Continuous cultures of fused cells secreting antibody of predefined specificity

Some perspectives on the transfer of cell-mediated immunity by immune-RNA

Ribonucleic acid extracts of lymphoid cells from immune hosts were used to transfer in vivo and in vitro cell-mediated immune reactivity to a variety of antigens. The in vivo immune responses transferred by RNA included the delayed cutaneous hypersensitivity reaction to fungal and chemically-defined antigens and the tumor-rejection reaction to guinea pig hepatoma antigens. The in vitro immune responses transferred by RNA included macrophage migration inhibition by fungal, chemically-defined, and tumor antigens. The transfer activity of RNA preparations was contained in the 8 s to 18 s species of RNA and was sensitive to RNase but not to DNase or trypsin. Antigen was not detectable in the RNA preparations and appeared to have no role in the transfer activity. Syngeneic, allogeneic, or xenogeneic sources of RNA could transfer immune reactivity. In each system tested, the transfer of cell-mediated reactivity by RNA was specific for the antigen used to sensitize the RNA donor. The potential use of RNA-mediated transfer of immunity is discussed.

The distribution of HLA on human lymphoid, bone marrow and peripheral blood cells

The cellular distribution and the differential expression of HLA on cell suspensions and tissue sections has been investigated using the monoclonal antibody W6-32, which reacts with the high molecular weight chain of the major histocompatibility antigen. Lymphocytes and platelets, as assessed by autoradiographic and immunoperoxidase labeling, were the most densely labeled cells. Myeloid precursors showed more labeling than mature neutrophils. Electron microscopic immunoperoxidase labeling showed a continuous distribution of HLA antigen on lymphoid and myeloid cell membranes. Erythroid precursors (including reticulocytes), although very weakly labeled, were clearly positive, in comparison with mature erythrocytes. In the thymus, HLA-negative, thymocyte antigen-positive cells (85%) can be distinguished from HLA-positive, thymocyte antigen-negative cells (15%). By using immunofluorescence techniques on tissue sections, the former cells were shown to be cortical thymocytes and the latter medullary cells.

Hybrid myelomas producing antibodies against a human neuroblastoma antigen present on fetal brain

Spleen cells from mice immunized with a cultured human neuroblastoma were hybridized with the mouse plasmacytoma P3X63Ag8. Hybrid myelomas were screened for production of antibodies that reacted with human neuroblastomas but not with cells from other tissues. One of these hybridoma antibodies reacted with an antigen present on the six human neuroblastomas tested, one of two retinoblastomas, a glioblastoma, and fetal brain, but did not react with other tumors or tissues including adult human brain.

A human thymocyte antigen defined by a hybrid myeloma monoclonal antibody

Spleen cells from a BALB/c mouse that had been immunized with human thymocytes were fused with the myeloma line P3-NS 1/1 Ag 4.1. One of the resulting hybrid clones (NA 1/34) secreted an antibody that was highly specific for human thymocytes. Eighty-five % of thymocytes expressed the antigen designated HTA1. There were an estimated 15 x 10(4) molecules of HTA 1 per cell, and it is therefore a major surface molecule. The expression of this antigen on thymocytes appears to be reciprocal to HLA, as recognized by another monoclonal antibody W6/32. Immunoprecipitated material from [125I]-labeled thymocyte membranes was analyzed by polyacrylamide gel electrophoresis in sodium dodecyl sulfate which disclosed a single component of 45,000 molecular weight.

Methods for binding cells to plastic: application to a solid-phase radioimmunoassay for cell-surface antigens

Two methods are described for attaching cells to plastic plates such that they may be used for antibody binding assays. In the first method, lymphoid cells or erythrocytes were attached to the wells of plastic plates using glutaraldehyde. This resulted in monolayers of fixed cells which retained surface antigens and were stable to storage. The second method involved binding of unfixed cells to the plastic surface by means of antibodies non-specifically adsorbed to the plate. Both methods resulted in cell layers which remained attached to the plate during the washing and incubation procedures of a radioimmunoassay. The cell layers were shown to be suitable for screening the product of hybrid cell lines for the presence of monoclonal antibodies to cell-surface antigens.

