scholarly journals The Bacterial Second Messenger cdiGMP Exhibits Promising Activity as a Mucosal Adjuvant

2007 ◽  
Vol 14 (8) ◽  
pp. 952-958 ◽  
Author(s):  
Thomas Ebensen ◽  
Kai Schulze ◽  
Peggy Riese ◽  
Michael Morr ◽  
Carlos A. Guzmán
Keyword(s):  
Cytotoxic T Lymphocyte ◽  
Second Messenger ◽  
Secretory Iga ◽  
Specific Lysis ◽  
Mucosal Adjuvant ◽  
Promising Tool ◽  
Iga Production ◽  
Cellular Immune ◽  
Lymphocyte Responses

ABSTRACT The development of mucosal adjuvants is still a critical need in vaccinology. In the present work, we show that bis(3′,5′)-cyclic dimeric GMP (cdiGMP), a second messenger that modulates cell surface properties of several microorganisms, exerts potent activity as a mucosal adjuvant. BALB/c mice were immunized intranasally with the model antigen β-galactosidase (β-Gal) coadministered with cdiGMP. Animals receiving cdiGMP as an adjuvant showed significantly higher anti-β-Gal immunoglobulin G (IgG) titers in sera than controls (i.e., 512-fold [P < 0.05]). Coadministration of cdiGMP also stimulated efficient β-Gal-specific secretory IgA production in the lung (P < 0.016) and vagina (P < 0.036). Cellular immune responses were observed in response to both the β-Gal protein and a peptide encompassing its major histocompatibility complex class I-restricted epitope. The IgG1-to-IgG2a ratio of anti-β-Gal antibodies and the observed profiles of secreted cytokines suggest that a dominant Th1 response pattern is promoted by mucosal coadministration of cdiGMP. Finally, the use of cdiGMP as a mucosal adjuvant also led to the stimulation of in vivo cytotoxic T-lymphocyte responses in C57BL/6 mice intranasally immunized with ovalbumin and cdiGMP (up to 30% of specific lysis). The results obtained indicate that cdiGMP is a promising tool for the development of mucosal vaccines.

scholarly journals Shifting immunodominance pattern of two cytotoxic T-lymphocyte epitopes in the F glycoprotein of the Long strain of respiratory syncytial virus

2004 ◽  
Vol 85 (11) ◽  
pp. 3229-3238 ◽  
Author(s):  
Carolina Johnstone ◽  
Patricia de León ◽  
Francisco Medina ◽  
José A. Melero ◽  
Blanca García-Barreno ◽  
...  
Keyword(s):  
Respiratory Syncytial Virus ◽  
Vaccinia Virus ◽  
T Lymphocyte ◽  
Cytotoxic T Lymphocyte ◽  
Recombinant Vaccinia Virus ◽  
Recombinant Vaccinia ◽  
F Protein ◽  
Syncytial Virus ◽  
Lymphocyte Responses

Human respiratory syncytial virus (RSV) is a major cause of respiratory infection in children and in the elderly. The RSV fusion (F) glycoprotein has long been recognized as a vaccine candidate as it elicits cytotoxic T-lymphocyte (CTL) and antibody responses. Two murine H-2Kd-restricted CTL epitopes (F85–93 and F92–106) are known in the F protein of the A2 strain of RSV. F-specific CTL lines using BCH4 fibroblasts that are persistently infected with the Long strain of human RSV as stimulators were generated, and it was found that in this strain only the F85–93 epitope is conserved. Motif based epitope prediction programs and an F2 chain deleted F protein encoded in a recombinant vaccinia virus enabled identification of a new epitope in the Long strain, F249–258, which is presented by Kd as a 9-mer (TYMLTNSEL) or a 10-mer (TYMLTNSELL) peptide. The results suggest that the 10-mer might be a naturally processed endogenous Kd ligand. The CD8+ T-lymphocyte responses to epitopes F85–93 and F249–258 present in the F protein of RSV Long were found to be strongly skewed to F85–93 in in vitro multispecific CTL lines and in vivo during a secondary response to a recombinant vaccinia virus that expresses the entire F protein. However, no hierarchy in CD8+ T-lymphocyte responses to F85–93 and F249–258 epitopes was observed in vivo during a primary response.

