Transfer of granulomatous inflammation with nonviable preparations of schistosome granulomas in naive mice

Hepatic granulomas of euthymic (nu/+) mice infected with Schistosoma mansoni were freeze-dried or freeze-thawed 3 times and transplanted subcutaneously into naive nu/+ and athymic (nu/nu) mice. The grafted sites, studied histologically, showed formation of organized granulomas in nu/+ mice similar to donor granulomas as observed after grafting of freshly isolated granulomas. On the other hand, in nu/nu mice, the nonviable transplants elicited small and disorganized granulomas, like hepatic granulomas in nu/nu mice with schistosomiasis, but different from fresh nu/+ transplants in nu/nu skin. The findings indicate viable cells are not required for transfer of granulomatous reactions, but T cells are needed for full expression.     

Local effects of granulomatous inflammation on functional activation of T cells in athymic mice

We investigated the effect of granulomatous inflammation in skin on lymphocyte maturation in athymic (nu/nu) mice. Hepatic egg granulomas developed in euthymic (nu/+) mice with schistosomiasis were transplanted into skin of nu/nu mice. During skin granuloma development the rate of DNA synthesis and interleukin 2 activity of lymphocytes from lymph nodes, with and without concanavalin A stimulation, showed that the nu/nu cells were activated to levels of untreated nu/+ lymph node cells. Activation of splenic lymphocytes was not detected in the grafted nu/nu mice. Also, immunohistochemical staining demonstrated an increase in cells expressing Thy 1.2, Lyt-1 or L3T4 surface markers in the skin and lymph nodes, but not in spleen. The findings indicate that a granulomatous reaction in nu/nu mouse skin induces local, but not systemic, proliferation and differentiation of lymphocytes, to a low degree compatible with resting nu/+ mice.     

Experimental histoplasmosis capsulati in athymic nude mice

Granuloma formation in nude (nu/nu) mice and their heterozygous littermates (nu/+ mice) against Histoplasma capsulatum var. capsulatum infection was studied.A culture of H. capsulatum var. capsulatum, isolated from a granuloma in the nasal cavity of a Japanese patient, was used in this experiment. Sixteen specific-pathogen-free male nu/nu and 32 nu/+ mice were used in this study.The nu/+ mice were divided into two groups. Sixteen nu/+ mice in one group and 16 nu/nu mice were inoculated intraperitoneally with 10⁶ yeast cells of the fungus, those in the other group of nu/+ mice were inoculated intravenously with the same number of the yeast cells. Two mice out of each group were sacrificed 2, 3, 7, 11, 14, 18, 25 and 30 days after inoculation, and each of their organs was examined histopathologically. In addition, pieces of these tissues were cultured on Sabouraud's dextrose agar slants.In the nu/+ mice inoculated intraperitoneally, although the fungus was recovered from the spleen, kidney and lymph nodes during the initial course of the infection, lesions were not detected in their histopathological sections. In the nu/+ mice inoculated intravenously, colonies were recovered from all of the organs examined, other than the brain and thymus, 7 days after inoculation.Histopathologically, a few microfoci consisting chiefly of mononuclear cells with or without yeast cells were found in the liver sections 4 days after inoculation. Seven and 11 days after inoculation the number of lesions had increased. They had large accumulations of mononuclear cells. From day 14 on, almost all of the yeast cells had lost most of their staining affinity or were destroyed in the granuloma. From day 25 on, the granulomatous lesions changed gradually to fibrous tissue.In the nu/nu mice the fungus was readily recovered from the spleen, liver, kidney and lymph nodes. Histopathologically, a few microfoci consisting of mononuclear cells were present in the liver sections 4 days after inoculation. That is to say, during the initial course of infection granulomas were formed. In the liver, from day 7 on, the lesions were large and their number increased. However, there was a definite difference between the nu/nu and nu/+ mice. In the former, the yeast cells were not killed, and they continued to multiply within the granulomas. These granulomas were never transformed into fibrous tissue.     

