Preterminal host dendritic cells in irradiated mice prime CD8+ T cell-mediated acute graft-versus-host disease

To understand the relationship between host antigen-presenting cells (APCs) and donor T cells in initiating graft-versus-host disease (GVHD), we followed the fate of host dendritic cells (DCs) in irradiated C57BL/6 (B6) recipient mice and the interaction of these cells with minor histocompatibility antigen- (miHA-) mismatched CD8+ T cells from C3H.SW donors. Host CD11c+ DCs were rapidly activated and aggregated in the T cell areas of the spleen within 6 hours of lethal irradiation. By 5 days after irradiation, <1% of host DCs were detectable, but the activated donor CD8+ T cells had already undergone as many as seven divisions. Thus, proliferation of donor CD8+ T cells preceded the disappearance of host DCs. When C3H.SW donor CD8+ T cells were primed in vivo in irradiated B6 mice or ex vivo by host CD11c+ DCs for 24-36 hours, they were able to proliferate and differentiate into IFN-gamma-producing cells in beta(2)-microglobulin-deficient (beta(2)m(-/-)) B6 recipients and to mediate acute GVHD in beta(2)m(-/-) --> B6 chimeric mice. These results indicate that, although host DCs disappear rapidly after allogeneic bone marrow transplantation, they prime donor T cells before their disappearance and play a critical role in triggering donor CD8+ T cell-mediated GVHD.     

Identification of an immunodominant mouse minor histocompatibility antigen (MiHA). T cell response to a single dominant MiHA causes graft-versus-host disease.

T cell responses to non-MHC antigens are targeted to a restricted number of immunodominant minor histocompatibility antigens whose identity remains elusive. Here we report isolation and sequencing of a novel immunodominant minor histocompatibility antigen presented by H-2Db on the surface of C57BL/6 mouse cells. This nonapeptide (AAPDNRETF) shows strong biologic activity in cytotoxic T lymphocyte sensitization assays at concentrations as low as 10 pM. C3H.SW mice primed with AAPDNRETF in incomplete Freund's adjuvant generated a potent anti-C57BL/6 T cell-mediated cytotoxic activity, and T lymphocytes from AAPDNRETF-primed mice caused graft-versus-host disease when transplanted in irradiated C57BL/6 recipients. These results (a) provide molecular characterization of a mouse dominant minor histocompatibility antigen, (b) identify this peptide as a potential target of graft-versus-host disease and, (c) more importantly, demonstrate that a single dominant minor antigen can cause graft-versus-host disease. These findings open new avenues for the prevention of graft-versus-host disease and should further our understanding of the mechanisms of immunodominance in T cell responses to minor histocompatibility antigens.     

体外阻断CD137-CD137L途径控制小鼠移植物抗宿主病的研究

目的探讨体外阻断活化的供鼠T淋巴细胞CD137-CD137L共刺激途径控制小鼠异基因骨髓移植（allo-BMT）后急性移植物抗宿主病（aGVHD）及其机制。方法供、受鼠的淋巴细胞体外混合培养，分别加入抗CD137L单抗或不加抗CD137L单抗培养后与供鼠骨髓细胞混合移植给受鼠。采用流式细胞术检测移植后受鼠T细胞亚群的变化，RT-PCR法检测细胞因子mRNA表达水平的变化，观察移植后受鼠GVHD的临床及病理改变。结果与未用抗CD137L单抗组相比，应用抗CD137L单抗组CD3^＋CD8^＋T细胞明显降低（P＜0．01）；IFN-γ表达水平明显减低（P＜0．01），IL-10的表达水平明显升高（P＜0．01）。移植后未预防GVHD组（A组）小鼠移植后15d内均死于aGVHD。采用甲氨蝶呤＋环孢素预防GVHD组（B组）小鼠100％发生aGVHD，但临床及病理改变程度较A组轻，平均存活时间[（9．5±2．5）d]较A组[（7．5±1．5）d]略有延长。采用抗CD137L单抗预防GVHD组（C组）受鼠aGVHD的发生率为70％，程度比A、B两组轻，与A、B两组相比生存率明显提高（P＜0．01），平均存活时间[（16．0±2．5）d]明显延长（P＜0．01），30％的小鼠生存时间大于30d。结论抗CD137L单抗体外阻断CD137-CD137L共刺激途径能有效控制小鼠GVHD，可能与影响Ⅰ类和Ⅱ类T细胞因子平衡有关。     

