Malignant syphilis in an AIDS patient.

Malignant syphilis is an uncommon, but not unknown, ulcerative variation of secondary syphilis. The lesions typically begin as papules, which quickly evolve to pustules and then to ulcers with elevated edges and central necrosis. It is usually, but not mandatory, found in patients with some level of immunosuppression, such as HIV patients, when the TCD4(+) cell count is >200 cells/mm(3). Despite the anxiety the lesions cause, this form of the disease has a good prognosis. The general symptoms disappear right after the beginning of treatment, and lesions disappear over a variable period. This study reports the case of a 27-year-old man who has been HIV positive for 6 years, uses antiretroviral therapy incorrectly, has a TCD4(+) cell count of 340 cells/mm(3), a VDRL of 1:128 and itchy disseminated hyperchromic maculopapular lesions with rupioid crusts compatible with malignant syphilis.

Network of phosphatases and HDAC complexes at repressed chromatin.

Tight regulation of gene expression is achieved by a variety of protein complexes that selectively bind chromatin, modify it and change its transcription competency. Histone acetylases (HATs) and deacetylases (HDACs) play an important role in this process. They can generate transcriptionally active or inactive chromatin through the addition (HATs) or removal (HDACs) of acetyl groups on histones, respectively. Repo-Man is a Protein Phosphatase 1 targeting subunit that accumulates on chromosomes during mitotic exit and mediates the removal of mitotic histone H3 phosphorylations. It was shown recently that Repo-Man also regulates heterochromatin formation in interphase and that its depletion favours the switch between transcriptionally inactive and active chromatin, demonstrating that its role goes well beyond mitosis. Here, we provide the first link between a phosphatase and HDAC complexes. We show that genome-wide Repo-Man binding sites overlap with chromatin regions bound by members of the three HDAC complexes (Sin3a, NuRD and CoREST). We establish that members of the NuRD and Sin3a HDAC complexes interact with Repo-Man by mass spectrometry and that Repo-Man is in close proximity to SAP18 (Sin3a) in interphase as observed by the Proximity Ligation Assay. Altogether, these data suggest a mechanism by which Repo-Man/PP1 complex, via interactions with HDACs, could stabilise gene repression.