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23 results on '"Preciado-Llanes, Lorena"'

3. A single dose of ChAdOx1 Chik vaccine induces neutralizing antibodies against four chikungunya virus lineages in a phase 1 clinical trial

Author

Folegatti, Pedro M., Harrison, Kate, Preciado-Llanes, Lorena, Lopez, Fernando Ramos, Bittaye, Mustapha, Kim, Young Chan, Flaxman, Amy, Bellamy, Duncan, Makinson, Rebecca, Sheridan, Jonathan, Azar, Sasha R., Campos, Rafael Kroon, Tilley, Mark, Tran, Nguyen, Jenkin, Daniel, Poulton, Ian, Lawrie, Alison, Roberts, Rachel, Berrie, Eleanor, Rossi, Shannan L., Hill, Adrian, Ewer, Katie J., and Reyes-Sandoval, Arturo

Published
2021
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4. Convergent trends and spatiotemporal patterns of Aedes-borne arboviruses in Mexico and Central America

Author

Gutierrez, Bernardo, primary, da Silva Candido, Darlan, additional, Bajaj, Sumali, additional, Rodriguez Maldonado, Abril Paulina, additional, Ayala, Fabiola Garces, additional, Rodriguez, María de la Luz Torre, additional, Rodriguez, Adnan Araiza, additional, Arámbula, Claudia Wong, additional, González, Ernesto Ramírez, additional, Martínez, Irma López, additional, Díaz-Quiñónez, José Alberto, additional, Pichardo, Mauricio Vázquez, additional, Hill, Sarah C., additional, Thézé, Julien, additional, Faria, Nuno R., additional, Pybus, Oliver G., additional, Preciado-Llanes, Lorena, additional, Reyes-Sandoval, Arturo, additional, Kraemer, Moritz U. G., additional, and Escalera-Zamudio, Marina, additional

Published
2023
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5. Inhibition of T-cell responses by microbes and immune cells

Author

Preciado-Llanes, Lorena, Read, Robert C., and Heath, Andrew W.

Subjects
610
Abstract

Some antigens can induce B-cell activation and antibody production without 'T cell help' and hence are called T-independent (TI) antigens. Similarly to bacterial capsular polysaccharides, anti- IgDconjugated dextran (α-δ-DEX) is a TI type 2 mimic which stimulates B lymphocytes by crosslinking of numerous B-cell receptor molecules. This thesis demonstrates that α-δ-DEX-activated B-cells directly inhibit TCR-induced CD4+ T-cell proliferation and activation in vitro. Experiments performed with purified cell populations excluded the possibility of α-δ-DEX acting directly on CD4+ T lymphocytes and confirmed that B lymphocytes exposed to α-δ-DEX for a period of 24 hours become activated and acquire a suppressive phenotype. Interestingly, these suppressor Bcells appear to be effective even when they are present at numbers below the physiological T:B ratio. Although the exact mechanism of action remains obscure, this is the first evidence of TI type 2 antigen activated B-cells mediating inhibition of activation and proliferation of helper T lymphocytes. Neisseria meningitidis is a bacterium which rarely causes invasive disease and sepsis, but perpetuates colonisation in the nasopharynx by avoiding immune recognition and killing. Because several N. meningitidis constituents are TI type 2 antigens and/or provide second signals to B-cells via TLRs, it was hypothesized that paraformaldehyde fixed meningococcus could exert immunomodulatory properties. A deep suppression of CD4+ T-cell responses occurred when aCD3-stimulated PBMCs where incubated with small meningococci counts (ratios between 0.1 to 10:1 bacteria per cell). A clear TH1 cytokine profile and IL-10 secretion was observed in supernatants from these cultures. Interestingly, outer membrane vesicles (OMVs) from N. meningitidis and N. lactamica replicated the suppression phenomenon induced by the whole organism. Bacterial capsule, lipooligosaccharides and Opa are not responsible for the suppressive effect. Depletion of B-cells, monocytes or NK cells does not reverse the meningococcus-mediated inhibition in PBMC cultures. Several bacterial components stimulate nitric oxide (NO) production, however N. meningitidis can counteract the bactericidal effect of reactive nitrogen intermediates by a partial denitrification pathway. Since NO is also produced as a result of TCR engagement, it was investigated whether NO donation or inhibition could influence CD4+ T-cell responses. A novel specific eNOS inhibitor (Cavtratin) derived from the caveolin-1 structure was tested for the first time in PBMC cultures. Cavtratin concentrations of 10 and 15 μM increases proliferation of CD4+ T lymphocytes and reduce the percentage of cell death in the PBMC culture after anti-CD3 stimulation.

