Project Title: 17. Effeccs of Radiation on Living Organisms Radiosensitivity of Immune Responses and Mechanisms of Immune Reactions Expected Results in FY 1974: RX-03-0)-(») (Cont'd.) Previous experiments on enhanced responses have been done with either xenogeneic or allogeneic antisera complexed to BSA or FTT. It seems likely that there may be at least two components which account for the enhanced response; one which is effected through the foreign antigenic determinants present on the gamma globulin and one which is effected by the antigen-antibody complex per se. To eliminate the possibility that the enhancement is due to foreign antigenic determinants, studies on enhancement will be performed with Lsogeneic antisera complexed to the antigen thus studying influence of the complex without possible xenogeneic or allogeneic influences. A series of experiments will test the hematological and immunological side effects of treating mice with TAP and CAP. These experiments will deal with the immediate toxic effect, comparative dose effects and duration of daily treatment in relation to immonusuppressive effects, Several studies with Cottier et al. on the incorporation of tritiated-histidine into lymphoid cells and specific antibody will continue. (Stoner) The initial phase of the project on tumor virus infection and tumorgenesis will deal with in vitro studies on the effects of radiation on avian and mammalian cell cultures infected with three tumor viruses: RIF virus (RNA - Type I), T virus (RNA - Type III), and JM virus(DNA - Type II). Fertile eggs from genetically susceptible and resistant chickens to leukosis : will be utilized for the preparation of chicken embryo fibroblasts. (Pavlova) Fd 18. Expected Results in FY 1975: Acquisition of information on the genetic control of antibody responses will allow selection of inbred strains and new recombinant inbred strains for use in study of lymphoid cellular kinetics during antibody responses. anaphylactogenic properties of antigen-antibody complexes prepared from The specific immunoglobulins and enzymatic digest fragments of antibody will be tested in irradiated mice and guinea pigs. Studies will continue concerning the efficacy of immunization of laboratory animals and man with complexes prepared from specific human immunoglobulins, Increased emphasis will be giver to poor antigens and particulate antigens. The study of hematologic and immunosuppressive side effects of thiamphenicol and chloramphenicol will be completed. (Stoner) in vitro studies will be continued and augmented by in vivo nts to determine the effects of various doses of radiation on chickens ally susceptible and resistant to leukosis. viruses will be used: RIF virus and JM virus (DNA - Type II). (See Continuation Sheet) b4b492 18 The following tumor (RNA - Type I), T virus (RNA - Type IIT) (Pavlova) RX-181