The I region transplantation antigens: immunogenicity and enhancement

Immunogenetic analysis of tolerance induction in anti-alloantigen delayed type hypersensitivity responses by portal venous pre-inoculation with allogeneic cells

The present study investigates some of the immunogenetic bases for tolerance of anti-allo-delayed type hypersensitivity (DTH) responses as induced by pre-inoculating allogeneic cells via portal venous (p.v.) route. BALB/c mice were injected with totally allogeneic C57BL/6 or H-2 incompatible BALB.B spleen cells via p.v. route. These mice not only failed to exhibit anti-H-2b DTH responses, but also abrogated the potential to generate H-2b-specific DTH responses as induced by the subsequent immunization with H-2b spleen cells via subcutaneous (s.c.) route. The p.v. presensitization with allogeneic spleen cells differing at either class I or class II of major histocompatibility complex (MHC) resulted in the tolerance induction of DTH responses to the respective allogeneic class I or class II MHC antigens. Moreover, the p.v. administration of the class I-positive allogeneic cell fraction depleted of class II-positive component into recipients differing at both class I and class II was capable of inducing anti-class I DTH tolerance. These results indicate that anti-allo-class I or class II DTH tolerance can be induced independently and that the existence of class II antigens on p.v.-presensitized cells is not necessarily required for the tolerance induction of anti-allo-class I DTH response.

Abrogation of lethal graft-versus-host reaction directed against non-H-2 antigens: role of Mlsa and K/I region antigens in the induction of unresponsiveness by alloimmunization

A graft-versus-host reaction (GVHR) directed against DBA/2 non-H-2 antigens alone can be induced by grafting B10.D2 bone marrow and spleen cells intravenously to heavily irradiated, H-2d compatible (DBA/2 X B10.D2)F1 adult mice. Under the experimental conditions used, only 0-10% of recipients survive, but the survival is greatly increased by donor alloimmunization, a few days prior to grafting, against host-specific (DBA/2) non-H-2 antigens and non-specific (foreign) H-2 antigens. The increased survival is mediated by alloimmunization-activated suppressor cells which can decrease the intensity of the immune reaction developed by normal B10.D2 cells both in vivo (GVHR) and in vitro (proliferative response measured in mixed lymphocyte culture, MLC). The present experiments were designed to explore the antigenic requirements for inducing suppression. The results showed that in GVHR the protective effect induced by donor alloimmunization against the specific non-H-2 antigens, which leads to 70-80% survival, is due primarily, if not entirely, to immunization against Mlsa antigens. Results of MLC experiments confirmed this conclusion, showing that immunization against Mlsa antigens is sufficient to account for the suppressive effect induced by the specific immunization. In addition, they indicated that the non-specific protective effect induced by donor alloimmunization against foreign H-2 antigens, which leads to 20-30% survival, is due to immunization against antigens encoded by the K and/or I region(s) of the H-2 complex; immunization against D region encoded antigens alone has no effect.

Secondary delayed type hypersensitivity to H-2 subregion-coded alloantigens

Secondary type delayed type hypersensitivity (DTH) in mice against class I alloantigens or non-H-2 alloantigens is characterized by an earlier appearance of DTH reactivity after booster immunization compared with the development of DTH reactivity after primary immunization. In contrast to the primary and secondary DTH against class I or non-H-2 alloantigens, the development of secondary DTH against class II alloantigens or a set of alloantigens that includes class II alloantigens is not faster than the development of primary DTH. Thus, primary and secondary immunization with class II alloantigens prevents secondary type DTH reactivity to simultaneously administered class I alloantigens and non-H-2 alloantigens.

