Regulation of immune responses by I-J gene products. VI. Recognition of I-E molecules by I-J-bearing suppressor factors

Poly(Glu50Tyr50) (GT) is not immunogenic in most inbred mouse strains. GT injection produces an I-J--bearing, GT-specific T-cell--derived suppressor factor (GT-TsF1) in H-2b,d,k haplotype mice. GT-TsF1 generates second-order suppressor T cells (Ts2) in H-2a,d,k haplotype mice. Here, we show that in order for GT-TsF1 to act, the recipient strain must express I-E molecules. This suggests that T cells are not the primary target of GT-TsF1. GT-TsF1 can be presented by Ia+ A20-2J B lymphoma cells. GT-TsF1 presentation is blocked by anti-I-E, but not by anti--I-A, mAb, whereas GAT presentation is blocked by anti-I-A, but not by anti--I-E, mAbs. These data suggest that I-J recognizes (or is recognized by) I-E. The existence and role of I-J molecules in immune regulation are discussed in light of these data.

I-J expression is not associated with murine chromosome 4

I-J originally mapped within the murine major histocompatibility complex (H-2) between the EB and Ea loci using intra-H-2 recombinants. Cloning of this segment of H-2 shows no DNA that can be ascribed to I-J. Various hypotheses have attempted to explain this dilemma. One hypothesis attributes a chromosome 4 locus with I-Jk expression. This hypothesis requires the AKR/J and A/WySn mouse strains to be I-Jk negative. In the present report we show that AKR/J spleen cells express I-Jk surface molecules and that both the AKR/J and A/WySn mouse strains produce functional I-Jk-bearing suppressor factors to poly(Glu50Tyr50). Our data imply that mapping of I-J-determining genes to chromosome 4 may be premature.

Non-Alu family interspersed repeats in human DNA and their transcriptional activity

Randomly selected human genomic clones have been surveyed for the presence of non-Alu family interspersed repeats. Four such families of repeats have been isolated and characterized with respect to repetition frequency, interspersion, base sequence, sequence divergence, in vitro RNA polymerase III transcription, elongation of transcripts in isolated nuclei, and in vivo transcription. The two most abundant of the four families of repeats correspond to previously reported families of repeats, namely the kpn I family and poly (CA). We conclude that most of the highly repetitive (greater than 50,000 copies) human interspersed repeats have already been identified. Two lower abundance repeats families are also described here. The abundance with which each of these families is represented in nuclear RNA qualitatively corresponds to their genomic reiteration frequencies. Further, the complementary strands of each repeat family are approximately symmetrically transcribed. The abundance of these repeats in cytoplasmic RNA is qualitatively less than in nuclear RNA. The bulk of the in vivo transcriptional activity of these repeats thus appears to be nonspecific read through from other promoters.

Translocation of cytoplasmic estrogen receptors to the nucleus: immunohistochemical demonstration utilizing rabbit antibodies to estrogen receptors of mammary carcinomas

Rabbit antibodies to cytoplasmic estrogen receptors (ER) of human breast carcinoma were utilized for investigating steroid-triggered in-vitro translocation of cytoplasmic ER to the nuclear compartment of the estrogen target cells. The immunofluorescent method (IF) previously described (S Raam et al., Eur J Cancer Clin Oncol 18: 1-12, 1982) was employed for immunohistochemical localization of ER. Four cases of normal endometrium, two cancers of the endometrium, and MCF-7 human breast cancer cells were maintained in a steroid free medium and exposed at 37 degrees C for two hours to growth medium alone (control) or to 2.5, 25 or 250 nanomoles of estradiol (E2), diethylstilbestrol (DES), or monohydroxytamoxifen (OH-TX). At the end of the incubation period the cells were processed for intracellular localization of ER. Complete traslocation of IF from the cytoplasm to the nuclear compartment was evident in all normal endometrial cells exposed to E2, DES or OH-TX for two hours. While cells from the endometrial cancer 'S', like the normal cells, translocated IF to the nucleus, cells of another cancer ('KLE') failed to translocate when exposed to E2 or OH-TX. Partial translocation was evident in 'KLE' cells exposed to DES. In MCF-7 cells grown in the absence of E2, IF was exclusively cytoplasmic. When these cells were exposed to the hormones, 50% showed a complete transfer of IF to the nucleus; in 40% a delayed response was evident; 10% failed to translocate. The results revealed the suitability of anti-ER antibodies for investigating the intracellular dynamics of ER in target cells responding to estrogens or antiestrogens.

