TY - JOUR
T1 - Appearance of reverse transcriptase activity in human fetal thymus cells stimulated by human b-cell
AU - Ono, Akira
AU - Saito, Hidetsugu
AU - Tsuchiya, Masaharu
AU - Nakamura, Tatsuya
AU - Higashinakagawa, Toru
AU - Kondo, Shunzo
AU - Yoshimatsu, Hiroshi
PY - 1983/1
Y1 - 1983/1
N2 - We have investigated three human fetal thymuses by various induction procedures in a search for retrovirus. Thymus cells were cultured for 7 days together with mitomycin C-treated B cells and examined for reverse transcriptase activity. The following results were obtained. 1) RNA-directed DNA polymerase (RDDP) activity was detected in the culture medium on day 3 and persisted until day 7. This enzyme, after partial purification on phos-phocellulose column, showed template-primer specificity of a typical reverse transcriptase. 2) In unstimulated thymus cells, no reverse transcriptase activity was detected. 3) Stimulation with lymphocyte mitogens such as phytohaemagglutinin (PHA) and concanavalin A (Con A) exerted no effect on inducing the reverse transcriptase activity. 4) No reverse transcriptase activity was obtained in the culture medium of B cells pretreated with mitomycin C. Taken together these results indicate that in human fetal thymus cells reverse transcriptase activity is induced by human B cell stimulation, pointing to an intriguing possibility of protovirus activation.
AB - We have investigated three human fetal thymuses by various induction procedures in a search for retrovirus. Thymus cells were cultured for 7 days together with mitomycin C-treated B cells and examined for reverse transcriptase activity. The following results were obtained. 1) RNA-directed DNA polymerase (RDDP) activity was detected in the culture medium on day 3 and persisted until day 7. This enzyme, after partial purification on phos-phocellulose column, showed template-primer specificity of a typical reverse transcriptase. 2) In unstimulated thymus cells, no reverse transcriptase activity was detected. 3) Stimulation with lymphocyte mitogens such as phytohaemagglutinin (PHA) and concanavalin A (Con A) exerted no effect on inducing the reverse transcriptase activity. 4) No reverse transcriptase activity was obtained in the culture medium of B cells pretreated with mitomycin C. Taken together these results indicate that in human fetal thymus cells reverse transcriptase activity is induced by human B cell stimulation, pointing to an intriguing possibility of protovirus activation.
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U2 - 10.2302/kjm.32.73
DO - 10.2302/kjm.32.73
M3 - Article
C2 - 6207335
AN - SCOPUS:0020967181
VL - 32
SP - 73
EP - 80
JO - Keio Journal of Medicine
JF - Keio Journal of Medicine
SN - 0022-9717
ER -