PHA-induced cell proliferation rescues human peripheral blood lymphocytes from X-ray-induced apoptosis.
Human peripheral blood G(0) lymphocytes were X-irradiated and allowed to recover for different periods both in the presence and absence of phytohemagglutinin (PHA). For each experimental condition the induction of apoptosis was investigated by nuclear morphology and formation of both DNA laddering and high molecular weight DNA fragments by pulsed field gel electrophoresis. The results showed that PHA cell growth stimulation could rescue peripheral blood lymphocytes (PBLs) from X-ray-induced apoptotic cell death. Instead, most X-irradiated lymphocytes held in G(0) phase, once they were committed to apoptosis, inexorably executed the process. These data indicate that the proliferative status of PBLs can influence apoptotic cell death: PHA-stimulated PBLs appear to be more radioresistant as a result of a less efficient apoptotic process. Therefore, in current tests for mutagenicity or cytotoxicity and in biodosimetrical studies the possible role of apoptosis has to be considered.
Carloni
M
M
Dipartimento di Agrobiologia e Agrochimica, Università degli Studi della Tuscia, Via San Camillo De Lellis, 01100 Viterbo, Italy.
Meschini
R
R
Ovidi
L
L
Palitti
F
F
D017209:Apoptosis / Q000528:radiation effects*; D002455:Cell Division / Q000528:radiation effects; D002467:Cell Nucleus / Q000528:radiation effects; D053938:DNA Fragmentation / Q000528:radiation effects; D006801:Humans; D008213:Lymphocyte Activation / Q000528:radiation effects; D008214:Lymphocytes / Q000166:cytology / Q000187:drug effects / Q000528:radiation effects*; D010835:Phytohemagglutinins / Q000494:pharmacology*; D014965:X-Rays
D010835:Phytohemagglutinins