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Biomedical subjects

D R Johnson

Publications and source records attributed to D R Johnson.

At least 253 records · Page 14Linked to original sources
PubMed1981

Herpesvirus-transformed cytotoxic T-cell lines.

Investigations of cellular cytotoxicity of the immune system are hampered by the lack of continuously growing, transformed cell lines which express a cytotoxic potential. Here we describe cytotoxic cell lines from the cotton-topped marmoset monkey, transformed by Herpesvirus Ateles (HVA) or Herpesvirus Saimiri (HVS), which can kill certain target cells in a short-term in vitro test. HVA/HVS-transformed cells have earlier been classified as belonging to the T-cell lineage in contrast to Epstein-Barr virus (EBV)-transformed cells derived from B lymphocytes. We suggest that the HVA/HVS-transformed killer cell lines described here represent an effector population resembling, or corresponding to, marmoset natural killer (NK) cells and that they may be used to define the cytolytic mechanism involved in cellular cytotoxicity and possibly also effector cell receptors and target cell antigens, as well as regulatory mechanisms of general biological interest.

Animals↗
PubMed1981

Chromosomes and cell surface markers of marmoset lymphocytes and Epstein-Barr virus-transformed marmoset cell lines.

The G-banded karyotypes of both normal lymphocytes and Epstein-Barr virus (EBV)-transformed lymphocytes of cotton-topped marmosets (Saguinus oedipus) were examined. The marmoset lymphocytes and EBV-transformed lymphoblastoid cells had normal diploid chromosomes (2n = 46) with no specific cytogenic change associated with transformation in vitro. EBV-transformed marmoset lymphocytes expressed the cell surface markers of B lymphocytes and EB viral antigens.

Animals↗
PubMed1981

Herpesvirus ateles and herpesvirus saimiri transform marmoset T cells into continuously proliferating cell lines that can mediate natural killer cell-like cytotoxicity.

Herpesvirus ateles (HVA) and herpesvirus saimiri (HVS) have the capacity to transform cotton-topped marmoset T lymphocytes into continuously proliferating cell lines that retain some functions associated with cell-mediated immunity. In the present paper, we demonstrate that HVA/HVS-transformed T cell lines are cytotoxic in a short-term 51Cr release assay and that this killing resembles killing by marmoset natural killer (NK) cells. The relationship between NK cells and HVA/HVS-transformed killer cell lines is discussed in view of present knowledge of the origin and function of the NK system. It is suggested that the described cytotoxic cell lines may be useful for further defining cellular cytotoxicity with regard to cell surface recognition, regulatory events, and lytic mechanisms.

Animals↗
PubMed1981

Relationship between Herpesvirus ateles-associated nuclear antigen (HATNA) and the number of virus genome equivalents in HVA-carrying lymphoid lines.

A DNA-binding antigen (HATNA) was demonstrated in 7 out of 14 cell lines carrying Herpesvirus ateles (HVA) by the acid-fixed nuclear-binding technique. The seven HATNA-positive lines had means of 95, 96, 103, 177, 240, 343 and 326 virus genome equivalents/cell. For the seven HATNA-negative lines, the figures were 4, 8, 10, 33, 39, 72 and 110. This indicates a relationship between the number of HVA genome equivalents/cell and the detectability of HATNA. This association was independent of the virus producer status of the lines.

Animals↗
PubMed1980

Heterogeneity of group A type-specific antibodies.

Extracting type 6 group A streptococcai with dilute nitrous acid releases an antigen that exhibits type-specific precipitating properties with anti-M6 serum but fails to neutralize the type-specific bactericidal reaction or to absorb the bactericidal antibody from anti-M6 serum. These studies suggest that the precipitating and antiphagocytic properties of the M protein are attributable to different antigenic determinants. The antigenic determinant responsible for bactericidal antibody is more sensitive to the deleterious effect of nitrous acid than is the moiety responsible for the precipitin reaction. Use of the indirect fluorescent technique with anti-M sera absorbed with lyophilized nitrous acid extracts permits the possible differentiation of the two M-protein determinants in situ on the surface of streptococcal cells.

Antibodies, Bacterial↗
PubMed1980

Interaction of Herpesvirus ateles and Hepesvirus saimiri with primate lymphocytes. I. Selective adsorption of virus by lymphoid cells.

A semiquantitative infectious bioassay, described by Sairenji and Hinuma for the measurement of Epstein-Barr virus (EBV) receptors, was adapted to study the adsorption of the lymphotropic New World herpesvirus ateles (HVA) to established lymphoid lines and lymphocytes of human versus marmoset origin. All marmoset T-cell lines [HVA- or HVS (herpesvirus saimiri)-carrying] had a high adsorbing capacity. EBV-carrying marmoset or human B-cell lines, one EBV-negative human B-lymphoma line, and one human myeloid leukemia-derived line failed to adsorb detectable virus. Two human T-cell derived cell lines of acute lymphatic leukemia origin showed moderate but significant adsorption, and the same was true for unfractionated marmoset lymphocytes. Human peripheral blood did not adsorb, before or after fractionation, whereas normal human thymocytes showed moderate but significant adsorption. It is concluded that HVA receptors are present on human T cells, probably belonging to certain subclasses.

Adsorption↗
PubMed1980

Formation of marrow cavity and ossification in mouse limb buds grown in vitro.

Explanted mouse limb buds aged 12, 13 or 14 days cultured for 9 days in vitro failed to develop a marrow cavity or show endochondral ossification. Explants aged 15 days developed a marrow cavity and showed signs of endochondral ossification. The periosteum in these limbs was perforated and laminated and cells appeared to be passing between the laminae to populate the marrow cavity. This suggests that there is a periosteal contribution to the bone marrow even in the absence of a blood supply.

Animals↗
PubMed1980

The relationship of biological indices of lead exposure to the health status of workers in a secondary lead smelter.

The fidelity with which common indices of lead exposure correlate with renal and hematopoietic function and with frequency of symptoms was studied. The subjects were men working in a secondary lead smelter. Among several indices of renal function, only serum urea nitrogen (SUN) was consistently correlated with any of the indices of lead exposure. The concentration of lead in blood(PbB), the rate of urinary excretion of lead (PbU) and of alpha aminolevulinic acid in the urine (ALAU) correlated with SUN. By contrast, erythrocytic porphyrin concentration (EP) did not correlate with SUN. Similarly, the frequency of occurrence of symptoms correlated well with PbB and ALAU but did not correlate with EP. All of the above indices of lead exposure, with the exception of PbU, correlated well with hemoglobin (Hb) status. In summary, these results suggest that PbB rather than EP is the best single exposure index for biological monitoring of lead workers. This measurement should be supplemented by peiodic determination of SUN and Hb.

Adult↗