In a fully H-2 incompatible chimera, T cells of donor origin can respond to minor histocompatibility antigens in association with either donor or host H-2 type

Fully H-2 incompatible radiation chimeras were prepared using BALB congenic mice. Such chimeric mice were immunized in vivo against histocompatibility antigens of the C57BL/10Sn (B10) background in association with either of the parental H-2 haplotypes, and their spleen cells subsequently boosted in vitro with the same minor antigens. Strong H-2-restricted cytotoxic activity against minor antigens was detected, and the specificity of the restriction could be to the H-2 haplotype of the donor or the host depending on the cells used for priming or boosting. Cross priming could also be demonstrated in these mice. The results show that fully allogenic radiation chimeras can produce H-2-restricted T-cell responses to minor histocompatibility (H) antigens, and are discussed in relation to contrasting results recently obtained against viral antigens.     

Cellular basis of graft versus host tolerance in chimeras prepared with total lymphoid irradiation

BALB/c mice given allogeneic (C57BL/Ka) bone marrow cells after toal lymphoid irradiation become stable chimeras approximately 80% donor- type and 20% host-type cells in the spleen. The chimeras doe not develop graft vs. host disease (GVHD). Purified cells of C57BL/Ka origin from the chimeras mediated GVHD in lightly irradiated C3H (third party), but not in BALB/c (host-strain) mice. Thus graft vs. host tolerance in the chimeras could not be explained by complete immunodeficiency of donor-type cells, serum blocking factors, or suppressor cells of host (BALB/c) origin. Clonal deletion or suppression of lymphocytes reactive with host tissues remain possible explanations. The transfer of donor-type chimeric spleen cells to BALB/c recipients given 500-550 rad whole-body irradiation WBI led to stable mixed chimerism in approximately 50% of recipients. The cells were presumably acting as tolerogens because similarly irradiated BALB/c mice given (BALB/c X C57BL/Ka)F1 spleen or bone marrow cells also became stable mixed chimeras.     

Alloimmunization to transfused platelets requires priming of CD4+ T cells in the splenic microenvironment in a murine model

BACKGROUND: Alloantibodies are a clinically significant sequelae of platelet (PLT) transfusion, potentially rendering patients refractory to ongoing PLT transfusion support. These antibodies are often IgG class switched, suggesting the involvement of CD4+ T‐cell help; however, PLT‐specific CD4+ T cells have not been visualized in vivo, and specifics of their stimulation are not completely understood. STUDY DESIGN AND METHODS: A murine model of alloimmunization to transfused PLTs was developed to allow in vivo assessment and characterization of CD4+ T cells specific for PLT major histocompatibility complex (MHC) alloantigen. PLTs were harvested from BALB/c mice, filter leukoreduced, and transfused into C57BL/6 recipients. PLT‐specific CD4+ T‐cell responses were visualized by using a T‐cell receptor transgenic mouse that detects peptide from donor MHC I presented on recipient MHC II. Antibody responses were determined by indirect immunofluorescence using BALB/c donor targets. RESULTS: C57BL/6 recipients of BALB/c leukoreduced PLT transfusions produced BALB/c antibodies, with proliferation of antigen‐specific CD4+ T cells seen in the spleen but not lymph nodes or liver. Depletion of recipient CD4+ cells or splenectomy independently abrogated the alloantibody response. CONCLUSION: We report a novel model to study antigen‐specific CD4+ T cells during alloimmunization to PLT transfusion. The presented data support a critical role for CD4+ T‐cell help in the humoral response to PLT transfusion and establish the spleen as a required microenvironment for effective CD4+ T‐cell priming against donor PLT–derived MHC I.     

