Human T-lymphotropic virus type 1 (HTLV-1) persists by driving clonal proliferation of infected T lymphocytes. A high proviral load predisposes to HTLV-1-associated diseases. Yet the reasons for the variation within and between persons in the abundance of HTLV-1-infected clones remain unknown. We devised a highthroughput protocol to map the genomic location and quantify the abundance of > 91 000 unique insertion sites of the provirus from 61 HTLV-1 ؉ persons and > 2100 sites from in vitro infection. We show that a typical HTLV-1-infected host carries between 500 and 5000 unique insertion sites. We demonstrate that negative selection dominates during chronic infection, favoring establishment of proviruses integrated in transcriptionally silenced DNA: this selection is significantly stronger in asymptomatic carriers. We define a parameter, the oligoclonality index, to quantify clonality. The high proviral load characteristic of HTLV-1- IntroductionHuman T-lymphotropic virus type 1 (HTLV-1) causes adult T-cell leukemia-lymphoma (ATLL), HTLV-1-associated myelopathy/ tropical spastic paraparesis (HAM/TSP), uveitis, and infective dermatitis. It is estimated that 15 to 20 million persons live with HTLV-1 infection worldwide. A small proportion (up to 7%, depending on the area) of HTLV-1-infected persons develop disease, whereas the majority remain asymptomatic carriers (ACs). Infection occurs via breastfeeding, transfusion of infected cellular blood products, or sexual intercourse. Symptoms appear after a long period (years or decades) of clinical latency. 1 The HTLV-1 proviral load (PVL) remains stable within each infected person and correlates with the outcome of infection. However, the PVL varies widely among infected people, even within a particular diagnostic group. [2][3][4] The sequence of HTLV-1 is also stable within a person, 5,6 indicating that the PVL is maintained in vivo mainly by mitosis of infected cells during the chronic phase of the infection. This interpretation is supported by the observation that individual clones of infected cells can persist in patients for several years. 7-9 Thus, it has been hypothesized that infectious transmission of HTLV-1 is important early in infection across the virologic synapse, 10 whereas mitotic replication is responsible for maintaining proviral load once a persistent infection has been established and reached an equilibrium with the immune response. 11 In approximately 5% of infected people, persistent clonal proliferation culminates in malignant transformation in the disease ATLL. 7,8 The leukemic clones carry generally one (complete or defective) provirus per cell. [12][13][14] There has been a longstanding debate on the question of whether HTLV-1 is latent or persistently expressed in vivo. Persistent expression is strongly suggested by the extensive evidence that the strong, chronically activated cytotoxic T lymphocyte (CTL) response to HTLV-1 limits the proviral load and reduces the risk of HAM/TSP. 11 Furthermore, there is both experimental evidence 15 and th...

We have analyzed host cell genes linked to HIV replication that were identified in nine genome-wide studies, including three independent siRNA screens. Overlaps among the siRNA screens were very modest (<7% for any pairwise combination), and similarly, only modest overlaps were seen in pairwise comparisons with other types of genome-wide studies. Combining all genes from the genome-wide studies together with genes reported in the literature to affect HIV yields 2,410 protein-coding genes, or fully 9.5% of all human genes (though of course some of these are false positive calls). Here we report an “encyclopedia” of all overlaps between studies (available at http://www.hostpathogen.org), which yielded a more extensively corroborated set of host factors assisting HIV replication. We used these genes to calculate refined networks that specify cellular subsystems recruited by HIV to assist in replication, and present additional analysis specifying host cell genes that are attractive as potential therapeutic targets.

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Cancer treatments are often more successful when the disease is detected early. We evaluated the feasibility and safety of multicancer blood testing coupled with positron emission tomography–computed tomography (PET-CT) imaging to detect cancer in a prospective, interventional study of 10,006 women not previously known to have cancer. Positive blood tests were independently confirmed by a diagnostic PET-CT, which also localized the cancer. Twenty-six cancers were detected by blood testing. Of these, 15 underwent PET-CT imaging and nine (60%) were surgically excised. Twenty-four additional cancers were detected by standard-of-care screening and 46 by neither approach. One percent of participants underwent PET-CT imaging based on false-positive blood tests, and 0.22% underwent a futile invasive diagnostic procedure. These data demonstrate that multicancer blood testing combined with PET-CT can be safely incorporated into routine clinical care, in some cases leading to surgery with intent to cure.