Effect of immune heterozygous spleen cell transfer on resistance to mouse hepatitis virus infection in nude mice

The role of cell mediated immune response to mouse hepatitis virus (MHV) infection in mice was studied by transferring spleen cells from immune heterozygous littermates (nu/+). A suppressive effect on viral growth was seen in infected nude (nu/nu) mice, whereas immune nu/+ serum transfer had no effect. The protective effect of immune nu/+ spleen cells was significantly reduced by treatment with anti-theta serum plus complement but not with anti-Ig serum. In infected nu/nu mice which received transfers of immune nu/+ cells, neutralizing antibody appeared although the titer was not high enough to protect nu/nu mice from fatal infection. Histopathologically, lymphocyte infiltration in hepatic lesions was evident in infected nu/nu mice with nu/+ cell transfer, while it was slight without nu/+ cell transfer.     

Histochemical studies of 3 beta- and 20alpha-hydroxysteroiddehydrogenase in the adrenals and ovaries of the nu/nu mouse.

Adrenal glands and ovaries of nu/+ and nu/nu female mice were examined histochemically throughout the postnatal life for changes in distribution, intensity and appearance of activities of 3 steroid-converting enzymes. While the 3beta-OH-steroid- and pregnenolone-dehydrogenase did not reveal any difference, the 20alpha-hydroxysteroid-dehydrogenase (20alpha-OH SDH) showed a constant behaviour: the onset of the enzyme activity was detectable in the adrenals of nu/+ mice after the second week of age, in nu/nu mice 3--4 weeks later. The localization of 20alpha-OH-SDH was strictly confined to the zone of small cells, a zone lying between the x-zone and the zona fasciculata. In nu/+ mice, after reached sexual maturity at about 6--8 weeks of age, the enzyme progressively disappeared from the adrenals and simultaneously appeared in the ovaries. In nu/+nu mice, which had been kept separated from mating animals, the 20alpha-OH SDH persisted in adrenals even in adult stages. After pregnancy, both--nu/nu and nu/+, showed 20alpha-OH SDH-activity in ovaries and none in adrenals. In both, the enzyme was localized in involuting corpora lutea, whilst in nu/nu it was also present in the intersitial cells. This study indicates no disturbance in the formation of progesterone, but the process of its degradation, as indicated by 20alpha-OH SDH-activity, is definitely different in nu/+ and nu/nu.     

Characterization of mononuclear phagocytes in schistosomal egg granulomas of athymic mice

Macrophages from schistosomal egg granulomas of athymic mice (nu/nu GM) and their euthymic littermates (nu/+ GM) were analyzed phenotypically for the expression of antigens encoded by the I-A subregion of the major histocompatibility complex and for their ability to perform as antigen-presenting cells. Only 11 to 15% of nu/nu GM expressed I-A antigens as compared to 61.5 to 75% of nu/+ GM. Although both populations of cells appeared to be equally effective as antigen-presenting cells appropriately sensitized lymphocytes in the presence of specific antigens--soluble schistosomal egg antigen (SEA) and human gamma-globulin (HGG)--only nu/nu GM, but not nu/+ GM, were found to stimulate I-A-restricted proliferation of schistosome-sensitized T cell populations in the absence of SEA added in vitro. Furthermore, nu/nu GM but not nu/+ GM were shown to exhibit significant proliferative capacity in vitro, but this phenomenon could not account for the observed difference in SEA-independent T cell stimulation. Finally, culture supernatants from nu/nu GM displayed significant thymocyte-stimulating activity, consistent with interleukin 1, which was not observed in nu/+ GM. These findings point to significant differences between nu/nu GM and nu/+ GM, which may be part of an adaptive mechanism of granulomatous reactivity in the absence of a competent T cell system.     

Frequency of natural regulatory CD4+CD25+ T lymphocytes determines the outcome of tolerance across fully mismatched MHC barrier through linked recognition of self and allogeneic stimuli

