Toxoplasmosis and intestinal protozoa
Research Lines
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Research
The Molecular Virology group focuses its research on the study of HIV-1 genetic variation and viral evolution using both in vitro and ex vivo approaches, structured around the following research lines:
- Non-progressor patients. These patients maintain control of the disease in the absence of antiretroviral therapy and have therefore been proposed as a model of functional cure. Our objective is to study the contribution of viral factors to disease control through biological characterization and analysis of viral evolution in individuals with undetectable viral loads (elite controllers, EC), compared with individuals showing other patterns of viral control.
- Viral envelope. This viral protein is key in determining viral fitness. Therefore, its functionality significantly affects infection progression. In collaboration with Dr. Blanco and Dr. Valenzuela, we study which specific events (CD4 binding, fusogenicity, etc.) are associated with envelope functionality. To this end, we have analyzed envelopes from individuals with different patterns of disease progression. Some of these have been contributed to the AIDS Research Network envelope biobank for broader use.
- Dual infection. Infection with more than one viral variant (either through co-infection or superinfection) may have consequences for infection pathogenesis. Within our group, different aspects of DI have been analyzed, including its detection in non-progressor patients, its prevalence and incidence in Spain, and its influence on the neutralizing antibody response.
- Molecular Epidemiology. The group has analyzed viral evolution throughout the epidemic in Spain and in other countries (the Netherlands, Italy, Germany, Uruguay, Panama, Brazil, etc.).
- Role of amino acid residues in reverse transcriptase. We study the role of specific amino acid residues in HIV-1 reverse transcriptase in enzymatic function and replication capacity using an infectious molecular clone previously obtained by the group.
- “In vitro” variability. Serial passage studies have been used to detect the mechanisms responsible for the gain or loss of viral fitness.
- Antiviral studies. We have analyzed the selection of resistance mutations in vitro against different antivirals, as well as the effect of these mutations on viral fitness, and the activity of new antivirals such as ATR inhibitors.
Virological Diagnosis and Reference in HIV and HTLV Infections
The research group provides diagnostic and reference activities through the service portfolio of the National Center for Microbiology to the entire Spanish National Health System.
These services include:
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Diagnosis and reference of HIV infection (types 1 and 2) through detection of specific antibodies and detection of proviral DNA by PCR.
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Diagnosis and reference of HTLV-I/II infection through detection of specific antibodies and detection of proviral DNA by PCR. Quantification of HTLV-1 proviral load by real-time PCR.
European Union Reference Laboratory (EURL) in the field of in vitro diagnostic medical devices for microbiological diagnosis (IVD) of HIV and HTLV (Regulation 2023/2713 of December 5th, 2023). Our role is to confirm the reliability and effectiveness of devices for detecting these pathogens and to ensure their specific performance requirements through laboratory testing before they can be marketed within the European Union.
Research projects
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- Towards a functional cure: Implications of early antiretroviral therapy and hormonal changes on the HIV reservoir in perinatally infected adolescents. Health Research Fund (FIS) – Carlos III Health Institute (01/01/2026 – 31/12/2028). €72,000. PI: María Pernas, Concepción Casado.
- Determination of factors associated with protection against Human Immunodeficiency Virus type 1 reinfection: Identification of correlates of protection. 9th Gilead Fellowship Program for Biomedical Research, Gilead Sciences, S.L. (01/07/2023 – 30/06/2025). €16,330. PI: María Pernas.
- Impact of the envelope on HIV viral replication: New avenues for vaccine development. Health Research Fund (FIS) – Carlos III Health Institute (01/01/2020 – 31/12/2023). €53,000. PI: María Pernas, Concepción Casado.
- Study of HIV-1 virulence in recently infected patients and its contribution, together with clinical and epidemiological factors, to disease progression. Ministry of Economy and Competitiveness. State Program for Scientific and Technical Research and Innovation (30/12/2016 – 30/06/2021). €145,000. PI: Concepción Casado, Cecilio López-Galíndez.
-Contribution of HIV-1 dual infection to virological and clinical evolution in homo/bisexual men. Health Research Fund (FIS) – Carlos III Health Institute (01/01/2014 – 31/01/2016). €74,410. PI: Cecilio López-Galíndez.
- Characterization of non-pathogenic HIV variants obtained “ex vivo” and “in vitro” for the study of disease pathogenesis. Ministry of Science and Innovation (01/01/2011 – 31/01/2014). €169,400. PI: Cecilio López-Galíndez.
- Spanish AIDS Research Network (RIS-RETIC). Carlos III Health Institute (02/01/2017 – 02/01/2022). €195,212. PI: Cecilio López-Galíndez, Concepción Casado.