在小鼠骨髓移植中CCR5与急性移植物抗宿主病的相关性研究

本研究评价供者CCR5在经过强化预处理的骨髓移植动物模型受者体内的作用,为今后的异基因造血干细胞移植的临床应用提供科学依据.经过致死剂量照射的BALB/c小鼠接受异基因C57BL/6小鼠的骨髓移植.根据回输的细胞不同实验分为4组:B6 CCR5 KO组,受者接受C57BL/6 CCR5-/-小鼠骨髓和脾脏细胞;B6 WT组,受者接受野生型C57BL/6小鼠骨髓和脾脏细胞;B6 CCR5 KO BMC组,受者只接受C57BL/6 CCR5-/-小鼠骨髓细胞;B6 WT BMC组,受者只接受野生型C57BL/6小鼠骨髓细胞.结果表明:较之B6 WT组,B6 CCR5 KO组小鼠以更快的速度死于急性GVHD;其受者体内的CD8+T细胞更大量的增殖;其T细胞恢复后产生更多的INF-γ和TNF-α并且由于其T细胞有丝分裂原刀豆素水平处于较高水平,从而进一步促进T细胞的增殖,提示CCR5的作用之一是下调参与排异反应的供者CD8+T细胞的增殖.组织学评价提示,移植剔除CCR5基因受者细胞的小鼠肾脏出现了病理损伤并且肝脏存在有更为严重的病理变化.结论:剔除CCR5基因的异基因骨髓移植使GVHD发病率的增加,供者CD8+T细胞在受者体内增殖增加以及肝肾损害加重,这提示CCR5在异基因骨髓移植中起着重要作用.     

应用扩增的Treg预防异基因骨髓移植后移植物抗宿主病的实验研究

目的：探讨扩增后的CD4+CD25+调节T细胞(regulatory T cell ,Treg)输注对异基因骨髓移植(allo-BMT)后小鼠移植物抗宿主病(GVHD)的影响。方法：利用免疫磁珠法分选小鼠Treg细胞； 以抗鼠 CD3ε 单抗、抗鼠CD28 单抗 、鼠重组 IL-2及辐射过的Balb/C小鼠脾细胞为共刺激因子，扩增TREG细胞；建立C57BL/6→BALB/c小鼠allo-BMT模型,接受移植小鼠随机分为3组,移植骨髓后6-8小时后分别予尾静脉输注扩增的Treg细胞、CD4+CD25-T细胞和RPMI 1640培养液(空白对照)。以移植后GVHD表现,肝、脾、小肠组织病理形态、生存期为观察指标并进行组间比较。结果：经免疫磁珠法分选可获得高纯度(91.80±2.15)%及具较强活力(97.58±1.23)%的Treg细胞；移植后(四周左右)的扩增后Treg细胞移植组小鼠肝、脾、小肠GVHD病理损害较同期CD4+CD25-T细胞移植组与空白对照组小鼠有一定程度的减轻。3组小鼠移植后平均存活时间分别为（61. 45±27. 88）天、(18.58±12. 39)天和(26. 37±15. 65)天, 扩增后Treg细胞移植组小鼠平均存活时间较CD4+CD25-T细胞、空白对照组小鼠延长(P<0.05)。结论：allo-BMT后输注增殖的Treg细胞可以减轻移植后GVHD程度,延长小鼠生存时间。     

T lymphocytes of allophenic mice do not reject spleen colony-forming units of the parental genotypes

Self-tolerance in BALB/c<-->C57BL/6 and BALB/c<-->B10.SM (SM) allophenic mice is examined in this study. Chimerism was determined by coat mosaicism, using electrophoresis of allozyme variants at the glucose phosphate isomerase-1 (GPI-1) in peripheral blood erythrocytes and a cytotoxity test for lymph node (LN) lymphocytes and blood nucleated cells. An age-dependent increase in the percent content of BALB/c erythrocytes was observed in both types of chimeras. The immunological status of chimeras was assessed by T cell interactions with spleen colony-forming cells (SFU-S) able to form colonies in the recipient spleens. LN lymphocytes of the chimeras, together with bone marrow cells (BMC) of the parental genotype, were transplanted to lethally irradiated F1 hybrids. Chimera T lymphocytes did not inactivate CFU-S of the parental genotype and colonies formed in the spleens of F1 hybrids. The absence of splenic colonies in (C x B6)F1 hybrids, in which BMC from B6 had been transplanted (either in combination with chimera lymphocytes or alone), was due to the reaction of host natural killer (NK) cells. The results obtained testify to the permanent immunological tolerance of chimera T lymphocytes to BMC antigens of the both parental genotypes. The chimeric shift in the erythrocyte population is not coupled to disturbances in self-tolerance of chimeric mice.     

