Syngeneic Lymphocytes Research Articles

HELICOBACTER PYLORI-DRIVEN CCR6-DEPENDENT ANTIGEN-SPECIFIC T CELL SUBSETS

Abstract Introduction. Helicobacter pylori can infect human gastric mucosa and cause various pathological conditions. In the blood of H. pylori-infected patients, the level of mature CD4+CCR6+ T-lymphocytes, especially pro-inflammatory CCR6+ T-helper types 1 and 17, significantly increases. Chemokine receptor CCR6 can direct cell migration from the blood into the inflamed gastric mucosa. In this work, we assessed the in vitro response of circulating CD4+CCR6+ and CD4+CCR6− T cells against H. pylori antigens in infected and intact individuals. Materials and methods. Monocytes and lymphocytes were isolated from blood samples. Monocytes were incubated with or without H. pylori. Monocyte expression of CD14, CD80 and CD86 was assessed, and monocytes were also used to stimulate syngeneic lymphocytes. Antigen-specific lymphocyte response was assessed by proliferation and expression of the activation marker OX40 on CD4+CCR6+ and CD4+CCR6- T cells. Results. Preliminary experiments have shown that incubation of monocytes with H. pylori causes a modestly increased expression of the costimulatory molecules CD80 and CD86 on monocytes and a slightly higher level of monocyte potential to stimulate syngeneic lymphocyte proliferation. Evaluation of OX40 expression in an in vitro antigen presentation model showed that blood CD4+ T lymphocytes from infected patients contain detectable number becoming activated by H. pylori antigens. In patients with H. pylori infection, the CD4+CCR6+ vs. CD4+CCR6- lymphocyte subset contains a larger number of H. pylori antigen-specific cells. In donors from comparison group lacking H. pylori infection, the presentation of H. pylori antigens in blood cell cultures and no significant effect on average CD4+ T-lymphocyte activation rates. Conclusion. The blood samples from patients with H. pylori infection contains CD4+ T cells becoming specifically activated in the presence of H. pylori antigens. Blood CD4+CCR6+ vs. CD4+CCR6- T cells from patients with H. pylori infection contain a greater number of antigen-specific lymphocytes.

Central effects of peripherally administrated immune cells modulated by a psychoactive substance in aggression

IntroductionIt is known that the formation of aggressive behavior is accompanied by neurodegenerative and neuroinflammatory changes. Immune cells have a regulatory effect on the central nervous system functions, including regulation of behavior.ObjectivesWe first demonstrated that ex vivo chlorpromazine - modulated immune cells have a positive aggressive behavior editing effect. The aim of the study was to investigate the influence of the indicated cells on some central mechanisms underlying the development of aggressive reactions.Methods(CBAxC57Bl/6) F1 aggressive male mice, developed in conditions of chronic social stress, were undergoing the transplantation of syngeneic spleen lymphocytes with ex vivo chlorpromazine-modulated functional activity. In recipients the immunohistochemical analysis was performed assessing the expression of the microglial marker Iba1. The levels of brain-derived neurotrophic factor (Bdnf ) and cytokines was assessed by ELISA. For histological examination Nissl staining was applied.ResultsAggressive behavior editing after the chlorpromazine-modulated immune cells transplantation registered against the background of some structural and functional changes in the brain. It was found an increase in the density of pyramidal neurons in CA1 and CA3 hippocampal regions and augmented level of Bdnf. The decreased expression of microglial activation marker Iba1, accompanied with decreased levels of pro-inflammatory cytokines (IL-1β, IL-2, IL-6, INF-γ) and increased anti-inflammatory (IL-4) cytokine was found. Visualization of functionally active lymphocytes pre-treated with chlorpromazine in the brain parenchyma of aggressive recipients suggests a direct effect of injected lymphocytes on CNS.ConclusionsThe effect of chlorpromazine - modulated immune cells that edits aggressive behavior is realized by stimulating neurogenesis, neuroplasticity and reducing neuroinflammation.Disclosure of InterestNone Declared

