scholarly journals Impaired Control of Brucella melitensisInfection in Rag1-Deficient Mice

2000 ◽  
Vol 68 (9) ◽  
pp. 5314-5320 ◽  
Author(s):  
Mina J. Izadjoo ◽  
Yury Polotsky ◽  
Mark G. Mense ◽  
Apurba K. Bhattacharjee ◽  
Chrysanthi M. Paranavitana ◽  
...  
Keyword(s):  
T Cells ◽  
Intranasal Administration ◽  
Brucella Melitensis ◽  
Mononuclear Phagocyte ◽  
Cell Mediated Immunity ◽  
Murine Spleen ◽  
Rag 1 ◽  
Bacterial Replication ◽  
High Level ◽  
Number Of Bacteria

ABSTRACT After intranasal inoculation, Brucella melitensischronically infects the mononuclear phagocyte system in BALB/c mice, but it causes no apparent illness. Adaptive immunity, which can be transferred by either T cells or antibody from immune to naive animals, confers resistance to challenge infection. The role of innate, non-B-, non-T-cell-mediated immunity in control of murine brucellosis, however, is unknown. In the present study, we documented that BALB/c and C57BL/6 mice had a similar course of infection after intranasal administration of 16M, validating the usefulness of the model in the latter mouse strain. We then compared the course of infection in Rag1knockout mice (C57BL/6 background) (referred to here as RAG-1 mice) which have no B or T cells as a consequence of deletion ofRag1 (recombination-activating gene 1), with infection in normal C57BL/6 animals after intranasal administration of B. melitensis 16M. C57BL/6 mice cleared brucellae from their lungs by 8 to 12 weeks and controlled infection in the liver and spleen at a low level. In contrast, RAG-1 mice failed to reduce the number of bacteria in any of these organs. From 1 to 4 weeks after inoculation, the number of splenic bacteria increased from 2 to 4.5 logs and remained at that level. In contrast to the consistently high numbers of brucellae observed in the spleens, the number of bacteria rose in the livers sampled for up to 20 weeks. Immunohistologic examination at 8 weeks after infection disclosed foci of persistent pneumonia and large amounts of Brucella antigen in macrophages in lung, liver, and spleen in RAG-1, but not C57BL/6, mice. These studies indicate that T- and B-cell-independent immunity can control Brucellainfection at a high level in the murine spleen, but not in the liver. Immunity mediated by T and/or B cells is required for clearance of bacteria from spleen and lung and for control of bacterial replication in the liver.

scholarly journals Development of cell mediated immunity to flagellar antigens and acquired resistance to infection by Trypanosoma cruzi in mice

1981 ◽  
Vol 76 (4) ◽  
pp. 367-381 ◽  
Author(s):  
S. C. Gonçalves da Costa ◽  
P. H. Lagrande
Keyword(s):  
T Cells ◽  
Acquired Resistance ◽  
Vero Cells ◽  
Mononuclear Phagocyte ◽  
Cell Mediated Immunity ◽  
Specific Antigens ◽  
Maximum Protection ◽  
Resistance To Infection ◽  
Early Phases

Modulation by BCG and/or cyclophosphamide of sensitization of mice with flagellar fraction (a tubulin-enriched fraction) prevented death of mice challenged with T. cruzi CL strain trypomastigotes recovered from Vero cells. A methodology was ceveloped to assay specific antigens and to determine optimal doses for sensitization and elicitation of DTH in mice. CL strain is predominantly myotropic strain which does not produce important parasitism of mononuclear phagocyte cells; these cells appear to control infection when activated in vivo. Maximum protection was seen in this study when BCG and cyclophosphamide were associated, but protection was observed also when cyclophosphamide, that prevents supressor T cells, was applied 2 days before flagellar fraction sensitization in normal mice. These experiments suggested that the macrophage may have an important role in the early phases of infection particularly when nonspecific stimulation is associated with specific sensitization. A correlation betwen delayed hypersensitivity to parasite antigens and protection was observed.