We show in this study that long-term tolerance to allogeneic skin grafts can be established in the absence of immunosuppression by the combination of the following elements: 1) augmenting the frequency of regulatory CD4(+)CD25(+) T cells (Treg) and 2) presentation of the allogeneic stimuli through linked recognition of allo- and self-epitopes on semiallogeneic F(1) APCs. BALB/c spleen cells enriched for CD4(+)CD25(+) T lymphocytes were transferred either to BALB/c nu/nu mice or to BALB/c nu/nu previously injected with F(1)(BALB/c x B6.Ba) spleen cells, or else grafted with F(1)(BALB/c x B6.Ba) skin (chimeric BALB/c nu/nu-F(1)). Chimeric BALB/c nu/nu-F(1) reconstituted with syngeneic CD25(+)-enriched spleen cells were unable to reject the previously transferred F(1)(BALB/c x B6.Ba) spleen cells or F(1)(BALB/c x B6.Ba) skin grafts, and a specific tolerance to a secondary B6 graft was obtained, with rejection of third-party CBA grafts. BALB/c nu/nu mice reconstituted only with syngeneic CD25(+)-enriched spleen cells rejected both B6 and CBA skin grafts. In contrast, when chimeric BALB/c nu/nu-F(1) were reconstituted with spleen populations comprising normal frequencies of Treg cells, the linked recognition of allo and self resulted in breaking of self tolerance and rejection of syngeneic grafts, strongly suggesting that linked recognition works in both directions, either to establish tolerance to allo, or to break tolerance to self, the critical parameter being the relative number of Treg cells.     

Role of L3T4+ and LyT-2+ cells in experimental visceral leishmaniasis

In contrast to euthymic (nu/+) BALB/c mice, athymic nude (nu/nu) BALB/c mice fail to control the visceral intracellular replication of Leishmania donovani, do not generate the macrophage-activating lymphokine IFN-gamma, and show little or no granulomatous tissue response. To characterize the T cell requirement for successful defense against L. donovani, nude mice were first reconstituted with unfractionated nu/+ immune spleen cells, which readily conferred the capacity to control and eliminate visceral (hepatic) L. donovani. In reconstituted mice, acquired resistance was paralleled by the ability of spleen cells to generate high levels of leishmanial Ag-stimulated IFN-gamma and the development of well formed liver granulomas. In contrast, nude mice reconstituted with either L3T4+- or Lyt-2+-enriched immune spleen cells alone failed to control visceral parasite replication and did not develop effective granulomas despite the finding that transfer of L3T4+ cells largely and Lyt-2+ cells partially restored the capacity to secrete IFN-gamma. To determine whether both T cell subsets were also required in a normal host, nu/+ BALB/c mice were treated with cell-depleting anti-L3T4 and anti-Lyt-2 mAb. Depletion of either T cell subset inhibited the acquisition of resistance to L. donovani and impaired the tissue granulomatous response. Thus, successful T cell-dependent host defense towards intracellular L. donovani and the tissue expression (granulomas) of this mechanism appear to require both L3T4+ and Lyt-2+ cells. A primary role for the L3T4+ cell may be IFN-gamma production; the role of the Lyt-2+ cell and the precise interaction of the two T cell subsets remain to be identified.     

Immunologic abnormality in NZB/NZW F1 mice. Thymus-independent occurrence of B cell abnormality and requirement for T cells in the development of autoimmune disease, as evidenced by an analysis of the athymic nude individuals

Both NZB nu/+ and NZW nu/+ mice were microbially clean by cesarean section. The (NZB x NZW)F1 hybrid (NZB/W) nu/nu mice and nu/+ littermates were then generated by mating of NZB nu/+ with NZW nu/+mice under specific pathogen-free conditions. The female NZB/W F1 nu/nu mice did not develop autoimmune kidney disease, whereas all of nu/+ female littermates mice exhibited proteinuria and died of renal failure with a 50% survival time of 35 wk. Namely, nude mice had no signs of proteinuria up to the time of their death caused by other diseases rather than glomerulonephritis, and their mean survival time was greater than 45 wk. Nude mice had also no anti-ssDNA antibody in their serum. However, splenic B cells of NZB/W nude mice exhibited hyper-responsiveness to both LPS and B151-TRF2, a T cell-derived polyclonal B cell-stimulation factor, and produced large numbers of Ig-secreting cells and anti-TNP plaque-forming cells as well as anti-ssDNA antibody comparable to the nu/+ littermate mice. Interestingly, thymus-engrafted NZB/W nude mice developed autoimmune disease exemplified by the induction of anti-ssDNA antibody and proteinuria at approximately the same time as their nu/+ littermates. These results indicate that the B cell hyper-responsiveness found in NZB/W mice is apparently determined by the T cell-independent process, and T cells are obligatorily required for the development of autoimmune disease in NZB/W mice.     

Surgical model for in vivo evaluation of cultured epidermal sheets in mice.