Publications
María José Ruiz-Lopéz, Milagros Muñoz-Chimeno, Jordi Figuerola, Ana M. Gavilán, Sarai Varona, Isabel Cuesta, Josué Martínez-de la Puente, Angel Zaballos, Francisca Molero, Ramón C. Soriguer, Mª Paz Sánchez-Seco, Santiago Ruiz, Ana Vázquez. Genomic analysis of West Nile virus lineage 1 isolated from mosquitoes
María José Ruiz-Lopéz, Milagros Muñoz-Chimeno, Jordi Figuerola, Ana M. Gavilán, Sarai Varona, Isabel Cuesta, Josué Martínez-de la Puente, Angel Zaballos, Francisca Molero, Ramón C. Soriguer, Mª Paz Sánchez-Seco, Santiago Ruiz, Ana Vázquez. Genomic analysis of West Nile virus lineage 1 isolated from mosquitoes from 2020-2021 outbreak occurred in Andalusia, Spain. Viruses 2023, 15, 266. https://doi.org/10.3390/v15020266
DOIJordi Figuerola, Miguel Ángel Jiménez-Clavero, María José Ruíz-López, Francisco Llorente, Santiago Ruiz, Andreas Hoefer, Pilar Aguilera-Sepúlveda, Jéssica Jiménez Peñuela1, Olaya García-Ruiz, Laura Herrero, Ramón C. Soriguer, Raúl Fernández Delgado, Mari Paz Sánchez-Seco, Josué Martínez-de la Puente, Ana Vázquez. A One Health view of the West Nile virus outbreak in Andalusía (Spain) in 2020
Jordi Figuerola, Miguel Ángel Jiménez-Clavero, María José Ruíz-López, Francisco Llorente, Santiago Ruiz, Andreas Hoefer, Pilar Aguilera-Sepúlveda, Jéssica Jiménez Peñuela1, Olaya García-Ruiz, Laura Herrero, Ramón C. Soriguer, Raúl Fernández Delgado, Mari Paz Sánchez-Seco, Josué Martínez-de la Puente, Ana Vázquez. A One Health view of the West Nile virus outbreak in Andalusía (Spain) in 2020. Emerg Microbes Infect. 2022 Dec;11(1):2570-2578. doi: 10.1080/22221751.2022.2134055.
DOIHCV eradication with IFN-based therapy does not completely restore gene expression in PBMCs from HIV/HCV-coinfected patients.
10.1186/s40249-021-00894-5. 9. Brochado O, Martínez I (*), Berenguer J, Medrano L, González-García J, Jiménez-Sousa MA, Carrero A, Hontañón V, Navarro J, Guardiola JM, Pérez-Latorre L, Micán R, Fernández-Rodríguez A (‡), Resino S (* ‡). HCV eradication with IFN-based therapy does not completely restore gene expression in PBMCs from HIV/HCV-coinfected patients. J Biomed Sci 2021; 28:23 (A; FI= 12.77; D1, Medicine, Research & Experimental; JCR 2021). PMID: 33785040. DOI: 10.1186/s12929-021-00718-6.
PUBMEDRelationship of vitamin D status with advanced liver fibrosis and response to hepatitis C virus therapy: A meta-analysis.
12. García-Álvarez M, Pineda-Tenor D, Jiménez-Sousa Ma, Fernández-Rodríguez A, Guzmán-Fulgencio M; Resino S (*). Relationship of vitamin D status with advanced liver fibrosis and response to hepatitis C virus therapy: A meta-analysis. Hepatology. 2014, 6(5):1541-1550. (A; FI= 11.05; D1, Gastroenterology & Hepatology; JCR 2014). PMID: 24975775. DOI: 10.1002/hep.27281.
PUBMEDContent with Investigacion .
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Javier García Pérez
Investigador Doctor
ORCID code: 0000-0001-7551-7803
Graduated in Biochemistry (1999) and Molecular Biology (2000) from the Autonomous University of Madrid (UAM), he obtained a predoctoral fellowship “ISCIII” in the AIDS Immunopathology laboratory, where he developed new techniques based on recombinant viruses. His doctoral thesis focused on the application of this technological development to the study of the replicative capacity of HIV-1 and its resistance to antiretroviral drugs, obtaining the degree of Doctor of Science from the UAM in 2007.
Thanks to a short postdoc in 2008 and several stays between 2009 and 2015 at the Viral Pathogenesis Unit of the Institut Pasteur in Paris he extended his training in the study of HIV-1 envelope and tropism. Between 2015 and 2019 he rejoins the AIDS Immunopathology Unit at ISCIII, focusing his work on the study of the functional capacity of founder viruses, as well as variants of the virus with interest in Public Health due to its recent expansion in our country. He is currently leading a project on the study of a mutation in transportin 3 observed in patients with a very rare muscular dystrophy (LGMDD2) that confers protection against HIV-1 infection.
