ABSTRACT
We compared the effect of human endothelial cell culture supernatant (HECS), ESG (Ewing sarcoma growth factor), IL-6 (interleukin-6) and peritoneal macrophages on the recovery of hybridoma cells after fusion with respect to growth, stability and distribution of isotype variants. A selective growth of murine IgM-producing hybridoma cells was observed in the presence of HECS after cell fusion.
Subject(s)
Endothelium, Vascular/cytology , Hybridomas/immunology , Immunoglobulin M/biosynthesis , Animals , Humans , Immunoglobulin G/biosynthesis , Interleukin-6/pharmacology , Mice , Mice, Inbred BALB CABSTRACT
In situ hybridization with whole chromosome painting probes (chromosome 1, 7, 11, 14, 17 and 21) in combination with a human pancentromeric alpha-satellite probe was used to analyse the presence of specific chromosomal material in micronuclei (MN) induced in human lymphocytes by ionizing radiation. The purpose was to investigate the nature of radiation-induced cytogenetic damage, especially to study whether the fraction of paint-positive MN is proportional to the relative DNA content of the respective chromosomes which might indicate a random breakage of chromosomes. Flow-sorted MN and MN in binucleated cells were analysed with the six chromosome specific painting probes. It was found that the fraction of paint-positive MN increased linearly with the DNA content of the respective chromosomes. About 13% radiation-induced MN in human lymphocytes were found to contain centromeric signals independent of the presence of specific chromosome painting signals. The data obtained on flow-sorted MN and MN in binucleated cells agreed well, indicating that flow-sorted MN can be used for studying their chromosomal content with the FISH technique. If it is assumed that the chromosomal content of MN reflects radiation-induced damage, then these results support a random model of radiation-induced cytogenetic damage in human lymphocytes for the six chromosomes studied.
Subject(s)
Cell Nucleus/radiation effects , Centromere/genetics , DNA Probes , In Situ Hybridization, Fluorescence/methods , Micronucleus Tests/methods , Adult , Chromosome Banding/methods , Chromosomes, Human, Pair 1 , Chromosomes, Human, Pair 11 , Chromosomes, Human, Pair 14 , Chromosomes, Human, Pair 17 , Chromosomes, Human, Pair 21 , Chromosomes, Human, Pair 7 , HumansABSTRACT
In this report, in situ hybridization with whole chromosome painting probes was used to paint radiation-induced micronuclei (MN) in three lymphoblastoid cells lines to investigate the frequency of radiation-induced MN. The results obtained for four different chromosomes showed that there was a significant deviation of the numbers of signal-positive MN from that expected on the basis of DNA proportionality. Restriction of the analysis to three chromosomes showed that the deviations arose primarily from chromosome 7, which was underrepresented in the numbers of signal-positive MN in the group of chromosomes studied.
