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Directory >> Lorenzo Giacani, PhD


Lorenzo Giacani, PhD

  • Assistant Professor, Department of Medicine, Division of Allergy and Infectious Diseases
  • Adjunct Assistant Profesor, Department of Global Health
    University of Washington

During syphilis infection, T. pallidum replication within early lesions triggers a strong inflammatory response that attracts macrophages, lymphocytes and plasma cells to the site of infection. Following the appearance of an adaptive host immune response, the majority of T. pallidum cells are cleared by opsonophagocytosis, and lesions spontaneously resolve, leading to the asymptomatic stage of the disease known as latency. Despite the host's efficient eradication, a few T. pallidum cells avoid immune clearance and persist in the host. In absence of treatment, this smoldering persistence can cause recrudescence of early symptoms or, after prolonged latency, can trigger disease reactivation and progression to its tertiary stage, characterized by manifestations such as gummatous disease, cardiovascular syphilis, general paresis or tabes dorsalis.

My work at the University of Washington focuses on the study of the pathogenesis of syphilis, and in particular, on the role of transcriptional regulation in T. pallidum in inducing phenotypic modifications that help the pathogen counteract the host defenses and persist in the face of a robust immune response. Additionally I use comparative genomics to identify T. pallidum genes that could be useful to devise new strain typing methods or polymorphic genes that could be involved in immune evasion and persistence. Another focus of my work is vaccine development. I am currently studying a novel putative outer membrane protein (OMP) of T. pallidum (named Tp0126) which is predicted to be T. pallidum OmpW homolog, to assess its ability to confer protective immunity against syphilis.

Selected Publications

Giacani L, Brandt S, Wujian K, Molini BJ, Iverson-Cabaral S, Ciccarese G, Drago F, Lukehart SA, Centurion-Lara A.Transcription of TP0126, Treponema pallidum subsp. pallidum Putative OmpW Homolog is Regulated by a Homopolymeric G Repeat. 2015. Infection and Immunity, Jun 83(6) 2275-89.
PubMed Abstract

Wujian K, Molini BJ, Lukehart SA, and Giacani L. Treponema pallidum subsp. pallidum TP0136 Protein Is Heterogeneous among Isolates and Binds Cellular and Plasma Fibronectin via its NH2-terminal end.2015. PLOS Neglected Tropical Diseases, Mar 20:9(3).
PubMed Abstract

Giacani L, Iverson-Cabral SL, King JC, Molini BJ, Lukehart SA, Centurion-Lara A. Complete Genome Sequence of the Treponema pallidum subsp. pallidum Sea81-4 Strain.Genome Announc. 2014 Apr 17;2(2).
PubMed Abstract

Giacani L, Tompa M, Denisenko O, Lukehart SA, and Centurion-Lara A.Identification of the Treponema pallidum subsp. pallidum TP0092 (s24) Regulon: Implications for Pathogen Persistence in the Host and Syphilis Pathogenesis. Journal of Bacteriology, 2013, 195(4):896-907.
PubMed Abstract

Giacani L, Brandt SL, Puray-Chavez M, Brinck Reid T, Godornes C, Molini BJ, Lukehart SA, Centurion-Lara A. Comparative Investigation of the Genomic Regions Involved in Antigenic Variation of the TprK Antigen among Treponemal Species, Subspecies, and Strains. Journal of Bacteriology, 2012. 194:16
PubMed Abstract

Giacani L, Chattopadhyay S, Centurion-Lara A, Jeffrey BM, Le HT, Molini BJ, Lukehart SA, Sokurenko E, Rockey DD. Footprint of positive selection in Treponema pallidum subsp. pallidum genome sequences suggests adaptive microevolution of the syphilis pathogen. PLoS Neglected Tropical Diseases, 2012.
PubMed Abstract

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