Tissue transplantation immunity in the adult newt, <i>Diemictylus viridescens</i>. II. The rejection phase: First‐ and second‐set allograft reactions and lack of sexual dimorphism

Following the allogeneic transplantation of dorsal pigmented skin to the throat and flank of field collected adult Dkmictylus viridescens there was, at 23 k 0.5"C, a long latent period of about 16 days when such grafts were histologically and grossly indistinguishable from autografts.Circulation was usually restored i n autografts and allografts between 10 and 11 days post-grafting apparently by end to end anastomoses of graft and host vessels. Restoration of circulation was usually preceded by an initial dilation of the grafts' vessels and by the trauma induced death of some melanophores.An approximate five fold increase in the thickness of the dermal collagen of all grafts was noted throughout the latent phase as well as during graft rejection.

Tissue transplantation immunity in the adult newt, Diemictylus viridescens. I. The latent phase: Healing, restoration of circulation, and pigment cell changes in autografts and allografts

Cohen

1966

Tissue transplantation immunity in the adult newt, Diemictylus viridescens. III. The effects of X‐irradiation and temperature on the allograft reaction

Cohen

1966

Graded dosages of x-irradiation from 500r to 3000r inhibited destruction of Diemictylus viridescens allografts at 23 k 0.5"C for at least as long as the survival time of the hosts (up to 35 days). Lymphocytes were observed in 20% of the grafts whose hosts received 500r and lOOOr but they were present in far weaker concentrations than seen in any control grafts at all stages of rejection. No lymphocytes were evident in any grafts on hosts irradiated with 1500r, 2000r, and 3000r.The effects of various temperatures on allograft rejection in the newt were also examined. There was no difference in the mean survival times of grafts maintained at 3OoC and 23°C. At 2OoC, however, hemostasis and hemorrhaging were significantly delayed by a factor of 1.6 and 1.7 times, respectively, when compared with the findings at 23OC. At lO-l5"C, no hemostasis or hemorrhaging were displayed for 191 days after transplantation. Lymphocytes, however, were apparent in very low concentrations in the tissues of some of the grafts and localized destruction of a few melanophores were noted. Two grafts maintained at l0-15"C for 155 days and then transferred to 2OoC were completely destroyed within 36 days. This destruction was more rapid than for grafts initially maintained at 20'C.The immunologic rejection of skin allografts in the adult newt, Diemictylus viridescens, is marked by a chronic infiltration of small lymphocytes during the third and fourth weeks following transplantation. Concomitant with this lymphocytic infiltration are a series of externally observable events which include in their proper chronology: secondary vasodilation, hemostasis, hemorrhaging, and melanophore degeneration (Cohen, '66b).The third paper in this series extends the existing information on tissue transplantation immunity in the newt by exploring the effects of x-irradiation and temperature on skin allograft rejection.X-irradiation of mammalian and avian hosts prior to skin grafting has been responsible for delaying or inhibiting allograft rejection (Dempster et al., '50; Main and Prehn, '57; Toolan, '51a). Cooper ('64) reported that x-irradiation of FunduZus delayed scale allograft rejection for several days, the delay being dependent on the dosage used. To confirm and extend information concerning the effect of irradiation on skin allograft survival in lower J. ExP. ZOOL,., 163: 231-240.vertebrates, adult D. viridescens were first irradiated with several different dosages of x-rays and then skin grafted.The immune response of diverse poikilothermic species to tissue allografts and to soluble and particulate antigens is strikingly affected by the ambient temperature; the lower the temperature the more delayed is graft rejection (Hildemann and Cooper, '64; Simnett, '65) or the lower the titer of antibodies elicited (Elek et al., '62; Evans, '64; Krueger and Twedt, '63).In the present study, the effects of 10-15"C, 20°C, and 30°C on allograft rejection were studied in Diemictylus and the results compared with skin graft rejection at 23"C, the temperat...

Chronic skin graft rejection in the urodela. I. A comparative study of first‐ and second‐set allograft reactions

Cohen¹

1968

Unlike acute skin allograft reactions observed in most randomly breeding ectothermic and endothermic vertebrates, a basic pattern of intermediate to prolonged chronic skin graft rejection characterized the alloimmune response of representatives of at least five genera of salamanders from three different families (Salamandridae, Ambystomatidae, and Proteidae). First-set median survival times (MST's) ranged from 33 to 55 days at 25°C. Individual zero end points (total melanophore destruction) occurred between 17 and 120 days. Several grafts appeared to have survived indehitely (> 300 days) with full to partial viability.MSYs of second-set grafts were sign%antly shorter than first-set MST's for all salamanders except Ambystoma tigrinum. For this species, the small sample of seven repeat grafts all exhibited either prolonged survival vis-a-vis first-set grafts or were destroyed well within the range of first-set rejections. About 25% of the combined individual Taricha and Necturus repeat grafts were completely destroyed at the same postoperative time as or significantly later than fist-set grafts from the same donor. Only curtailed survival of Cynops second-set grafts was noted. When the post transplantation period was resolved into a latent phase and a rejection phase, the curtailed survival of 50% of the Traricha and 60% of the Cynops second-set grafts was attributable solely ot a comparatively shorter latent period. The curtailed zero end points of other Taricha repeat grafts resulted from both shorter latent and shorter rejection intervals. The overall prolonged second-set survival noted for some Taricha allografts was referable only to longer rejection phases; the latent phases for these repeat grafts were either shorter than or similar to those of the corresponding primary grafts.In previous studies (Cohen, '66a, b, c), it was clearly demonstrated that the immunologic rejection of skin allografts by field collected newts (Diemictylus viridescens) was typically chronic. Unlike the acute rejection response observed in fishes (Hildemann and Haas, '60) and bullfrogs (Hildemann and Haas, '59), total destruction of Diemictylus skin at comparable temperatures was usually completed four to six weeks postgrafting. Recent studies (Cohen and Hildemann, in preparation) of inter-and intrapopulation grafts with newts collected from geographically separate ponds have revealed a high incidence of acute and subacute allograft rejection (8-20 days) in one intrapopulation combination. This observation completely rules out the possibility that the more typical chronic rejection reaction of Diemictylus is a function of an impaired immune response capacity. Since rejection in Diemictytus contrasts so dramatically with acute rejection of grafts by teleosts and anurans, it is important to determine whether the chronic alloimmune response is unique for this species or typical of the taxonomic order, Urodela. While there are reports of chronic first-set allograft rejection in a few other urodele species (Anderson, '33; Hildemann...