摘要:

Sera from rats carrying tolerated skin allografts were tested for the presence of blocking activity in vitro. Sera with blocking activity had no effect on transplantation tolerance induction in newborn animals. Immunological enhancement of tumor growth was procured by passive transfer of serum from tolerant animals bearing skin allografts. It made no difference whether or not the serum contained blocking activity in vitro. These results suggest that there is no relationship between blocking factors and enhancing activity in vivo.

ISSN:0041-1337    

出版商:OVID    

年代:1975

数据来源: OVID

摘要:

It was previously shown that lethal doses of busulfan (BU) were not immunosuppressive in the rat. In the present studies the effect of rabbit antirat thymocyte serum (RARTS) and cyclophosphamide (CY) as immunosuppressive preparation for marrow allografts in the rat given supralethal doses of BU was investigated. Lewis or LBNF1rats were given RARTS for 4–12 consecutive daily doses. They were given a supralethal dose of BU in addition on the last day of RARTS administration. Ag-B-incompatible (ACI), Ag-B-compatible (F344), or syngeneic marrow was infused 24 hr later. In general, RARTS was not toxic to the marrow graft and permitted engraftment of Ag-B-incompatible and compatible marrow. All animals given Ag-B-incompatible marrow and Ag-B-compatible marrow that survived to day 21 were shown to be chimeric, but all those with incompatible marrow subsequently died from severe graft-versus-host disease (GVHD). In other experiments Lewis or LBNF1rats were given Ag-B-incompatible (ACI) and compatible (F344) marrow after a supralethal dose of BU and single graded doses of CY. Doses of CY as low as 25–50 mg/kg provided sufficient immunosuppression to allow allogeneic engraftment. Transient chimerism was seen up to doses of 100 mg/kg of CY. Permanent chimerism was seen with doses of C Y from 150 to 250 mg/kg. The incidence of lethal GVHD increased in parallel with the percentage of animals that were demonstrated to be chimeric. Mild but transient GVHD was seen with Ag-B-compatible marrow given to Lewis rats.

ISSN:0041-1337    

出版商:OVID    

年代:1975

数据来源: OVID

摘要:

Marmosets are unique in that all members may be considered to be natural blood chimeras because of the high frequency of fraternal twinning and placental vascular anastomoses between the fetuses. The mixed lymphocyte culture (MLC) reaction utilizing blood lymphocytes was evaluated to determine whether this in vitro test could detect histocompatibility differences among related and unrelated marmosets. It was found that the responses could be correlated with the probable immunogenetic relationships of these animals. Thus, an allogeneic MLC reaction in which the responding (R) and stimulating (S) cells were obtained from unrelated animals within one subspecies of marmosets (Saguinus fuscicollis illigeri) yielded a lower response than a semi-xenogeneic reaction involving R and S cells from two different subspecies of marmosets (S.f. illigeri (R) versus S.f. lagonotus (S)). In contrast, MLC reactions between cells from chimeric marmoset co-twins were essentially negative, indicating specific immune tolerance. Under certain experimental conditions, however, it was suggested that the dual lymphocyte cell population from a chimeric marmoset could undergo “autostimulation” as measured by label incorporation studies. The necessity of further experiments was recognized before the data could be truly accepted as reflecting an in vitro manifestation of incompatibility between the two different genetic populations of blood lymphocytes from a chimera.

ISSN:0041-1337    

出版商:OVID    

年代:1975

数据来源: OVID

摘要:

The purpose of the present study was to develop a model in the busulfan (BU)-treated aplastic rat for investigating sensitization to donor marrow in various donor and recipient combinations differing in their degree of histocompatibility. In addition, cyclophosphamide (CY) and rabbit antirat thymocyte serum (RARTS) were studied as potential agents for reversing the presensitized state. Marrow transplantation was studied in the following donor-host combinations: ACI-Lewis (Ag-B-histoin-compatible), F344-Lewis (Ag-B-histocompatible), and F344-LBNF1(“very histocompatible”). The administration of 107donor-type spleen cells i.v. 9 days before marrow infusion sensitized (prevented marrow takes) in all three systems. BN cells were able to sensitize Lewis recipients to F344 marrow because of minor antigens shared by the BN and F344 rat strains. RARTS given as six consecutive daily doses (1.5 ml each) beginning 1 day after immunization and ending 1 day before marrow grafting failed to abolish the presensitized state in all three systems studied. A single dose of CY (150 mg/kg), given alone or combined with RARTS, was able to reverse the measurable effects of presensitization in the histocompatible and “very histocompatible” situations, but was without effect on the histoincompatible system. The present studies were performed in a limited number of rat strain combinations, and the general and specific effects of CY on presensitization to minor histocompatibility antigens in other situations such as outbred mammalian systems remain to be determined.

ISSN:0041-1337    

出版商:OVID    

年代:1975

数据来源: OVID

摘要:

Patients receiving renal allografts from relatively incompatible donors were randomly assigned to one of two immunosuppressive regimens: azathioprine and prednisone with or without a 2-week course of horse antihuman thymocyte globulin (ATG). The number of circulating lymphocytes fell to about one-third of pretreatment values in both groups of patients. In patients given ATG, the proportion of sheep red blood cell-rosetting lymphocytes (SRBC-R) fell promptly to less than 10% of pretreatment values. In contrast, the percentage of SRBC-R remained at about 70% in patients receiving only prednisone and azathioprine. The addition of ATG reduced the number of SRBC-R/mm3to one-tenth to one-thirtieth the number seen in non-ATG-treated patients. Plasma of patients undergoing therapy did not inhibit rosetting in vitro. It is proposed that the monitoring of circulating rosetting cells may be a useful clinical guide to the degree of T cell immunosuppression. It is also suggested that the regimen of azathioprine, prednisone, and ATG results in a more effective suppression of circulating T cells than that produced by azathioprine and prednisone alone.

