Accession Number:

AD0640261

Title:

DNA SYNTHESIS IN MIXED CULTURES OF DOG LEUCOCYTES: DIFFERENTIAL EFFECT OF X-RADIATION AND FREEZE-THAWING ON CELLULAR ISOANTIGENICITY.,

Descriptive Note:

Corporate Author:

NAVAL RADIOLOGICAL DEFENSE LAB SAN FRANCISCO CALIF

Report Date:

1966-08-30

Pagination or Media Count:

32.0

Abstract:

A marked induction of DNA synthesis occurred in 50-50 mixed cultures of peripheral blood leucocytes derived from sets of allogeneic Beagle and mongrel normal dog donors. DNA-synthetic activity at selected times was determined by liquid scintillation counting following pulse labeling of cell populations with 3H-thymidine. In a typical experiment, DNA synthesis is mixed cultures attained a maximum value at the 6th day 61,000 CPM followed by a steady decline thereafter to 7,500 CPM by day 9, as contrasted with control values 65-86 CPM. In leucocyte cultures of cells isolated and mixed on the same day, considerable DNA labeling 1900-3000 CPM occurred at time 0. These values declined, 600 CPM at 18 hours 230 CPM at day 2, and then rose later 2400 CPM at day 4. Incubation of individual cell suspensions for 18 hours prior to mixing eliminated the elevated zero time label. X-irradiation 2500 rads of one or the other of the cell components of the mixture changed the reation from a two way immunological reaction. When one or the other of a pair was frozen -196C and thawed 37C three times and momentarily homogenized before mixing with intact allogeneic leucocytes, no induction of DNA synthesis occurred. These results suggest that leucocyte isoantigenic factors are not inactivated or destroyed by X-irradiation and can induce DNA synthesis in allogeneic leucocytes whereas, they are labile to freeze-thawing. The results are compatible with the known chemical and immunological properties of transplantation antigens. Author

Subject Categories:

  • Medicine and Medical Research
  • Radiobiology

Distribution Statement:

APPROVED FOR PUBLIC RELEASE