scholarly journals Murine γδ T Lymphocytes Elicited duringPlasmodium yoelii Infection Respond to PlasmodiumHeat Shock Proteins

1999 ◽  
Vol 67 (1) ◽  
pp. 57-63 ◽  
Author(s):  
Jeffrey Kopacz ◽  
Nirbhay Kumar

ABSTRACT γδ T cells accumulate during Plasmodium infections in both murine and human malarias. The biological role of these cells and the antigens that they recognize are not clearly understood, although recent findings indicate that γδ T cells in general influence both innate and antigen-specific adaptive host responses. We examined the accumulation of γδ T cells elicited during infection with virulent and avirulent Plasmodium yoelii parasites in relatively susceptible and resistant strains of mice. Our results indicated that in nonlethal malaria infections, γδ T cells comprise a larger proportion of splenic T cells than in lethal infections and that only a live infection is capable of inducing an increase in the percentage of γδ T cells in vivo. Furthermore, we demonstrate that γδ T cells elicited during a P. yoelii infection respond by proliferation in vitro to P. falciparum heat shock proteins (HSPs) of 60 and 70 kDa, suggesting a possible immunological involvement of parasite HSPs in this arm of the cellular immune response during malarial infection in mice.

Blood ◽  
2003 ◽  
Vol 102 (1) ◽  
pp. 200-206 ◽  
Author(s):  
Martin Wilhelm ◽  
Volker Kunzmann ◽  
Susanne Eckstein ◽  
Peter Reimer ◽  
Florian Weissinger ◽  
...  

Abstract There is increasing evidence that γδ T cells have potent innate antitumor activity. We described previously that synthetic aminobisphosphonates are potent γδ T cell stimulatory compounds that induce cytokine secretion (ie, interferon γ [IFN-γ]) and cell-mediated cytotoxicity against lymphoma and myeloma cell lines in vitro. To evaluate the antitumor activity of γδ T cells in vivo, we initiated a pilot study of low-dose interleukin 2 (IL-2) in combination with pamidronate in 19 patients with relapsed/refractory low-grade non-Hodgkin lymphoma (NHL) or multiple myeloma (MM). The objectives of this trial were to determine toxicity, the most effective dose for in vivo activation/proliferation of γδ T cells, and antilymphoma efficacy of the combination of pamidronate and IL-2. The first 10 patients (cohort A) who entered the study received 90 mg pamidronate intravenously on day 1 followed by increasing dose levels of continuous 24-hour intravenous (IV) infusions of IL-2 (0.25 to 3 × 106 IU/m2) from day 3 to day 8. Even at the highest IL-2 dose level in vivo, γδ T-cell activation/proliferation and response to treatment were disappointing with only 1 patient achieving stable disease. Therefore, the next 9 patients were selected by positive in vitro proliferation of γδ T cells in response to pamidronate/IL-2 and received a modified treatment schedule (6-hour bolus IV IL-2 infusions from day 1-6). In this patient group (cohort B), significant in vivo activation/proliferation of γδ T cells was observed in 5 patients (55%), and objective responses (PR) were achieved in 3 patients (33%). Only patients with significant in vivo proliferation of γδ T cells responded to treatment, indicating that γδ T cells might contribute to this antilymphoma effect. Overall, administration of pamidronate and low-dose IL-2 was well tolerated. In conclusion, this clinical trial demonstrates, for the first time, that γδ T-cell–mediated immunotherapy is feasible and can induce objective tumor responses. (Blood. 2003;102:200-206)


2006 ◽  
Vol 74 (7) ◽  
pp. 3817-3824 ◽  
Author(s):  
Karen L. Wozniak ◽  
Jatin M. Vyas ◽  
Stuart M. Levitz

ABSTRACT Dendritic cells (DC) have been shown to phagocytose and kill Cryptococcus neoformans in vitro and are believed to be important for inducing protective immunity against this organism. Exposure to C. neoformans occurs mainly by inhalation, and in this study we examined the in vivo interactions of C. neoformans with DC in the lung. Fluorescently labeled live C. neoformans and heat-killed C. neoformans were administered intranasally to C57BL/6 mice. At specific times postinoculation, mice were sacrificed, and lungs were removed. Single-cell suspensions of lung cells were prepared, stained, and analyzed by microscopy and flow cytometry. Within 2 h postinoculation, fluorescently labeled C. neoformans had been internalized by DC, macrophages, and neutrophils in the mouse lung. Additionally, lung DC from mice infected for 7 days showed increased expression of the maturation markers CD80, CD86, and major histocompatibility complex class II. Finally, ex vivo incubation of lung DC from infected mice with Cryptococcus-specific T cells resulted in increased interleukin-2 production compared to the production by DC from naïve mice, suggesting that there was antigen-specific T-cell activation. This study demonstrated that DC in the lung are capable of phagocytosing Cryptococcus in vivo and presenting antigen to C. neoformans-specific T cells ex vivo, suggesting that these cells have roles in innate and adaptive pulmonary defenses against cryptococcosis.