Antigens displayed on murine B lymphocyte precursors

The surface antigen phenotype of the immediate precursors of clonable B lymphocytes was investigated with conventional alloantisera and monoclonal antibodies directed by B lineage antigens. Ia was demonstrable on B cells, but not their immediate precursors in adult marrow. Adult, but not fetal, B cell precursors were susceptible to lysis with anti-Lyb-2 or anti-Qa. A panel of monoclonal rat antibodies was prepared and placed into categories on the basis of recognition patterns obtained with established cell lines. Of 2 groups that are described here, 1 (typified by antibodies from clone 14.8) detect an antigen that is preferentially expressed on B cells and their precursors, a proportion of antibody-secreting cells, and a subpopulation of peripheral T lymphocytes. Cells that did not display demonstrable amounts of antigen include brain, granulocytes, macrophages, mastocytoma cells, and erythroleukemia cells. A 2nd category of antibodies revealed an antigen that was more widely distributed on hemopoietic cells. Cells capable of quickly maturing into functional, colony-forming B lymphocytes in culture or after transfer to irradiated recipients specifically adhered to 14.8 antibody-coated, polystyrene petri dishes in the cold. Reductions in numbers of stem cells (CFU-s) and myeloid progenitors (CFU-c) by this treatment were minimal. Of particular importance was the fact that these antibodies recognized cells in embryonic liver as well as in adults that were destined to become B lymphocytes. These observations provide new perspective on B lineage precursor heterogeneity and suggest ways of localizing and dissecting some of the earliest events that are critical to development of the humoral immune system.

Antigens displayed on murine B lymphocyte precursors

The surface antigen phenotype of the immediate precursors of clonable B lymphocytes was investigated with conventional alloantisera and monoclonal antibodies directed by B lineage antigens. Ia was demonstrable on B cells, but not their immediate precursors in adult marrow. Adult, but not fetal, B cell precursors were susceptible to lysis with anti-Lyb-2 or anti-Qa. A panel of monoclonal rat antibodies was prepared and placed into categories on the basis of recognition patterns obtained with established cell lines. Of 2 groups that are described here, 1 (typified by antibodies from clone 14.8) detect an antigen that is preferentially expressed on B cells and their precursors, a proportion of antibody-secreting cells, and a subpopulation of peripheral T lymphocytes. Cells that did not display demonstrable amounts of antigen include brain, granulocytes, macrophages, mastocytoma cells, and erythroleukemia cells. A 2nd category of antibodies revealed an antigen that was more widely distributed on hemopoietic cells. Cells capable of quickly maturing into functional, colony-forming B lymphocytes in culture or after transfer to irradiated recipients specifically adhered to 14.8 antibody-coated, polystyrene petri dishes in the cold. Reductions in numbers of stem cells (CFU-s) and myeloid progenitors (CFU-c) by this treatment were minimal. Of particular importance was the fact that these antibodies recognized cells in embryonic liver as well as in adults that were destined to become B lymphocytes. These observations provide new perspective on B lineage precursor heterogeneity and suggest ways of localizing and dissecting some of the earliest events that are critical to development of the humoral immune system.