ISSN:0041-1337    

出版商:OVID    

年代:1975

数据来源: OVID

摘要:

Saline cell-free extracts of normal pig liver, but not normal pig spleen, contain a noncytotoxic factor (or factors) capable of suppressing the blastogenic response of pig lymphocytes to stimulation with a number of plant mitogens: phytohemagglutinin, pokeweed, and concanavalin A. This reaction is generally considered to be a reflection of the capacity of the cell to participate in an immune reaction. Normal pig serum does not display inhibitory activity. The liver extract must be in contact with the lymphocytes for at least the final 48 hr of the 72-hr culture period in order to suppress the blastogenic response. Whether this active constituent in normal pig liver extract is an immunosuppressive agent in vivo remains to be determined.

ISSN:0041-1337    

出版商:OVID    

年代:1975

数据来源: OVID

摘要:

Papain solubilization of rat Ag-B histocompatibility antigens produces Ag-B molecules of about 59,000 daltons which have been shown to contain two fragments bound noncovalently: one fragment about 37,000 daltons carrying Ag-B allospecificity, and another about 11,000 daltons, an apparent rat homologue of human β2-micro-globulin. Beside the 59,000-dalton Ag-B molecules, papain digests of liver cell membranes of ACI strain rats were found to contain Ag-B molecules of about 25,000 and 35,000 daltons. These smaller Ag-B molecules carried Ag-B private specificity of the rat strain (i.e., Ag-B4), as did the 59,000-dalton Ag-B molecules, and accounted for 40% of the solubilized Ag-B alloantigenic activity. The smaller Ag-B molecules were tested for the antigenic specificities that are characteristic of each of the two fragments of the 59,000-dalton molecules and detected by rabbit antiserum against rat cell membranes. The 35,000-dalton Ag-B molecules were found to contain the Ag-B 11,000-dalton fragment (i.e., rat β2-microglobulin homologue) and to differ from the 59,000-dalton Ag-B molecules only in absence of a part of the 37,000-dalton fragment portion. The 25,000-dalton Ag-B molecules did not contain the rat β2-microglobulin homologue and contained only a single component that is similar to the alloantigenic fragment portion of the 35,000-dalton Ag-B molecules. Similar 25,000-dalton Ag-B molecules (carrying Ag-B1 private specificity) of a single component were found in Fischer rat material. They accounted for 10% of the solubilized Ag-B alloantigenic activity.

ISSN:0041-1337    

出版商:OVID    

年代:1975

数据来源: OVID

摘要:

Skin grafting in untreated rats and bone marrow transplantation into minimally immunosuppressed recipients have been used to investigate histocompatibility differences associated with the Y chromosome. Male skin survived for upwards of 120 days with no signs of rejection when grafted into female rats in circumstances where male bone marrow was rejected. Y chromosome-associated antigens were only detected with skin grafting by prior exposure of the female rats to male cells. It is concluded that bone marrow grafting into minimally immunosuppressed recipients may provide a more sensitive index of minor histocompatibility differences than skin grafting. The need to recognise donor cells in recipients prepared for bone marrow grafting with cytotoxic chemicals is emphasized.

ISSN:0041-1337    

出版商:OVID    

年代:1975

数据来源: OVID

摘要:

Fox kidney and skin grafts were transplanted into dog recipients. Fox kidneys, transplanted en bloc into untreated dogs, survived 6.2 ± 0.4 days. The skin transplants survived 5.9 ± 1.4 days. The grafted kidneys showed almost normal function before rejection. Both skin and kidney rejection were mediated through a cellular mechanism. Preformed natural antibodies against donor tissue were not present in the serum of the recipients. These results combined with absorption studies suggested a close relationship between fox and dog, but different number and morphology of chromosomes, immunoelectrophoretic patterns of serum proteins, and disparities of the transplantation antigens proved that the fox is a species quite separate from the dog. It was concluded that the fox-dog system, with its similarity to the chimpanzeeman relationship, offers a unique model to study clinically applicable methods of managing xenografts between closely related species.

ISSN:0041-1337    

出版商:OVID    

年代:1975

数据来源: OVID

摘要:

Injection of parental bone marrow cells into 12-day-old lethally irradiated F, hybrid chickens resulted in chimaerism of donor-type graft-versus-host (GVH)-reactive cells and suppression of antisheep red blood cell antibody response. These manifestations of a chronic graft-versus-host reaction were prevented by pretreatment of the donor marrow with specific anti-T cell globulin. In some chimaeras donor-type GVH-reactive cells developed gradually from T cell precursors of donor origin. Transplantation of spleen and marrow cells from sheep red blood cell-primed F1hybrid donors into lethally irradiated parental recipients resulted in the loss of memory potential within 1–2 weeks of transfer, whereas donor-type IgG allotype synthesis was preserved. Injection of goat antichicken thymocyte serum to recipients 1 day before reconstitution enabled the antibody response of memory cells at 1–2 weeks, although it failed to prevent their rejection by 8–9 weeks after transplantation. Split chimaerism of donor-type GVH-reactive cells was demonstrated in chickens which had previously rejected the B cells derived from the same graft.

ISSN:0041-1337    

出版商:OVID    

年代:1975

数据来源: OVID