Correlations between components of the immune system

Background No evidence of the possibility of altering a constituent of the immune system without directly affecting one of its associated components has yet been shown. Methods A schematic model was developed in which two triggers, fasting and splenectomy, were studied for their ability to affect the expression of cell membrane epitopes and the cytokine secretion of out-of-body autogeneic and syngeneic lymphocytes. Results The effect of fasting and/or splenectomy on promoting correlations between immune systems was studied by determining the alterations in expressions of cell membrane epitopes and in cytokine secretion by out-of-body autogeneic and syngeneic lymphocytes. The effect of fasting as a trigger decreased expression of CD8 and CD25 and increased TNFα levels. The effect of splenectomy as a trigger was investigated in non-fasting mice by comparing splenectomized and non-splenectomized mice. An increase in the CD8 expression and in TNFα, IFNg, and IL10 secretion was noted. The effect of splenectomy as a trigger in fasting mice was determined by comparing splenectomized and non-splenectomized mice. Splenectomy significantly affected the expression of CD25 and CD4 CD25 and on secretion of TNFα, IFNg, and IL10. To determine the effect of keeping the cells in an out-of-body location on the expression of lymphocyte epitopes, tubes kept on top of the cages of the fasting mice were compared with tubes kept on top of empty cages. The results showed a significant change in the CD8 expression was noted. To determine the effect of keeping cells in an out-of-body location on cytokine secretion, tubes kept on cages were tested for cytokine levels significant decrease was noted in the secretion of TNFα and IFNg. Conclusions The study showed that a mouse could affect cells at a distance and alter the expression of surface markers and cytokine secretion following two types of triggers: fasting and/or splenectomy. The data characterized a system for the induction of correlations between two’s immune system components without a transfer of mediators. It suggests that an out-of-body correlation can be induced between two components of the immune system.

Correlations between components of the immune system

Background: No evidence of the possibility to alter a constituent of the immune system without directly affecting one of its associated components has been shown yet. Methods: A schematic model was developed in which two triggers, fasting and splenectomy, were studied for their ability to affect the expression of cell membrane epitopes and the cytokine secretion of out-of-body autogeneic and syngeneic lymphocytes. Results: Fasting decreased expression of CD8 and CD25 and increased TNFα levels. The effect of splenectomy as a trigger was investigated in non-fasting mice by comparing splenectomized and non-splenectomized mice. An increase in the CD8 expression and in TNFα, IFNg, and IL10 secretion was noted. The effect of splenectomy as a trigger was investigated in fasting mice by comparing splenectomized and non-splenectomized mice. Splenectomy had a significant effect on expression of CD25 and CD4 CD25 and on secretion of TNFα, IFNg, and IL10. To determine the effect of keeping the cells in an out-of-body location on the expression of lymphocyte epitopes, tubes kept on top of the cages of the fasting mice were compared with tubes kept on top of empty cages. A significant change in the CD8 expression was noted. To determine the effect of keeping cells in an out-of-body location on cytokine secretion, tubes kept on top of cages were tested for cytokine levels. A significant decrease was noted for the secretion of TNFα and IFNg. Conclusions: The data obtained from this study characterized a system for induction of correlations between two components of the immune system without a transfer of mediators. The study showed that a mouse could affect cells at a distance and alter the expression of surface markers and cytokine secretion following two types of triggers: fasting and/or splenectomy. Thus, an out-of-body correlation can be induced between two components of the immune system.

Correlations between components of the immune system.

No evidence of the possibility of altering a constituent of the immune system without directly affecting one of its associated components has yet been shown. A schematic model was developed in which two triggers, fasting and splenectomy, were studied for their ability to affect the expression of cell membrane epitopes and the cytokine secretion of out-of-body autogeneic and syngeneic lymphocytes. The effect of fasting and/or splenectomy on promoting correlations between immune systems was studied by determining the alterations in expressions of cell membrane epitopes and in cytokine secretion by out-of-body autogeneic and syngeneic lymphocytes. The effect of fasting as a trigger decreased expression of CD8 and CD25 and increased TNFα levels. The effect of splenectomy as a trigger was investigated in non-fasting mice by comparing splenectomized and non-splenectomized mice. An increase in the CD8 expression and in TNFα, IFNg, and IL10 secretion was noted. The effect of splenectomy as a trigger in fasting mice was determined by comparing splenectomized and non-splenectomized mice. Splenectomy significantly affected the expression of CD25 and CD4 CD25 and on secretion of TNFα, IFNg, and IL10. To determine the effect of keeping the cells in an out-of-body location on the expression of lymphocyte epitopes, tubes kept on top of the cages of the fasting mice were compared with tubes kept on top of empty cages. The results showed a significant change in the CD8 expression was noted. To determine the effect of keeping cells in an out-of-body location on cytokine secretion, tubes kept on cages were tested for cytokine levels significant decrease was noted in the secretion of TNFα and IFNg. The study showed that a mouse could affect cells at a distance and alter the expression of surface markers and cytokine secretion following two types of triggers: fasting and/or splenectomy. The data characterized a system for the induction of correlations between two's immune system components without a transfer of mediators. It suggests that an out-of-body correlation can be induced between two components of the immune system.