Reactivity of monoclonal anti-melanoma antibodies with melanoma cells freshly isolated from primary and metastatic melanoma

Human melanoma cells, freshly obtained from nine primary and metastatic melanoma cases, were tested for binding of monoclonal anti-melanoma antibodies produced in vitro by hybridoma clones. Monoclonal anti-melanoma antibodies bind to melanoma cells but do not react with nonmalignant cells obtained from the same patients or with cells obtained from giant hairy nevus. These results confirm the existence of tumor-specific antigens. Binding of monoclonal antibodies to melanoma cells of several origins, primary or metastatic, from different patients suggests the existence of tumor antigens shared by human melanoma cells. The binding pattern of different antibodies to various cells also predicts the existence of more than one tumor-specific antigenic determinant on melanoma cells.

The immunoendocrinology of estrophilin

Immunoglobulin from the serum of rabbits immunized with highly purified estradiol-receptor complex from calf uterine nuclei has been shown to contain specific antibodies to estrophilin by five criteria. Antibodies to calf nuclear estrophilin cross react with nuclear estradiol-receptor complexes of rat, rabbit and sheep uterus, rat endometrial and pituitary tumor, and MCF-7 human breast cancer cell line. They also react with extranuclear receptor of calf, rat, mouse, rabbit, guinea pig, monkey and sheep uterus, rat mammary, endometrial and pituitary tumor, and human breast cancer. There is no interaction of the antibody with estradiol itself. The nuclear form of estrophilin appears to bind more immunoglobulin molecules than does the cytosol form. The antibodies do not react with either the nuclear or extranuclear dihydrotestosterone-receptor complexes of rat prostate, with the extranuclear progesterone-receptor complexes of rabbit uterus, chick oviduct or rat endometrial tumor, or with rat and mouse alpha-fetoprotein. These findings indicate an immunochemical similarity among estrophilins from several mammalian species, as well as between nuclear and extranuclear forms of the receptor, but not among receptor proteins for different steroid hormones. Immunoglobulin from the serum of a goat immunized with similar antigen shows a considerably higher titer of antibodies to estrophilin. These react with nuclear and extranuclear estradiol-receptor complexes of calf uterus to produce somewhat larger entities than those formed with the rabbit antibody. Unlike the rabbit antibody, interaction with the goat antibody causes a noticeable decrease in estradiol-binding affinity of the extranuclear estrophilin as well as an apparent decrease in the total hormone-binding capacity. Specific antibodies to estrophilin offer promise as valuable reagents for receptor analysis and purification, as well as for the elucidation of many still unresolved questions concerning receptor synthesis, localization and function.

Production of monoclonal antibodies against a cell surface concanavalin A binding glycoprotein

Concanavalin A-binding (Con-A)-binding cell surface glycoproteins were isolated, via Con A-affinity chromatography, from Triton X-100-solubilized Chinese hamster ovary (CHO) cell plasma membranes. The Con A binding glycoproteins isolated in this manner displayed a significantly different profile on sodium dodecyl sulfate--polyacrylamide gels than did the Triton-soluble surface components, which were not retarded by the Con-A-Sepharose column. [125I]-Con A overlays of the pooled column fractions displayed on sodium dodecyl sulfate--polyacrylamide gel electro-phoresis (SDS-PAGE) demonstrated that there were virtually no Con A receptors associated with the unretarded peak released by the Con A-Sepharose column, whereas the material which was bound and specifically eluted from the Con A-Sepharose column with the sugar hapten alpha-methyl-D-mannopyranoside contained at least 15 prominent bands which bound [125I]-Con A. In order to produce monoclonal antibodies against various cell surface Con A receptors, Balb/c mice were immunized with the pooled Con A receptor fraction. Following immunization spleens were excised from the animals and single spleen cell suspensions were fused with mouse myeloma P3/X63-Ag8 cells. Numerous hybridoma clones were subsequently picked on the basis of their ability to secrete antibody which could bind to both live and glutaraldehyde-fixed CHO cells as well as to the Triton-soluble fraction isolated from the CHO plasma membrane fraction. Antibody from two of these clones was able to precipitate a single [125I]-labeled CHO surface component of approximately 265,000 daltons.

