Ricardo Rajsbaum, Ph.D.

Dr. Rajsbaum received his BSc from the National Autonomous University of Mexico (UNAM), in Mexico City, and his MSc from the Weizmann Institute of Science, Israel. He then received his Ph.D. from the National Institute for Medical Research, London, UK, in the laboratory of Anne O’Garra, and completed his postdoctoral training at Mount Sinai School of Medicine, New York in the laboratory of Adolfo Garcia-Sastre. Dr Rajsbaum joined the University of Texas Medical Branch (UTMB) as faculty in 2014 where he first developed his independent research program. While at UTMB Dr Rajsbaum’s lab made important contributions on the regulation of cytokine expression in immune cells, Pattern Recognition Receptor (TLR and RIG-I-like receptors) signaling, regulation and function of type-I Interferons (IFNs), and virus–host interactions, with a specific focus on the role of ubiquitin and TRIM E3-ubiquitin ligases in innate antiviral function. The lab identified novel mechanisms used by viruses to enhance their replication, by targeting host factors that can normally have antiviral functions. Dr. Rajsbaum's lab moved to Rutgers in May 2022 to develop the new Center for Virus-Host-Innate Immunity (CVHII). Current research is focused on the role of the E3-ubiquitin ligase TRIM6 during infections with highly pathogenic viruses (Ebola, Influenza, SARS-CoV-2), the role of the ubiquitin system in promoting replication of flaviviruses (Zika, dengue, West Nile), and SARS-CoV-2 replication,  and the role of unanchored polyubiquitin chains in regulation of innate immune signaling. The lab uses biochemical and in vitro approaches to understand molecular mechanisms as well as animal models to study physiological relevance. The lab is a highly collaborative and inclusive environment and extremely values diversity career development.

Relevant Publications
van Tol, Kalveram, Ilinykh, Ronk, Huang, Aguilera-Aguirre, Bharaj, Hage, Giraldo, Bukreyev, Freiberg, Rajsbaum (2022). Ubiquitination of Ebola virus VP35 at Lysine 309 Regulates VP35's Polymerase Co-Factor Function in Facilitating Viral Transcription and Virus Assembly. PLoS Pathog. 18(5):e1010532. doi: 10.1371/journal.ppat.1010532. eCollection 2022 May. PMID: 35533195
 
Hage A, Bharaj P, van Tol S, Giraldo MI, Gonzalez-Orozco M, Valerdi KM, Warren AN, Aguilera-Aguirre L, Xie X, Widen SG, Moulton HM, Lee B, Johnson JR, Krogan NJ, Garcia-Sastre A, Shi PY, Freiberg AN, and Rajsbaum R (2022). The RNA Helicase DHX16 recognizes specific viral RNA to trigger RIG-I-dependent Innate Antiviral Immunity. Cell Reports. 38(10):110434. doi: 10.1016/j.celrep.2022.110434. PMID: 35263596
 
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. (2020) Envelope protein ubiquitination drives entry and pathogenesis of Zika virus. Nature. 585, 414-419. DOI: 10.1038/s41586-020-2457-8. PMCID: PMC7501154. PMID: 32641828
 
Lokugamage KG*, Hage A*, de Vries M, Valero-Jimenez AM, Schindewolf C, Dittmann M, Rajsbaum R, Menachery VD. (2020). Type I interferon susceptibility distinguishes SARS-CoV-2 from SARS-CoV. J Virol. Sep 16;JVI.01410-20. doi: 10.1128/JVI.01410-20. PMID: 32938761
 
Xia H, Cao Z, Xie X, Zhang X, Chen JY, Wang H, Menachery VD, Rajsbaum R, Shi PY. (2020). Evasion of type-I interferon by SARS-CoV-2. Cell Reports. 33(1):108234. PMID: 32979938 DOI: https://doi.org/10.1016/j.celrep.2020.108234
 
Hage A and Rajsbaum R. (2019). To TRIM or not to TRIM: The balance of host-virus interactions mediated by the ubiquitin system. J Gen. Virol. 100(12), 1641-1662. PMID: 31661051
 
Bharaj P, Atkins C, Luthra P, Giraldo MI, Dawes BE, Miorin L, Johnson JR, Krogan NJ, Basler CF, Freiberg AN, Rajsbaum R (2017). The host E3-Ubiquitin ligase TRIM6 ubiquitinates the Ebola virus VP35 protein and promotes virus replication. J Virol. 91:e00833-17. PMID 28679761.
 