Published
2013

6. Clonal analysis of Salmonella-specific effector T cells reveals serovar-specific and cross-reactive T cell responses

Author

Napolitani, Giorgio, Kurupati, Prathiba, Teng, Karen Wei Weng, Gibani, Malick M., Rei, Margarida, Aulicino, Anna, Preciado-Llanes, Lorena, Wong, Michael Thomas, Becht, Etienne, Howson, Lauren, de Haas, Paola, Salio, Mariolina, Blohmke, Christoph J., Olsen, Lars Rønn, Pinto, David Miguel Susano, Scifo, Laura, Jones, Claire, Dobinson, Hazel, Campbell, Danielle, Juel, Helene B., Thomaides-Brears, Helena, Pickard, Derek, Bumann, Dirk, Baker, Stephen, Dougan, Gordon, Simmons, Alison, Gordon, Melita A., Newell, Evan William, Pollard, Andrew J., and Cerundolo, Vincenzo

Published
2018
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7. Convergent trends and spatiotemporal patterns of arboviruses in Mexico and Central America

Author

Gutierrez, Bernardo, primary, Candido, Darlan da Silva, additional, Bajaj, Sumali, additional, Rodriguez Maldonado, Abril Paulina, additional, Ayala, Fabiola Garces, additional, Torre Rodriguez, María de la Luz, additional, Araiza Rodriguez, Adnan, additional, Wong Arámbula, Claudia, additional, Ramírez González, Ernesto, additional, Martínez, Irma López, additional, Díaz-Quiñónez, José Alberto, additional, Pichardo, Mauricio Vázquez, additional, Hill, Sarah C., additional, Thézé, Julien, additional, Faria, Nuno R., additional, Pybus, Oliver G., additional, Preciado-Llanes, Lorena, additional, Reyes-Sandoval, Arturo, additional, Kraemer, Moritz U.G., additional, and Escalera-Zamudio, Marina, additional

Published
2023
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9. Publisher Correction: Clonal analysis of Salmonella-specific effector T cells reveals serovar-specific and cross-reactive T cell responses

Author

Napolitani, Giorgio, Kurupati, Prathiba, Teng, Karen Wei Weng, Gibani, Malick M., Rei, Margarida, Aulicino, Anna, Preciado-Llanes, Lorena, Wong, Michael Thomas, Becht, Etienne, Howson, Lauren, de Haas, Paola, Salio, Mariolina, Blohmke, Christoph J., Olsen, Lars Rønn, Pinto, David Miguel Susano, Scifo, Laura, Jones, Claire, Dobinson, Hazel, Campbell, Danielle, Juel, Helene B., Thomaides-Brears, Helena, Pickard, Derek, Bumann, Dirk, Baker, Stephen, Dougan, Gordon, Simmons, Alison, Gordon, Melita A., Newell, Evan William, Pollard, Andrew J., and Cerundolo, Vincenzo

Published
2019
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11. Homologous and heterologous re-challenge with Salmonella Typhi and Salmonella Paratyphi A in a randomised controlled human infection model

Author

Gibani, Malick M., primary, Jin, Celina, additional, Shrestha, Sonu, additional, Moore, Maria, additional, Norman, Lily, additional, Voysey, Merryn, additional, Jones, Elizabeth, additional, Blackwell, Luke, additional, Thomaides-Brears, Helena, additional, Hill, Jennifer, additional, Blohmke, Christoph J., additional, Dobinson, Hazel C., additional, Baker, Philip, additional, Jones, Claire, additional, Campbell, Danielle, additional, Mujadidi, Yama F., additional, Plested, Emma, additional, Preciado-Llanes, Lorena, additional, Napolitani, Giorgio, additional, Simmons, Alison, additional, Gordon, Melita A., additional, Angus, Brian, additional, Darton, Thomas C., additional, Cerundulo, Vincenzo, additional, and Pollard, Andrew J., additional

Published
2020
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12. Evasion of MAIT cell recognition by the AfricanSalmonellaTyphimurium ST313 pathovar that causes invasive disease