Long-term passive enhancement of allogeneic skin grafts with monoclonal antibodies

Monoclonal antibodies (mAb) to graft-specific class I or class II major histocompatibility antigens were tested for their ability to enhance the survival of allogeneic skin transplants. Mutant mouse strains were grafted with wild type tissue to restrict the antigenic differences being recognized. For allogeneic recognition of the class I antigen Ld, mutant BALB/c-H-2dm2 (dm2) mice were grafted with wild type BALB/cKh skin, and two dm2 anti-BALB/cKh mAb, 23-10-1 and 30-5-7, were tested for their ability to enhance. The anti-Ld antibody 23-10-1 (IgM) was found not to enhance the survival of BALB/c skin on dm2 mice. 30-5-7, however, an IgG2a antibody of indistinguishable specificity from 23-10-1, prolonged graft survival for approximately 5 days. For recognition of selected Iab determinants, mutant B6.C-H-2bm12 (bm12) mice were grafted with wild type B6/Kh skin, and mAb specific for the serological change(s) in bm12 were tested for their ability to enhance. The anti-Iab antibody 25-9-17 (IgG2a) was found not to enhance B6 grafts on bm12 mice. However, the enhancement seen with 25-9-17 using (C3H X bm12)F1 recipients was extraordinary, such that treated mice had a mean survival time three times that of the controls. Since 25-9-17 is of C3H origin, these results suggest that allotype (or possibly idiotype) compatibility is important in antibody enhancement. Another anti-Iab antibody 28-16-8 (IgM), also of C3H origin, failed to enhance a B6 graft on (C3H X bm 12)F1 mice.(ABSTRACT TRUNCATED AT 250 WORDS)

Massive induction of donor-type class I and class II major histocompatibility complex antigens in rejecting cardiac allografts in the rat

DA (RT1a) hearts were transplanted into PVG (RT1c) or DA recipients, excised on days 1, 3, 5, or 7 after grafting, and examined by immunohistological techniques and quantitative absorption analyses, using allospecific mouse anti-rat class I and class II major histocompatibility complex (MHC) monoclonal antibodies. Cryostat sections stained by the peroxidase technique demonstrated that, in the normal heart, class I antigens were largely restricted to vascular endothelium and interstitial cells, with no observable staining of the myocardial cells except at the intercalated discs. Class II antigens were found only on occasional interstitial dendritic cells. The picture at day 1 after transplantation was not noticeably different. By day 3, however, there was clear patchy induction of both class I and class II antigens on the myocardial cells, usually in the region of cellular infiltrates. By day 5, class I antigens had been strongly induced throughout the graft, with the myocardial cells being very strongly positive. Class II antigens were also uniformly expressed on myocardial cells at day 5, and at this stage the vascular endothelium was also strongly positive. Quantitative absorption analyses showed a 10-fold increase in class I antigen content in cardiac allografts at day 5 after transplantation when compared with normal DA heart. DA heart isografts showed no increase in class II antigens, but it was interesting that, by 5 d after grafting, there appeared to be some expression of class I antigens on the myocardial cells. Quantitative absorptions showed a threefold increase in class I antigens on 5-d isografts when compared with normal DA heart.

The immunosuppressive effect of monoclonal anti-Lyt-1.1 antibodies in vivo

Monoclonal anti-Lyt-1.1 alloantibody was produced as tissue culture supernatant and administered to mice. The antibody, given intraperitoneally, resulted in the suppression of all T cell functions studied, but was without direct effect on B cells. Thus, skin and tumour allograft survival was prolonged and there was suppression of the delayed-type hypersensitivity response; T cell help inthe anti-sheep red blood cell antibody response, responder cells in the mixed lymphocyte reaction (MLR), leucoagglutinin-responsive cells, cytotoxic T cell (Tc) function and the induction of Tc were either totally or partially suppressed, all these responses being mediated by Lyt-1+2- or Lyt-1+2+ cells in CBA/H mice. By contrast, there was no inhibitory effect on the MLR-stimulating or lipopolysaccharide-responsive cells. The administration of the anti-Lyt-1.1 antibody was accompanied by a depletion of Lyt-1.1+ T cells from both spleen and lymph node. These studies indicate that the monoclonal anti-Lyt-1.1 antibody is active in vivo with a selective effect on T cells. The results also have important implications for studies of T cell interactions in the mouse in vivo, and for similar studies in man.