HCA587 protein vaccine induces specific antitumor immunity mediated by CD4+ T-cells expressing granzyme B in a mouse model of melanoma

2020 ◽  
Vol 20 ◽  
Author(s):  
Weiming Yang ◽  
Weiheng Zhang ◽  
Xiaozhong Wang ◽  
Liming Tan ◽  
Hua Li ◽  
...  
Keyword(s):  
T Cells ◽  
Cd4 T Cells ◽  
Antitumor Effect ◽  
Granzyme B ◽  
Cell Subset ◽  
Cell Mediated Immunity ◽  
Protein Vaccine ◽  
Tumor Tissues ◽  
Wide Range ◽  
Ifn Γ

Background: The antigen HCA587 (also known as MAGE-C2), which is considered a cancer-testis antigen, exhibits upregulated expression in a wide range of malignant tumors with unique immunological properties, and may thus serve as a promising target for tumor immunotherapy. Objective: To explore the antitumor effect of the HCA587 protein vaccine and the response of humoral and cell-mediated immunity. Methods: The HCA587 protein vaccine was formulated with adjuvants CpG and and ISCOM. B16 melanoma cells were subcutaneously inoculated to C57BL/6 mice, followed by treatment with HCA587 protein vaccine subcutaneously. Mouse survival was monitored daily, and tumor volume was measured every 2 to 3 days. The tumor sizes, survival time and immune cells in tumor tissues were detected. And the vital immune cell subset and effector molecules were explored. Results: After treatment with HCA587 protein vaccine, the vaccination generated elicited significant immune responses, which delayed tumor growth and improved animal survival. The vaccination increased the proportion of CD4+ T cells expressing IFN-γ and granzyme B in tumor tissues. Depletion of CD4+T cells resulted in an almost complete abrogation of the antitumor effect of the vaccination, suggesting that the antitumor efficacy was mediated by CD4+ T cells. In addition, knockout of IFN-γ resulted in a decrease in granzyme B levels which were secreted by CD4+ T cells, and the antitumor effect was also significantly attenuated. Conclusion: The HCA587 protein vaccine may increase the levels of granzyme B expressed by CD4+ T cells, and this increase is dependent on IFN-γ, and the vaccine resulted in a specific tumor immune response and subsequent eradication of the tumor.

scholarly journals CCL19 enhances CD8+ T-cell responses and accelerates HBV clearance

2021 ◽  
Author(s):  
Yan Yan ◽  
Wei Zhao ◽  
Wei Liu ◽  
Yan Li ◽  
Xu Wang ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Activation ◽  
Crucial Role ◽  
Cell Activation ◽  
Hbv Infection ◽  
Host Immune System ◽  
Tnf Α ◽  
Ifn Γ ◽  
High Level

Abstract Background Chemokine (C–C motif) ligand 19 (CCL19) is a leukocyte chemoattractant that plays a crucial role in cell trafficking and leukocyte activation. Dysfunctional CD8+ T cells play a crucial role in persistent HBV infection. However, whether HBV can be cleared by CCL19-activated immunity remains unclear. Methods We assessed the effects of CCL19 on the activation of PBMCs in patients with HBV infection. We also examined how CCL19 influences HBV clearance and modulates HBV-responsive T cells in a mouse model of chronic hepatitis B (CHB). In addition, C–C chemokine-receptor type 7 (CCR7) knockdown mice were used to elucidate the underlying mechanism of CCL19/CCR7 axis-induced immune activation. Results From in vitro experiments, we found that CCL19 enhanced the frequencies of Ag-responsive IFN-γ+ CD8+ T cells from patients by approximately twofold, while CCR7 knockdown (LV-shCCR7) and LY294002 partially suppressed IFN-γ secretion. In mice, CCL19 overexpression led to rapid clearance of intrahepatic HBV likely through increased intrahepatic CD8+ T-cell proportion, decreased frequency of PD-1+ CD8+ T cells in blood and compromised suppression of hepatic APCs, with lymphocytes producing a significantly high level of Ag-responsive TNF-α and IFN-γ from CD8+ T cells. In both CCL19 over expressing and CCR7 knockdown (AAV-shCCR7) CHB mice, the frequency of CD8+ T-cell activation-induced cell death (AICD) increased, and a high level of Ag-responsive TNF-α and low levels of CD8+ regulatory T (Treg) cells were observed. Conclusions Findings in this study provide insights into how CCL19/CCR7 axis modulates the host immune system, which may promote the development of immunotherapeutic strategies for HBV treatment by overcoming T-cell tolerance.

scholarly journals IL-22-dependent dysbiosis and mononuclear phagocyte depletion contribute to steroid-resistant gut graft-versus-host disease in mice