Author

Preciado-Llanes, Lorena, primary, Aulicino, Anna, additional, Canals, Rocío, additional, Moynihan, Patrick J., additional, Zhu, Xiaojun, additional, Jambo, Ndaru, additional, Nyirenda, Tonney S., additional, Kadwala, Innocent, additional, Sousa Gerós, Ana, additional, Owen, Siân V., additional, Jambo, Kondwani C., additional, Kumwenda, Benjamin, additional, Veerapen, Natacha, additional, Besra, Gurdyal S., additional, Gordon, Melita A., additional, Hinton, Jay C. D., additional, Napolitani, Giorgio, additional, Salio, Mariolina, additional, and Simmons, Alison, additional

Published
2020
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14. African Salmonella Typhimurium sequence type 313 lineage 2 evades MAIT cell recognition by overexpressing RibB

Author

Preciado-Llanes, Lorena, primary, Aulicino, Anna, additional, Canals, Rocío, additional, Moynihan, Patrick, additional, Zhu, Xiaojun, additional, Jambo, Ndaru, additional, Nyirenda, Tonney, additional, Kadwala, Innocent, additional, Owen, Siân V., additional, Veerapen, Natacha, additional, Besra, Gurdyal S., additional, Gordon, Melita A., additional, Hinton, Jay C. D., additional, Napolitani, Giorgio, additional, Salio, Mariolina, additional, and Simmons, Alison, additional

Published
2019
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16. Invasive Salmonella exploits divergent immune evasion strategies in infected and bystander dendritic cell subsets

Author

Aulicino, Anna, primary, Rue-Albrecht, Kevin C., additional, Preciado-Llanes, Lorena, additional, Napolitani, Giorgio, additional, Ashley, Neil, additional, Cribbs, Adam, additional, Koth, Jana, additional, Lagerholm, B. Christoffer, additional, Ambrose, Tim, additional, Gordon, Melita A., additional, Sims, David, additional, and Simmons, Alison, additional

Published
2018
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17. Adenoviral-Vectored Mayaro and Chikungunya Virus Vaccine Candidates Afford Partial Cross-Protection From Lethal Challenge in A129 Mouse Model.

Author

Kroon Campos, Rafael, Preciado-Llanes, Lorena, Azar, Sasha R., Kim, Young Chan, Brandon, Olivia, López-Camacho, César, Reyes-Sandoval, Arturo, and Rossi, Shannan L.

Subjects
CHIKUNGUNYA virus, VIRAL vaccines, ANTIBODY titer, CYTOSKELETAL proteins, ACUTE diseases
Abstract

Mayaro (MAYV) and chikungunya viruses (CHIKV) are vector-borne arthritogenic alphaviruses that cause acute febrile illnesses. CHIKV is widespread and has recently caused large urban outbreaks, whereas the distribution of MAYV is restricted to tropical areas in South America with small and sporadic outbreaks. Because MAYV and CHIKV are closely related and have high amino acid similarity, we investigated whether vaccination against one could provide cross-protection against the other. We vaccinated A129 mice (IFNAR −/−) with vaccines based on chimpanzee adenoviral vectors encoding the structural proteins of either MAYV or CHIKV. ChAdOx1 May is a novel vaccine against MAYV, whereas ChAdOx1 Chik is a vaccine against CHIKV already undergoing early phase I clinical trials. We demonstrate that ChAdOx1 May was able to afford full protection against MAYV challenge in mice, with most samples yielding neutralizing PRNT80 antibody titers of 1:258. ChAdOx1 May also provided partial cross-protection against CHIKV, with protection being assessed using the following parameters: survival, weight loss, foot swelling and viremia. Reciprocally, ChAdOx1 Chik vaccination reduced MAYV viral load, as well as morbidity and lethality caused by this virus, but did not protect against foot swelling. The cross-protection observed is likely to be, at least in part, secondary to cross-neutralizing antibodies induced by both vaccines. In summary, our findings suggest that ChAdOx1 Chik and ChAdOx1 May vaccines are not only efficacious against CHIKV and MAYV, respectively, but also afford partial heterologous cross-protection. [ABSTRACT FROM AUTHOR]

Published
2020
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18. Single-Cell and Time-Resolved Profiling of Intracellular SalmonellaMetabolism in Primary Human Cells

Author

Xu, Jiabao, Preciado-Llanes, Lorena, Aulicino, Anna, Decker, Christoph Martin, Depke, Maren, Gesell Salazar, Manuela, Schmidt, Frank, Simmons, Alison, and Huang, Wei E.

