Lymphomas in C3H mice perinatally inoculated with (C3H X T6) F1 or C3H spleen cells

Autoimmunity, hyporeactivity to T cell mitogens and lymphoproliferative disorders following neonatal induction of transplantation tolerance in mice

We have reported that, in A/J (A) (H-2a) mice, a partial tolerance to C57BL/10ScSn (B10) (H-2b) skin allografts and a high incidence of lethal lymphoproliferative disorders (LPD) can be induced by the neonatal i.v. injection of 2 x 10(7) semiallogeneic (B10 x A)F1 spleen cells (SC) (Végh, P., Baranyi, L. and Jánossy, T., Cell. Immunol. 1990, 129: 56). In this study, we show that the incidence and mortality of LPD were continuously growing from 1 month of age until the end of the experiment at 1 year (64% and 36%, respectively). Based on histology, 27% of the diseased mice suffered from lymphoid malignancies. In the remaining cases (73%), reactive histopathological changes were seen in the spleen, lymph nodes (LN), liver and kidneys. The proportion of CD4+ T cells in the spleen and LN as well as that of splenic B cells decreased, while the percentages of mature and immature myeloid cells doubled. The total cell number of each (sub)population, however, was elevated in both lymphoid organs. The cells taking part in the lymphoproliferation were of host (A) and not of donor (F1) origin. Preceding the development of apparent LPD, the SC, LN cell and thymus cell suspensions of 1-month-old tolerized mice showed reduced in vitro proliferative responses to T cell and T cell-dependent B cell mitogens (Con A or PWM), while their reactivity to a T cell-independent B cell mitogen (lipopolysaccharide) was essentially unimpaired. This hyporeactivity seems to be functional, because neither histology nor immunophenotyping by flow cytometry revealed significant alterations in the spleen and thymus of such animals, apart from a slight reduction in the ratio of CD4+/CD8+ T cell subpopulations in the spleen. The in vivo T cell-mediated immune response of the tolerized mice was practically normal to third party CBA/Ca (H-2k) allografts. Antithymocyte autoantibodies (ATA) were detected in the sera of 76% of the tolerized mice at 1 month of age (i.e., even before the mass appearance of LPD). ATA as well as antinuclear Ab were present in 65% of the adult tolerized mice, independently of the presence of LPD. Taken together, in A mice neonatally injected with (B10 x A)F1 SC, a partial, specific allograft tolerance and a chronic host-vs.-graft disease-like syndrome developed. The latter is manifested in hyporeactivity to T cell mitogens, development of autoantibodies and, subsequently, in progressive LPD and lymphoid malignancies.

MHC-specific graft-protective and delayed-type hypersensitivity (DTH) suppressive activity of a CD4+ CD8+, alpha beta T cell receptor (TCR) positive lymphoma isolated from a tolerant mouse

Two lymphomas were found in, and isolated from A (H-2a) mice in which permanent transplantation tolerance was induced to CBA (H-2k) histocompatibility antigens by the neonatal injection of (CBAxA)F1 spleen cells. They proved to be of recipient origin and were transferable to syngeneic A mice, growing as disseminated lymphomas (L33 and L46) and killing the recipients rapidly. Analysis of the cell surface antigens disclosed that both lymphomas had an immature T cell phenotype [Thy-1+, CD5+, CD3low, TCR alpha beta low, CD4low, CD8high, heat-stable antigen (HSA) positive, and CD44-, MHC class II-, CD45R-, sIg-, Gr-1-, CD11b-]. Intraperitoneal (i.p.) injection of syngeneic A mice with viable L33 lymphoma cells resulted in a dose-dependent, significant prolongation of the mean survival times of "specific" CBA and MHC-identical B10.BR skin allografts as compared to the survival of appropriate grafts in non-lymphoma-bearing controls. The survival times of third party MHC-incompatible B10 (H-2b) and B10.D2 (H-2d) allografts were only slightly prolonged in A mice inoculated with L33 cells. The graft-protective effect was not abrogated if the proliferative capacity of the L33 cells was blocked by in vitro mitomycin C (MMC) pretreatment. Furthermore, the inoculation of L33 lymphoma into A mice significantly inhibited their DTH response to the sensitizing CBA histocompatibility antigens. In contrast, the L46 lymphoma had no effect on the survival of CBA allografts and the DTH reactivity. These data suggest that the CD4+CD8+TCR alpha beta + L33 T cell lymphoma originating from a neonatally tolerant mouse has a specific immunosuppressive effect on the in vivo reactivity of syngeneic mice to the tolerance-inducing (MHC class I) alloantigens.

