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J F Hagemann

Publications and source records attributed to J F Hagemann.

10 recordsLinked to original sources
PubMed1980

The effect of 2-mercaptoethanol on IgM and IgG antibody activity.

The effect of reduction by 2-mercaptoethanol (2-ME) on antibody activity was studied in antisera with high and low IgG concentrations. Sera obtained from B10.LP nu/nu mice during a primary response against a rat PVG/c skin graft contained only 2-ME sensitive antibodies. However, when analyzed on sucrose gradients, IgG as well as IgM antibody activity was present. After raising the low serum IgG concentration (0.3-0.7 mg/ml) of these sera by addition of normal mouse serum (5.1 mg IgG/ml), 2-ME resistant antibodies became detectable. Hyperimmune C57BL6 anti PVG/c lymphocyte serum with a high IgG concentration (20.2 mg/ml) and antibody activity predominantly located in the IgG class was not affected by 2-ME treatment. These data show that IgG antibodies, although less susceptible to reduction than IgM antibodies, are not resistant to this treatment. At high IgG concentrations the proportion of inactivated IgG with specific antibody activity will be negligible but at low IgG concentrations the use of this method leads to serious underestimation of IgG antibody activity.

Animals↗
PubMed1980

Patterns of vascular damage in the antibody-mediated rejection of skin xenografts in the mouse.

Established rat skin grafts carried by immunosuppressed mice were acutely destroyed by an intravenous administration of mouse antirat lymphocyte serum. The histologic pattern of destruction was dependent on the amount of antiserum administered. At low doses (0.01 ml) an Arthus-like reaction was seen with early accumulation of granulocytes. At high doses (0.25 ml) a Shwartzman-like pattern occurred, with early intravascular thrombosis and without evident participation of granulocytes in the initial phases. Groups of mice that received intermediate doses showed graft changes that were transitional between these two types of destruction. Similar histologic patterns have been described in clinical transplantation. Our results show that they are not fundamentally different and that the severity of the triggering reaction determines which of either type will occur.

Animals↗
PubMed1978

A sensitive haemolytic assay of mouse complement.

Under appropriate conditions the haemolytic activity of mouse complement can be measured in a 51Cr release assay. Modifications that increase the sensitivity are the following: (a) mouse 7 S anti-SRBC antibodies as amboceptor; (b) low amount of target cells; (c) ionic strength of 0.13 M NaCl in the test medium; (d) incubation temperature of 30 degrees C; (e) incubation time of 90 min; (f) total reaction volume of 1 ml.

Animals↗
PubMed1977

Role of antiserum and complement in the acute antibody-mediated rejection of mouse skin allografts in strain combinations with increasing histoincompatibility.

Acute antibody-mediated rejection (AAR) of mouse skin allografts was studied in nine donor-recipient combinations with increasing histoincompatibility ranging from an H-Y to a complete H-2 plus on-H-2 disparity. AAR was induced by the injection of specific alloantiserum along with a heterologous complement on day 7 after grafting. Sera from rabbits, guinea pigs, and from a human volunteer were used as complement sources. The recipients were treated with antilymphocyte serum on days 0, 2, and 4 to postpone cell-mediated rejection. With increasing histoincompatibility the mean survival time of untreated grafts decreased, the in vitro cytotoxic activity of the alloantiserum rose, and AAR could be induced with lower amounts of antiserum. The higher efficiency of rabbit complement compared with guinea pig complement and human complement, that is known to exist in in vitro cytotoxicity, was also found in vivo. Rabbit complement could induce AAR in combination with relatively weak histoincompatibility (H-2K, H-2D, or non H-2 differences), where guinea pig complement and human complement were ineffective. All three complement species elicited AAR if there was a disparity for H-2D plus non-H2 H-2K plus non H-2, H-2, or H-2 plus non-H2. The rules for immunogenicity of the different histocompatibility loci as they have been described for cell-mediated graft destruction also apply to this humorally mediated rejection process.

Animals↗
PubMed1975

Enhancement of skin grafts in the mouse. The combined used of specific and nonspecific immunosuppression.

Enhancement of skin grafts in mice by passively administered alloantiserum was examined in conjunction with the simultaneous use of other immunosuppressive regimens. It could be clearly shown that when a "weak" antilymphocyte serum (ALS) was used, a significant further prolongation of graft survival occurred over that obtained with the enhancing antiserum alone, and these two separate effects were synergistic. When a "strong" ALS was used, no synergistic effects were apparent unless the enhancing alloantiserum was given almost continuously. A similar, but less impressive synergism was seen when the enhancing alloantiserum and azathioprine were used together. Azathioprine, like ALS, presumably acts on T cells, whereas drugs directed against B cells, such as cyclophosphamide and prednisolone, failed to show any synergistic effect.

Animals↗
PubMed1975

Hyperacute rejection of skin allografts in the mouse. Sensitivity of ingrowing skin grafts to the action of alloantibody and rabbit complement.

The destructive action of alloantiserum and exogenous complement on ingrowing skin allografts was studied. B6AF1 recipients of a B10.D2 skin graft received a single intravenous injection of B6AF1 anti-B10.D2 serum (antiserum to H-2K.31) together with rabbit complement (RC) within the first 10 days after transplantation. Different models were used: recipients without immunosuppression, recipients treated with antilymphocyte serum, x-irradiation, or enhancing antibody. If the injection was given between day 5 and 10 after grafting, hyperacute rejection occurred in all cases. The rejection seemed to be most violent when the injection was given on days 7 or 8. Injections given on days 1, 2 or 3 after grafting could not induce hyperacute-rejection, but resulted, on the contrary, in a prolongation of graft survival, probably due to immunological enhancement. Injections on day 4 produced patchy necrosis, but the grafts recovered and the residual tissue showed a prolonged survival. The results suggest that the presence of a functioning vascular network is a prerequisite for the occurrence of hyperacute rejection of skin allografts in the mouse.

Animals↗
PubMed1975

Hyperacute rejection and enhancement of mouse skin grafts by antibodies with a distinct specificity.

Pure 7S IgG2 was prepared from B6AF1 anti-B10.D2 ascites fluid by affinity chromatography. This preparation was extensively absorbed with B10.D2 red blood cells to remove the antibodies directed against the serologically defined antigens of the major histocompatibility complex. After absorption the serum had retained in vitro cytotoxic activity against 45 percent of B10.D2 spleen cells. The absorbed and unabsorbed 7S IgG2 antibodies were tested for their capacity to induce enhancement and, in the presence of rabbit complement, hyperacute rejection of B10.D2 skin grafts in B6AF1 recipient mice. The enhancing capacity of 7S IgG2 was completely unimpaired after absorption. However, the absorbed preparation was unable to induce hyperacute rejection of the grafts even if very high doses were administered. The results show that hyperacute rejection of skin grafts in this model is mediated by antibodies directed against the serologically defined antigens (i.e., H-2K antigens) of the H-2 complex. They further support the hypothesis that immunologic enhancement is mediated by antibodies directed against Ir-region-as-sociated antigens.

Absorption↗