Abstract 2978: Unique 3D organoids autologous TIL coculture platform enables high throughput immune-oncology drug response studies

Abstract Background: Cancer progression and response to therapy are governed by complex cellular interactions in the tumor microenvironment (TME). A better understanding of TME and the immune microenvironment requires robust experimental systems modeling patient specific immune interactions. Conventional 2D cultures lack in recapitulating 3D morphological structures and complex immune biology of native human tumors. A vastly heterogenous TME impacts patient treatment response. There is a dearth of 2D or 3D in vitro models that mimic in vivo diversity of TME, including infiltrating immune populations. 3D organoid cultures typically contain neoplastic epithelium and fail to retain syngeneic tumor-infiltrating lymphocytes (TILs) interactions vital for exhibiting a clinically significant drug response. Here we describe patient-derived xenograft (PDX) derived 3D organoid (PDXO) cultures with autologous TILs to avoid alloreactivity and simulate tumor specific immune response. The described model allows the evaluation of TIL infiltration and high throughput screening of immune-modulatory therapies. Methods: Patient-derived xenografts from mice were enzymatically digested to establish PDXO. PDXO were characterized for expression of cancer specific cell-surface markers. TILs were expanded in culture from PBMCs from matching patients and characterized using flow cytometry. Organoids and TILs from the same patient were fluorescently labeled and cocultured for four days, and tumor infiltration and drug cytotoxicity with and without immune-therapeutics was evaluated. CellInsight CX7 high content imaging platform was used to track TILs, and cancer cells, and TIL infiltration was confirmed via immunofluorescence. Luminex technology was used to quantify changes in the cytokine profile upon drug treatment. Results: PDXO were established to mimic in vivo tumor biology. Tumor-specific TILs were expanded and characterized for expression of memory, inhibitory, proliferation, and regulatory T cell markers. TIL infiltration in organoids was observed from day one in culture and maintained over four days. Immunofluorescence for T cell marker CD3 (cluster of differentiation 3) within PDXO confirmed TIL infiltration. Infiltrating TILs and tumor cell killing evaluation using fluorescent dyes via high throughput imaging platform showed disease and patient-specific response. PDXO treatment with immune-modulatory therapeutics led to changes in the secreted levels of cytokines IL2 (interleukin 2), IFNγ (interferon gamma), and TNFα (tumor necrotic factor alpha). Conclusion: Our patient autologous TILs - PDXO culture platform can be used for high throughput drug screening to model immune-therapeutic response with the tumor specific immune microenvironment. Citation Format: Garima Kaushik, Padma Kamineny, Amy Wesa. Unique 3D organoids autologous TIL coculture platform enables high throughput immune-oncology drug response studies [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 2978.

Long-term in vivo survival of receptor-modified syngeneic T cells in patients with human immunodeficiency virus infection