Prolongation of murine islet allograft survival by pretreatment of islets with antibody directed to Ia determinants

Islets of Langerhans treated with donor-specific anti-Ia serum and complement were transplanted across a major histocompatibility barrier into nonimmunosuppressed diabetic mice. The allografts survived in all recipients for at least 200 days after transplantation. Rejection of an established allograft could be induced by intravenous injection of donor splenocytes. This demonstrates that allografts can serve as targets for immune rejection and supports the possible role of Ia-positive passenger lymphoid cells in initiation of immune rejection. The results show that immunosuppression of the recipient is not a prerequisite for successful transplantation.

Leukemia-cell rejection due to T-region encoded antigens

The role of H-2- and T-region products in determining allogeneic cell rejection was evaluated in H-2 congenic and recombinant mice by transplanting A1ATH and A6ATL leukemia cell lines induced in A.TH and A.TL strains, respectively, by Moloney murine leukemia virus.--In K- or D-region incompatible hosts transplant failure was observed, while in I + T-region incompatible hosts either rejection or prolonged survival was seen. In mice preimmunized with spleen cells from I- and/or T-region incompatible donors, leukemia cells were rejected by mice immune only to T-region products, and accepted by mice immune only to I-region products.--Cell-mediated cytotoxicity studies confirmed in vivo results. Secondary CTLs specifically directed against I-region products did not lyse the A1ATH and A6ATL cells, and secondary CTLs from A.TH and A.TL mice sensitized against A6ATL and A1ATH cells respectively exerted a lytic action specific for T-region products, while no activity was observed against I determinants.--The data suggest that tumor-transplant rejection may also be governed by histocompatibility antigens encoded in the T region.

Preparation and properties of antisera to Mph-1, the mouse macrophage alloantigen

Mph-1 is an alloantigen demonstrable on mouse peritoneal macrophages. Two lines, B10M.I and C.I, have been bred for use with strains I/StDa or BALB/c to produce appropriate alloantisera. Optimal immunization procedures for production of anti-Mph-1.2 (the common antigen) are described. Antisera against Mph-1.1 have so far been obtained only erratically. Antisera show complement dependent cytotoxicity against normal peritoneal macrophages and cultured blood monocytes but have no obvious effect on peritoneal lymphocytes or cultured blood neutrophils. Absorption studies show that cell for cell normal peritoneum has about fifteen times more antigen than lymph node, spleen, liver or bone marrow and at least eighty times more than thymus. We were unable to use the antiserum to cause passive enhancement of skin grafts in mice.

Expression of Ia antigens on Langerhans cells in mice, guinea pigs, and man

In all mammalian species so far examined, Langerhans cells or their precursors are the only epidermal cells expressing Ia antigens or their equivalents. In man, xenoantisera raised in rabbits against purified B lymphocyte cell membrane antigens were utilized to stain the Langerhans cells, by either fluorescence or immunoferritin methods. A high proportion of the indeterminate cells in the epidermis also expressed HLA-DR antigens, and a relationship to Langerhans cells is suggested. Confirmation of these results was obtained in mouse. Alloantisera raised against I-A and I-EC subregion products again stained only Langerhans cells. Fluorescence, immunoperoxidase, and immunoferritin methods were used, and confirmation of the specificity of the reaction was achieved at the electron microscope level. Langerhans cells were shown, by ATPase staining, to be absent from the epithelium of the central cornea, but were present in the limbus. Population of the entire corneal epithelium surface was induced by application or irritants or contact sensitizing agents such as dinitrochlorobenzene. Grafting of corneas either deficient or populated with Langerhans cells, to skin beds, may answer the question of the influence of such cells on allograft rejection.