Author(s):  
Mohammad H. Rashid ◽  
Thaiz F. Borin ◽  
Roxan Ara ◽  
Raziye Piranlioglu ◽  
Bhagelu R. Achyut ◽  
...  

AbstractMyeloid-derived suppressor cells (MDSCs) are an indispensable component of the tumor microenvironment (TME), and our perception regarding the role of MDSCs in tumor promotion is attaining extra layer of intricacy in every study. In conjunction with MDSC’s immunosuppressive and anti-tumor immunity, they candidly facilitate tumor growth, differentiation, and metastasis in several ways that yet to be explored. Alike any other cell types, MDSCs also release a tremendous amount of exosomes or nanovesicles of endosomal origin and partake in intercellular communications by dispatching biological macromolecules. There has not been any experimental study done to characterize the role of MDSCs derived exosomes (MDSC exo) in the modulation of TME. In this study, we isolated MDSC exo and demonstrated that they carry a significant amount of proteins that play an indispensable role in tumor growth, invasion, angiogenesis, and immunomodulation. We observed higher yield and more substantial immunosuppressive potential of exosomes isolated from MDSCs in the primary tumor area than those are in the spleen or bone marrow. Our in vitro data suggest that MDSC exo are capable of hyper activating or exhausting CD8 T-cells and induce reactive oxygen species production that elicits activation-induced cell death. We confirmed the depletion of CD8 T-cells in vivo by treating the mice with MDSC exo. We also observed a reduction in pro-inflammatory M1-macrophages in the spleen of those animals. Our results indicate that immunosuppressive and tumor-promoting functions of MDSC are also implemented by MDSC-derived exosomes which would open up a new avenue of MDSC research and MDSC-targeted therapy.


2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Fengjie Jiang ◽  
Xiaozhu Tang ◽  
Chao Tang ◽  
Zhen Hua ◽  
Mengying Ke ◽  
...  

AbstractN6-methyladenosine (m6A) modification is the most prevalent modification in eukaryotic RNAs while accumulating studies suggest that m6A aberrant expression plays an important role in cancer. HNRNPA2B1 is a m6A reader which binds to nascent RNA and thus affects a perplexing array of RNA metabolism exquisitely. Despite unveiled facets that HNRNPA2B1 is deregulated in several tumors and facilitates tumor growth, a clear role of HNRNPA2B1 in multiple myeloma (MM) remains elusive. Herein, we analyzed the function and the regulatory mechanism of HNRNPA2B1 in MM. We found that HNRNPA2B1 was elevated in MM patients and negatively correlated with favorable prognosis. The depletion of HNRNPA2B1 in MM cells inhibited cell proliferation and induced apoptosis. On the contrary, the overexpression of HNRNPA2B1 promoted cell proliferation in vitro and in vivo. Mechanistic studies revealed that HNRNPA2B1 recognized the m6A sites of ILF3 and enhanced the stability of ILF3 mRNA transcripts, while AKT3 downregulation by siRNA abrogated the cellular proliferation induced by HNRNPA2B1 overexpression. Additionally, the expression of HNRNPA2B1, ILF3 and AKT3 was positively associated with each other in MM tissues tested by immunohistochemistry. In summary, our study highlights that HNRNPA2B1 potentially acts as a therapeutic target of MM through regulating AKT3 expression mediated by ILF3-dependent pattern.


2011 ◽  
Vol 4 (4) ◽  
pp. 211
Author(s):  
Serena Meraviglia ◽  
Carmela La Mendola ◽  
Valentina Orlando ◽  
Francesco Scarpa ◽  
Giuseppe Cicero ◽  
...  

The potent anti-tumor activities of γδ T cells, their ability to produce pro-inflammatory cytokines, and their strong cytolytic activity have prompted the development of protocols in which γδ agonists or ex vivo-expanded γδ cells are administered to tumor patients. γδ T cells can be selectively activated by either synthetic phosphoantigens or by drugs that enhance their accumulation into stressed cells as aminobisphosphonates, thus offering new avenues for the development of γδ T cell-based immunotherapies. The recent development of small drugs selectively activating Vγ9Vδ2 T lymphocytes, which upregulate the endogenous phosphoantigens, has enabled the investigators to design the experimental approaches of cancer immunotherapies; several ongoing phase I and II clinical trials are focused on the role of the direct bioactivity of drugs and of adoptive cell therapies involving phosphoantigen- or aminobisphosphonate-activated Vγ9Vδ2 T lymphocytes in humans. In this review, we focus on the recent advances in the activation/expansion of γδ T cells in vitro and in vivo that may represent a promising target for the design of novel and highly innovative immunotherapy in patients with hematologic malignancies.<br />


2010 ◽  
Vol 23 (7) ◽  
pp. 962-976 ◽  
Author(s):  
Stephanie A. Gardiner ◽  
Jayanand Boddu ◽  
Franz Berthiller ◽  
Christian Hametner ◽  
Robert M. Stupar ◽  
...  