The objective of this study was to establish a novel surgical model for the grafting of cultured epidermal sheets in mice in order to optimize studies on the behavior of these grafts. Graft-related skin immunology and wound-healing studies also would benefit from this adapted surgical approach. Adapted tie-over surgical procedures were established for mice and promptly applied. Early-stage observation of grafts was made possible by replacing the cotton dressing with a saddle-like plastic tube dressing with a screw cap. We grafted normal Balb/c mice and athymic nude (nu/nu) mice with cultured human epidermis. Evaluation of graft rejection was carried out with the first group, whereas the second provided information on epidermal stratification and terminal differentiation. This innovation permitted direct evaluation of the grafted tissue at any time. Advances in applied transplantation research will certainly provide additional tools for human applications.     

Antigen-induced acceleration of shedding and replacement of B cell antigen receptors requires mature T cells

To determine which early and intermediate events in the response of antigen-binding B cells to a T-dependent antigen (sheep erythrocytes [SRC]) require T help, the antigen-induced changes in receptor turnover and surface IgD loss in BALB/c athymic nu/nu mice were compared with that of nu/+ littermates and +/+ BALB/c mice. Nonimmune SRC antigen-binding spleen B cells (ABC) from +/+, nu/+, and nu/nu BALB/c mice coexpressed IgM and IgD, and 85 to 95% retained receptors well when incubated for 2.5 hr in 100 micrograms/ml cycloheximide (which prevents receptor replacement). Also they were able to regain their ability to bind antigen by 18 hr after pronase treatment, but not by 2 hr. However, 5 days after in vivo immunization, 1) the proportion of ABC expressing surface IgD declined from around 90% to less than 50% in +/+ mice and nu/+ mice but not in nu/nu mice; 2) substantial recovery of antigen-binding occurred by 2 hr after pronase treatment in +/+ and nu/+ ABC but not in nu/nu ABC; and 3) when spleen cells were incubated in cycloheximide, uncompensated receptor shedding reduced +/+ and nu/+ ABC by around 80% but produced only about a 10% reduction in nu/nu ABC. Thus, although the ABC in nonimmune nu/nu mice appeared normal with respect to their surface Ig turnover and expression, they failed to undergo the normal antigen-induced loss of IgD or acceleration of surface Ig shedding and replacement, suggesting that these intermediate activation events require interaction with mature T cells. To determine whether this interaction had to occur during B cell development, during the development of the immune response, or during receptor shedding or replacement itself, cell transfer experiments were carried our wherein nu/+ T cells were transferred i.v. to nu/nu littermates 1 day before immunization with SRC. In the transfer recipients, pronase-treated day 5 ABC were then able to replace and shed their receptors at the accelerated rate, like ABC from +/+ and nu/+ mice. In contrast, the co-incubation of 5-day immune nu/+ T cells with nu/nu B cells did not alter the rate of shedding or replacement.     

Defense mechanisms of mice against Fonsecaea pedrosoi infection

Defense mechanisms of a host against Fonsecaea pedrosoi infection were studied histopathologically using athymic nude (nu/nu) mice of BALB/c background and their heterozygous (nu/+) littermates. Thirty male nu/nu and 30 nu/+ mice, weighing 16–19 g, were employed in this experiment. The nu/nu or nu/+ mice were divided into 3 groups consisting of 10 each. Furthermore, 4 nu/nu mice were supplemented to investigate effects of lymph node cell transfer. Subglobose cells of F. pedrosoi Tsuchiya strain were obtained from a culture in brain heart infusion glucose (1%) broth with reciprocal shaking at 37 °C for 17 days, and then 0.02, 0.1 and 0.5% cells suspensions were prepared. Each cell suspension was allotted to one group of the nu/nu or nu/+ mice. 0.1 ml of the cell suspension was inoculated into a tail vein, then one mouse from each group was sacrificed 1, 2, 4, 6, 8, 10, 14, 18, 21 and 25 days after inoculation. In both the nu/nu and nu/+ mice, the brain, kidneys and heart were affected severely with the strain in that order. Histopathologically, the defense mechanisms of the nu/+ mice against the fungus infection consisted chiefly of 2 steps: first, of non-immune phagocytosis by polymorphonuclear leucocytes (PMNs), and second, of granuloma formation induced by cell-mediated immunity. Those of the nu/nu mice consisted only of one step: phagocytosis by PMNs. A difference in susceptibility to the strain between the nu/nu and nu/+ mice changed according to the amount of the fungal cells inoculated. When inoculated with the 0.02% cell suspension, the resistance of the nu/nu mice was stronger than that of the nu/+ mice. In contrast, when inoculated with the 0.5% cell suspension, the former was affected more severely than the latter. There were little differences in the susceptibility to the strain between the nu/nu and nu/+ mice inoculated with the 0.1% cell suspension. These data seem to indicate that the phagocytic function of PMNs of the nu/nu mice was more active than that of the nu/+ mice, and the nu/nu mice inoculated with the 0.5% cells suspension (beyond the phagocytic capacity) lost resistance against the fungus infection. When the nu/nu mice were transferred with lymph node cells before inoculation of the strain, granulomata were formed to prevent hyphae from growing freely in the tissue.     