The failure of a major histocompatibility antigen to stimulate a thyroid allograft reaction after culture in oxygen

The lymphocytic infiltration found in multiple cultured BALB/c thyroids placed in the same C57BL/6 recipient was found to be highly correlated and the high variability between animals was not influenced by the number of lobes. It was concluded that the variable infiltration was largely due to host factors. Because a similar correlation was found between BALB/c and C3H grafts, the response to a minor antigen common to these two strains was suggested as a cause of the infiltration. When the response of C57BL/6 mice to cultured B6.C (H-2d) and BALB.B (H-2b) grafts was compared, a synergism between major and minor antigens was suggested. However, when the time of culture was increased from 48 to 60 h and the response of BALB/c and C57BL/6 mice were compared with identically cultured B6.C (H-2d) grafts, a striking difference between major and minor antigens was observed. None of 10 such grafts in C57BL/6 recipients (major antigens only) showed any infiltration, whereas 8 out of the 9 grafts in BALB/c recipients (minor antigens only) were infiltrated.     

非清髓造血干细胞移植后致敏供者淋巴细胞输注对嵌合状态及GVHD影响的实验研究

本研究目的是探讨经受者皮肤致敏后的异基因供者淋巴细胞输注(DLI)是否能在促进形成完全供者嵌合(CC)的同时减轻移植物抗宿主病(GVHD)。以C57BL/6小鼠(H-2b,B6)为受者,于第0天接受60Coγ线全身照射(TBI),总剂量为5.5Gy,照射当天移植经粒细胞集落刺激因子(G-CSF)动员后的BALB/c小鼠(H-2d,BA)外周血干细胞(2×107个),移植后第2天腹腔注射环磷酰胺200mg/kg,并分别于移植后第28天输注致敏/未致敏的供者淋巴细胞2×106。结果显示,致敏后DLI的受鼠(黑色)无1例出现GVHD,60天时转变为完全供者嵌合,表型明显呈现为供鼠(白色)特征,CD4+/CD8+T淋巴细胞比值在DLI后早期下降,半月后有所升高,但仍低于正常水平;未致敏的DLI受鼠出现不同程度的GVHD,嵌合率稍有上升,仍表现为混合嵌合体(MC),CD4+/CD8+比值在DLI后早期升高,后期降至正常水平。结论:经受者皮肤致敏后的DLI在诱导CC的同时降低GVHD发病率,CD4+/CD8+比值与GVHD发病率间具有良好的相关性。     

Targeting cannabinoid receptors as a novel approach in the treatment of graft-versus-host disease: evidence from an experimental murine model

Allogeneic hematopoietic cell transplantation (HCT) is widely used to treat patients with life-threatening malignant and nonmalignant hematological diseases. However, allogeneic HCT often is accompanied by severe and lethal complications from graft-versus-host disease (GVHD), in which activated donor T cells recognize histocompatibility antigenic mismatches and cause significant toxicity in the recipient. In the current study, we tested the hypothesis that activation of cannabinoid receptors on donor-derived T cells may prevent GVHD. We tested the effect of Δ(9)-tetrahydrocannabinol (THC) in an acute model of GVHD that was induced by transferring parental C57BL/6 (B6) spleen cells into (C57BL/6 × DBA/2) F(1)(BDF1) mice. Transfer of B6 cells into BDF1 mice produced severe acute GVHD in the recipient, characterized by lymphoid hyperplasia, weight loss, T helper l cytokine production and mortality. THC administration led to early recovery from body weight loss, reduced tissue injury in the liver and intestine, as well as complete survival. THC treatment reduced the expansion of donor-derived effector T cells and blocked the killing of host-derived immune cells while promoting Foxp3(+) regulatory T cells. Impaired hematopoiesis seen during GVHD was rescued by treatment with THC. The ability of THC to reduce the clinical GVHD was reversed, at least in part, by administration of cannabinoid receptor (CB) 1 and CB2 antagonists, thereby demonstrating that THC-mediated amelioration of GVHD was cannabinoid receptor-dependent. Our results demonstrate for the first time that targeting cannabinoid receptors may constitute a novel treatment modality against acute GVHD.     