scholarly journals Specialized and shared functions of diguanylate cyclases and phosphodiesterases in Streptomyces development

2020 ◽  
Author(s):  
Julian Haist ◽  
Sara Alina Neumann ◽  
Mahmoud M Al-Bassam ◽  
Sandra Lindenberg ◽  
Marie A Elliot ◽  
...  
Keyword(s):  
Antibiotic Production ◽  
Second Messenger ◽  
Natural Product Synthesis ◽  
Regulatory Role ◽  
Adverse Conditions ◽  
Promising Tool ◽  
Diguanylate Cyclases ◽  
Genome Wide ◽  
Protein Variants

AbstractLevels of the second messenger bis-3’-5’-cyclic di-guanosinemonophosphate (c-di-GMP) determine when Streptomyces initiate sporulation to survive under adverse conditions. c-di-GMP signals are integrated into the genetic differentiation network by the regulator BldD and the sigma factor σWhiG. However, functions of the development-specific c-di-GMP diguanylate cyclases (DGCs) CdgB and CdgC, and the phosphodiesterases (PDEs) RmdA and RmdB, are poorly understood. Here, we provide biochemical evidence that the GGDEF-EAL domain protein RmdB from S. venezuelae is a monofunctional PDE that hydrolyzes c-di-GMP to 5’pGpG. Despite having an equivalent GGDEF-EAL domain arrangement, RmdA cleaves c-di-GMP to GMP and exhibits residual DGC activity. We show that an intact EAL motif is crucial for the in vivo function of both enzymes since strains expressing protein variants with an AAA motif instead of EAL are delayed in development, similar to null mutants. Global transcriptome analysis of ΔcdgB, ΔcdgC, ΔrmdA and ΔrmdB strains revealed that the c-di-GMP specified by these enzymes has a global regulatory role, with about 20 % of all S. venezuelae genes being differentially expressed in the cdgC mutant. Our data suggest that the major c-di-GMP-controlled targets determining the timing and mode of sporulation are genes involved cell division and the production of the hydrophobic sheath that covers Streptomyces aerial hyphae and spores. Altogether, this study provides a global view of the c-di-GMP-dependent genes that contribute to the hyphae-to-spores transition and sheds light on the shared and specific functions of the key enzymes involved in c-di-GMP metabolism in S. venezuelae.ImportanceStreptomyces are important producers of clinical antibiotics. The ability to synthesize these natural products is connected to their developmental biology, which includes a transition from filamentous cells to spores. The widespread bacterial second messenger c-di-GMP controls this complex switch and is a promising tool to improve antibiotic production. Here, we analyzed the enzymes that make and break c-di-GMP in S. venezuelae by studying the genome-wide transcriptional effects of the DGCs CdgB and CdgC and the PDEs RmdA and RmdB. We found that the c-di-GMP specified by these enzymes has a global regulatory role. However, despite shared enzymatic activities, the four c-di-GMP enzymes have specialized inputs into differentiation. Altogether, we demonstrate that altering c-di-GMP levels through the action of selected enzymes yields characteristically distinct transcriptional profiles; this can be an important consideration when modulating c-di-GMP for the purposes of natural product synthesis in Streptomyces.