AbstractTo study human immunodeficiency virus (HIV)–specific cellular immunity in vivo, we transferred syngeneic lymphocytes after ex vivo expansion and transduction with a chimeric receptor gene (CD4/CD3-ζ) between identical twins discordant for HIV infection. Single and multiple infusions of 1010 genetically modified CD8+ T cells resulted in peak fractions in the circulation of approximately 104 to 105modified cells/106 mononuclear cells at 24 to 48 hours, followed by 2- to 3-log declines by 8 weeks. In an effort to provide longer high-level persistence of the transferred cells and possibly enhance anti-HIV activity, we administered a second series of infusions in which both CD4+ and CD8+ T cells were engineered to express the chimeric receptor and were costimulated ex vivo with beads coated with anti-CD3 and anti-CD28. Sustained fractions of approximately 103 to 104 modified cells/106 total CD4+ or CD8+cells persisted for at least 1 year. Assessment of in vivo trafficking of the transferred cells by lymphoid tissue biopsies revealed the presence of modified cells in proportions equivalent to or below those in the circulation. The cell infusions were well tolerated and were not associated with substantive immunologic or virologic changes. Thus, adoptive transfer of genetically modified HIV-antigen–specific T cells was safe. Sustained survival in the circulation was achieved when modified CD4+ and CD8+ T cells were infused together after ex vivo costimulation, indicating the important role played by antigen-specific CD4+ T cells in providing “help” to cytotoxic effectors.

Follicular Lymphoma Organoids for Investigating the Tumor Microenvironment

Background: Current in vitro lymphoma models, including three-dimensional organoids, generally contain exclusively neoplastic lymphocytes and require artificial reconstitution to recapitulate the tumor microenvironment (TME). The co-culture of syngeneic tumor-infiltrating lymphocytes (TILs) alongside endogenous primary malignant lymphocytes could be useful for modeling complex interactions in the TME, and for immunological maneuvers and therapies relying on TILs. However, such conditions for maintaining lymphomas in their syngeneic TME as a cohesive unit have remained elusive. Methods: We adapted an air-liquid interface (ALI) method that we previously described (Neal JT et al 2019 Cell) for propagating patient-derived organoids (PDOs) from primary human follicular lymphomas. Surgically excised lymphoma samples were tested for the ability to maintain lymphoma cell viability in vitro using a lymph node organoid technique. Lymph nodes containing lymphoma cells (and in one case, a PBMC sample including circulating lymphoma cells) were processed into a single cell suspension and frozen until use. Samples were thawed and prepared into immune organoids (see figure). We assessed cell composition by flow cytometry on day 7, and in a subset of samples, up to 21 days post-thaw. Results: A total of 6 patients were profiled for PDO formation, PDO composition and stability, and PDO longevity. 4 of 6 samples showed good cell viability at day 7 post-culture and in a subset of samples, up to 21 days post-culture. Cell composition was well-maintained over time, with presence of lymphoma cells (CD19+ CD10+ CD5-) easily detectable and maintenance of supporting cells of the lymph node such as T follicular helper cells (CD3+ CD4+ CXCR5+ PD-1+) and non-B, non-T cells. Supporting lymph node cells were not detected in the PBMC sample, suggesting the cell composition is related to the initial composition and not due to differentiation in vitro. Genotyping, gene expression phenotyping, and T-cell/B-cell receptor profiling data will be presented at the meeting, including accuracy of PDOs for preserving the original spectrum of these indices. Conclusions: Propagation of PDOs of primary lymphomas with endogenous immune stroma is feasible and maintains cohesive elements of the TME. This system should allow immunoncology investigations within the TME and to facilitate personalized immunotherapy testing. Fig 1: Human lymphoma organoid cultures as a model to study tumor microenvironments and immune responses in vitro. (A) Experimental schema for preparing lymphoma organoids from tumor explants. In an adapted workflow optimized for ex vivo culture of human tonsillar germinal centers (Wagar L et al, submitted), we subject cryopreserved FL samples to organoid culture. (B) An example of follicular lymphoma organoid reorganization in vitro after four days in culture. (C) Total cell viability in FL organoids for up to 21 days in culture. Six samples were tested. (D) Frequency of major cell types in FL samples after organoid culture. Although there is variation among donors' samples, an individual's cell composition is well maintained for at least 14 days in most organoids. Figure 1 Disclosures Khodadoust: Corvus Pharmaceuticals: Research Funding. Davis:Vir Biotechnology: Consultancy, Equity Ownership, Honoraria; PACT Bio: Consultancy, Equity Ownership, Honoraria; Adicet Inc: Consultancy, Equity Ownership, Honoraria; Chuga Pharmabody: Consultancy, Honoraria; Amgen: Consultancy, Research Funding; Atreca: Consultancy, Equity Ownership, Honoraria; Juno: Consultancy, Equity Ownership, Honoraria. Alizadeh:Pfizer: Research Funding; Chugai: Consultancy; Celgene: Consultancy; Gilead: Consultancy; Pharmacyclics: Consultancy; Janssen: Consultancy; Genentech: Consultancy; Roche: Consultancy.