T cell and non-T cell compartments can independently determine resistance to Leishmania major

In experimental murine cutaneous leishmaniasis caused by Leishmania major (Lm), the cellular determinants governing development of protective or exacerbative T cells are not well understood. We, therefore, attempted to determine the influence of T cell and non-T cell compartments on disease outcome. To this end, T cell chimeric mice were constructed using adult thymectomized lethally irradiated, bone marrow-reconstituted (ATXBM) animals of genetically resistant, C57BL/6, or susceptible, BALB/c, backgrounds. These hosts were engrafted with naive T cell populations from H-2-congenic susceptible, BALB.B6-H-2b, or resistant, C57BL/6.C-H-2d, animals, respectively. Chimeric mice were then infected with Lm, and disease outcome was monitored. BALB/c T cell chimeric mice, BALB/c ATXBM hosts given naive C57BL/6.C-H-2d T cells, resolved their infections as indicated by reductions in both lesion size and parasite numbers. Furthermore, the mice developed typical Th1 (interferon[IFN]-gamma hiinterleukin[IL]-4lo) cytokine patterns. In contrast, both sham chimeric, BALB/c ATXBM hosts given naive BALB/c T cells, and control irradiated euthymic mice succumbed to infection, producing Th2 profiles (IFN-gamma loIL-4hiIL-10hi). C57BL/6 T cell chimeras, C57BL/6 ATXBM hosts given naive BALB.B6-H-2b T cells, resolved their infections as did C57BL/6 sham chimeras and euthymic controls. Interestingly, whereas C57BL/6 control animals produced Th1 cytokines, chimeric animals progressed from Th0 (IFN-gamma hiIL-4hiIL- 10hi) to Th2 (IFN-gamma loIL-4hiIL-10hi) cytokine profiles as cure ensued. Both reconstitution and chimeric status of all mice were confirmed by flow cytometry. In addition, T cell receptor V beta usage of Lm-specific blasts was determined. In all cases, V beta use was multiclonal, involving primarily V beta 2, 4, 6, 8.1, 8.2, 8.3, 10, and 14, with relative V beta frequencies differing between H-2b and H-2d animals. Most importantly, however, these differences did not segregate between cure and noncure outcomes. These findings indicate that: (a) genetic traits determining cure in Lm infection can direct disease outcome from both T cell and non-T cell compartments; (b) the presence of the curing genotype in only one compartment is sufficient to confer cure; (c) curing genotype T cells autonomously assume a Th1 cytokine profile-mediating cure; (d) noncuring genotype T cells can mediate cure in a curing environment, despite the onset of Th2 cytokine production; and lastly, (e) antigen specificity of responding T cells, as assessed by V beta T cell receptor diversity, is not a critical determinant of disease outcome.     

Bone marrow NK1.1(-) and NK1.1(+) T cells reciprocally regulate acute graft versus host disease

Sorted CD4(+) and CD8(+) T cells from the peripheral blood or bone marrow of donor C57BL/6 (H-2(b)) mice were tested for their capacity to induce graft-versus-host disease (GVHD) by injecting the cells, along with stringently T cell-depleted donor marrow cells, into lethally irradiated BALB/c (H-2(d)) host mice. The peripheral blood T cells were at least 30 times more potent than the marrow T cells in inducing lethal GVHD. As NK1.1(+) T cells represented <1% of all T cells in the blood and approximately 30% of T cells in the marrow, the capacity of sorted marrow NK1.1(-) CD4(+) and CD8(+) T cells to induce GVHD was tested. The latter cells had markedly increased potency, and adding back marrow NK1.1(+) T cells suppressed GVHD. The marrow NK1.1(+) T cells secreted high levels of both interferon gamma (IFN-gamma) and interleukin 4 (IL-4), and the NK1.1(-) T cells secreted high levels of IFN-gamma with little IL-4. Marrow NK1.1(+) T cells obtained from IL-4(-/-) rather than wild-type C57BL/6 donors not only failed to prevent GVHD but actually increased its severity. Together, these results demonstrate that GVHD is reciprocally regulated by the NK1.1(-) and NK1.1(+) T cell subsets via their differential production of cytokines.     