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Qingxiao Song ◽  
Xiaoning Wang ◽  
Xiwei Wu ◽  
Tae Hyuk Kang ◽  
Hanjun Qin ◽  
...  
Keyword(s):  
T Cells ◽  
Graft Versus Host Disease ◽  
Mononuclear Phagocyte ◽  
Mononuclear Phagocytes ◽  
Dependent Manner ◽  
Steroid Resistant ◽  
Host Disease ◽  
Graft Versus Host ◽  
Potential Efficacy ◽  
Ifn Γ

AbstractEfforts to improve the prognosis of steroid-resistant gut acute graft-versus-host-disease (SR-Gut-aGVHD) have suffered from poor understanding of its pathogenesis. Here we show that the pathogenesis of SR-Gut-aGVHD is associated with reduction of IFN-γ+ Th/Tc1 cells and preferential expansion of IL-17−IL-22+ Th/Tc22 cells. The IL-22 from Th/Tc22 cells causes dysbiosis in a Reg3γ-dependent manner. Transplantation of IFN-γ-deficient donor CD8+ T cells in the absence of CD4+ T cells produces a phenocopy of SR-Gut-aGVHD. IFN-γ deficiency in donor CD8+ T cells also leads to a PD-1-dependent depletion of intestinal protective CX3CR1hi mononuclear phagocytes (MNP), which also augments expansion of Tc22 cells. Supporting the dual regulation, simultaneous dysbiosis induction and depletion of CX3CR1hi MNP results in full-blown Gut-aGVHD. Our results thus provide insights into SR-Gut-aGVHD pathogenesis and suggest the potential efficacy of IL-22 antagonists and IFN-γ agonists in SR-Gut-aGVHD therapy.

scholarly journals Quantitative analysis of the CD8 + T–cell response to readily eliminated and persistent viruses

2000 ◽  
Vol 355 (1400) ◽  
pp. 1093-1101 ◽  
Author(s):  
P. C. Doherty ◽  
J. M. Riberdy ◽  
G. T. Belz
Keyword(s):  
T Cells ◽  
T Cell ◽  
Influenza A ◽  
Flow Cytometric Analysis ◽  
T Cell Response ◽  
Basic Question ◽  
Cell Mediated Immunity ◽  
Specific Response ◽  
Turnover Rates

The recent development of techniques for the direct staining of peptide–specific CD8 + T cells has revolutionized the analysis of cell–mediated immunity (CMI) in virus infections. This approach has been used to quantify the acute and long–term consequences of infecting laboratory mice with the readily eliminated influenza A viruses (fluA) and a persistent γherpesvirus (γHV). It is now, for the first time, possible to work with real numbers in the analysis of CD8 + T CMI, and to define various characteristics of the responding lymphocytes both by direct flow cytometric analysis and by sorting for further in vitro manipulation. Relatively little has yet been done from the latter aspect, though we are rapidly accumulating a mass of numerical data. The acute, antigen–driven phases of the fluA and γHV–specific response look rather similar, but CD8 + T–cell numbers are maintained in the long term at a higher ‘set point’ in the persistent infection. Similarly, these ‘memory’ T cells continue to divide at a much greater rate in the γHV–infected mice. New insights have also been generated on the nature of the recall response following secondary challenge in both experimental systems, and the extent of protection conferred by large numbers of virus–specific CD8 + T cells has been determined. However, there are still many parameters that have received little attention, partly because they are difficult to measure. These include the rate of antigen–specific CD8 + T–cell loss, the extent of the lymphocyte ‘diaspora’ to other tissues, and the diversity of functional characteristics, turnover rates, clonal life spans and recirculation profiles. The basic question for immunologists remains how we reconcile the extraordinary plasticity of the immune system with the mechanisms that maintain a stable milieu interieur. This new capacity to quantify CD8 + T–cell responses in readily manipulated mouse models has obvious potential for illuminating homeostatic control, particularly if the experimental approaches to the problem are designed in the context of appropriate predictive models.

scholarly journals Immunologically mediated regression of a murine lymphoma after treatment with anti-L3T4 antibody. A consequence of removing L3T4+ suppressor T cells from a host generating predominantly Lyt-2+ T cell-mediated immunity.

