Survival Time Of Skin Allografts Research Articles

T CELL-SPECIFIC ACTIVITY IN RABBIT ANTI-HUMAN THYMOCYTE GLOBULIN

Spotaneous E rosette-forming (T) lymphocytes were monitored in the peripheral blood of rhesus monkeys receiving a 5-day course of rabbit anti-human thymocyte globulin (RATG) after skin allotransplantation. Mean graft survival in RATG-treated recipients was 32.3 +/- 7.6 (SD) days compared with 8.2 +/- 1.7 (SD) days in controls. The percentage and total number of circulating T cells fell precipitously after RATG treatment and recovered slowly. Linear regression analysis showed that the recovery pattern of the total number of circulating T cells, but not the percentage of T cells, was significantly correlated with rejection. Specific antihuman T cell antibody was detected in RATG preparations after extensive absorption with human erythrocytes, platelets, and B lymphoblastoid cells. The cytotoxic titers of B cell-absorbed RATG preparations to human peripheral blood lymphocytes showed a significant correlation with the mean skin allograft survival times obtained in RATG-treated primates. Overall the data suggest that the immunosuppressive potency of RATG in the primate skin graft assay is related in large part to its anti-T cell activity.

Improved compatibility of ALG therapy by application of aggregate free globulin.

Horse anti-human lymphocyte globulin (ALG) solutions contain, like human gamma-globulin preparations, a varying amount of IgG aggregates, which increase during longer periods of storage. Aggregate formation does not impair the immunosuppressive potency of ALG, as has been shown by prolongation of skin allograft survival time in primates. Deaggregated ALG, which can be obtained by ultracentrifugation at 100,000 g over 2 h, is less immunogenic than aggregate containing ALG. The clinical compatibility of ALG was significantly improved by ultracentrifugal deaggregation.

THE GENETIC BASIS OF ANTIGENIC STRENGTH IN HEART AND SKIN ALLOGRAFTING

SUMMARYThirty‐one combinations of congenic and recombinant mouse strains were tested for heart and skin allograft survival times with and without ALS and the results compared with those obtained for MLR and CML. Although the genes for Lads, Ir and Ia specificities are all in the K end, on the average no greater strength of K end incompatibilities than D end were found. Some of the shortest survivals were D region only incompatible.We specifically wanted to find out if there were any special genes concerned with the control of antigenic strength within the H‐2 complex and if so, did they correlate with those already described for CML—the effector cell stimulating or ECS genes. We found no evidence that the ECS genes in themselves were concerned with allograft strength but instead found evidence for certain genes in the I region and others outside the I region which could be acting as allograft potentiating genes. In some combinations there was an association with the ECS genes and the allograft potentiating genes, and we concluded that in these combinations the two types were closely linked but separate.We wanted to know if there was a specific lymphocyte subpopulation concerned with antigenic strength that was sensitive to ALS; the results of our experiments were consistent with this hypothesis but did not prove it.

Characteristics of histocompatibility barriers in congenic strains of mice. III. Passive enhancement of skin allografts in X-irradiated hosts.

Passive immunological enhancement of skin allografts was investigated in three donor-host combinations of congenic mice disparate at non-H-2 loci. Serum against the graft donor was derived from mice that had received donor strain lymphoid cells as neonates, and thereby were rendered specifically tolerant of a skin allograft. We refer to this serum as "allograft-tolerant" serum. Each strain combination was chosen to provide only two non-H-2 histoincompatibilities present in the donor and absent in the host. The differences are categorized as immunogenetically strong, moderate, or weak, on the basis of skin allograft survival times. With passively administered allograft-tolerant serum significantly prolonged graft survivals were noted for the weakest combination only. Combined treatment with sublethal X-irradiation and allograft-tolerant serum signigicantly prolonged graft survivals were noted for the weakest combination only. Combined treatment with sublethal X-irradiation and allograft-tolerant serum significantly prolonged graft survival in both the moderate and weak combinations, with the largest effect present in the weakest disparity. A hyperimmune alloantiserum (produced in adults) directed against the graft donor prolonged allograft survival in the strongest disparity when given in combination with irradiation. In this combination, graft survival time was increased in hosts exposed to X-ray alone, but joint treatment with X-ray and the alloantiserum gave the largest increment. In contrast, combined treatment with the serum and an antithymocyte alloantiserum did not affect graft survival times. Treatment with both radiation and antithymocyte serum did not prolong graft survival beyond that in mice given only X-radiation. Immunological enhancement with central inhibition is assumed as the mechanism underlying prolonged graft survival, and it is suggested that a population of thymus-derived "killer" cells, sensitive to X-irradiation, is required for normal graft rejection.