在小鼠骨髓移植中CCRS与急性移植物抗宿主病的相关性研究

本研究评价供者CCR5在经过强化预处理的骨髓移植动物模型受者体内的作用，为今后的异基因造血干细胞移植的临床应用提供科学依据。经过致死剂量照射的BALB／c小鼠接受异基因C57BL／6小鼠的骨髓移植。根据回输的细胞不同实验分为4组：B6CCR5KO组，受者接受C57BL／6CCR5^-/-小鼠骨髓和脾脏细胞；B6WT组，受者接受野生型C57BL／6小鼠骨髓和脾脏细胞；B6CCR5KOBMC组，受者只接受C57BL／6CCR5^-/-小鼠骨髓细胞；B6、WT BMC组，受者只接受野生型C57BL／6小鼠骨髓细胞。结果表明：较之B6、WT组，B6CCR5KO组小鼠以更快的速度死于急性GVHD；其受者体内的CD8^＋T细胞更大量的增殖；其T细胞恢复后产生更多的INF-γ和TNF-α并且由于其T细胞有丝分裂原刀豆素水平处于较高水平，从而进一步促进T细胞的增殖，提示CCR5的作用之一是下调参与排异反应的供者CD8^＋T细胞的增殖。组织学评价提示，移植剔除CCR5基因受者细胞的小鼠肾脏出现了病理损伤并且肝脏存在有更为严重的病理变化。结论：剔除CCR5基因的异基因骨髓移植使GVHD发病率的增加，供者CD8^＋T细胞在受者体内增殖增加以及肝肾损害加重，这提示CCR5在异基因骨髓移植中起着重要作用。     

Donor-derived interferon gamma is required for inhibition of acute graft-versus-host disease by interleukin 12.

We have demonstrated that a single injection of interleukin (IL)-12 on the day of bone marrow transplantation (BMT) inhibits acute graft-versus-host disease (GVHD) in mice. This effect of IL-12 can be diminished by anti-interferon (IFN)-gamma mAb. To determine the mechanism by which IFN-gamma affects IL-12-mediated GVHD protection, we have compared the effect of IL-12 on GVHD in C57BL/6 wild-type (WT) or IFN-gamma gene knockout (GKO) recipients of fully major histocompatibility complex plus minor antigen-mismatched allogeneic BMT from WT or GKO BALB/c mice. Lethal acute GVHD was readily induced in the absence of IFN-gamma. IL-12 inhibited GVHD mortality to a similar extent in WT and GKO recipients of WT allogeneic BMT. However, neither WT nor GKO recipients were protected by IL-12 from GVHD induced by GKO allogeneic BMT. Moreover, the effective inhibition of host-reactive donor T cell activation and expansion that is associated with IL-12-mediated GVHD protection was dependent on the ability of BALB/c donors to produce IFN-gamma. These results demonstrate that (a) acute GVHD can be induced in the absence of IFN-gamma, (b) host IFN-gamma does not play a critical role in IL-12-induced GVHD protection, and (c) the protective effect of IL-12 against GVHD is dependent on the ability of the donor to produce IFN-gamma.     

Humoral and cell-mediated immune responses in fully allogeneic bone marrow chimera in mice

AKR mice were protected from lethal irradiation and established as long-lived chimeras by transplanting allogeneic C57BL/6 (B6) bone marrow that had been treated in vitro with anti-Thy-1 antiserum without complement. In these chimeras, which were designated [B6 {arrow} AKR], virtually all the thymus and spleen cells were shown to be derived from the B6 donor; several immune functions studied in these chimeras were as follows: (a) The chimeric mice were tolerant of histocompatibility antigens of both donor and recipient strain and nearly fully reactive to antigens of third party, as revealed by Simonsen's splenomegaly assay. The tolerance of these chimeras could not be attributed to suppressor cells but was compatible with clonal depletion. (b) Proliferative responses to concanavalin A, phytohemagglutinin, and lipopolysaccharide as well as natural killer and antibody-dependent cell- mediated cytotoxicity activity of the chimeric mice was normal. (c) Plaque- forming cell (PFC) assays of antibody responses to sheep erythrocytes (SRBC) showed gross deficiency in the primary response of the [B6 {arrow} AKR] and [AKR {arrow} B6] chimeras. By contrast, [B6-H-2(k)(E(k)) {arrow} AKR] H-2-compatible chimeras and [AKR {arrow} AKR] syngeneic marrow transplanted mice had normal primary PFC responses. PFC responses after secondary stimulation with SRBC, however, revealed vigorous direct plaque formation and substantial but somewhat smaller indirect plaque formation in the [B6 {arrow} AKR] chimeras. This observation favors operationally the concept of adaptive differentiation proposed by Katz et al. (44). (d) Analysis of ability of the chimeras to develop and express delayed-type hypersensitivity responses to contact sensitizer (2,4-dinitro-l-fluorobenzene [DNFB]) showed no apparent immunodeficiency of either chimeras to this form of immunization. Development of immunologic tolerance to DNFB, however, was grossly deficient in [B6 {arrow} AKR] chimeras but normal in [AKR {arrow} AKR], [B6 {arrow} B6], and [E(k) {arrow} AKR] chimeras. These findings indicate that full chimeras across major histocompatibility complex have considerable immunologic vigor even though primary immune responses that require histocompatibility between interacting cell types are initially defective.     