During the last 5 years he combines this activity in HIV-1 with the participation and leadership of different clinical trials and studies investigating the immunity generated in people vaccinated against SARS-CoV-2 infection.
Since 2024 he is a “Investigador Doctor fuera de Convenio” at the Spanish National Centre of Microbiology and he currently coordinates together with Dr. Francisco Díez Fuertes the AIDS Immunopathology Unit.
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Francisco Díez Fuertes
Investigador Doctor Indefinido
ORCID code: 0000-0003-2413-9229
Degree in Biology from the University of León, PhD specialized in molecular virology from the Complutense University of Madrid in 2010 and master's degree in bioinformatics and computational biology from the same university in 2012. He has done research stays at University of Illinois at Urbana Champaign (USA) in 2010, Nebraska Center for Virology (USA) in 2011, Institut Pasteur (France) in 2013 and J. Craig Venter Institute (USA) in 2015-2016.
He joined the AIDS Immunopathology Unit in 2013 with a contract from the “Sara Borrell” postdoctoral program. After a period at the August Pi i Sunyer Biomedical Research Institute in Barcelona he rejoins the AIDS Immunopathology Unit in 2020 as a PhD researcher.
His lines of research have focused on the genomic and transcriptomic characterization of extreme phenotypes in HIV-1 infection, including long-term non-progressors and elite controllers. He collaborates with other laboratories of the center in the analysis of outbreaks caused by viruses with interest in Public Health, as well as in evolutionary studies on genomic epidemiology. Since 2020 he has led different clinical studies on COVID-19. Currently, he combines omics sciences with different bioinformatics tools to answer different scientific questions in the field of virology, especially in HIV-1 and SARS-CoV-2 research. He currently coordinates together with Dr. Javier García Pérez the AIDS Immunopathology Unit.
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Nuria González Fernández
Investigadora Contratada indefinida
ORCID code: 0000-0002-0087-5144
She completed her PhD in 2007 (Universidad Autónoma de Madrid), focused on the development of an envelope recombinant virus system to characterize HIV-1 tropism, as well as on the study of the role of the chemokine CXCL12 in virus propagation at the infectious synapse. Part of this work was carried out in the laboratory of Dr. Quentin Sattentau at the University of Oxford.
During her postdoctoral period, she expanded her research on the mechanisms of HIV entry and specialized in the study of the neutralizing response. She developed a system to measure neutralizing activity, which has been used in clinical trials of HIV vaccine candidates. During a stay at the Vaccine Research Center, NIH (USA), she acquired experience in various techniques for the characterization of broadly neutralizing antibodies, leading to new collaborations and research projects, which she is currently developing in the AIDS Immunopathology Unit of the Carlos III Health Institute.
She has participated in research networks such as EAVI2020 (co-PI), CIBERINFEC, RIS and EUROPRISE (EU). Since 2014 she is a professor of the Master in Microbiology applied to Public Health and Infectious Diseases Research at the University of the University of Alcalá and, since 2023, of the Master in Human Immunodeficiency Virus Infection at the University Rey Juan Carlos.
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Mercedes Bermejo Herrero
Investigadora post-doctoral contratada
ORCID code: 0000-0001-9909-8578
Degree and PhD in Biological Sciences (Biochemistry and Molecular Biology) from the Autonoma University of Madrid. Her doctoral thesis studied the expression of CXCR4 and SDF-1/CXCL12 in lymphocytes and dendritic cells and their implications in HIV-1 infection.
She has completed internships in various laboratories: the Immunology Department of the Gregorio Marañón University Hospital in Madrid, the Research Center of the 12 de Octubre University Hospital in Madrid (where she was head of the flow cytometry service) and is currently at the CNM (National Research Center) of the Carlos III Health Institute.
Her research interests have focused on the study of HIV biology and its interaction with the immune system. She has currently participated in clinical trials, CombiVacs and ENE-Covid Senior, and in collaboration with Hipra.
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Rubén Ayala Suárez
Técnico Superior Especializado OPI
ORCID code: 0000-0002-1271-646.
Graduated in Biotechnology from the University of Cadiz (2015), Master in Microbiology of Infectious Diseases (2016) and PhD in Functional Biology from the University of Alcalá (2023). He carried out his PhD Thesis at the AIDS Immunopathology laboratory (CNM) on post-translational epigenetic mechanisms of natural control of HIV infection. In the same period, he completed a Diploma in Bioinformatics at Pablo de Olavide University (2021).