Nematospiroides dubius: susceptibility to infection and the development of resistance in hypothymic (nude) BALB/c mice.

BALB/c-nu/nu mice and their intact nu/+ littermates are equally susceptible to infection with third-stage larvae of Nematospiroides dubius. Unlike their heterozygous littermates, however, the nu/nu mice are unable to form ganulomata in the intestinal wall and become only partially resistant to rechallenge. Following two or more infections, nu/nu mice maintain a high burden of adult intestinal worms, whereas worms are lost from immune nu/+ mice. Studies in T cell-injected nu/nu mice suggest that a full complement of T cells is needed to develop maximum resistance against the infective third-stage larvae and to expel adult worms. Measurement of serum immunoglobulin levels indicate that infected nu/+ mice have very high levels of IgG1 whereas the levels of IgG2a are reduced. In infected T cell-injected nu/nu mice, IgG1 levels increase with the number of T cells injected, whereas IgG2a levels are variable but always higher than in infected nu/+ mice.     

Mycoplasma pulmonis Arthritis in Congenitally Athymic (Nude) Mice

Histopathological examinations were performed on arthritic joints and other organs of strain BALB/cA nu/nu and nu/+ mice intravenously injected with Mycoplasma pulmonis strain m53. In both groups of mice suffering from polyarthritis, acute inflammatory lesions with infiltration of polymorphonuclear leukocytes in the synovia and periarticular tissues were observed one to two weeks after injection. In nu/nu mice, the acute inflammation appeared repeatedly up to 20 weeks after inoculation, when the experiment was terminated, and furthermore, extensive synovial and periarticular necrosis were characteristically present after the 4th week. Only a small number of lymphocytes and plasma cells were in the lesions. In nu/+ mice, after the early acute inflammation of arthritis, relapses of the infiltration of polymorphonuclear leukocytes were also observed in some mice in and after the 10th week. In addition, infiltration of lymphocytes and plasma cells was substantial after the 15th week. Focal necrosis was sometimes found in the liver of nu/nu mice. Perivascular infiltration of small lymphocytes and plasma cells was found in the lungs, liver and kidney of nu/+ mice in and after the 15th week. Repair mechanisms of injured articular tissues in nu/nu mice were histopathologically poor, while those in nu/+ mice seemed to be progressive and quite similar to those reported by many investigators for mice with the thymus intact. The histopathological differences are discussed in respect to the thymus-dependent immune responses.     

Regional variations in the distributions of small intestinal intraepithelial lymphocytes (IELs) in BALB/c +/+, nu/+, and nu/nu mice

Regional variations in intraepithelial lymphocytes (IELs) in the small intestine were examined in BALB/c +/+, nu/+, and nu/nu mice. The small intestine was obtained from 11- to 12-week-old mice and divided equally into three (proximal, middle, and distal) parts. The IELs were isolated from each part of the intestine, and the total numbers of IELs in nu/+ and nu/nu mice were about a fifth of those in +/+ mice. Regional variations in the distribution of the IEL alphabeta, but not the gammadelta T-cell subset were found by use of flow cytometry in +/+ and nu/+ mice. On the other hand, such differences were not found in nu/nu mice, suggesting that thymus-independent development of T cells is not different among regions. Different local expansion of thymus-dependent alphabeta T cells may cause the regional variations seen in the distribution of alphabeta T cell IELs in +/+ and nu/+ mice.     