Studies on in Vivo Induction of Cytotoxic T Lymphocyte Responses by Synthetic Peptides from E6 and E7 Oncoproteins of Human Papillomavirus Type 16

1995 ◽  
Vol 8 (3) ◽  
pp. 165-174 ◽  
Author(s):  
ASIS K. SARKAR ◽  
GUILLERMO TORTOLERO-LUNA ◽  
PRAMOD N. NEHETE ◽  
RALPH B. ARLINGHAUS ◽  
MICHELE FOLLEN MITCHELL ◽  
...  
Keyword(s):  
Human Papillomavirus ◽  
T Lymphocyte ◽  
Synthetic Peptides ◽  
Cytotoxic T Lymphocyte ◽  
Human Papillomavirus Type 16 ◽  
E6 And E7 Oncoproteins ◽  
E6 And E7 ◽  
Lymphocyte Responses ◽  
In Vivo Induction

Cytotoxic T lymphocytes and viral evolution in primary HIV-1 infection*

1999 ◽  
Vol 97 (6) ◽  
pp. 707-718 ◽  
Author(s):  
David A. PRICE ◽  
Chris A. O'CALLAGHAN ◽  
Joseph A. WHELAN ◽  
Philippa J. EASTERBROOK ◽  
Rodney E. PHILLIPS
Keyword(s):  
T Lymphocytes ◽  
Cytotoxic T Lymphocytes ◽  
T Lymphocyte ◽  
Cytotoxic T Lymphocyte ◽  
Viral Evolution ◽  
Case Series ◽  
Effector Cells ◽  
Lymphocyte Responses ◽  
Hiv 1

Efforts to develop immune-based therapies for HIV infection have been impeded by incomplete definition of the immunological correlates of protection. Despite many precedents demonstrating that CD8+ cytotoxic T lymphocytes are key mediators of protective anti-viral immunity in non-human animal models, direct evidence that these effector cells control viral replication in HIV-1 infection has remained elusive. The first part of this paper describes a detailed immunological and genetic study founded on evolutionary considerations. Following infection with HIV-1, virus variants which escaped recognition by autologous cytotoxic T lymphocytes were shown to possess a selection advantage within the host environment. Cytotoxic T lymphocytes therefore exert anti-viral pressure in vivo. This observation provides compelling evidence that cytotoxic T lymphocytes comprise a significant element of anti-retroviral immunity. Subsequently, the quantification of peripheral cytotoxic T lymphocyte frequencies utilizing peptide–(human leucocyte antigen class I) tetrameric complexes is described. Five patients with qualitatively similar immunodominant cytotoxic T lymphocyte responses during symptomatic primary HIV-1 infection were studied longitudinally. Expansions of virus-specific CD8+ lymphocytes comprising up to 2% of the total CD8+ T cell population were observed in the acute phase of infection. Antigenic load was identified as an important determinant of circulating HIV-1-specific CD8+ lymphocyte levels; however, significant numbers of such cells were also found to persist following prolonged therapeutic suppression of plasma viraemia. In addition, an analysis of antigenic sequence variation with time in this case series suggests that the early administration of combination anti-retroviral therapy may limit HIV-1 mutational escape from host cytolytic specificities. The implications of these preliminary data are discussed. The data presented suggest that vaccination protocols should aim to elicit vigorous cytotoxic T lymphocyte responses to HIV-1. Attempts to stimulate polyvalent responses to mutationally intolerant epitopes are likely to be most effective. Optimal management of HIV-1 infection requires an understanding of dynamic host–virus interactions, and may involve strategies designed to enhance cytotoxic T lymphocyte activity following periods of anti-retroviral drug therapy.

scholarly journals Riboflavin as a Mucosal Adjuvant for Nasal Influenza Vaccine

Vaccines ◽  
2021 ◽  
Vol 9 (11) ◽  
pp. 1296
Author(s):  
Yinyan Yin ◽  
Jinyuan Wang ◽  
Xing Xu ◽  
Bangyue Zhou ◽  
Sujuan Chen ◽  
...  
Keyword(s):  
Low Cost ◽  
Mapk Signaling ◽  
Mitogen Activated Protein Kinase ◽  
Secretory Iga ◽  
Mucosal Adjuvant ◽  
Intranasal Immunization ◽  
Mitogen Activated Protein ◽  
Nasal Vaccine ◽  
Living Organisms ◽  
Cellular Immune

