scholarly journals Protective Effect of Vaccination with a Combination of Recombinant Surface Antigen 1 and Interleukin-12 against Toxoplasmosis in Mice

1998 ◽  
Vol 66 (9) ◽  
pp. 4503-4506 ◽  
Author(s):  
Valerie Letscher-Bru ◽  
Odile Villard ◽  
Bernhard Risse ◽  
Michael Zauke ◽  
Jean-Paul Klein ◽  
...  

ABSTRACT We studied the immune response induced in mice by recombinantToxoplasma gondii surface antigen 1 (rSAG1) protein, alone or combined with interleukin-12 (IL-12) as an adjuvant, and the protective effect against toxoplasmosis. Immunization with rSAG1 alone induced a specific humoral type 2 immunity and did not protect the animals from infection. In contrast, immunization with rSAG1 plus IL-12 redirected humoral and cellular immunity toward a type 1 pattern and reduced the brain parasite load by 40%.

2002 ◽  
Vol 70 (2) ◽  
pp. 498-503 ◽  
Author(s):  
Brian Hondowicz ◽  
Phillip Scott

ABSTRACT BALB/c mice infected with Leishmania major developed a type 2 immune response which failed to control parasite replication. We found that scid mice that received splenocytes from BALB/c mice that had been infected for 3 weeks with L. major (a type 2 cell population) and that were subsequently infected with L. major were protected when they were treated with interleukin 12 (IL-12). In contrast, IL-12 was ineffective at protecting BALB/c mice infected for 3 weeks, suggesting that a high parasite load regulates the development of protective immunity. To determine how this regulation operates, we performed a series of adoptive transfers of naïve, type 1 or type 2 splenocytes into scid mice. The recipient scid mice were infected either for 5 weeks prior to cell transfer (and thus had a high parasite load) or at the time of cell transfer. scid mice that were infected for 5 weeks and received a type 1 cell population were able to cure their lesions. However, when 5-week-infected scid mice received both type 1 and 2 cell populations, they were unable to control their infections. In contrast, the same type 1 and 2 cells transferred to naïve scid mice, which were subsequently infected, provided protection. In addition, we found that naïve cells mediated protection in scid mice with established lesions. These results show that high parasite numbers do not block type 1 protective responses or the development of type 1 responses. Instead, the influence of a high parasite load is dependent on the presence of a type 2 cell population.


2003 ◽  
Vol 71 (1) ◽  
pp. 465-473 ◽  
Author(s):  
Francesca Sisto ◽  
Annarita Miluzio ◽  
Orazio Leopardi ◽  
Maurizio Mirra ◽  
Johan R. Boelaert ◽  
...  

ABSTRACT Penicillium marneffei is an intracellular opportunistic fungus causing invasive mycosis in AIDS patients. T cells and macrophages are important for protection in vivo. However, the role of T-cell cytokines in the immune response against P. marneffei is still unknown. We studied by semiquantitative reverse transcription-PCR and biological assays the patterns of expression of Th1 and Th2 cytokines in the organs of wild-type (wt) and gamma interferon (IFN-γ) knockout (GKO) mice infected intravenously with P. marneffei conidia. At 3 × 105 conidia/mouse, a self-limiting infection developed in wt BALB/c mice, whereas all GKO mice died at day 18 postinoculation. Splenic and hepatic granulomas were present in wt mice, whereas disorganized masses of macrophages and yeast cells were detected in GKO mice. The infection resolved faster in the spleens than in the livers of wt mice and was associated with the local expression of type 1 cytokines (high levels of interleukin-12 [IL-12] and IFN-γ) but not type 2 cytokines (low levels of IL-4 and IL-10). Conversely, both type 1 and type 2 cytokines were detected in the livers of wt animals. Disregulation of the cytokine profile was seen in the spleens but not in the livers of GKO mice. The inducible nitric oxide synthase mRNA level was low and the TNF-α level was high in both spleens and livers of GKO mice compared to wt mice. These data suggest that the polarization of a protective type 1 immune response against P. marneffei is regulated at the level of individual organs and that the absence of IFN-γ is crucial for the activation of fungicidal macrophages and the development of granulomas.


