摘要:

SUMMARYThe immunosuppressive effects of ara-cytidine were studied on the cellular and humoral antibody response of mice. The immunosuppressive activity of ara-cytidine allowed dissection of the slow and rapid phases of antibody-forming cell (AFC) appearance. The cellular and humoral antibody responses both exhibited the same time of greatest sensitivity to ara-cytidine. The antibody-forming cell, hemolysin, and hemagglutinin responses were most susceptible to ara-cytidine inhibition 2 days after sheep red blood cell challenge. Injections of ara-cytidine had little effect except during the period of rapid AFC appearance. A normal but diminished primary antibody response occurred after ara-cytidine injections were stopped, except when multiple daily injections were continued for 11 days. In this case, no antibody could be detected after 22 days, and it was speculated that after 11 days insufficient amounts of antigen were present to initiate a detectable response. In contrast to the primary response, no delayed response was found during ara-cytidine inhibition of a secondary antibody response. The primary and secondary antibody forming cell responses were equally sensitive to ara-cytidine inhibition. IgM and IgG antibody-forming cells (detected -by the indirect plaque technique) were inhibited to the same extent by ara-cytidine injections. The immunosuppressive activity of ara-cytidine was dramatically increased by multiple daily injections which suggests that ara-cytidine has a very short immunosuppressive half-life in the mouse, and which corroborates previous reports describing increased anti-leukemic activity of ara-cytidine using multiple daily injections.

ISSN:0041-1337    

出版商:OVID    

年代:1968

数据来源: OVID

摘要:

SUMMARYThe effects of ara-cytidine (ara-C) on the graft-versus-host reaction (GVHR) have been studied. The immunosuppressive activity of ara-C in the GVHR was extremely dependent upon timing of injection. Injections of ara-C on day 3 in the host undergoing a GVHR were most effective in inhibiting GVHR splenomegaly. This indicates that in the mouse strains employed (C57BLC3BF1), the donor cells were proliferating most rapidly on day 3. The immunocompetence of donor cells to elicit a GVHR was not affected by a 5-day course of ara-G injection. The data reported here and in a companion report suggest that (1) the immunosuppressive half-life of ara-C in the mouse is extremely short, (2) ara-C injections are immunosuppressive only during phases of immunocyte proliferation initiated by antigenic stimulation, and (3)ara-C would be very useful for dissection of immune responses into rapid and slow periods of immunocyte proliferation.

ISSN:0041-1337    

出版商:OVID    

年代:1968

数据来源: OVID

摘要:

SUMMARYA model of the graft-versus-host reaction (GVHR) was produced in BALB/c newborn mice by injection of 6 X 10° viable adult C57BL spleen cells i.p. within the first 24 hr of life. The mortality from the GVHR was significantly modified by the use of heterologous antilymphocyte serum produced in rabbits. Early and prolonged treatment increased the effectiveness of the antilymphocyte serum. Donor cells could be demonstrated in about two-thirds of the survivors in the treated animals after cessation of therapy.

ISSN:0041-1337    

出版商:OVID    

年代:1968

数据来源: OVID

摘要:

SUMMARYMice ofA, CBA, and C57/B strains received injections of purified, radioisotopically labeled γ-globulin obtained from nonimmuneCBAmice as well as fromCBAmice immunized with transplantation and nontissue antigens. These studies were performed in an attempt to quantitate the cross-reaction of transplantation antibody with host and otherH-2 antigens. The total tissue fixation and the tissue catabolic rate of the injected preparations were measured. All hyperimmune preparations fixed equally in the tissues of all three strains of mice, but the tissue catabolic rate of the γ-globulin from animals sensitized to transplantation antigens was twice that of the other preparations. There was no difference among strains in the kinetics of the γ -globulin tissue catabolism, which indicated the large number of non-H-2 cross-reacting antigens. These studies suggest that the accelerated tissue catabolism of γ-globulin from animals sensitized with transplantation antigens was due to the specific fixation of tissue antibody and its resultant “immune elimination.” The specificity of fixation was confirmed by preferential absorption into skin grafts of γ -globulin obtained from animals immunized with transplantation antigens. Thus, the specific cross-reaction of transplantation antibody with host tissue was confirmed. The significance of these findings as they relate to the humoral demonstration of transplantation antibody is discussed.

ISSN:0041-1337    

出版商:OVID    

年代:1968

数据来源: OVID

摘要:

SUMMARYSkin allografts were derived from inbred mice bearing transplanted tumors or methylcholanthrene-induced sarcomas or spontaneous mammary carcinomas. Significantly increased median survival times were noted for skin from strain A (H-2a) orDBA/2 (H-2d) donors, bearing the strain A tumor Sarcoma I, when grafted to C57BL/Ks (H-2d) mice. Accelerated rejections by C57BL/Ks recipients occurred for strain A skin from donors with a transplanted strain A leukemia. No significant alterations in survival times were found for skin from mice bearing autochthonous tumors or fromDBA/2 mice bearing a transplantedDBA/2 sarcoma. It is postulated that the acquisition of tumor antigens by the normal tissues of the tumor-bearer will account for both the accelerated and delayed rejections reported by other investigators and ourselves, and that immunological enhancement, mediated by “autoantibodies,” may account for the delayed rejections.

ISSN:0041-1337    

出版商:OVID    

年代:1968

数据来源: OVID

摘要:

SUMMARY51Cr-labelled(A X CBA)F1strain lymph node cells were injected either i.v. or i.p. into strain A mice of three age groups: adult (8-12 weeks old), “adolescent” (14 days old) and newborn (12-18 hr old). The distribution of radioactivity in various organs was studied over a period of 48 hr. Despite major similarities in the results for the three age groups, certain differences were noted: (1) The effective dose to the lymphoid tissue of a body weight adjusted dose is much higher for adolescent than adult mice. After i.v. injection of cells, it was found that (2) the spleens of adult and adolescent mice lose label from 4 hr onwards, label accumulates in the spleens of newborns. (3) Some changes in the distribution of label in newborn animals resemble those following the injection of syngeneic cells into adults. After intraperitoneal injection, it was discovered that (4) changes in the distribution of label occur which can be interpreted as slower release of donor cells from the peritoneal cavity and delayed redistribution from the liver in younger animals.

ISSN:0041-1337    

出版商:OVID    

年代:1968

数据来源: OVID

摘要:

SUMMARYAnaemic mice (genotype WVWV) were injected with allogeneicCBAlymphoid cells within the 1st day of life. When adult, they were challenged with aCBAskin graft, and the subsequent tolerant (accepted the skin graft), nontolerant (rejected the graft) and control (untreated) mice were injected withCBAhaemopoietic tissue. The control mice showed no change in their erythrocyte count (RBC) during the next 100 days, while the tolerant mice showed a marked increase after 10 days and had a normalRBCby 50 days. Some of the nontolerant mice showed no change in theirRBC, while others had a delayed increase inRBC. This suggests that the conditions which permit the survival of a haemopoietic graft are less stringent than those needed for the persistence of a skin graft.

ISSN:0041-1337    

出版商:OVID    

年代:1968

数据来源: OVID

ISSN:0041-1337    

出版商:OVID    

年代:1968

数据来源: OVID

ISSN:0041-1337    

出版商:OVID    

年代:1968

数据来源: OVID

ISSN:0041-1337    

出版商:OVID    

年代:1968

数据来源: OVID