Intranasal immunization with whole inactivated virus (WIV) is an important strategy used for influenza prevention and control. However, a powerful mucosal adjuvant is required to improve nasal vaccine efficacy. Riboflavin, as a food additive with the advantages of being safe and low-cost, widely exists in living organisms. In this paper, the mucosal adjuvant function of riboflavin was studied. After intranasal immunization with H1N1 WIV plus riboflavin in mice, we found that the mucosal immunity based on the secretory IgA (sIgA) levels in the nasal cavity, trachea, and lung were strongly enhanced compared with H1N1 WIV alone. Meanwhile, the IgG, IgG1, and IgG2a levels in serum also showed a high upregulation and a decreased ratio of IgG1/IgG2a, which implied a bias in the cellular immune response. Moreover, riboflavin strongly improved the protection level of H1N1 inactivated vaccine from a lethal influenza challenge. Furthermore, riboflavin was found to possess the capacity to induce dendritic cell (DC) phenotypic (MHCII, CD40, CD80, and CD86) and functional maturation, including cytokine secretion (TNF-α, IL-1β, IL-12p70, and IL-10) and the proliferation of allogeneic T cells. Lastly, we found that the DC maturation induced by riboflavin was dependent on the activation of the mitogen-activated protein kinase (MAPK) signaling pathway, which plays an important role in immune regulation. Therefore, riboflavin is expected to be developed as an alternative mucosal adjuvant for influenza nasal vaccine application.

Shaping the Repertoire of Cytotoxic T-Lymphocyte Responses: Explanation for the Immunodominance Effect Whereby Cytotoxic T Lymphocytes Specific for Immunodominant Antigens Prevent Recognition of Nondominant Antigens

Blood ◽  
1999 ◽  
Vol 93 (3) ◽  
pp. 952-962 ◽  
Author(s):  
Stéphane Pion ◽  
Gregory J. Christianson ◽  
Pierre Fontaine ◽  
Derry C. Roopenian ◽  
Claude Perreault
Keyword(s):  
T Lymphocyte ◽  
Cytotoxic T Lymphocyte ◽  
Cell Receptor ◽  
Rapid Expansion ◽  
Class I ◽  
Tcr Signals ◽  
Lymphocyte Responses ◽  
Antigen Presenting ◽  
Dominant Epitope

The immunodominance effect, whereby the presence of immunodominant epitopes prevents recognition of nondominant determinants presented on the same antigen-presenting cell (APC) considerably restricts the repertoire of cytotoxic T lymphocyte (CTL) responses. To elucidate the molecular basis of the immunodominance effect, we compared the interactions of a dominant (B6dom1) and a nondominant epitope (H-Y) with their restricting class I molecule (H2-Db), and their ability to trigger cognate CTLs. We found that B6dom1/Db complexes behaved as optimal T-cell receptor (TCR) ligands and triggered a more rapid in vivo expansion of cognate CTLs than H-Y/Db complexes. The superiority of the dominant epitope was explained by its high cell surface density (1,012 copies/cell for B6dom1v 10 copies/cell for H-Y) and its optimal affinity for cognate TCRs. Based on these results, we conclude that dominant class I–associated epitopes are those that have optimal ability to trigger TCR signals in CTLs. We propose that the rapid expansion of CTLs specific for dominant antigens should enable them to compete more successfully than other CTLs for occupancy of the APC surface.

scholarly journals Protection against Simian Immunodeficiency Virus Vaginal Challenge by Using Sabin Poliovirus Vectors

2001 ◽  
Vol 75 (16) ◽  
pp. 7435-7452 ◽  
Author(s):  
Shane Crotty ◽  
Christopher J. Miller ◽  
Barbara L. Lohman ◽  
Martha R. Neagu ◽  
Lara Compton ◽  
...  
Keyword(s):  
Simian Immunodeficiency Virus ◽  
Cytotoxic T Lymphocyte ◽  
Vaccination Strategy ◽  
Vaccine Vector ◽  
Mucosal Antibody ◽  
Immunodeficiency Virus ◽  
Cellular Immune ◽  
Lymphocyte Responses ◽  
Pronounced Reduction ◽  
Human Vaccine