Monoclonal rat antibodies to murine IgM determinants

A series of 6 hybrid clones are described which produced antibodies directed to murine IgM. These were derived by immunizing rats with W279 B-lymphoma cells and then fusing the immune spleen cells to enzyme-deficient murine plasmacytoma cell lines. Immunoenzymatic techniques were used to select clones producing desirable antibodies to cell surface or soluble antigens. Antibodies from 3 of the clones (293.14, 414.18 and 307.5) preferentially bound to idiotypic determinants of W279 immunoglobulin whereas the remaining 3 clones made antibodies which bound to various myeloma and normal cell surface IgM molecules. One IgM-specific clone (287.2) produced antibody of relatively low avidity. The two other clones (81.20 and 331.12) which secreted anti-mu antibodies appeared to be directed to determinants which differed in glutaraldehyde lability and expression in F(ab')2 preparations.

Colorimetric rate method for the determination of creatinine as implemented by the Beckman Creatinine Analyzer 2

We evaluated the performance characteristics of the Beckman Creatinine Analyzer 2, a kinetic colorimetric analyzer which utilizes a modified Jaffé reagent. The instrument gave linear measurements to at least 300 mg/L and its within-run precision on a 50 mg/l creatinine standard was 1.1%. Its between-day precision on the 50 mg/L creatinine standard was less than 5.0%. Its results correlated well with those from the manual Jaffé. CentrifiChem System 400, TechniconTM SMATM 6/60 System, and TraceTM systems I and III. Interferences from 19 possible serum constituents and 32 drugs were almost nonexistent. The extended linear range of the Creatinine Analyzer 2 allowed the direct assay of samples from patients undergoing periodic hemodialysis.

Isolation and identification of lymphocytic and myelogenous leukemia-specific sequences in genomes of gibbon oncornaviruses

Five gibbon ape leukemia virus substrains (two from gibbons with lymphocytic leukemia and three from gibbons with myelogenous leukemia) were examined for unique genomic sequences specific for each form of leukemia. By using sequential adsorption procedures, the genome from each gibbon ape leukemia virus was fractionated into four sets of distinct nucleotide sequences. Based on their hybridization specificities toward DNAs of leukemic tissues, these sequences were designated as follows: (i) "COM," (ii) "LYM" or "MYE," (iii) "UNI," and (iv) "UND." The COM fraction represented sequences common to all of the viral genomes. The LYM fraction, which was isolated only from gibbon ape leukemia viruses associated with lymphocytic leukemia, represented genomic sequences associated with lymphocytic leukemia since the RNA hybridized at a 4- to 15-fold-higher rate to infected tissue DNA from lymphocytic leukemic gibbons than to infected tissue DNA from myelogenous leukemic gibbons. The MYE fraction, which was isolated only from gibbon ape leukemia viruses associated with myelogenous leukemia, represented genomic sequences associated with myelogenous leukemia since the RNA hybridized at a 5- to 15-fold-higher rate to infected tissue DNA from myelogenous leukemic gibbons than to infected tissue DNA from lymphocytic leukemic gibbons. The UNI fraction contained sequences unique to one virus substrain. The UND fraction contained sequences which varied depending upon the substrains involved in the adsorption procedures. These findings suggest that each gibbon ape leukemia virus examined in this study contains subgenomic sequences that are specifically identifiable only with the form of leukemia from which the virus was isolated.

Biosynthesis of murine terminal deoxynucleotidyltransferase

An immunoprecipitation assay for measuring synthesis of murine terminal deoxynucleotidyltransferase (EC 2.7.7.31) has been developed using rabbit antiserum to calf terminal transferase. The antiserum precipitates a single Mr = 60,000 polypeptide (TdT-60) from all cell lines and tissues that contain enzymologically demonstrable terminal transferase. This polypeptide is not precipitated from labeled extracts of cells that lack terminal transferase by enzymological criteria. TdT-60 fractionates with terminal transferase during phosphocellulose chromatography and sediments with it in a sucrose gradient. TdT-60 is not detectably processed to lower molecular weight polypeptides, and terminal transferase activity sediments as a Mr = 60,000 activity; thus, we believe it to be the active form of terminal transferase. Using this assay we have demonstrated that terminal transferase is synthesized in both the murine thymus and the bone marrow at a rate proportional to its biochemically measured steady state level. After cortisone treatment of mice, the Mr = 60,000 polypeptide disappears from the thymus and then reappears as the thymus begins to be repopulated.