1999 ◽  
Vol 67 (9) ◽  
pp. 4570-4577 ◽  
Author(s):  
Yiguang Chen ◽  
Dov L. Boros

ABSTRACT In schistosomiasis mansoni, helminth eggs secrete soluble egg antigens (SEA) that induce T-cell-mediated granulomatous tissue responses. The cloned 38-kDa peptide (p38) of SEA was shown to induce and elicit Th1-type responsiveness in H-2k mice. Subsequently, the immunodominant T-cell epitope (P4) of p38 was shown to elicit pulmonary granuloma formation and Th1-type cytokine production in sensitized or infected mice. Here, we report that the immune response to p38 or P4 can be polarized to a Th1 or Th2 profile when the peptides are presented intraperitoneally in soluble recombinant interleukin-12 (IL-12) or alum adjuvant, respectively. The Th1 or Th2 profile was verified by cytokine secretion, enzyme-linked spot assay, and antibody isotype characterization. Importantly, the polarized immune response generated two types of pulmonary granulomas around injected P4-coated beads. The type 1 granulomas were smaller and contained mononuclear cells and occasional thin strands of deposited collagen. In contrast, the type 2 lesions were larger and contained mononuclear cells, large numbers of eosinophils, and several thick bands of deposited collagen. By reverse transcription-PCR cytokine, message in the type 1 granuloma-bearing lungs was found for gamma interferon, tumor necrosis factor alpha, and inducible nitric oxide synthase but not for IL-4 or IL-5. Conversely, lungs with type 2 granulomas had message only for IL-4 and IL-5. These results show that in the proper cytokine environment, the response to a strong Th1 inducer peptide can be deviated to a Th2 profile.


2002 ◽  
Vol 70 (12) ◽  
pp. 6715-6725 ◽  
Author(s):  
D. F. Hoft ◽  
C. S. Eickhoff

ABSTRACT Chagas' disease results from infection with Trypanosoma cruzi, a protozoan parasite that establishes systemic intracellular infection after mucosal invasion. We hypothesized that ideal vaccines for mucosally invasive, intracellular pathogens like T. cruzi should induce mucosal type 2 immunity for optimal induction of protective secretory immunoglobulin A (IgA) and systemic type 1 immunity protective against intracellular replication. However, differential mucosal and systemic immune memory could be difficult to induce because of reciprocal inhibitory actions between type 1 and type 2 responses. To test our hypotheses, we investigated the protective effects of type 1 and type 2 biased vaccines against mucosal and systemic T. cruzi challenges. Intranasal vaccinations were given with recombinant interleukin-12 (IL-12)- and IL-4-neutralizing antibody (Ab) for type 1 immune bias, or recombinant IL-4 and gamma interferon-neutralizing Ab for type 2 immune bias. Cytokine RNA and protein studies confirmed that highly polarized memory immune responses were induced by our vaccination protocols. Survival after virulent subcutaneous T. cruzi challenge was used to assess systemic protection. Mucosal protection was assessed by measuring the relative inhibition of parasite replication in mucosal tissues early after oral T. cruzi challenge, using both PCR and quantitative culture techniques. As expected, only type 1 responses protected against systemic challenges (P < 0.01). However, contrary to our original hypothesis, type 1 responses optimally protected against mucosal challenges as well (P < 0.05). Type 1 and type 2 biased vaccines induced similar secretory IgA responses. We conclude that future vaccines for T. cruzi and possibly other mucosally invasive, intracellular pathogens should induce both mucosal and systemic type 1 immunity.


2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Hua Cong ◽  
Min Zhang ◽  
Qingli Zhang ◽  
Jing Gong ◽  
Haizi Cong ◽  
...  

