Ia-Like Antigens of the Chicken
Soldano Ferrone, Chella S. David in Ia Antigens: Man and Other Species, 1982
Anti-la antisera produced in noncongenic lines of chickens are useful for immunofluorescence and cytotoxic assays, but have generally been ineffective for immunoprecipitation of solubilized antigens. Presumably this is a consequence of the low titer and affinity of the antibodies produced by this regimen. Continual immunization of inbred chickens, in which the initial antibody response is directed against the Ia alloantigens of the donor cells, results in stimulation of antibodies to other alloantigens. Thus the production of high titer and high affinity antibody with narrow specificity comparable to those obtained in congenic mice which differ only at subregions of the H-2 complex has not been possible in chickens. To circumvent this problem, we have prepared mouse monoclonal antibodies to avian Ia antigens using splenic lymphocytes for immunization.13 One such antibody, an IgM, kappa mouse monoclonal antibody, was shown by immunofluorescence to co-cap cell membrane antigens stained by alloanti-Ia antibody and to co-stain the same cell populations as the alloantibody. The monoclonal antibody apparently binds a constant, nonallotypic portion of the Ia molecule as indicated by its reaction with B lymphocytes from all avian species tested, i.e., chicken, duck, quail, dove, and pigeon.9 This antibody has been useful for the structural analysis of the Ia molecules.
Maternal Immunological Recognition of the Conceptus
Gérard Chaouat in The Immunology of the Fetus, 2020
It has long been established that the female in many species is able to recognize the foreign histocompatibility antigens of the developing embryo and respond by the production of antibody.20 However, this is by no means a consistent phenomenon. The majority of females, in fact, do not generate such antibodies. Our own extensive studies on the pregnant mouse have identified the following features of the antipaternal alloantibodies: (1) their presence is restricted to a few inbred strains21 (apparently only H-2b or H-2b-derived strains); (2) they are produced only after repeated matings and only with males from certain his-toincompatible strains;22 and (3) they exhibit little or no complement-dependent cytotoxicity,23 are limited primarily to the IgGl subclass,23 and have very restricted specificity.22 Other investigators have examined the alloantibody response of the pregnant rat and have confirmed that it is under MHC-linked genetic control and has characteristics that differ markedly from a conventional alloimmune reaction elicited by tissue transplantation or spleen cell immunization.24,26 The absence of antibody from the peripheral circulation of nonres-ponder females is not due to its absorption by antigenic determinants of the placenta, as has been suggested, since such absorption is seen only in those females where serum antibody is detectable.27
Immunosuppressive Properties of Serum and Lymph from Liver Grafted Rats
Naoshi Kamada in Experimental Liver Transplantation, 2019
In the preceding chapter, the serological events following orthotopic liver transplantation in the nonrejector combination of DA into PVG were described. Recipient serum (“liver graft serum”) contains a high level of antibodies to class II RT1a alloantigens; in contrast, the level of anti-class I alloantibodies is very low and evidence was described for the effective tolerization of the anti-class I response after liver grafting. It is possible that the strong anticlass II alloantibody response which follows liver grafting in this combination is central to the survival of the liver graft and the manifestations of transplantation tolerance in vivo. Antibodies against rat class II antigens are known to be potent mediators of enhancement, and the rat is one of the species most susceptible to prolongation of graft survival by this means.7,23,26 Moreover, there are parallels between the split tolerance induced by liver grafting (Chapter 7) and the situation after enhancement, where proliferative T-cell responses have been found to be normal in rats made unresponsive by enhancement.23
Exploring the rationale for red cell transfusion in myelodysplastic syndrome patients: emerging data and future insights
Published in Expert Review of Hematology, 2022
Carlo Finelli, Sarah Parisi, Stefania Paolini
The rate of anti-RBC alloimmunization in TD MDS patients is not significantly different compared to other polytransfused patients [28], and ranges from 11% to 57%, according to the transfusion modalities (prophylactic matching or not) [29]. The cumulative incidence of alloimmunization increases in relation to the load of RBC units, and in most cases the Rh or Kell antigens are involved. The appearance of alloantibodies may be associated with an increase in transfusion requirement, and can be followed by an increase in transfusion intensity, while its incidence seems to be decreased following the administration of disease modifying therapies (HMAs). Also, severe delayed hemolytic transfusion reactions may rarely occur [30,31,33]. A variable percentage (3,6–10%) of TD MDS patients may also develop autoantibodies (more frequent in alloimmunized subjects), with a positive direct antiglobulin test (DAT), which can be associated with clinically significant autoimmune hemolysis, and consequent shortened RBC survival and increase of transfusion intensity. The pathogenetic mechanism of the onset of alloimmunization following alloimmunization has not yet been elucidated, although a failure to regulate alloantibody-induced lymphoproliferation has been hypothesized [30,33].
Prolongation of allograft survival by artemisinin treatment is associated with blockade of OX40-OX40L
Published in Immunopharmacology and Immunotoxicology, 2021
Lihua Liu, Juanzhi Zhao, An Li, Xuan Yang, Ben Sprangers, Shengqiao Li
In the first set of experiments, the use of ART was evaluated in allogeneic skin transplantation (C57BL/6 skin grafts into BALB/c mice). As shown in Figure 1, treatment with ART alone resulted in a significant prolongation of skin allograft survival in comparison to grafts in vehicle control (MST: 12.4 versus 15.2 days in control versus ART, n = 5, p < .05). Treatment with CsA also significantly prolonged survival of skin grafts (MST > 19 days, n = 5, p < .01). However, additional ART administration to CsA in the combination group did not further improve graft survival in contrast to CsA alone (graft loss: 2/5 in CsA + ART versus 2/5 in CsA at day 19). Next, we evaluated the production of alloantibody IgG in the different treatment protocols. Alloantibody IgG production was measured at day 18 post-transplantation. As shown in Figure 1, levels of IgG alloantibody production in ART-treated mice were similar to the levels observed in control mice (MFI: 472 ± 86 in ART group and 450 ± 100 in control, p > .05, n = 5). In contrast, CsA treatment resulted in significantly lower levels of IgG alloantibody compared to the levels in the control group (MFI: 90 ± 109 versus 405 ± 100 in CsA control, n = 5, p < .01). These data indicate that ART is able to prolong allograft survival, but is not able to suppress alloantibody production when used as a single immunosuppressive agent at a dose of 150 mg/kg.
Emerging drugs for antibody-mediated rejection after kidney transplantation: a focus on phase II & III trials
Published in Expert Opinion on Emerging Drugs, 2022
Katharina A. Mayer, Klemens Budde, Bernd Jilma, Konstantin Doberer, Georg A. Böhmig
At present, there is limited formal evidence for the efficacy of the available repertoire of ABMR treatment (SOC) [11,22]. Thus, there is a need for adequately powered trials that prove the benefits and risks of specific treatment strategies. Given the fact that ABMR is a cardinal cause of graft failure [1–6], accomplishing the goal of an effective treatment would potentially improve overall transplant outcomes. This would also be beneficial for other organs as well as for other types of transplantation (e.g. xenotransplantation), where humoral alloimmunity is known to play a pivotal role. However, the development of new therapies to improve clinically relevant outcomes (patient and graft survival; safety; quality of life) in patients diagnosed with ABMR will be a lengthy process, because overall ABMR is a rare condition. Thus, effective prevention of ABMR remains an important goal in transplantation.
Related Knowledge Centers
- Allotransplantation
- Antibody
- Blood Transfusion
- Fetus
- Histocompatibility
- Immune System
- Antigen
- Species
- Blood Type
- Transplant Rejection