Abstract

The intracellular pathogen Salmonella entericahas evolved an array of traits for propagation and invasion of the intestinal layers. It remains largely elusive how Salmonellaadjusts its metabolic states to survive inside immune host cells. In this study, single-cell Raman biotechnology combined with deuterium isotope probing (Raman-DIP) have been applied to reveal metabolic changes of the typhoidal SalmonellaTyphi Ty2, the nontyphoidal SalmonellaTyphimurium LT2, and a clinical isolate Typhimurium D23580. By initially labeling the Salmonellastrains with deuterium, we employed reverse labeling to track their metabolic changes in the time-course infection of THP-1 cell line, human monocyte-derived dendritic cells (MoDCs) and macrophages (Mf). We found that, in comparison with a noninvasive serovar, the invasive Salmonellastrains Ty2 and D23580 have downregulated metabolic activity inside human macrophages and dendritic cells and used lipids as alternative carbon source, perhaps a strategy to escape from the host immune response. Proteomic analysis using high sensitivity mass spectrometry validated the findings of Raman-DIP analysis.

Published
2019
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22. Contact-dependent suppression of CD4 T-cell activation and proliferation by B cells activated through IgD cross-linking.

Author

Preciado‐Llanes, Lorena, Wing, James B., Foster, Rachel A., Carlring, Jennifer, Lees, Andrew, Read, Robert C., and Heath, Andrew W.

Subjects
*CD4 antigen, *IMMUNOGLOBULIN D, *IMMUNOSUPPRESSION, *T cells, *B cells, *CELL proliferation, *PROTEIN crosslinking
Abstract

Although the co-stimulatory interaction between B and T cells is well defined, recent evidence suggests that B cells also have a regulatory role. Here, we show that B cells activated using anti-IgD conjugated to dextran (α-δ-dex) directly inhibit T-cell receptor-induced CD4 T-cell activation, proliferation and cytokine production. This effect was observed in CD4 T cells activated both with and without CD28 co-stimulation. T-cell viability was unaffected, and the T-cell suppressive effect was mediated by contact with IgD-activated purified B cells and not by interleukin-10 or other soluble factors. This is the first evidence of IgD-activated B cells mediating inhibition of activation and proliferation of CD4 T cells in humans. [ABSTRACT FROM AUTHOR]

Published
2015
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23. A Single and Un-Adjuvanted Dose of a Chimpanzee Adenovirus-Vectored Vaccine against Chikungunya Virus Fully Protects Mice from Lethal Disease.

Author

Campos, Rafael Kroon, Preciado-Llanes, Lorena, Azar, Sasha R., Lopez-Camacho, Cesar, Reyes-Sandoval, Arturo, and Rossi, Shannan L.

Subjects
CHIKUNGUNYA virus, AEDES aegypti, CHIKUNGUNYA, CHIMPANZEES, VACCINES, ALPHAVIRUS diseases, WEIGHT loss, ADENOVIRUS diseases
Abstract

The mosquito-borne chikungunya virus (CHIKV) has become a major global health problem. Upon infection, chikungunya fever (CHIKF) can result in long-term joint pain and arthritis, and despite intense research, no licensed vaccine for CHIKV is available. We have developed two recombinant chimpanzee adenovirus-vectored vaccines (ChAdOx1) that induce swift and robust anti-CHIKV immune responses with a single dose, without the need for adjuvants or booster vaccines. Here, we report the vaccines' protective efficacies against CHIKV infection in a lethal A129 mouse model. Our results indicate that a single, un-adjuvanted ChAdOx1 Chik or ChAdOx1 Chik ΔCap dose provided complete protection against a lethal virus challenge and prevented CHIKV-associated severe inflammation. These candidate vaccines supported survival equal to the attenuated 181/25 CHIKV reference vaccine but without the vaccine-related side effects, such as weight loss. Vaccination with either ChAdOx1 Chik or ChAdOx1 Chik ΔCap resulted in high titers of neutralizing antibodies that are associated with protection, indicating that the presence of the capsid within the vaccine construct may not be essential to afford protection under the conditions tested. We conclude that both replication-deficient ChAdOx1 Chik vaccines are safe even when used in A129 mice and afford complete protection from a lethal challenge. [ABSTRACT FROM AUTHOR]

Published
2019
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