Toxoplasma gondiiis a protozoan parasite capable of infecting humans and animals. Surface antigen glycoproteins, SAG2C, -2D, -2X, and -2Y, are expressed on the surface of bradyzoites. These antigens have been shown to protect bradyzoites against immune responses during chronic infections. We studied structures of SAG2C, -2D, -2X, and -2Y proteins using bioinformatics methods. The protein sequence alignment was performed by T-Coffee method. Secondary structural and functional domains were predicted using software PSIPRED v3.0 and SMART software, and 3D models of proteins were constructed and compared using the I-TASSER server, VMD, and SWISS-spdbv. Our results showed that SAG2C, -2D, -2X, and -2Y are highly homologous proteins. They share the same conserved peptides and HLA-I restricted epitopes. The similarity in structure and domains indicated putative common functions that might stimulate similar immune response in hosts. The conserved peptides and HLA-restricted epitopes could provide important insights on vaccine study and the diagnosis of this disease.


Author(s):  
Andrea Mastinu ◽  
Marika Premoli ◽  
Giulia Ferrari-Toninelli ◽  
Simone Tambaro ◽  
Giuseppina Maccarinelli ◽  
...  

Abstract The use of different natural and/or synthetic preparations of Cannabis sativa is associated with therapeutic strategies for many diseases. Indeed, thanks to the widespread diffusion of the cannabinoidergic system in the brain and in the peripheral districts, its stimulation, or inhibition, regulates many pathophysiological phenomena. In particular, central activation of the cannabinoidergic system modulates the limbic and mesolimbic response which leads to food craving. Moreover, cannabinoid agonists are able to reduce inflammatory response. In this review a brief history of cannabinoids and the protagonists of the endocannabinoidergic system, i.e. synthesis and degradation enzymes and main receptors, will be described. Furthermore, the pharmacological effects of cannabinoids will be outlined. An overview of the involvement of the endocannabinoidergic system in neuroinflammatory and metabolic pathologies will be made. Finally, particular attention will also be given to the new pharmacological entities acting on the two main receptors, cannabinoid receptor type 1 (CB1) and cannabinoid receptor type 2 (CB2), with particular focus on the neuroinflammatory and metabolic mechanisms involved.


Author(s):  
Matthew J. Simmonds ◽  
Stephen C. L. Gough

Dysfunction within the endocrine system can lead to a variety of diseases with autoimmune attack against individual components being some of the most common. Endocrine autoimmunity encompasses a spectrum of disorders including, e.g., common disorders such as type 1 diabetes, Graves’ disease, Hashimoto’s thyroiditis, and rarer disorders including Addison’s disease and the autoimmune polyendocrine syndromes type 1 (APS 1) and type 2 (APS 2) (see Table 1.6.1). Autoimmune attack within each of these diseases although aimed at different endocrine organs is caused by a breakdown in the immune system’s ability to distinguish between self and nonself antigens, leading to an immune response targeted at self tissues. Investigating the mechanisms behind this breakdown is vital to understand what has gone wrong and to determine the pathways against which therapeutics can be targeted. Before discussing how self-tolerance fails, we first have to understand how the immune system achieves self-tolerance.


2016 ◽  
Vol 8 (5) ◽  
pp. 865-874 ◽  
Author(s):  
Caroline Felicio Braga-Silva ◽  
Camila Santa Rosa Suhett ◽  
Ricardo Nascimento Drozino ◽  
Neide Martins Moreira ◽  
Débora de Mello Gonçales Sant’Ana ◽  
...  

2001 ◽  
Vol 69 (5) ◽  
pp. 2808-2814 ◽  
Author(s):  
Donatella Pietrella ◽  
Robert Cherniak ◽  
Carla Strappini ◽  
Stefano Perito ◽  
Paolo Mosci ◽  
...  

ABSTRACT Our previous observations showed that mannoprotein (MP) induces early and massive production of interleukin-12 (IL-12) in vitro. This study was designed to investigate whether this phenomenon could be applied in vivo and to determine the biological significance of MP inCryptococcus neoformans infection. The results reported here show that MP treatment induces IL-12 secretion by splenic macrophages and IL-12 p40 mRNA in the brain. During C. neoformans infection, MP reinforced IL-12 and IFN-γ secretion that coincided with enhanced antifungal activity of natural effector cells, early resolution of the inflammatory process, and clearance of fungal load from the brain. These studies show that MP is a key inflammatory mediator that induces a protective immune response againstC. neoformans infection. This information can be used to facilitate the design of a rational approach to manipulate the immune response to C. neoformans.


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