Bharaj P, Wang YE, Dawes BE, Yun TE, Park A, Yen B, Basler CF, Freiberg AN, Lee B, Rajsbaum R. (2016). The Matrix Protein of Nipah Virus Targets the E3-Ubiquitin Ligase TRIM6 to Inhibit the IKK?? Kinase-Mediated Type-I IFN Antiviral Response. PLoS Pathog. 12(9): e1005880. PMID 27622505.
 
Rajsbaum R*, Versteeg GA*, Schmid S, Maestre AM, Belicha-Villanueva A, Patel JR, Morrison J, Pisanelli G, Miorin L, Laurent-Rolle M, Fernandez-Sesma A, tenOever BR, Garc??a-Sastre A (2014). Unanchored K48-Linked Polyubiquitin Synthesized by the E3-Ubiquitin Ligase TRIM6 Stimulates the Interferon-IKK?? Kinase-Mediated Antiviral Response. Immunity 40(6), 880-95. PMID: 24882218
 
Versteeg GA*, Rajsbaum R*, S??nchez-Aparicio MT, Valdiviezo J, Shi M, Inn KS, Jung JU, Garc??a-Sastre A (2013). The E3-Ligase TRIM Family of Proteins Regulates Signaling Pathways Triggered by Innate Immune Pattern-Recognition Receptors. Immunity 38(2), 384-398. *These authors contributed equally

Innate immune responses are essential to protect host cells against pathogens. Upon infection, viruses are recognized by the host cell triggering signaling pathways leading to induction of type-I Interferons (IFN-I) and other cytokines that protect against infections. These responses need to be carefully balanced to avoid detrimental effects to the host. Post-translational modifications, including ubiquitination and phosphorylation, regulate the activity of immune signaling components. However, viruses have adapted to antagonize these responses. In addition, viruses can also take advantage of the host ubiquitin system to enhance their replication resulting in increased pathology. The Rajsbaum lab is interested in elucidating the molecular mechanisms of protective innate immune responses and the interplay that takes place with viruses.

The Rajsbaum lab focuses in three different aspects of virus-host interactions. 1) How viruses are recognized by the host cell via pattern recognition receptors (PRRs), especially RIG-I-like receptors and TLRs, and the regulation of these pathways, 2) how viruses have adapted to inhibit these antiviral pathways, and 3) How viruses hijack antiviral factors and turn them into host factors that promote virus replication.

Current projects include studies on E3-ubiquitin ligases of the TRIM family of proteins and their roles as proviral or antiviral factors. NIH-funded projects include studies on Influenza, SARS-CoV-2 and Ebola. The lab is also interested in flaviviruses (e.g. Zika, dengue, West Nile), and Paramyxoviruses (e.g. Nipah virus). The lab is highly collaborative and is involved in a large program project (P01) with UTMB. In this project (RP3) the Rajsbaum lab studies the Role of Posttranslational Protein Modifications in the Pathogenesis of Ebola Virus Disease
(see: https://www.utmb.edu/cbeid/projects/research-program-project/projects/rp3).

The Rajsbaum lab aims to understand these molecular mechanisms of the antiviral response using in vitro biochemical methods, primary immune cells, and in vivo animal models. The goal is to identify new components of innate immune signaling pathways and viral factors that could be targeted for therapeutic intervention. The lab highly values and inclusive and diverse environment. The lab encourages teamwork and new ideas and supports career development.