Ricardo Rajsbaum, PhDRicardo Rajsbaum, PhD
Associate Professor
Department of Microbiology & Immunology

Phone: (409) 772-4917
Email: rirajsba@utmb.edu

Education:  PhD | 2009 | MRC National Institute for Medical Research, London, England
MSc | 1999 | Weizmann Institute of Science, Rehovot, Israel
BSc | 1996 | Universidad Nacional Autonoma de Mexico, Mexico

Overview: Innate immunity to virus infection. Pattern recognition receptor signaling, ubiquitin and E3- ubiquitin ligases in regulation of virus replication. Antagonism of innate immune response by viruses.

Work in the Rajsbaum laboratory focuses on the study of host-pathogen interactions and innate immune responses to viruses. Innate and cell-intrinsic immune responses are essential to protect host cells against pathogens. Members of the tripartite motif (TRIM) family of E3-ubiquitin ligases are involved in antiviral immunity by directly inhibiting viral replication or by sensing and transmitting signals to induce antiviral cytokines. However, to establish productive infection, viruses have developed sophisticated mechanisms to counteract host immune responses, including targeting TRIM proteins. Our lab is interested in elucidating the mechanisms by which TRIM proteins and other signaling molecules regulate antiviral functions and how viruses (Influenza, dengue, Zika, West Nile, Ebola, Nipah and other viruses) evade these immune responses. We and others have shown that members of the TRIM family (TRIM5, TRIM6, TRIM25) catalyze the synthesis of unanchored polyubiquitin chains that activate antiviral signaling pathways. In addition, new evidence indicates that TRIMs and ubiquitination of viral proteins can have both antiviral and proviral functions depending on the host environment. Our lab aims to dissect these molecular mechanisms that regulate virus replication using in vitro biochemical methods, primary immune cells, and in vivo animal models. We also hope to identify new components of innate immune signaling pathways and viral factors that could be targeted for therapeutic intervention.

Selected Publications:

  1. Envelope protein ubiquitination drives entry and pathogenesis of Zika virus.

    Giraldo MI, Xia H, Aguilera-Aguirre L, Hage A, van Tol S, Shan C, Xie X, Sturdevant GL, Robertson SJ, McNally KL, Meade-White K, Azar SR, Rossi SL, Maury W, Woodson M, Ramage H, Johnson JR, Krogan NJ, Morais MC, Best SM, Shi PY, Rajsbaum R. Nature. 2020 Jul 8. doi: 10.1038/s41586-020-2457-8. PMID: 32641828

  2. VAMP8 Contributes to the TRIM6-Mediated Type I Interferon Antiviral Response during West Nile Virus Infection.

    van Tol S, Atkins C, Bharaj P, Johnson KN, Hage A, Freiberg AN, Rajsbaum R. J Virol. 2020 Jan 6;94(2):e01454-19. doi: 10.1128/JVI.01454-19. Print 2020 Jan 6. PMID: 31694946

  3. To TRIM or not to TRIM: the balance of host-virus interactions mediated by the ubiquitin system.

    Hage A, Rajsbaum R. J Gen Virol. 2019 Dec;100(12):1641-1662. doi: 10.1099/jgv.0.001341. PMID: 31661051. Review

  4. The Host E3-Ubiquitin Ligase TRIM6 Ubiquitinates the Ebola Virus VP35 Protein and Promotes Virus Replication.

    Bharaj P, Atkins C, Luthra P, Giraldo MI, Dawes BE, Miorin L, Johnson JR, Krogan NJ, Basler CF, Freiberg AN, Rajsbaum R. J Virol. 2017 Aug 24;91(18):e00833-17. doi: 10.1128/JVI.00833-17. Print 2017 Sep 15. PMID: 28679761

  5. The Matrix Protein of Nipah Virus Targets the E3-Ubiquitin Ligase TRIM6 to Inhibit the IKKε Kinase-Mediated Type-I IFN Antiviral Response.

    Bharaj P, Wang YE, Dawes BE, Yun TE, Park A, Yen B, Basler CF, Freiberg AN, Lee B, Rajsbaum R. PLoS Pathog. 2016 Sep 13;12(9):e1005880. doi: 10.1371/journal.ppat.1005880. eCollection 2016 Sep. PMID: 27622505

  6. Unanchored K48-linked polyubiquitin synthesized by the E3-ubiquitin ligase TRIM6 stimulates the interferon-IKKε kinase-mediated antiviral response.

    Rajsbaum R, Versteeg GA, Schmid S, Maestre AM, Belicha-Villanueva A, Martínez-Romero C, Patel JR, Morrison J, Pisanelli G, Miorin L, Laurent-Rolle M, Moulton HM, Stein DA, Fernandez-Sesma A, tenOever BR, García-Sastre A. Immunity. 2014 Jun 19;40(6):880-95. doi: 10.1016/j.immuni.2014.04.018. Epub 2014 May 29. PMID: 24882218