TNF-α/IL-1β-licensed mesenchymal stromal cells promote corneal allograft survival via myeloid cell-mediated induction of Foxp3+ regulatory T cells in the lung.

Mesenchymal stromal cells (MSCs) have shown promise as a therapy for immune-mediated disorders, including transplant rejection. Our group previously demonstrated the efficacy of pretransplant, systemic administration of allogeneic but not syngeneic MSCs in a rat cornea transplant model. The aim of this study was to enhance the immunomodulatory capacity of syngeneic MSCs. In vitro, MSCs licensed with TNF-α/IL-1β (MSCsTNF-α/IL-1β) suppress syngeneic lymphocyte proliferation via NO production. In vivo, when administered post-transplantation, nonlicensed syngeneic MSCs improved graft survival from 0 to 50% and MSCsTNF-α/IL-1β, in an NO-dependent manner, improved survival to 70%. Improved survival was associated with increased CD4+CD25+forkhead box P3+ regulatory T (Treg) cells and decreased proinflammatory cytokine expression in the draining lymph node. MSCsTNF-α/IL-1β demonstrated a more potent immunomodulatory capacity compared with nonlicensed MSCs, promoting an immune-regulatory CD11b+B220+ monocyte/macrophage population and significantly expanding Treg cells in the lungs and spleen. Ex vivo, we observed that lung-derived myeloid cells act as intermediaries of MSC immunomodulatory function. MSC-conditioned myeloid cells suppressed stimulated lymphocyte proliferation and promoted expansion of Treg cells from naive lymphocytes. This work illustrates how syngeneic MSC therapy can be enhanced by licensing and optimization of timing strategies and further highlights the important role of myeloid cells in mediating MSC immunomodulatory capacity.-Murphy, N., Treacy, O., Lynch, K., Morcos, M., Lohan, P., Howard, L., Fahy, G., Griffin, M. D., Ryan, A. E., Ritter, T. TNF-α/IL-1β-licensed mesenchymal stromal cells promote corneal allograft survival via myeloid cell-mediated induction of Foxp3+ regulatory T cells in the lung.

Characterization of IL-17-producing T helper cells-like autoreactive T cells in aged mice.

IL-17-producing T helper cells (Th17) are attracting attention as a new CD4-positive subset of T cells, reported to be responsible for various autoimmune diseases through stimulation of the release of inflammatory cytokines from target cells. However, most investigations of Th17 mediation of autoimmune diseases have focused on the experimental autoimmune models derived from young animals, with few studies that have analyzed physiological factors such as aging. The present study analyzed autoreactive T cells established in a syngeneic mixed lymphocyte culture (sMLC) from aged mice and examined their similarity with Th17. IL-17-producing autoreactive CD4-intermediate T cells were observed in the sMLC; these expressed several stem cell markers or an immunosuppressive receptor PD-1 on the cell surface and so seemed to be different to typical Th17 cells. RT-PCR analysis revealed that purified Th17-like cells also expressed Il17a, Il17f, Il23r, Rorc and Tdt mRNA, but not Rag1 or Rag2 mRNA. These findings that it is likely that Th17-like cells are involved in autoimmune responses in aged mice.

Organoid Modeling of the Tumor Immune Microenvironment

Invitro cancer cultures, including three-dimensional organoids, typically contain exclusively neoplastic epithelium but require artificial reconstitution to recapitulate the tumor microenvironment (TME). The co-culture of primary tumor epithelia with endogenous, syngeneic tumor-infiltrating lymphocytes (TILs) as a cohesive unit has been particularly elusive. Here, an air-liquid interface (ALI) method propagated patient-derived organoids (PDOs) from >100 human biopsies or mouse tumors in syngeneic immunocompetent hosts as tumor epithelia with native embedded immune cells (T, B, NK, macrophages). Robust droplet-based, single-cell simultaneous determination of gene expression and immune repertoire indicated that PDO TILs accurately preserved the original tumor Tcell receptor (TCR) spectrum. Crucially, human and murine PDOs successfully modeled immune checkpoint blockade (ICB) with anti-PD-1- and/or anti-PD-L1 expanding and activating tumor antigen-specific TILs and eliciting tumor cytotoxicity. Organoid-based propagation of primary tumor epithelium en bloc with endogenous immune stroma should enable immuno-oncology investigations within the TME and facilitate personalized immunotherapy testing.