Trichothecenes are a major group of toxins produced by phytopathogenic fungi, including Fusarium graminearum. Trichothecenes inhibit protein synthesis in eukaryotic cells and are toxicologically relevant mycotoxins for humans and animals. Because they promote plant disease, the role of host responses to trichothecene accumulation is considered to be an important aspect of plant defense and resistance to fungal infection. Our overall objective was to examine the barley response to application of the type B trichothecene deoxynivalenol (DON). We found that DON is diluted by movement from the application site to acropetal and basipetal florets. A susceptible barley genotype converted DON to DON-3-O-glucoside, indicating that UDP-glucosyltransferases capable of detoxifying DON must exist in barley. RNA profiling of DON-treated barley spikes revealed strong upregulation of gene transcripts encoding ABC transporters, UDP-glucosyltransferases, cytochrome P450s, and glutathione-S-transferases. We noted that transcripts encoding cysteine synthases were dramatically induced by DON, and that toxin-sensitive yeast on glutathione- or cysteine-supplemented media or carrying a gene that encodes a cysteine biosynthetic enzyme exhibit DON resistance, suggesting that preventing glutathione depletion by increasing cysteine supply could play a role in ameliorating the impact of DON. Evidence for nonenzymatic formation of DON-glutathione adducts in vitro was found using both liquid chromatography–mass spectrometry and nuclear magnetic resonance analysis, indicating that the formation of DON-glutathione conjugates in vivo may reduce the impact of trichothecenes. Our results indicate that barley exhibits multiple defense mechanisms against trichothecenes.


2010 ◽  
Vol 16 (5) ◽  
pp. 1402-1415 ◽  
Author(s):  
Marius Grzelinski ◽  
Olaf Pinkenburg ◽  
Thomas Büch ◽  
Maike Gold ◽  
Stefanie Stohr ◽  
...  

2011 ◽  
Vol 79 (10) ◽  
pp. 3940-3946 ◽  
Author(s):  
Cuixia Shi ◽  
Bikash Sahay ◽  
Jennifer Q. Russell ◽  
Karen A. Fortner ◽  
Nicholas Hardin ◽  
...  

ABSTRACTLittle is known regarding the function of γδ T cells, although they accumulate at sites of inflammation in infections and autoimmune disorders. We previously observed that γδ T cellsin vitroare activated byBorrelia burgdorferiin a TLR2-dependent manner. We now observe that the activated γδ T cells can in turn stimulate dendritic cellsin vitroto produce cytokines and chemokines that are important for the adaptive immune response. This suggested thatin vivoγδ T cells may assist in activating the adaptive immune response. We examined this possibilityin vivoand observed that γδ T cells are activated and expand in number duringBorreliainfection, and this was reduced in the absence of TLR2. Furthermore, in the absence of γδ T cells, there was a significantly blunted response of adaptive immunity, as reflected in reduced expansion of T and B cells and reduced serum levels of anti-Borreliaantibodies, cytokines, and chemokines. This paralleled a greaterBorreliaburden in γδ-deficient mice as well as more cardiac inflammation. These findings are consistent with a model of γδ T cells functioning to promote the adaptive immune response during infection.


1994 ◽  
Vol 180 (4) ◽  
pp. 1273-1282 ◽  
Author(s):  
M B Graham ◽  
V L Braciale ◽  
T J Braciale

T lymphocytes play a primary role in recovery from viral infections and in antiviral immunity. Although viral-specific CD8+ and CD4+ T cells have been shown to be able to lyse virally infected targets in vitro and promote recovery from lethal infection in vivo, the role of CD4+ T lymphocytes and their mechanism(s) of action in viral immunity are not well understood. The ability to further dissect the role that CD4+ T cells play in the immune response to a number of pathogens has been greatly enhanced by evidence for more extensive heterogeneity among the CD4+ T lymphocytes. To further examine the role of CD4+ T cells in the immune response to influenza infection, we have generated influenza virus-specific CD4+ T cell clones from influenza-primed BALB/c mice with differential cytokine secretion profiles that are defined as T helper type 1 (Th1) clones by the production of interleukin 2 (IL-2) and interferon gamma (IFN-gamma), or as Th2 clones by the production of IL-4, IL-5, and IL-10. Our studies have revealed that Th1 clones are cytolytic in vitro and protective against lethal challenge with virus in vivo, whereas Th2 clones are noncytolytic and not protective. Upon further evaluation of these clonal populations we have shown that not only are the Th2 clones nonprotective, but that pulmonary pathology is exacerbated as compared with control mice as evidenced by delayed viral clearance and massive pulmonary eosinophilia. These data suggest that virus-specific CD4+ T cells of the Th2 subset may not play a primary role in virus clearance and recovery and may lead to immune mediated potentiation of injury.


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