Genomic stability of gibbon oncornavirus

The 70S RNAs from several gibbon type C viruses were examined for sequence homology by molecular hybridization using complementary DNA probes. The sequence homology was found to vary with each virus isolate. The genome from one isolate was examined for genomic stability after the virus was experimentally passaged through three unrelated gibbons. The genomic homology remained unchanged after three passages, having greater than 93% homology based on complementary DNA-70S RNA hybridization and melting temperature analysis of the duplex. The genome from another isolate was similarly found to be unchanged after the virus was naturally transmitted in gibbons. The genomic variation found in the various isolates is not the consequence of recent horizontal transmission from a common virus.

Natural transmission of gibbon leukemia virus

Gibbon leukemia virus can infect prenatal gibbons through in utero infection or postnatal gibbons through contact transmission. The transmission of infectious virus was from viremic gibbons and not from uninfected or antibody-positive animals. The two modes of transmission could be distinguished by the amount of proviral DNA integrated into the muscle tissue of viremic gibbons. Muscle of gibbons infected postnatally had little or no proviral DNA, whereas gibbons infected prenatally had a large quantity of proviral DNA.

Comparison of enzyme immunoassay and gas chromatography for determination of carbamazepine and ethosuximide in human serum

Patients' sera were analyzed for carbamazepine and ethosuximide by enzyme immunoassay (x) and gas chromatography (y), and the results were compared. The correlation coefficients were: for carbamazepine, x vs. y 0.94 (n = 93); for ethosuximide, x vs. y 0.99 (n = 30). These results suggest that the two methods could be used interchangeably. Ten serum samples supplemented with carbamazepine (2.5 to 12.5 mg/liter) and ethosuximide (20.0 to 130.0 mg/liter) were analyzed by both methods. The correlation coefficients were: x vs. y 0.99 (n = 10) for carbamazepine and x vs. y 0.99 (n =10) for ethosuximide.

Comparison of enzyme immunoassay and gas chromatography for determination of carbamazepine and ethosuximide in human serum

Patients' sera were analyzed for carbamazepine and ethosuximide by enzyme immunoassay (x) and gas chromatography (y), and the results were compared. The correlation coefficients were: for carbamazepine, x vs. y 0.94 (n = 93); for ethosuximide, x vs. y 0.99 (n = 30). These results suggest that the two methods could be used interchangeably. Ten serum samples supplemented with carbamazepine (2.5 to 12.5 mg/liter) and ethosuximide (20.0 to 130.0 mg/liter) were analyzed by both methods. The correlation coefficients were: x vs. y 0.99 (n = 10) for carbamazepine and x vs. y 0.99 (n =10) for ethosuximide.

Radioimmunoassay and enzyme immunoassay compared for determination of digoxin

Patients' sera were analyzed for digoxin by using two different radioimmunoassays and an enzyme immunoassay. Quantitative results obtained by enzyme immunoassay (I) were compared to results obtained on aliquots of the same sample by the radioimmunoassays (II and III). The correlation coefficients were: I vs. II 0.90, n=108; I vs. III 0.94, n=102; and II vs. III 0.95, n=158. Day-to-day precision (10 days) on a low control (1.3 mug/liter) and a high control 3.0 mg/liter), expressed as coefficients of variation, were: I, 13% and 7.8%, II, 4.0% and 4.7%; and III, 8.9% and 4.2%. Ten digoxin-supplemented samples (0-8 mug/liter) were analyzed by the three methods. Correlation coefficients were: supplemented sample vs. I, O.99; supplemented sample vs. II, 0.97; supplemented sample vs. III, 0.98.