereas none of the 16 IM patients lacking detectable peripheral CTL were HLA-A1 positive (mean specific lysis of T5-1 target cells by T cells from HLA-A1 positive patients: 29.3 vs. 0.6% in HLA-A1-negative patients) (P less than 10(-9)). These data suggest an HLA-A1-linked gene control of the magnitude of the anti-EBV CTL response. Thus, the HLA region appears to act at two different level sin the T-cell-mediated lysis of EBV-infected cells by controlling first, the development of anti-EBV and second, the expression of HLA-A, B, and C molecules involved as recognition structures at the target cell surface.

Phenotype and surface antigens of mouse teratocarcinoma x fibroblast cell hybrids

Numerous colonies of hybrids between PCC4-aza 1 teratocarcinoma cells and fibroblasts of the heteroploid Cl.1D cell line were examined. All of the hybrids were fibroblasts showing extinction of the multiple developmental potentialities of the teratocarcinoma cell parent, irrespective of whether the teratocarcinoma parent was diploid or tetraploid. The hybrids did not show loss of any specific chromosome contributed by the PCC4-aza 1 cell parent. In contrast with the PCC4 parental cells which carry F9 antigens and do not express H-2b, the hybrids do not express F9 antigens and carry H-2 alloantigens of both parental specificities. These results suggest that in hybrids whose phenotype is that of the Cl.1D parent, a change may occur in the genetic program of the teratocarcinoma cells.

Distinctive properties of fucosyl glycopeptides on human teratoma cells

Fucose-labeled glycopeptides from four human teratoma cell lines of independent origin show similar elution profiles on Sephadex G-50 column chromatography. The fucosyl glycopeptides elute in two major regions: one near the void volume, the other in fractions corresponding to a molecular weight of 2500-3000. These elution profiles are very different from those obtained with the other human cell lines examined which included 3 lymphomas, 2 colon carcinomas, and HeLa. The elution profiles of the human teratomas, however, show remarkable similarities to those obtained with murine embryonal carcinoma cell culture and early mouse embryos. These results suggest that the excluded G-50 fraction may well contain glycopeptides playing a role in mammalian embryogenesis.

Receptors for IgM on human lymphoblastoid B and T cell lines

Receptors for the Fc of IgM were studied together with other lymphocyte markers on cells from nineteen human lymphoblastoid cell lines. Receptors for IgM were found on three of seven T lines and three of twelve B lines studied. Culture conditions needed for an optimal detection of the receptor were different for B and T lines. The presence of the receptor for IgM could not be correlated with that of any other membrane marker.

Enhanced expression of HLA antigens and beta 2-microglobulin on interferon-treated human lymphoid cells

Human leukocyte interferon increased the expression of HLA-A, B antigens and beta 2-microglobulin on two lines of human lymphoblastoid cells and on peripheral blood lymphocytes. No effect was observed on the expression of HLA-DR antigens.

[Detection of human antigens on the surface of mouse cells transformed by chromosome transfer]

Mouse embryo cells, transformed in vitro by the transfer of chromosomes from HeLa human tumour cells, express a surface antigen (s) also found on HeLa cells. This antigen(s), which has been detected both by indirect immunofluoresence and by a 125I-protein A binding assay, is not an antigen(s) shared by both Human and Mouse cells.

Cytogenetic study of a European Burkitt's lymphoma cell line

The chromosomes of an Epstein-Barr virus-negative European Burkitt's lymphoma cell line were studied. All the cells carried the t(8;14) translocation. One clone had 51 chromosomes and was (+1,+7,+16,+15,+21), whereas another clone also had 51 chromosomes but was (+1q+,+7,+16,+15,+21). A third clone had 46 chromosomes (4q+/-).

Regional mapping of the HLA on the short arm of chromosome 6

A detailed gene marker study was performed on a partial 6p trisomic child resulting from a balanced maternal translocation t (2;6) (p 2505; p2105). HLA typing and mixed lymphocyte reaction showed that the breakpoint on chromosome 6 was located within the HLA gene cluster, allowing an accurate location of the D determinants. Localization of the P blood group locus within the region 6 p 2105 to 6 p ter was excluded.

[beta2-Microglobulin in human seminal fluid (author's transl)]

The expression of human beta2-microglobulin (beta2m) on human spermatozoa cell surface was investigated by cytotoxicity and immunofluorescence tests. beta2m was also found in human seminal fluid by use of immunochemical techniques. Seminal fluids obtained from couples with infertility problems were tested for beta2m, albumin and total proteins concentration. A higher level of beta-2m was found in azoospermia compared with that of normal sperms.

Association of the H-Y male antigen with beta2-microglobulin on human lymphoid and differentiated mouse teratocarcinoma cell lines

The expression of the H-Y antigen has been tested on several human lymphoid lines and mouse teratocarcinoma cell lines during differentiation. The human male lymphoid cell line Raji is a very useful target for studies of the H-Y antigen by lymphocytotoxicity test with rat anti-H-Y sera. With a few exceptions, all cells carrying the Y chromosome were H-Y positive. One of the exceptions is the human Daudi cell line which, besides lacking H-Y antigen, also lacks beta2-microglobulin. We have studied a possible association between the H-Y antigen, beta2-microglobulin, and HLA antigen with redistribution experiments. The results strongly suggest that H-Y antigen is not associated with HLA antigens but with beta2-microglobulin.