1988 ◽  
Vol 168 (6) ◽  
pp. 2193-2206 ◽  
Author(s):  
M Awwad ◽  
R J North
Keyword(s):  
T Cells ◽  
T Cell ◽  
Tumor Regression ◽  
Cell Mediated Immunity ◽  
Complete Regression ◽  
Suppressor T Cells ◽  
Antibody Treatment ◽  
P815 Mastocytoma ◽  
Thymectomized Mice

This study shows that intravenous injection of 1 mg of anti-L3T4 mAb (GK1.5) into thymectomized mice bearing the syngeneic L5178Y lymphoma results, after a delay of 2-3 d, in complete regression of this tumor and in long-term host survival. A flow cytofluorometric examination of the spleen cells of mAb-treated mice revealed that antibody treatment resulted in the elimination of greater than 98% of L3T4+ T cells, but had no effect on the Lyt-2+ T cells subset. Tumor regression was immunologically mediated, because L5178Y lymphoma cells were shown to be L3T4-, and regression of the tumor failed to occur in mice that had been lethally irradiated before anti-L3T4 mAb was given. Tumor regression was mediated by tumor-sensitized Lyt2+ T cells, as evidenced by the finding that treatment of tumor-bearing mice with anti-Lyt-2 mAb alone, or in combination with anti-L3T4 mAb, resulted in enhancement of tumor growth and a significant decrease in host survival time. Moreover, the spleens of mice whose tumors were undergoing regression in response to anti-L3T4 mAb treatment contained Lyt-2+ T cells capable, on passive transfer, of causing regression of a tumor in recipient mice. These results can be interpreted as showing that removal of tumor-induced L3T4+ suppressor T cells results in the release of Lyt-2+ effector T cells from suppression, and consequently in the generation of enough Lyt-2+ T cell-mediated immunity to cause tumor regression. This can only be achieved, however, if immunity to the tumor is mediated exclusively by Lyt-2+ T cells, as is the case for the L5178Y lymphoma. In the case of the P815 mastocytoma, treatment with anti-L3T4 mAb was without a therapeutic effect, and this was in keeping with the finding that immunity to this tumor is mediated by L3T4+, as well by Lyt-2+ T cells.

Splenocyte transfer from hypertensive donors eliminates premenopausal female protection from Ang II-induced hypertension

2022 ◽  
Author(s):  
Megan A Sylvester ◽  
Dennis P Pollow ◽  
Caitlin Moffett ◽  
Wendy Nunez ◽  
Jennifer L Uhrlaub ◽  
...  
Keyword(s):  
Blood Pressure ◽  
T Cells ◽  
Adoptive Transfer ◽  
T Regulatory Cells ◽  
Estrogen Signaling ◽  
Ang Ii ◽  
Regulatory Cells ◽  
Adaptive Immune Cells ◽  
Induced Hypertension ◽  
Rag 1

Premenopausal females are protected from Angiotensin II (Ang II)-induced hypertension following the adoptive transfer of T cells from normotensive donors. For the present study, we hypothesized that the transfer of hypertensive T cells (HT) or splenocytes (HS) from hypertensive donors would eliminate premenopausal protection from hypertension. Premenopausal Rag-1-/- females received either normotensive (NT) or hypertensive cells, three weeks prior to Ang II infusion (14 days, 490 ng/kg/min). Contrary to our hypothesis, no increase in Ang II-induced blood pressure was observed in the NT/Ang or HT/Ang groups. Flow cytometry demonstrated that renal FoxP3+ T regulatory cells were significantly decreased and IHC showed an increase in renal F4/80+ macrophages in HT/Ang, suggesting a shift in the renal inflammatory environment despite no change in blood pressure. Renal mRNA expression of MCP-1, Endothelin-1, GPER-1 were significantly decreased in HT/Ang. The adoptive transfer of hypertensive splenocytes prior to Ang II infusion (HS/Ang) eliminated premenopausal protection from hypertension and significantly decreased splenic FoxP3+ T regulatory cells compared to females receiving normotensive splenocytes (NS/Ang). Expression of MIP-1a/CCL3, a potent macrophage chemokine was elevated in HS/Ang, however no increase in renal macrophage infiltration occurred. Together, these data show that in premenopausal females T cells from hypertensive donors are not sufficient to induce a robust Ang II mediated hypertension, in contrast, transfer of hypertensive splenocytes (consisting of T/B lymphocytes, dendritic cells, macrophages) is sufficient. Further work is needed to understand how innate and adaptive immune cells and estrogen signaling coordinate to cause differential hypertensive outcomes in premenopausal females.

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