Publications by authors named "Yarchoan R"

The clinical management of people with multidrug-resistant (MDR) human immunodeficiency virus (HIV) remains challenging despite continued development of antiretroviral agents. A 58-year-old male individual with MDR HIV and Kaposi sarcoma (KS) was treated with a new antiretroviral regimen consisting of anti-CD4 domain 1 antibody UB-421 and capsid inhibitor lenacapavir. The individual experienced delayed but sustained suppression of plasma viremia and a substantial increase in the CD4 T cell count.

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In this editorial, we highlight the potential use of inhibitors of hypoxia-inducible factors (HIFs) for the use in Kaposi's sarcoma associated herpesvirus (KSHV) (also known as human herpesvirus-8) related malignancies. The past 20 years has accumulated detailed knowledge of the role of these factors in ensuring the maintenance of the KSHV in infected cells, in aiding the growth of the virus infected cells and aiding in the spread of virus from infected cells by inducing lytic reactivation. Today, a wide range of inhibitors for HIFs are currently being clinically evaluated for use in treating a variety of cancers.

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Article Synopsis
  • Kaposi sarcoma (KS) is a cancer linked to abnormal blood vessel growth, primarily caused by the Kaposi sarcoma herpesvirus (KSHV) found in specialized tumor cells.
  • Researchers have developed a method to grow patient-derived KS tumors in mice, allowing them to maintain the KSHV infection and tumor characteristics for extended periods, which is crucial for studying the disease.
  • The study found that the resulting tumors displayed increased density of KSHV-infected cells, higher proliferation rates, and maintained gene expressions associated with KS, indicating that these mouse models can help in understanding the disease and testing new treatments.
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Coronaviruses rely on the viral-encoded chymotrypsin-like main protease (M or 3CL) for replication and assembly. Our previous research on M of SARS-CoV-2 identified cysteine 300 (Cys300) as a potential allosteric site of M inhibition. Here, we identified tixocortol (TX) as a covalent modifier of Cys300 which inhibits M activity as well as in a cell-based M expression assay.

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Article Synopsis
  • The Cancer Immunotherapy Trials Network 12 study showed that pembrolizumab is safe and effective for treating advanced Kaposi sarcoma (KS) in people with HIV on antiretroviral therapy.
  • In a phase I trial involving 32 participants, 62.1% had a positive response to pembrolizumab, with even higher rates (87.5%) for those who hadn't received previous KS treatments.
  • The treatment led to significant progression-free survival, with a median of 28.2 months, and immune-mediated adverse events were effectively managed according to established guidelines.
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Recently published near full-length KSHV genomes from a Cameroon Kaposi sarcoma case-control study showed strong evidence of viral recombination and mixed infections, but no sequence variations associated with disease. Using the same methodology, an additional 102 KSHV genomes from 76 individuals with KSHV-associated diseases have been sequenced. Diagnoses comprise all KSHV-associated diseases (KAD): Kaposi sarcoma (KS), primary effusion lymphoma (PEL), KSHV-associated large cell lymphoma (KSHV-LCL), a type of multicentric Castleman disease (KSHV-MCD), and KSHV inflammatory cytokine syndrome (KICS).

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Kaposi sarcoma herpesvirus (KSHV)-associated diseases include Kaposi sarcoma (KS), primary effusion lymphoma (PEL), KSHV-associated multicentric Castleman disease (MCD), and KS inflammatory cytokine syndrome (KICS). PEL, MCD, and KICS are associated with elevated circulating inflammatory cytokines. However, activation of the inflammasome, which generates interleukin-1β (IL-1β) and IL-18 via active caspase-1/4/5, has not been evaluated in patients with KSHV-associated diseases (KADs).

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SUMMARYWithin weeks of the first report of acquired immunodeficiency syndrome (AIDS) in 1981, it was observed that these patients often had Kaposi sarcoma (KS), a hitherto rarely seen skin tumor in the USA. It soon became apparent that AIDS was also associated with an increased incidence of high-grade lymphomas caused by Epstein-Barr virus (EBV). The association of AIDS with KS remained a mystery for more than a decade until Kaposi sarcoma-associated herpesvirus (KSHV) was discovered and found to be the cause of KS.

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Objective: Kaposi sarcoma is a vascular tumor that affects the pulmonary system. However, the diagnosis of airway lesions suggestive of pulmonary Kaposi sarcoma (pKS) is reliant on bronchoscopic visualization. We evaluated the role of Kaposi sarcoma herpesvirus (KSHV) viral load in bronchoalveolar lavage (BAL) as a diagnostic biomarker in patients with bronchoscopic evidence of pKS and evaluated inflammatory cytokine profiles in BAL and blood samples.

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Primary effusion lymphoma (PEL) and a form of multicentric Castleman's disease (MCD) are both caused by Kaposi sarcoma herpesvirus (KSHV). There is a critical need for improved therapies for these disorders. The IL-6/JAK/STAT3 pathway plays an important role in the pathogenesis of both PEL and KSHV-MCD.

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Background: Kaposi sarcoma (KS) is a multicentric tumor caused by Kaposi sarcoma herpesvirus (KSHV) that leads to morbidity and mortality among people with HIV worldwide. KS commonly involves the skin but can occur in the gastrointestinal tract (GI) in severe cases.

Methods: RNA sequencing was used to compare the cellular and KSHV gene expression signatures of skin and GI KS lesions in 44 paired samples from 19 participants with KS alone or with concurrent KSHV-associated diseases.