Presence of SLA and Ia-like antigen on boar spermatozoa

Several parameters for serological tests on boar spermatozoa were studied, and a reliable technique was developed and employed. Using SLA (the MHC system in pig) genotyped boars, and specific reagents, SLA and Ia-like antigens were demonstrated on the sperm using both the cytotoxic and the absorption test. No SLA activity was detected in the seminal fluid.

[Cytotoxicity of human T-lymphocytes sensitized by Epstein-Barr virus. Role of HLA antigens at the surface of target cells infected by the virus]

Peripheral T-lymphocytes from patients with infectious mononucleosis are cytotoxic towards target cells from Epstein-Barr virus-genome carrying human lumphoblastoid lines. Thus, these T-cells appear to be sensitized to viral coded determinants. Daudi cells, that carry EBV-genome, but lack HLA antigens are resistant to specific cytolysis in this model. These results suggest direct HLA involvement in the target structure recognized by birus-sensitized cytolytic T-lymphocytes in human.

Studies on the biosynthetic pathway of human P erythrocyte antigen using genetic complementation tests between fibroblasts from rare p and Pk phenotype donors

Using the indirect immunofluorescence technique, P antigen is not detected on skin fibroblasts from Pk1, Pk2 or p donors. P antigen is reexpressed on polykaryon cells obtained by fusion of Pk x p fibroblasts. On the contrary, P antigen is not expressed on polykaryon cells from Pk x Pk or p x p fusion. All these data suggest that in Pk and p fibroblasts, at least two distinct genes are modified, one in the p phenotype, and the other in the Pk phenotype. The two Pk phenotypes studied seem to be homogeneous from a genetic point of view, as do the five p phenotypes.

The study of human Aa-like specificities using antibody eluates from human lymphoblastoid cell lines

Five sera from multiparous women were absorbed and eluted from the Daudi cell line devoid of HLA antigens. These eluates recognized a specificity, Ly-Lil, of the Ly-Li system. Further absorption of one eluate in Bjab or Raji cell line subdivided this specificity. Family studies showed that the five eluates from the Daudi cell line segregate into two distinct groups.

Absorption analysis of H-2D and K antigens on spermatozoa

The presence of H-2D and K antigens on mouse spermatozoa has been investigated by absorption followed by testing on the proper target lymphocytes. It is concluded that, in addition to Ia antigens, H-2D and K antigens are indeed expressed on mouse sperm cells.

The expression and relation of HLA, beta2-microglobulin and receptor for marmoset red blood cells on man/mouse and man/Chinese hamster hybrid cells

The expression of HLA, human and mouse beta2-microglobulin (beta2m), P red blood cell antigen and a receptor for marmoset red blood cells (MaRBC) were studied on 18 man/mouse and man/Chinese hamster hybrids. A positive correlation was found between the expression of HLA, P, and the receptor for MaRBC, which we interpret as a possible synteny between these different loci. We studied 3 hybrid clones where HLA antigens are still expressed despite the absence of human beta2m and where redistribution experiments demonstrate that HLA is associated with mouse beta2m. Synteny between HLA and the receptor for MaRBC can be a useful tool to select HLA-positive hybrid clones.

The time of appearance of Ia antigens during spermatogenesis in the mouse

Ia specificities were studied on germinal cells from C3H and 129 mice by using an AT.H anti-AT.L antiserum. By absorption experiments and immunofluorescence studies on sections of testes from mice of various ages, we were able to detect Ia specificities on cells of the germinal line from primary spermatocyte to spermatozoa. Ia specificities were not detectable on gonocytes or spermatogonia.

Absence of a serologically detectable association of murine beta2-microglobulin with the embryonic F9 antigen

The association of murine beta2-microglobulin to the early embryonic F9 antigen has been investigated by indirect immunofluorescence and by radioimmunoassay. Although some cell lines carry both types of molecules, the beta2-microglobulin was not found expressed on primitive teratocarcinoma cells, where F9 antigen was primarily detected. It is concluded that the low m.w. (12,000 daltons) subunit that was reported to be associated to the F9 antigen is not the adult beta2-microglobulin.

The expression of human beta2-microglobulin on human spermatozoa

The expression of human beta2-microglobulin was detected on human spermatozoa from 7 donors using a cytotoxicity assay and indirect immunofluorescence. Inhibition experiments using purified beta2-microglobulin demonstrated the specificities of these reactions. We were able to localize beta2-microglobulin on human spermatozoa on the post-acrosomal region at a similar location to those described for HL-A antigen and for early embryonic antigen +t12, but also at the end of the intermediary piece and the beginning of the tail.

Formal genetics of the HL-A region

The extreme polymorphism of the HL-A system is due to the presence of two (SD1, SD2) and perhaps three linked polyallelic genes. The distinction of "bridging antibodies" (reacting with several HL-A specificities recognizing separate sites on the HL-A molecule) from the main HL-A determinant as it is demonstrated by absorption/inhibition experiments increases this complexity. The HL-A linkage group is composed of other systems: LD1, LD2, PGM3, ADA (?), P, ME1, IPO-B and possibly a "hay fever gene". No gametic or zygotic selection was found in spite of the presence of HL-A antigens on spermatozoa. Mixed lymphocyte reaction (MLR) is principally governed by LD genes. The main (LD2) gene is probably situated outside the interval SD1, SD2, near SD2. Other LD genes (LD1 inside the interval SD1-SD2 and LD3) are suspected. The presence of an immune response gene (Ir) has not yet been demonstrated although several diseases associated with specific SD2 antigens are known. These different genes (SD1, SD2, LD1, LD2, LD3 and Ir) probably form a functional unit in the allo-immunozation.