Syngeneic Syrian hamster tumors feature tumor-infiltrating lymphocytes allowing adoptive cell therapy enhanced by oncolytic adenovirus in a replication permissive setting

ABSTRACTAdoptive transfer of tumor-infiltrating lymphocytes (TIL) has shown promising yet sometimes suboptimal results in clinical trials for advanced cancer, underscoring the need for approaches improving efficacy and safety. Six implantable syngeneic tumor cell lines of the Syrian hamster were used to initiate TIL cultures. TIL generated from tumor fragments cultured in human interleukin-2 (IL-2) for 10 d were adoptively transferred into tumor-bearing hamsters with concomitant intratumoral injections of oncolytic adenovirus (Ad5-D24) for the assessment of antitumor efficacy. Pancreatic cancer (HapT1) and melanoma (RPMI 1846) TIL exhibited potent and tumor-specific cytotoxicity in effector-to-target (E/T) assays. MHC Class I blocking abrogated the cell killing of RPMI 1846 TIL, indicating cytotoxic CD8+ T-cell activity. When TIL were combined with Ad5-D24 in vitro, HapT1 tumor cell killing was significantly enhanced over single agents. In vivo, the intratumoral administration of HapT1 TIL and Ad5-D24 resulted in improved tumor growth control compared with either treatment alone. Additionally, splenocytes derived from animals treated with the combination of Ad5-D24 and TIL killed autologous tumor cells more efficiently than monotherapy-derived splenocytes, suggesting that systemic antitumor immunity was induced. For the first time, TIL of the Syrian hamster have been cultured, characterized and used therapeutically together with oncolytic adenovirus for enhancing the efficacy of TIL therapy. Our results support human translation of oncolytic adenovirus as an enabling technology for adoptive T-cell therapy of solid tumors.

Effects of Malignant Melanoma Initiating Cells on T-Cell Activation.

Although human malignant melanoma is a highly immunogenic cancer, both the endogenous antitumor immune response and melanoma immunotherapy often fail to control neoplastic progression. Accordingly, characterizing melanoma cell subsets capable of evading antitumor immunity could unravel optimized treatment strategies that might reduce morbidity and mortality from melanoma. By virtue of their preferential capacity to modulate antitumor immune responses and drive inexorable tumor growth and progression, malignant melanoma-initiating cells (MMICs) warrant closer investigation to further elucidate the cellular and molecular mechanisms underlying melanoma immune evasion and immunotherapy resistance. Here we describe methodologies that enable the characterization of immunoregulatory effects of purified MMICs versus melanoma bulk populations in coculture with syngeneic or allogeneic lymphocytes, using [3H]thymidine incorporation, enzyme-linked immunosorbent spot (ELISPOT), or ELISA assays. These assays were traditionally developed to analyze alloimmune processes and we successfully adapted them for the study of tumor-mediated immunomodulatory functions.

Preimmunization of donor lymphocytes enhances antitumor immunity of autologous hematopoietic stem cell transplantation

Lymphopenia-induced homeostatic proliferation (HP) of T cells following autologous hematopoietic stem cell transplantation (HSCT) skews the T-cell repertoire by engaging tumor-associated antigens (TAAs), leading to an induction of antitumor immunity. Here, as the tumor-reactive lymphocytes preferentially proliferate during the condition of HP, we examined whether the priming of a donor lymphocytes to TAAs could enhance HP-induced antitumor immunity in autologous HSCT recipients. First, to examine whether the tumor-bearing condition of donor influences the antitumor effect of HSCT, the lymphocytes isolated from CT26 tumor-bearing mice were infused into lethally irradiated mice. The growth of tumors was substantially suppressed in the mice that received HSCT from a tumor-bearing donor compared with a naïve donor, suggesting that a fraction of donor lymphocytes from tumor-bearing mice are primed in response to TAAs and remain responsive upon transplantation. We previously reported that type I interferon (IFN) maturates the dendritic cells and promotes the priming of T cells. We then investigated whether the further priming of donor cells by IFN-α can strengthen the antitumor effect of HSCT. The intratumoral IFN-α gene transfer significantly increased the number of IFN-γ-positive lymphocytes in response to CT26 cells but not the syngeneic lymphocytes in donor mice. The infusion of primed donor lymphocytes markedly suppressed the tumor growth in recipient mice, and cured 64% of the treated mice. Autologous HSCT with the infusion of primed donor lymphocytes is a promising strategy to induce an effective antitumor immunity for solid cancers.