Induction of transplantation tolerance and development of lymphomas in mice: lack of interdependence

Neonatal transplantation tolerance was induced in five different H-2-incompatible donor----recipient mouse strain combinations by the iv injection of semiallogeneic (F1 hybrid) spleen cells. The highest degree of tolerance (expressed by the survival time of the specific test skin allografts) was observed in the (CBA X A)F1----CBA combination (approximately 95% permanent tolerance) but some degree of tolerance was achieved in all strain combinations. An increased incidence of malignant lymphoproliferative disorders was observed in all groups of mice which underwent neonatal tolerance induction. The highest incidence of lymphoproliferative malignancies was observed in the (B10 X A)F1----A tolerance induction system, in which approximately 50% of the recipient mice died within 1 year. In further experiments, spleen cells of mice which proved to be permanently tolerant after the neonatal tolerance induction were transferred into syngeneic, normal, adult, ATS-pretreated, allografted recipients; by this method, in approximately 50% of the recipients permanent "adult" tolerance was achieved. The spleen cells of the "adult" tolerant mice were able to transfer the tolerance to other adult, syngeneic, ATS-pretreated recipients. Even the fourth serial transfer resulted in essentially the same degree of tolerance in the new recipients. We consider the serial transfer a classical instance of "infectious tolerance" based on suppressor mechanisms. However, an increasing number (and malignancy) of lymphomas occurred in the course of the serial transfers and prevented the "indefinite" transfer of tolerance after the fourth occasion. We conclude that both the degree of transplantation tolerance and the high frequency of lymphomas are determined by (immuno)genetic factors but the two phenomena are not interrelated. Thus, successful transplantations do not seem to be necessarily accompanied by an increased incidence of malignancies.

Expression of murine leukemia viruses in RFM mice with host versus graft disease after perinatal inoculation of (T6 X RFM)F1 lymphohemopoietic cells

Host versus graft disease is the fatal syndrome of altered immunity that follows the perinatal inoculation of related F1 hybrid spleen cells to susceptible strains of inbred mice. The allogenic reaction results in severe depletion of T-lymphocytes, but causes hyperplasia and hypersecretion of B-cells. Among the long-term survivors of acute host versus graft reactions, there is a high incidence of nonthymic lymphomas associated with ecotropic murine leukemia virus that may be of donor F1 origin. The present studies were done to determine whether ecotropic murine leukemia virus played any role in the pathogenesis of acute host versus graft disease in RFM mice perinatally inoculated with (T6 X RFM)F1 spleen cells. In RFM/(T6 X RFM)F1 chimeras, N-tropic murine leukemia virus can be detected as early as 3 days. The progression of the disease was accompanied by increasing viral expression. The inoculation of N-tropic virus of F1 donor origin into RFM neonates failed to induce disease, although the virus proliferated. Detection of progressively rising titers of antibody to murine leukemia virus linked the virus to the development of hyperimmunoglobulinemia by virtue of its ability to serve as a replicating source of antigens. These and other studies provided evidence that the seemingly paradoxical appearance of hyperimmunoglobulinemia in T-cell-deficient mice with the host versus graft syndrome is due, at least in part, to the stimulation of presensitized F1 donor B-cells, which are not destroyed in the allogenic reaction, as are the T-cells. Another unusual finding was the detection of polytropic murine leukemia virus in 25-day-old RFM/(T6 X RFM)F1 chimeras. It is suggested that the allogenic host versus graft reaction favored the formation of recombinants.