Carcinogen metabolism in human skin grafted onto athymic nude mice: a model system for the study of human skin carcinogenesis

Human skin grafted onto athymic nude mice maintains its major histological features and may provide a useful system with which to assess the carcinogen interaction with human skin. Significant differences were observed in basal levels of cytochrome P-450 and cytochrome P-448-dependent monooxygenase activities between human grafted and nude mouse epidermis. Topical application of crude coal tar (CCT) to human skin transplanted onto nude mice resulted in 3.9 & 3.5; 3.2 & 2.9 and 1.1 & 1.2 fold increases in mouse and human epidermal aryl hydrocarbon hydroxylase (AHH), ethoxyresorufin deethylase (ERD) and ethoxycoumarin deethylase (ECD) activities, respectively. CCT applied topically to mouse skin resulted in 27.8 & 6.4; 12.8 & 3.3 and 1.7 & 2.6 fold increases in mouse and human epidermal AHH, ERD and ECD activities, respectively. Topical application of coal tar either onto human transplanted skin or to mouse skin also resulted in substantial induction of hepatic and pulmonary AHH and ERD activities. These studies indicate that human skin grafted onto nude mice preserves its metabolic capacity and offers a useful model system with which to assess the effects of polycyclic aromatic hydrocarbons and CCT on cutaneous xenobiotic metabolism in the human population.     

Cells with natural killer activity in the cerebrospinal fluid of normal mice and athymic nude mice with acute Sindbis virus encephalitis

Sindbis virus causes an acute, nonfatal inflammatory encephalitis in weanling BALB/c mice. Mononuclear inflammatory cells are present in the cerebrospinal fluid (CSF) as well as in the parenchyma of the brain. Both aspects of this inflammatory response were eliminated by treatment with cyclophosphamide. Athymic nude (nu/nu) mice developed no inflammation in the brain, but did develop a CSF pleocytosis that peaked on day 2 after infection. The time course of the appearance of cells in the CSF was earlier in nu/nu mice than their heterozygote (nu/+) littermates. The pleocytosis in nu/nu mice reached a peak on day 2, whereas in nu/+ mice the peak was on day 4, as it is in normal BALB/c mice. To determine whether some of the CSF cells in nu/nu mice may be natural killer (NK) cells, NK activity was measured in a 4-hr assay by using a YAC-1 target cell. NK cell activity in the spleen and peripheral blood was induced by infection with Sindbis virus in nu/nu mice with a similar time course to that of nu/+ mice (peak 1 day after infection). CSF from nu/nu mice had NK activity present 2 days after infection that was greater than that present in either the peripheral blood or spleen. BALB/c and nu/+ mice had insufficient cells present for assay at day 2, but BALB/c mice had NK activity present in the CSF 3 and 5 days after infection that exceeded that in the peripheral blood or spleen. Brain interferon was detectable on day 1 in nu/nu mice, but not until day 2 in nu/+ mice even though the amounts of brain virus were the same in the two groups at all time points. It is concluded that cells with NK activity contribute to the CSF pleocytosis induced by acute Sindbis virus encephalitis.     

Defensive role of granuloma againstSporothrix schenckii infection

The defensive role of granuloma againstSporothrix schenckii infection was studied histopathologically using nude(nu/ nu) and their heterozygous(nu/+) littermates.Three strains ofS. schenckii (Sp.-1, Sp-17 and Sp-56) were used in this experiment. Each mouse was inoculated into a tail vein with 10⁶ yeast cells of the Sp-1, Sp-17 or Sp-56. The mice were sacrificed at adequate intervals until the 30th day and histopathological sections were prepared from various organs.The numbers of lesions and yeast cells were counted using the liver sections. Furthermore, an experiment of lymph node cell transfer and immunological examinations were carried out.As results the susceptibility of mice to three strains were conspicuously different from each other. The Sp-1 showed the strongest pathogenicity and the Sp-56, the weakest. The susceptibility of the nu/ nu mice inoculated with the Sp-1 was much higher than that of the nu/+ mice and the difference was due to the killing functions of granuloma. Even though about two days' delay was observed in the granuloma formation in the nu/ nu mice in comparison with that in the nu/+ mice, these granulomata could not be distinguished from those of the nu/+ mice. However, functionally there was a definite difference between the granulomata formed in the nu/+ and nu/nu mice. Mononuclear cells forming the granulomata in the nu/ nu mice did not have the ability to kill the yeast cells they had engulfed. Cooperation with T-lymphocytes was necessary for the killing of the yeast cells. A significant response of MIF developed in the immunocompetent mice 11 days after inoculation of the Sp-56, and that day nearly coincided with the day when yeast cells of the Sp-1 began to be destroyed in the granulomata. It was also confirmed by the experiment of lymph node cell transfer that T-cell functions were indispensable for the killing of the yeast cells by mononuclear cells.From these results the authors hypothesize that the mononuclear cells activated with T-lymphocytes could play a leading role as the defense mechanism of mice againstS. schenckii infection.     