ABSTRACT Here we provide the first report of protection against a vaginal challenge with a highly virulent simian immunodeficiency virus (SIV) by using a vaccine vector. New poliovirus vectors based on Sabin 1 and 2 vaccine strain viruses were constructed, and these vectors were used to generate a series of new viruses containing SIV gag,pol, env, nef, andtat in overlapping fragments. Two cocktails of 20 transgenic polioviruses (SabRV1-SIV and SabRV2-SIV) were inoculated into seven cynomolgus macaques. All monkeys produced substantial anti-SIV serum and mucosal antibody responses. SIV-specific cytotoxic T-lymphocyte responses were detected in three of seven monkeys after vaccination. All 7 vaccinated macaques, as well as 12 control macaques, were challenged vaginally with pathogenic SIVmac251. Strikingly, four of the seven vaccinated animals exhibited substantial protection against the vaginal SIV challenge. All 12 control monkeys became SIV positive. In two of the seven SabRV-SIV-vaccinated monkeys we found no virological evidence of infection following challenge, indicating that these two monkeys were completely protected. Two additional SabRV-SIV-vaccinated monkeys exhibited a pronounced reduction in postacute viremia to <103 copies/ml, suggesting that the vaccine elicited an effective cellular immune response. Three of six control animals developed clinical AIDS by 48 weeks postchallenge. In contrast, all seven vaccinated monkeys remained healthy as judged by all clinical parameters. These results demonstrate the efficacy of SabRV as a potential human vaccine vector, and they show that the use of a vaccine vector cocktail expressing an array of defined antigenic sequences can be an effective vaccination strategy in an outbred population.

scholarly journals Development of Safe and Non-Self-Immunogenic Mucosal Adjuvant by Recombinant Fusion of Cholera Toxin A1 Subunit with Protein Transduction Domain

2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
Byoung-Shik Shim ◽  
In Su Cheon ◽  
Eugene Lee ◽  
Sung-Moo Park ◽  
Youngjoo Choi ◽  
...  
Keyword(s):  
Cholera Toxin ◽  
Cytotoxic T Lymphocyte ◽  
Antibody Responses ◽  
Mucosal Vaccine ◽  
Protein Transduction ◽  
Protein Transduction Domain ◽  
Igg Antibody ◽  
Mucosal Adjuvant ◽  
Virus Challenge

Potential use of cholera toxin (CT) as a mucosal vaccine adjuvant has been documented in a variety of animal models. However, native CT is highly toxic to be used as a mucosal adjuvant in humans. Here, we demonstrate a new approach to generate a mucosal adjuvant by replacing the B subunit of CT with HIV-1 Tat protein transduction domain (PTD), which efficiently delivers fusion proteins into the cell cytoplasm by unspecific binding to cell surface. We compared the adjuvanticity and toxicity of Tat PTD-CTA1-Tat PTD (TCTA1T) with those of CT. Our results indicate that intranasal (i.n.) delivery of ovalbumin (OVA) with TCTA1T significantly augments the OVA-specific systemic and mucosal antibody responses to levels comparable to those seen with CT adjuvant. Moreover,in vivocytotoxic T lymphocyte activity elicited by TCTA1T was significantly higher than that elicited by a mutant TCTA1T (TmCTA1T) lacking ADP-ribosyltransferase function. In addition, coadministration of influenza M2 protein with TCTA1T conferred near complete protection against lethal influenza virus challenge. Importantly, TCTA1T, in contrast to CT, did not induce serum IgG antibody responses to itself and was shown to be nontoxic. These results suggest that TCTA1T may be a safe and effective adjuvant when given by mucosal routes.

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