Anti-peroxidase antibody-secreting hybrid lines. I. Identification, cloning and cell characterization

Anti-peroxidase antibody (Ab)-secreting hybrids have been produced by fusion of peroxidase (PO)-immunized mouse lymph node cells and immunoglobulin (Ig)-secreting P3-X63-Ag8 (X63) myeloma cells. Identification of Ab-secreting hybrids can be performed as early as day 5 after cell fusion by the hemolytic plaque assay. Immediately after identification, hybrids were directly isolated, by means of a micropipette, into Terasaki microchambers containing nutrient medium and a thymocyte filler layer. The yield of secreting hybrids is improved by using this procedure. All the cells of the PO 772 C2 clone show the same ultrastructural pattern and immunocytological properties; they are proplasmocytes, as are the parental X63 cells; they present intracisternae Ab and show no Ig or Fc receptors at the cell surface. Over 90% of viable PO 772 C2 cells form specific plaques. Isoelectric focusing and sodium dodecyl sulfate polyacrylamide gel electrophoresis show that the cells of this clone secrete Ab; the secreted Ig are formed with chi and gamma 1 chains from the parental X63 cells and specific L and H chains from the lymphoid parent. These biological investigations demonstrate the relative stability of the PO 772 C2 clone secreting anti-peroxidase antibody.

Substance P in the vagus nerve. Immunochemical and immunohistochemical evidence for axoplasmic transport

1. The presence of immunoreactive substance P (I-SP) in the vagus nerve of 5 species was demonstrated by radioimmunoassay. Different amounts of SP per unit weight were found: Guinea pig greater than cat greater than rabbit, rat and cattle. 2. Infranodose ligations of the vagus nerve of cats and rabbits caused an accumulation of I-SP proximal but not distal to the ligation. The results obtained by radioimmunoassay and immunohistochemistry indicate a somatofugal axoplasmic transport of SP. 3. Double ligation experiments revealed that about 37% of I-SP of the cat vagus nerve are mobile. The transport rate of this mobile I-SP was found to be 170 mm per day. 4. Locally applied colchicine resulted in a similar accumulation of I-SP as after ligations. This is evidence favouring the involvement of microtubuli in the axoplasmic transport of SP. 5. Immunohistochemical data show that SP-fibers account for about 10% of the axons in the cat vagus nerve. Most of these SP-fibers seem to be unmyelinated. 6. Supranodose extracranial ligations of the cat vagus nerve led to an accumulation of I-SP on both sides of the ligature. Part of the SP-fibers are, therefore, afferent and their cell bodies are located in the nodose ganglion. The presence of efferent SP-fibers cannot be excluded.

Somatic cell fusion in the study of glucocorticoid action

The basic phenomena of cell fusion and hybrid cell formation are briefly described and the potential of somatic cell hybridization in studies on the expression of differentiated cellular functions is discussed. The technique of cell hybridization has been applied to two types of cellular responses to glucocorticoids. The induction of specific proteins has been investigated in hybrids of inducible cells with uninducible cells. Most studies dealt with the liver-specific enzyme tyrosine aminotransferase, whose inducibility was extinguished in the majority of the hybrids between hepatoma and nonliver cells. However, upon chromosome segregation, inducibility reappeared in some of these hybrid cells. The current ideas about cellular control of inducibility are discussed. The other major glucocorticoid-responsive system investigated in cell hybridization studies consists of lymphoid cells which are killed when exposed to the steroid. Such sensitive cells were hybridized with several types of glucocorticoid-resistant lymphoid lines, and sensitivity was found to be dominant over resistence. Hybrids between sensitive and resistant lymphoid cells, however, showed an increase in the frequency at which resistance occurred as compared to the rate observed with the wild-type parental cells. No complementation to steroid sensitivity was found in hybrids between different types of resistant cells with defects in the glucocorticoid-specific receptor system.

B lymphocytes contain three species of mu chains

The murine B cell line cloned from a single cell, 38C-13, synthesizes three species of mu chains, that of cell surface membrane IgM (m-mu), that of secreted IgM (s-mu) and that of intracellular IgM (i-mu). They differ in their mobility on sodium dodecyl sulfate polyacrylamide gel electrophoresis. Sequence analysis of the different mu chains suggests that they are identical in the N-terminal as well as in their C-terminal positions. The ratio between incorporated radioactive monosaccharides to radioactive amino acids into the three different mu chains was higher in s-mu than in m-mu, but nevertheless m-mu migrated more slowly than s-mu on sodium dodecyl sulfate polyacrylamide gel electrophoresis. However, since this ratio may also be influenced by the rate of synthesis, it may not represent a real molar ratio of carbohydrate to protein. Studies with normal spleen cells clearly indicated the presence of the same three types of mu chains.