Prolongation of skin allografts after oral application of ALS in rats.

THE potency of anti-lymphocytic serum (ALS) in prolonging skin allografts has been well investigated. Four different routes of administration are being used: intravenous1, intraperitoneal2, intramuscular3 and subcutaneous4. Every route has its own advantages and disadvantages from the immunological and clinical point of view and these have been discussed elsewhere5,6. Oral application of ALS was never tried because it was assumed that intact proteins like gamma globulins are enzymatically metabolised before they pass through the intestinal wall. But we shall demonstrate, that even oral application of ALS can prolong the survival time of skin allografts.

Rabbit anti rat lymphocyte serum: immunosuppression mediated by a pure IgM fraction.

Eleven rabbits were immunized i.v. weekly for 3 weeks with rat thymus cells during azathioprine administration. The antisera were pooled and fractionated on Sephadex G‐200 to obtain IgM and IgG fractions. The lymphocytotoxic activity was stronger in the IgM than in the IgG fraction. Whole serum, the IgM fraction and the IgG fraction prolonged the survival time of skin allografts from 12.0 to 16.5, 19.2 and 14.4 days respectively. It is concluded that IgM antibodies in antilymphocyte sera also can exhibit immunosuppressive activity.

Characteristics of Disparate Histocompatibility Barriers in Congenic Strains of Mice

Abstract Characteristics of specific immunologic suppression were investigated in C57BL/10 congenic mouse strain combinations disparate at non-H-2 loci as a function of strong, moderate, and weak incompatibilities. These immunogenetic barriers were defined by both graft-vs-host reactivity and distinctive skin allograft survival times. Intraperitoneal injection of neonates with varying doses (2 × 106 to 20 × 106) of allogeneic spleen cells led to degrees of subsequent donor skin allograft acceptance which were closely dependent upon the interallelic combination. However, long-term skin allograft acceptors consistently produced serum alloantibodies against donor cells detectable in vitro by both cytotoxicity and hemagglutination-migration assays. The effectiveness of this specific antibody-associated suppression of transplantation immunity suggestive of enhancement was inversely proportional to the strength of the immunogenetic barrier and directly proportional to donor cell dosage. Increased immunogenetic incompatibility required increased dosage of allogeneic cells to induce specific suppression. The weaker the incompatibility the higher the incidence of effective allogeneic suppression and of concomitant alloantibody production obtained at lower antigen dosage. Coexistence of suppression of transplantation immunity (thymus-derived cell pathway blocked) with continuing anti-donor alloantibody production (bone marrow-derived cell pathway open) was found to be characteristic of the allograft-tolerant state.

CHARACTERISTICS OF DISPARATE HISTOCOMPATIBILITY BARRIERS IN CONGENIC STRAINS OF MICE

SUMMARY The nature and components of “antigenic strength.” were investigated in C57BL/10 congenic strain combinations disparate at non-H-2 loci and selected for strong, moderate, and weak incompatibilities based on skin allograft survival times. Graft-versus-host reactions (GVHR) were studied following injection of varying doses (1 X 106-40 X 106) of normal or preimmunized adult spleen cells into newborn mice. The distinctive strengths of non-H-2 immunogenetic barriers were consistent and parallel as measured by GVHR and skin allograft survival times. The interallelic combination rather than the H locus as such determined the intensity of the histoincompatibility. Decreasing immunogenetic incompatibility was correlated with increasing dosage of spleen cells required to evoke allogeneic disease. The stronger the immunogenetic barrier, by contrast, the greater the efficacy of small doses of immunocompetent cells in producing measurable GVH disease. The weaker the histoincompatibility, the later the time of onset of GVHR and the greater the interval between onset and death. Profound splenic and thymic atrophy coupled with peripheral lymphopenia were the central features of terminal allogeneic disease in non-H-2 disparate mice. GVHR intensified by preimmunized donor spleen cells led to increased deaths and decreased median survival times. The weaker the histocompatibility barrier, the greater was the potential efficacy of preimmunization of evoking GVHR; the longer time required to achieve maximum effectiveness of donor cell preimmunization, the weaker the immunogenetic barrier.

