Search PubMed⌕ Search

Biomedical subjects

G Miller

Publications and source records attributed to G Miller.

At least 505 records · Page 28Linked to original sources
PubMed1974

Expression of Epstein-Barr viral capsid, complement fixing, and nuclear antigens in stationary and exponential phase cultures.

Three continuous lymphoblastoid cell lines, 2 productive of nucleocapsids and 1 nonproductive line, were studied for their content of Epstein-Barr viral (EBV) antigens during transition from stationary to logarithmic phase growth. As a preliminary step, viable cells were separated from degenerating ones in discontinuous gradients of serum albumin. Viral capsid antigens were found in both living and dead cells of the 2 producer lines; however, complement fixing (CF) antigens and nuclear antigen were detected only in viable cell subpopulations. The content of antigen detectable in extracts of viable cells by complement fixation remained constant in replicating and resting cultures; further, all viable cells of the 3 lines demonstrated intranuclear antigen by anticomplement immunofluorescence in all stages of growth. In contrast, the proportion of cells with viral capsid antigen in the producer lines increased 7- to 24-fold following entry of resting populations into the phase of exponential growth.The results suggest that expression of viral capsid antigens is discontinuous and is initiated in response to events in log phase, possibly DNA synthesis or mitosis. Expression of the complement fixing and nuclear antigens in continuous in viable cells. These findings emphasize the intimate relationship of the CF and nuclear antigen to the transformed state and suggest that study of this antigen complex will shed light on the mechanisms of lymphocyte transformation by EBV.

Animals↗
PubMed1973

Comparison of the yield of infectious virus from clones of human and simian lymphoblastoid lines transformed by Epstein-Barr virus.

Three lymphoblastoid cell lines, of human, squirrel monkey, and marmoset origin, all transformed by the same strain of Epstein-Barr virus (EBV), differed markedly in their content of infectious virus. Single cell clones were obtained from each line to learn whether these differences were dependent upon factors shared by all cells in each line or upon factors present only in a proportion of the total cell population. A total of 17 primary clones were examined: 6 human, 6 squirrel monkey, and 5 marmoset. Cloning efficiency on human placental cell feeder layers varied from 16 to 24%. EBV antiserum, present in the cloning suspension, was shown to neutralize all extracellular virus. 15 of the 17 clones released EBV as measured by the transformation assay. Titers of infectious virus released by daughter clones paralleled titers of virus in the parent line. The median virus titers from human, squirrel monkey, and marmoset clones were respectively 10(1.5), 10(3.0), and 10(4.3) 50% transforming doses per 0.2 ml. The median yield of virus from clones of the three species was, respectively, 4, 96, and 786 transforming units per 1,000 cells containing viral capsid antigen. Two nonproducer clones (one human and one squirrel monkey) did not release infectious virus after treatment with 5'-bromodeoxyuridine, or with X ray followed by co-cultivation with marmoset leukocytes. The nonproducer clones could not be superinfected by biologically active EBV. These results show that differences in production of infectious EBV among the lines tested are reflected in the majority of cells of these lines. The data imply that the mechanism for regulation of the expression of the EBV genome is cellular rather than viral in origin. There are presumably genetic differences among primate species in this regulatory process.

Animals↗
PubMed1973

Epstein-Barr virus. Heterophile responses in squirrel monkeys inoculated with virus-transformed autologous leukocytes.

Epstein-Barr virus (EBV)-transformed autologous lymphoblasts were repeatedly inoculated into three squirrel monkeys. Each animal developed the heterophile antibodies of infectious mononucleosis and EBV-specific antibodies. After serologic responses had disappeared or markedly declined, the animals were challenged with either whole cells, cell filtrate, or cell ghosts. Animals challenged with living cells and cell ghosts developed agglutinin responses; the recipient of filtrate did not. The results suggest that EBV induces the appearance of the infectious mononucleosis heterophile antigen on the transformed cell membrane.

Animals↗
PubMed1973

Release of infectious Epstein-Barr virus by transformed marmoset leukocytes.

Marmoset blood leukocytes transformed in vitro by Epstein-Barr virus regularly release extracellular infectious Epstein-Barr virus with high titers of transforming activity. By comparison, human umbilical cord leukocytes and adult human leukocytes transformed by Epstein-Barr virus release either no extracellular infectious virus or small amounts, irregularly.

Animals↗