In vitro-activated tumor-bearing host T cells and the effectiveness of tumor vaccine immunotherapy

BACKGROUND AND OBJECTIVEVaccination during periods of lymphopenia may facilitate immune responses to weak self-antigens and enhance antitumor immunity. The objective of this study was to determine the effectiveness of tumor vaccine immunotherapy combined with immune reconstruction using tumor-bearing host immune cells in lymphopenia, and to investigate the role of tumor-bearing host T cells activated in vitro during immunotherapy.DESIGN AND SETTINGAnimal study conducted in the First Affiliated Hospital of Xi’an Jiaotong University from January 2009 to January 2010.PATIENTS AND METHODSLymphopenia was induced by cyclophosphamide. A reconstituted immune system with different syngeneic lymphocytes was employed, including lymphocytes from naïve rats (unsensitized group), tumor-bearing rats (tumor-bearing group), and tumor-bearing rats activated in vitro (activated group). All rats were immunized with granulocyte-macrophage colony-stimulating factor (GM-CSF)-modified NuTu-19 ovarian cancer (GM-CSF/NuTu-19) cells. Tumor vaccine-draining lymph nodes (TVDLNs) were harvested, and then stimulated to induce effector T cells (TE). TE were then adoptively transferred to rats bearing a 3-day pre-established abdominal tumor (NuTu-19), and the survival rate was calculated.RESULTSCompared with the unsensitized group, the levels of interleukin-2 (IL-2) were significantly lower in the tumor-bearing group, whereas that of IL-4 were significantly higher (P<.05). The number of CD4+ T cells secreting interferon-γ and the specific cytotoxicity of CD8+ cytotoxic T lymphocytes were significantly lower (P<.05). The survival was significantly higher in the activated group compared with the other groups.CONCLUSIONSLymphocytes from tumor-bearing rats activated in vitro can effectively reverse the immunosuppressive effects of tumor-bearing hosts.

Rv0315, a novel immunostimulatory antigen of Mycobacterium tuberculosis, activates dendritic cells and drives Th1 immune responses

Tuberculosis (TB) caused by Mycobacterium tuberculosis (Mtb) is one of the most deadly infectious diseases, with approximately two million people dying of TB annually. An effective therapeutic method for activating dendritic cells (DCs) and driving Th1 immune responses would improve host defenses and further the development of a TB vaccine. Given the importance of DC maturation in eliciting protective immunity against TB, we investigated whether Rv0315, a newly identified Mtb antigen, can prompt DC maturation. We found that Rv0315 functionally activated DCs by augmenting the expression of the co-stimulatory molecules CD80 and CD86 as well as MHC class I/II molecules. Moreover, it increased DC secretion of the pro-inflammatory cytokines IL-6, IL-1β, and TNF-α. Unlike LPS, however, Rv0315 induced the secretion of IL-12p70, but not IL-10. In addition, Rv0315-treated DCs accelerated the proliferation of CD4(+) and CD8(+) splenic T cells from Mtb-infected mice, with increased levels of IFN-γ, in syngeneic and allogeneic mixed lymphocyte reactions, indicating that Rv0315 contributes to Th1 polarization of the immune response. Importantly, both mitogen-activated protein kinases and nuclear factor κB signaling mediated the expression of DC surface markers and cytokines. Taken together, our results indicate that Rv0315 is a novel DC maturation-inducing antigen that drives T cell immune responses toward Th1 polarization, suggesting that Rv0315 plays a key role in determining the nature of the immune response to TB.