Some effects of a partially purified lymphocyte-inhibiting factor from calf thymus.

The partial purification of a lymphocyte-specific inhibitory factor from calf thymus (LIFT) is reported. It is not species-specific and appears to act on immune reactions in which thymus-dependent lymphocytes are involved, as suggested by its capacity to decrease lymphocyte transformation by phytohemagglutinin (PHA) and graft-versus-host reaction (GVHR), and to increase skin allograft survival time. The material seems to be an acidic protein.

Mixed lymphocyte-platelet, lymphocyte-kidney cell and lymphocyte-liver cell reactions in rats.

The lymphocyte-platelet reaction (MLPR) in various donor-recipient combinations in rats showed a nearly coincident relationship with the mixed lymphocyte culture reaction (MLC). The kidney cells had not enough stimulating effect against allogeneic lymphocytes to induce blastoid transformation. The liver cells stimulated allogeneic lymphocytes to induce blastoid transformation and to increase incorporation of 3H-thymidine, and the magnitude of the mixed lymphocyte-liver cell culture reaction in various donor recipient combinations corresponded to MLC and survival time of skin allografts.

Synthetic and biological polycations in prolongation of skin allograft survival time.

The degree of immuno-auppressive activity of the lysine-rich F1-fraction and the arginine-rich F3-fraction of histone extracted from calf thymus nuclei was compared with that of total histone and of synthetic polycations using transplantation immunity as experimental model. Under comparable conditions total histone and the F1-fraction were likewise active in prolongation of allograft survival time, whereas the F3-fraction was significantly less active. Poly-l-lysine induced also an inhibition of graft rejection, but its activity was less pronounced compared with the F1-fraction. Poly-l-arginine showed no activity at all.

Combined Effect of Phytohemagglutinin and Antithymocyte Serum on Skin Xenograft Survival in Mice

Abstract Phytohemagglutinin (PHA) is generally regarded as a weak immunosuppressive agent. Calne et al. (1) initially reported that it can potentiate the immunosuppressive action of azathioprine in dogs with renal allografts when the two substances were given together. Later on, Gertner et al. (2) recorded again that combination of PHA with either azathioprine or prednisone increased markedly the survival time of skin allografts in dogs and decreased the need for toxic doses of azathioprine and prednisone. Recently, Stefani and Moore (3) suggested that there might be a synergistic effect of PHA and antilymphocyte serum (ALS) in preventing allograft rejection in the clinical situation. In view of the previous evidence that PHA can significantly prolong the survival time of skin xenografts in mice (4) and that antithymocyte serum (ATS) has a greater immunosuppressive effect than ALS on allograft survival (5, 6), it seemed justifiable to do a preliminary experiment concerning skin xenografts in mice treated with a combination of PHA and ATS to see whether a significant synergistic effect could be obtained in this model.

The effect of repeated "therapeutic" courses of antilymphocytic globulin administration on skin allograft survival time in rats.

The effect of repeated "therapeutic" courses of antilymphocytic globulin administration on skin allograft survival time in rats.

The immunosuppressive activity of 9-butylazathioprine, used alone and with azathioprine

9-Butylazathioprine, a derivative of azathioprine that is converted into 9-butyl-6-mercaptopurine in vivo shows significant immunosuppressive activity. When given to mice, 9-butylazathioprine significantly prolonged the survival time of skin allografts and increased the survival of dogs which received renal allografts.

Sex differences in survival of H-2 incompatible skin grafts in mice treated with antithymocyte serum.

THE survival time of skin allografts in mice incompatible at non H-2 histocompatibility loci is frequently shorter in females than in males1–3. As far as we know, comparable differences have not been observed for allografts of normal tissue incompatible at the H-2 locus, although the enhanced suppression of tumour growth by female hosts has been reported for both H-24 and non H-22,5 histoincompatibilities. In the normal animal, the mean survival time for grafts on male and female mice varies by less than a day in the combination CBA→strong A. This is true for our own strains, whose origin has been described6, and this does not seem to have been contra dieted. We have found, however, that when the recipients are treated with rabbit anti-mouse thymocyte serum (ATS) there are differences in the survival time for grafts on males and on females.