非清髓同种异基因小鼠外周血造血干细胞移植模型的建立及其相关研究

目的探讨不同方式异基因外周造血干细胞移植(allo-PBHSCT)后联合供者淋巴细胞输注(DLI)对嵌合率及移植物抗宿主病(GVHD)发病率的影响。方法 C57BL/6受鼠(H-2b)接受全身照射(TBI)预处理后,4 h内分别经尾静脉(IV)或髓腔内(IBM)输注BALB/c小鼠(H-2d)经rhG-CSF动员后的外周造血干细胞3×107个,并予5×106个供鼠DLI,第2天腹腔注射200 mg/kg环磷酰胺。结果移植后第7天各组均为混合嵌合状态,IBM-PBCST-DLI组嵌合率明显高于其他各组;尾静脉移植组均出现不同程度GVHD症状,以IV-PBSCT-DLI组较为显著,而髓腔内移植组均无明显GVHD症状;IV-PBSCT-DLI组CD4+CD25+调节性T细胞(Treg)比例明显下降,髓腔内移植组则显著升高。结论经rhG-CSF动员后髓腔内注射可以成功建立非清髓性allo-PBHSCT小鼠移植模型,DLI进一步促进了供者嵌合;IBM明显降低了GVHD的发病率,其机制可能与T细胞亚群的改变有关。     

Cell surface antigens of chemically induced sarcomas of the mouse. I. Murine leukemia virus-related antigens and alloantigens on cultured fibroblasts and sarcoma cells: description of a unique antigen on BALB/c Meth A sarcoma.

As background for a serological definition of the unique antigens of chemically induced sarcomas, we have typed a series of fibroblast and sarcoma cell lines of BALB/c and C57BL/6 origin by cytoxicity and absorption tests for murine leukemia virus (MuLV)-related cell surface antigens and known alloantigens. 7 of the 17 cultured lines expressed the range of cell surface antigens associated with MuLV (GIX, GCSA, gp70, p30), and this was invariably associated with MuLV production. In nonproducer lines of C57BL/6 (but not BALB/c) origin, a MuLV-gp70-like molecule was found on the surface of fibroblasts and sarcoma cells. The alloantigenic phenotype of these MuLV+ and MuLV- cell lines was H-2D+, H-2K+, Thy-1.2+ or -, PC.1+ or -, Lyt-1.2-, Lyt-2.2-, Ia.7-, and TL.2-. A unique antigen was defined on the BALB/c ascites sarcoma Meth A with antisera prepared in BALB/c or (BALB/c X C57BL/6)F1 mice. Tissue culture lines derived from this tumor were MuLV-, which facilitated serological study of the antigen. Absorption analysis indicated that the antigen was restricted to Meth A; it could not be detected in normal or fetal BALB/c tissue MuLV+ or MuLV- fibroblast lines, 12 syngeneic or allogeneic sarcomas, or normal lymphoid cells from 13 different inbred mouse strains.     

Cross-priming for a secondary cytotoxic response to minor H antigens with H-2 congenic cells which do not cross-react in the cytotoxic assay

Cytotoxic effector T cells of F1 (BALB/c X BALB.B) (H-2d/b) mice immunized against the minor histocompatibility differences of C57BL/10 (H-2b) can lyse targets from C57BL/10, but cannot lyse B10.D2 (H-2d) targets. Despite this lack of cross-reaction in the cytotoxic assay, C57BL/10 cells do prime F1 (BALB/c X BALB.B) mice for a secondary cytotoxic response to B10.D2. C57BL/10-primed, B10.D2-boosted cytotoxic cells lyse B10.D2 targets but not C57BL/10 targets. DBA/2 (H-2d) spleen cells or thymocytes prime F1 mice for a secondary response to DBA/2, B10.D2, and C57BL/10 cells, but DBA/2 mastocytes, P815, do not prime for a response to C57BL/10. Whether H-2 congenic lymphoid cells express minor histocompatibility determinants which cross-react at the cytotoxic T-cell level or the helper T-cell level is discussed.