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An estimated 38 million people live with human immunodeficiency virus (HIV) worldwide and are at excess risk for multiple cancer types. Elevated cancer risks in people living with HIV (PLWH) are driven primarily by increased exposure to carcinogens, most notably oncogenic viruses acquired through shared transmission routes, plus acceleration of viral carcinogenesis by HIV-related immunosuppression. In the era of widespread antiretroviral therapy (ART), life expectancy of PLWH has increased, with cancer now a leading cause of co-morbidity and death.

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Kaposi sarcoma-associated herpesvirus (KSHV) is the causative agent of Kaposi sarcoma and several other tumors and hyperproliferative diseases seen predominantly in human immunodeficiency virus-infected and other immunocompromised persons. There is an increasing body of evidence showing that hypoxia and hypoxia-inducible factors (HIFs) play important roles in the biology of KSHV and in the pathogenesis of KSHV-induced diseases. Hypoxia and HIFs can induce lytic activation of KSHV and KSHV can in turn lead to a hypoxic-like state in infected cells.

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Introduction: Kaposi sarcoma herpes virus (KSHV) is associated with several diseases including Kaposi sarcoma, a form of multicentric Castleman's disease, primary effusion lymphoma, and an inflammatory cytokine syndrome. These KSHV-associated diseases (KAD) can present with heterogenous signs and symptoms that are often associated with cytokine dysregulation that may result in multiorgan dysfunction. The inability to promptly diagnose and treat these conditions can result in long-term complications and mortality.

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Epstein-Barr virus (EBV) downregulates immune surface markers to avoid immune recognition. Pomalidomide (Pom) was previously shown to increase immune surface marker expression in EBV-infected tumor cells. We explored the mechanism by which Pom leads to these effects in EBV-infected cells.

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Nuclear localization signal (NLS) of HIV-1 integrase (IN) is implicated in nuclear import of HIV-1 preintegration complex (PIC). Here, we established a multiclass drug-resistant HIV-1 variant (HIV) by consecutively exposing an HIV-1 variant to various antiretroviral agents including IN strand transfer inhibitors (INSTIs). HIV was extremely susceptible to a previously reported HIV-1 protease inhibitor, GRL-142, with IC of 130 femtomolar.

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Objective: The aim of this study was to evaluate baseline differences by HIV status and the impact of pomalidomide on lymphocyte counts and T-cell subsets in patients with Kaposi sarcoma.

Design: We prospectively evaluated CD4 + and CD8 + T-cell phenotypes in 19 participants with Kaposi sarcoma enrolled on a phase 1/2 study of pomalidomide (NCT01495598), seven without HIV and 12 with HIV on antiretroviral therapy.

Methods: Trial participants received pomalidomide 5 mg orally for 21 days of 28-day cycles for up to 1 year.

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Lymphomas are among the most common cancers in people with HIV (PWH). The lymphoma subtypes and pathogenesis of lymphoma in PWH are different from the immunocompetent population. It is well-known that HIV causes severe CD4 T cell lymphopenia in the absence of antiretroviral therapy (ART); however, the risk of developing certain subtypes of lymphoma remains elevated even in people receiving ART with preserved CD4 T cells.

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Article Synopsis
  • Primary effusion lymphoma (PEL) is an aggressive form of non-Hodgkin lymphoma linked to Kaposi sarcoma-associated herpesvirus (KSHV), with limited treatment options and a median survival of 10-22 months with combination chemotherapy.
  • Research showed that PEL cells from patients express high levels of CD38, which is targeted by the drug daratumumab (Dara); however, Dara did not effectively kill these PEL cells due to the presence of complement-inhibitory proteins.
  • Despite this limitation, Dara increased antibody-dependent cell-mediated cytotoxicity (ADCC) in PEL cell lines, and two case studies demonstrated that combining Dara with other drugs like pomalidomide led to improved responses in
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Most viruses encode their own proteases to carry out viral maturation and these often require dimerization for activity. Studies on human immunodeficiency virus type 1 (HIV-1), type 2 (HIV-2) and human T-cell leukemia virus (HTLV-1) proteases have shown that the activity of these proteases can be reversibly regulated by cysteine (Cys) glutathionylation and/or methionine oxidation (for HIV-2). These modifications lead to inhibition of protease dimerization and therefore loss of activity.

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A biopsy of lymphoid tissue is currently required to diagnose Kaposi sarcoma-associated herpesvirus (KSHV)-associated multicentric Castleman disease (KSHV-MCD). Patients showing clinical manifestations of KSHV-MCD but no pathological changes of KSHV-MCD are diagnosed as KSHV inflammatory cytokine syndrome. However, a lymph node biopsy is not always feasible to make the distinction.

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Article Synopsis
  • * A study involved whole-genome sequencing of 230 BL and 295 diffuse large B-cell lymphoma (DLBCL) tumors, revealing key mutated genes and new subgroups of BL with specific genetic traits.
  • * The research findings indicate significant genetic and clinical disparities between pediatric and adult BL, suggesting that identifying these subtypes could inform better approaches to diagnosis and treatment.
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Background: The Food and Drug Administration recommends that people living with HIV (PWH) with a CD4+ T cell count (CD4) ≥350 cells/µL may be eligible for any cancer clinical trial, but there is reluctance to enter patients with lower CD4 counts into cancer studies, including immune checkpoint inhibitor (ICI) studies. Patients with relapsed or refractory cancers may have low CD4 due to prior cancer therapies, irrespective of HIV status. It is unclear how baseline CD4 prior to ICI impacts the proportion of treatment-emergent adverse events (TEAE) and whether it differs by HIV status in ICI treated patients.

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