In 2023 he joined as a postdoctoral researcher in the HIV and AIDS research group at the August Pi i Sunyer Biomedical Research Institute (Barcelona), where he worked on the relationship of HIV and senescence until his incorporation as a Técnico Superior Especializado in the AIDS Immunopathology unit of the Spanish National Center of Microbiology (ISCIII) in 2025.
The main research projects in which he participates focus on resistance and natural control to HIV infection, as well as the evaluation of the immune response in vaccine trials, using mainly bioinformatics techniques focused on massive sequencing (RNA-Seq, single-cell, genome sequencing), the application of biostatistics and machine learning in data management.
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Almudena Cascajero Díaz
Técnico de laboratorio
ORCID code: 0000-0002-9654-3100
Técnico Superior de Actividades Técnicas y Profesionales (Unidades de Inmunopatología del SIDA y Legionella, Centro Nacional de Microbiología). Clinical Diagnostic Laboratory Technician by IES Renacimiento de Madrid.
Experience in cloning techniques and characterization of neutralizing antibodies and participation in different projects on the pathogenesis of HIV by studying the viral envelope and the mechanisms of resistance to antiretroviral drugs. This experience has subsequently allowed me to participate in 5 multicenter clinical studies studying the immune response against different variants of SARS-CoV-2.
Since 2021, I also participate as a laboratory technician in the Legionella Unit as a support to the Spanish National Health System through the microbiological surveillance of the disease to contribute to the prevention and control of legionellosis.
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Manuela Beltrán Vicente
Técnico de Laboratorio Indefinido
ORCID code: 0000-0001-6185-2280
Senior Technician of Technical and Professional Activities (AIDS Immunopathology Unit, Spanish National Center of Microbiology).
Clinical Analysis Laboratory Specialist Technician by IES Las Musas (Madrid, 1996). Demonstrated experience in the development of strategies against HIV, focused on the screening of compounds of both natural and synthetic origin with antiviral activity and identification and evaluation of potential therapeutic agents, as well as the screening of serological samples for the study of immunity for the identification of possible strategies for the development of vaccines against HIV. -

Silvia Jara Herrera
Técnico de Laboratorio Contratado CIBERINFEC
ORCID code: 0009-0001-2842-2040
Clinical and Biomedical Diagnostic Laboratory Technician.
She is currently working in the AIDS Immunopathology Unit of the Spanish National Center of Microbiology (ISCIII) with a contract through the Spanish Biomedical Research Networking Centre in Infectious Diseases (CIBER-INFEC).
She worked from March 2020 to September 2024 at the Department of Animal Health (Faculty of Veterinary Medicine) of the Universidad Complutense de Madrid.
She has experience in serological techniques (ELISA, Western Blot and IFA), cell culture and molecular biology.
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Irene Díaz Marín
Técnico de laboratorio contratado
Clinical and Biomedical Diagnostics laboratory technician by CIFP Politécnico de Murcia-CESUR and graduated in Journalism from the Complutense University of Madrid.
She is currently at the AIDS Immunopathology Unit of the Spanish National Center of Microbiology with a contract of the “Garantía Juvenil” program (Community of Madrid), where she performs technical tasks in several research projects about HIV-1 and COVID-19.
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Laura Capa Muñoz
Investigadora post-doctoral contratada
ORCID code: 0000-0002-0234-331X
Degree in Biological Sciences from the Universidad Autónoma de Madrid and PhD from the Universidad Complutense de Madrid, she has a master's degree in AIDS (Universidad Complutense de Madrid) and a master's degree in HIV infection (Universidad Rey Juan Carlos de Madrid).
Professional activity developed mainly in the study of infectious diseases, both in the field of basic research in public research centers and in the pharmaceutical industry, as well as in the field of public health and scientific management. She has worked in the international response to the HIV pandemic, representing the Ministry of Health as an expert in meetings of the European Commission and collaborated with the WHO. At the Instituto de Salud Carlos III, she has led the scientific management of national and European projects in the AIDS Immunopathology Unit and has been part of the Institute's Data Protection Working Group. Currently, she continues to coordinate the Cohort of Long-Term Non-Progressing Patients created by the Spanish AIDS Research Network (RIS), is part of the coordination team of the PhD Program in Biomedical Sciences and Public Health IMIENS-UNED-ISCIII and of the Institute's Working Group on Equality.