Mycobacterium tuberculosislpdC, Rv0462, induces dendritic cell maturation and Th1 polarization

Mycobacterium tuberculosis, the etiological factor of pulmonary tuberculosis, causes significant morbidity and mortality worldwide. Activation of host immune responses for containment of mycobacterial infections involves participation of innate immune cells, such as dendritic cells (DCs). In this study, we demonstrated that the gene encoding lipoamide dehydrogenase C ( lpdC) from M. tuberculosis, Rv0462, induce maturation and activation of DCs involved in the MAPKs signaling pathway. Moreover, Rv0462-treated DCs activated naïve T cells, polarized CD4 + and CD8 + T cells to secrete IFN-γ in syngeneic mixed lymphocyte reactions, which would be expected to contribute to Th1 polarization of the immune response. Our results suggest that Rv0462 can contribute to the innate and adaptive immune responses during tuberculosis infection, and thus modulate the clinical course of tuberculosis.

培養尿細管上皮細胞を用いての間質性腎炎発症機序の解析―尿細管基底膜(TBM)抗原感作リンパ球によるICAM-1の誘導

Cultured PTC clearly expressed intercellular adhesion molecule-1 (ICAM-1) under the influence of tubular basement membrane antigen (TBM)-primed lymphocytes. These TBM-primed lymphocytes also demonstrated a high cytotoxic activity against cultured PTC. A pure preparation of isolated PTC from BALB/c mouse kidney was brought into primary culture. PTC was prepared by the method of Boogaard PJ et al, and our modification. Briefly, kidney was perfused with buffer containing 0.08% (w/v) collagenase. The cortical tissue was then filtered through nylon-gauze. Viable PTC were separated from other materials by isopycnic centrifugation on a discontinuous Nycodenz gradient. The confluent monolayer of PTC showed a typical epithelial morphology with cobblestone-like cells in the center of the cell-islands. Typical dome formation was observed in PTC cultures. These cells also strongly expressed gamma-glutamyl transpeptitase activity. Coculture of PTC with syngeneic lymphocytes primed with TBM antigen induced ICAM-1 expression in PTC. The TBM-primed lymphocytes had a cytotoxic activity without complement. However, neither virgin lymphocytes nor liver antigen-primed lymphocytes had cytotoxic activity. This simple syngeneic experimental model may allow us further molecular biological examination of renal tubulointerstitial diseases.

Eliciting protective immune responses against murine myeloma challenge in lymphopenia mice through adoptive transfer of tumor antigen-specific lymphocytes and immunization of tumor vaccine secreting mIL-21

Previous studies have indicated that the cytokine interleukin (IL)-21 may induce both innate and adaptive immune responses against tumors. The goal of this study was to evaluate a new adoptive immunotherapy strategy that combined lymphocytes from mice immunized with a murine myeloma vaccine secreting murine IL-21 (mIL-21-Sp2/0) in lymphopenic mice induced by cyclophosphamide. The data indicate that effective antitumor immunity was induced in mice receiving syngeneic murine lymphocytes from the mice immunized with the mIL-21-Sp2/0. More importantly, the efficacy against the Sp2/0 cell challenge was enhanced after the lymphocytes were activated and proliferated ex vivo before administration into the lymphopenic mice. We conclude that the adoptive transfer of tumor antigen-specific lymphocytes into mice immunized with mIL-21-Sp2/0 induced protective immune responses against myeloma challenge.

Induction of HIV-1-specific cellular and humoral immune responses following immunization with HIV-DNA adjuvanted with activated apoptotic lymphocytes

Delivery of DNA encoding foreign antigens into mammalian cells can induce adaptive immune responses. There are currently many DNA-based vaccines in clinical trials against infectious diseases and cancer but there is a lack of adjuvants for improvement of responses to DNA-based vaccines. Here, we show augmented systemic and mucosa-associated B cell responses after immunization with a cocktail of seven different plasmids (3 env, 2 gag, 1 rev, 1 RT) combined with mitogen activated apoptotic syngeneic lymphocytes in mice. In addition we show that apoptotic cells can function as adjuvant for induction of cellular immune responses in a magnitude comparable to the cytokine adjuvant GM-CSF in mice. These data suggest that activated apoptotic lymphocytes can act independent as adjuvants to improve antigen-specific DNA vaccines.