Defensive role of granuloma againstSporothrix schenckii infection

The defensive role of granuloma againstSporothrix schenckii infection was studied histopathologically using nude(nu/nu) and their heterozygous(nu/+) littermates. Three strains ofS. schenckii (Sp.-1, Sp-17 and Sp-56) were used in this experiment. Each mouse was inoculated into a tail vein with 10⁶ yeast cells of the Sp-1, Sp-17 or Sp-56. The mice were sacrificed at adequate intervals until the 30th day and histopathological sections were prepared from various organs. The numbers of lesions and yeast cells were counted using the liver sections. Furthermore, an experiment of lymph node cell transfer and immunological examinations were carried out. As results the susceptibility of mice to three strains were conspicuously different from each other. The Sp-1 showed the strongest pathogenicity and the Sp-56, the weakest. The susceptibility of the nu/nu mice inoculated with the Sp-1 was much higher than that of the nu/+ mice and the difference was due to the killing functions of granuloma. Even though about two days’ delay was observed in the granuloma formation in the nu/nu mice in comparison with that in the nu/+ mice, these granulomata could not be distinguished from those of the nu/+ mice. However, functionally there was a definite difference between the granulomata formed in the nu/+ and nu/nu mice. Mononuclear cells forming the granulomata in the nu/nu mice did not have the ability to kill the yeast cells they had engulfed. Cooperation with T-lymphocytes was necessary for the killing of the yeast cells. A significant response of MIF developed in the immunocompetent mice 11 days after inoculation of the Sp-56, and that day nearly coincided with the day when yeast cells of the Sp-1 began to be destroyed in the granulomata. It was also confirmed by the experiment of lymph node cell transfer that T-cell functions were indispensable for the killing of the yeast cells by mononuclear cells. From these results the authors hypothesize that the mononuclear cells activated with T-lymphocytes could play a leading role as the defense mechanism of mice againstS. schenckii infection.     

Effects of hyperprolactinemia on activities of 17-hydroxylase, 17 beta-ol-dehydrogenase and 5 alpha-reductase in neonatally grafted and host testes in mice

Male and female (WB X C57BL/6)F1 hybrid mice were used. Two pituitaries from 60-80-day-old female mice were grafted under the capsule of the left kidney of 60-80-day-old male mice. One week after grafting, 2 testes from neonatal mice were grafted under the capsule of the right kidney of the grafted mice and 70-90-day-old intact male mice. The grafted and host testes, in groups of 10-26, were removed 15, 30, 40, 60 and 120 days after transplantation of the neonatal testes. Testicular homogenates were incubated with [3H]progesterone or [14C]4-androstene-3,17-dione, and enzyme activities per g tissue were estimated. Significantly elevated prolactin levels, slightly lower LH levels and normal testosterone levels were found in the mice with pituitary grafts, compared with those in the mice without pituitary grafts. Activities of 17-hydroxylase and 17 beta-ol-dehydrogenase increased clearly with age in the grafted testes in the mice without pituitary grafts, though the increases were inhibited significantly by the pituitary grafts. However, the pituitary grafts had no significant effect on activities of 17-hydroxylase and 17 beta-ol-dehydrogenase in the host testes under similar gonadotrophic stimulation. 5 alpha-Reductase activities in the grafted and host testes were unaffected by the pituitary grafts. These results show that hyperprolactinemia may directly inhibit increases in activities of 17-hydroxylase and 17 beta-ol-dehydrogenase with testicular age in neonatally grafted testes in mice.