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José Alcamí Pertejo
Profesor de Investigación
ORCID code: 0000-0003-0023-7377
Degree in Medicine from the Universidad Autónoma and Doctor of Medicine from the Universidad Complutense de Madrid. Specialist in Internal Medicine at Hospital 12 de Octubre (1982-1986). Training in immunology by means of a Research Staff grant (1986-1988). Research associate at the Viral Immunology Unit of the Pasteur Institute in Paris (1988-1992) where he obtained a Master in Immunopathology from the Institute. Research Professor since 2015, he directed the AIDS Immunopathology Unit at the National Microbiology Center since 2000. Coordinator since 2003 of the Spanish AIDS Research Network, he participates as group leader in European networks of excellence whose objective is the development of new vaccines, drugs and microbicides against HIV/AIDS: EUROPRISE, AIM-HIV, CHAARM and EAVI2020. Since 2019 he has been the Scientific Director of the HIV Unit at the Hospital Clinic of Barcelona. He has been Professor of Immunology and Virology at the European University of Madrid between 2012 and 2014 and Director of the Master in Public Health and Research in Infectious Diseases at the University of Alcalá de Henares from 2014 to 2023.
Author of more than 200 scientific articles in high impact journals such as Nature, Nature Reviews in Microbiology, Nature Medicine, Lancet and Journal of Clinical Investigation and more than 80 chapters in books. Scientific disseminator through his YouTube channel and on the X platform. He has been principal investigator of more than 50 research projects, including European projects and an American NIH project.
Consultant for FIS and ANEP since 1992, member of the scientific council of the French Evaluation Agency in AIDS between 2008 and 2014, evaluator of EU FP6, FP7 and H2020 programs, member of the external scientific council of the Global Health Institute (Hospital Ramón y Cajal), scientific collaborator of the EMA and AEMPS where he has been part of the biotechnology, antivirals and vaccines committees. Scientific member of the EU Vaccelerate consortium and associate editor of the Journal of Virology, Frontiers in Cellular and Infection Microbiology and HIV medicine.
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Paloma Jiménez Santana
Técnico de laboratorio contratado
List of staff
Additional Information
Our group carries out research studies in the diagnosis, reference and epidemiology of zoonoses and emerging diseases, both indigenous and imported, caused by protozoa. Coordinates the study in the human field with the relevance of the animal field and the environment (One Health initiative), with special interest in Toxoplasmosis, a highly prevalent zoonosis (WHO lists it as the 3rd food-borne zoonosis in Europe), presents a complex epidemiological cycle and causes neurological, ocular and systemic symptoms. We carry out diagnostic and characterization studies of Toxoplasma gondii from human and animal cases, to obtain greater epidemiological information and analyze the possible relationship with virulence and pathology.
Cryptosporidium, Giardia, Blastocystis and Entamoeba histolytica cause gastrointestinal diseases, affecting children, immunosuppressed people and travelers. They can cause outbreaks. We develop diagnostic and characterization studies of isolates from humans and animals, from different areas and countries, to establish the presence of the main species and genotypes and the epidemiological situation. We are beginning the study of associations between these parasites and the intestinal microbiota.
The pathogenic Free-Living Amoebas, Acanthamoeba, Naegleria fowleri and Balamuthia mandrillaris, cause emerging diseases, highlighting the importance of the environment in transmission. They cause underdiagnosed neurological and ocular cases. The diagnostic and genotyping study of human and animal isolates that we are carrying out aims to establish the real prevalence, transmission routes and epidemiology.
Our group carries out research studies in the diagnosis, reference and epidemiology of zoonoses and emerging diseases, both indigenous and imported, caused by protozoa. Coordinates the study in the human field with the relevance of the animal field and the environment (One Health initiative), with special interest in Toxoplasmosis, a highly prevalent zoonosis (WHO lists it as the 3rd food-borne zoonosis in Europe), presents a complex epidemiological cycle and causes neurological, ocular and systemic symptoms. We carry out diagnostic and characterization studies of Toxoplasma gondii from human and animal cases, to obtain greater epidemiological information and analyze the possible relationship with virulence and pathology.
Cryptosporidium, Giardia, Blastocystis and Entamoeba histolytica cause gastrointestinal diseases, affecting children, immunosuppressed people and travelers. They can cause outbreaks. We develop diagnostic and characterization studies of isolates from humans and animals, from different areas and countries, to establish the presence of the main species and genotypes and the epidemiological situation. We are beginning the study of associations between these parasites and the intestinal microbiota.
The pathogenic Free-Living Amoebas, Acanthamoeba, Naegleria fowleri and Balamuthia mandrillaris, cause emerging diseases, highlighting the importance of the environment in transmission. They cause underdiagnosed neurological and ocular cases. The diagnostic and genotyping study of human and animal isolates that we are carrying out aims to establish the real prevalence, transmission routes and epidemiology.