Effect of storage on skin allograft survival

Skin autografts stored up to three weeks at 4 C are regularly used in surgical practice. With the introduction of antilymphocyte serum (ALS), clinical use of skin allografts has become a practical possibility. In certain situations, such as burns, stored allografts may be superior to autografts, especially from the supply viewpoint. There is no precise information available on the behavior of stored allografts, even though there have been suggestions in the literature1that the survival time may not be the same as for fresh allografts. Also, several workers have recently demonstrated antigenic changes in skin grafts after apparently simple in vitro manipulations.2-4In view of these considerations, a systematic study of the survival time of skin allografts stored for various periods of time was undertaken. Materials and Methods Female, adult, Sprague-Dawley rats were used as donors throughout, and female, adult, Long-Evans rats as recipients. Skin was either grafted

Effect of Storage on Skin Allograft Survival

Skin autografts stored up to three weeks at 4 C are regularly used in surgical practice. With the introduction of antilymphocyte serum (ALS), clinical use of skin allografts has become a practical possibility. In certain situations, such as burns, stored allografts may be superior to autografts, especially from the supply viewpoint. There is no precise information available on the behavior of stored allografts, even though there have been suggestions in the literature1that the survival time may not be the same as for fresh allografts. Also, several workers have recently demonstrated antigenic changes in skin grafts after apparently simple in vitro manipulations.2-4In view of these considerations, a systematic study of the survival time of skin allografts stored for various periods of time was undertaken. Materials and Methods Female, adult, Sprague-Dawley rats were used as donors throughout, and female, adult, Long-Evans rats as recipients. Skin was either grafted

Alloantibody production measured by plaque assay in relation to strong and weak histoincompatibility.

A plaque technique which provides a sensitive and quantitative determination of allohemolysin (isohemolysin) production by lymphoid cells of mice and Syrian hamsters is described. Much ongoing attention has been given to minimizing sources of spurious plaques while improving the reproducibility of the technique. Primary intravenous immunization with allogeneic blood cells led to the early appearance of plaque-forming spleen cells responding to both strong and weak histocompatibility antigens in inbred strains of mice. The strongest histoincompatibility (A/J --> BL/6), characterized by H-2 plus non-H-2 differences and a median skin allograft survival time of 8.2 +/- 0.5 days, gave a peak average plaque production of 29.6 per 10 x 10(6) viable spleen cells after 6 days. At the other extreme with an average allograft survival time of 91 days, C3H(H-1(a)) --> C3H.K(H-1(b)) showed a feeble production of plaque-forming cells with a peak response of 3.7 per 10 x 10(6) viable spleen cells at 9 days. Histocompatibility antigens determined by genes at the H-1, H-Y, and H-X loci were demonstrated to be erythrocyte antigens as well. Peak plaque production occurred earlier and reached higher levels across the stronger histocompatibility barriers (H-2 plus non-H-2 or H-2 alone) in temporal accord with the rapidity of skin allograft rejection. Weak H-Y or H-1 differences leading to prolonged allograft survival were associated with moderate, but not commensurate delays in the initial occurrence and recruitment of plaque-forming cells. With one exception (C57BL/10 --> B10.A), the average plaque counts found at the peak of the primary responses were inversely proportional to the median survival times of skin allografts in the same strain combinations. Nevertheless, in light of the disparity between the times of allograft rejection and the time course of appearance of plaque-forming cells with the "weaker" congenic combinations, the early 19S antibodies do not appear to be directly involved in allograft rejection. There appears to be no limitation in the weakness of histocompatibility antigens capable of evoking antibodies detectible by plaque assay. The extent to which molecular species of mouse antibodies other than 19S hemolysins are induced and detected under the conditions employed remains to be determined. The responses in strain combinations involving stronger histocompatibility barriers were characterized by exponential increases in plaque-forming cells, for 2 to 4 days until maximal levels were reached. Repeated immunization in several trials led to substantial increases over the maximum primary response in the number of demonstrable plaque-forming cells. Further preliminary results are reported concerning alloimmune plaque production in three strains of Syrian hamsters exhibiting intermediate to weak histocompatibility differences.