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Order Ortervirales
Published in Paul Pumpens, Peter Pushko, Philippe Le Mercier, Virus-Like Particles, 2022
Paul Pumpens, Peter Pushko, Philippe Le Mercier
Altogether, the order Ortervirales belongs to the class Revtraviricetes of the phylum Artverviricota, kingdom Pararnavirae, realm Riboviria. According to the latest ICTV issues (Krupovic et al. 2018; ICTV 2020), the order Ortervirales consists of 5 families, 2 subfamilies, 28 genera, and 238 species. The reverse-transcribing viruses are widespread in animals, plants, algae, and fungi, and this broad distribution suggests the ancient origin(s) of these viruses, possibly concomitant with the emergence of eukaryotes (Krupovic et al. 2018). From the point of view of public health, the order Ortervirales is important because of such prominent human pathogens as human immunodeficiency viruses 1 and 2 (HIV-1; HIV-2) of the subfamily Orthoretrovirinae from the family Retroviridae.
Human T lymphotropic virus type 1 (HTLV-1)
Published in Avindra Nath, Joseph R. Berger, Clinical Neurovirology, 2020
HTLV-1 is a retrovirus in the genus Deltaretrovirus, subfamily Orthoretrovirinae. Risk of transmission increases with number of exposures and depends on the route of transmission, infectivity of the donor, and susceptibility of the recipient. Routes of exposure and their risk of transmission include: Non-leukocyte depleted blood transfusion (8.6%–64%), sharing needles and syringes (presumed high), breastfeeding (22%), transplacental exposure (3%–5%) and unprotected sexual intercourse (1% per year) [7]. Cell-free blood product transmission risk is negligible, and therefore direct cell-to-cell contact is a presumed requirement for virus transmission. The virologic synapse that enables cell to cell transmission between HTLV-1 infected and uninfected cells is likely mediated by the glucose transporter 1 (GLUT-1), heparin sulfate proteoglycans (HSPG), and neuropilin 1 (NRP-1). Investigations continue in fully characterizing viral transmission [10,11].
Recent advances in nanoformulation development of Ritonavir, a key protease inhibitor used in the treatment of HIV-AIDS
Published in Expert Opinion on Drug Delivery, 2022
Srinivas Reddy Jitta, Navya Ajitkumar Bhaskaran, Shirleen Miriam Marques, Lalit Kumar
Acquired immunodeficiency syndrome (AIDS) is one of the serious healthcare problems causing significant mortality and morbidity globally [1]. AIDS was first recognized in 1981 and is caused by the human immunodeficiency virus (HIV) [2]. HIV is a retrovirus belonging to the genus Lentivirus subfamily of Orthoretrovirinae within the family of Retroviridae. According to global HIV and AIDS statistics 2020, approximately 37.6 million people were living with HIV at the end of 2020. In 2020, 690,000 people died because of HIV-related issues, and 1.5 million were newly infected. As per the statistics, only 27.4 million people received antiretroviral therapy in 2020. Only 53% of children living with HIV received antiretroviral therapy (ART) in 2020. WHO has recommended that all people infected with HIV, including children, adolescents, adults, and pregnant and breastfeeding women, be provided with lifelong ART treatment irrespective of clinical status or CD4 cell count [3]. Even though the death rate fell in the past two decades, people on HIV treatment are still suffering from several adverse effects of antiretroviral therapy. It is one of the main reasons for the lack of adherence to the treatment by HIV patients.
Antiviral therapy for the sexually transmitted viruses: recent updates on vaccine development
Published in Expert Review of Clinical Pharmacology, 2020
Kimia Kardani, Parya Basimi, Mehrshad Fekri, Azam Bolhassani
HIV causing AIDS has become one of the most serious problems in health since the first cases were reported in 1981 [208]. HIV was grouped to the genus Lentivirus, the family of Retroviridae, and the subfamily Orthoretrovirinae. The full length HIV genome is encoded on 9.5 kb RNA strand [209]. Based on geographical origin, genetic characteristics, organization of genome and differences in the viral antigens, HIV-1 and HIV-2 were differentiated in the world. The HIV-1 was divided into groups M, N, O and P [210]. M group of HIV-1 was further divided into A-D, F-H, J and K subtypes. The present global epidemic has occurred by M group more than N and O groups. The HIV-1 is more common than HIV-2 in the world. HIV-2 was identified in West Africa region. The majority of the people in America, Europe, Asia and Australia were infected with the subtype B of M group. The subtypes A, C and D of M group were observed in Africa [211]. In Argentina, most people were infected with BF recombinant forms. The recombination was found when a target cell was infected with two different HIV subtypes [212,213]. The HIV genome encodes 16 viral proteins which play essential roles during the HIV life cycle. The gag, pol, and env major genes express the structural proteins (i.e. matrix, capsid, nucleocapsid and p6), the viral enzymes (i.e. reverse transcriptase, protease, and integrase), and the envelope proteins (gp120 and gp41), respectively. Other genes express the accessory proteins (i.e. Vif, Vpu/Vpx, Vpr and Nef), and the regulatory proteins (i.e. Tat and Rev) [214].
Retroviruses in the pathogenesis of systemic lupus erythematosus: Are they potential therapeutic targets?
Published in Autoimmunity, 2020
Rossella Talotta, Fabiola Atzeni, Magdalena Janina Laska
Retroviruses belong to the family of Retroviridae. This family is further subdivided in two subfamilies: the Orthoretrovirinae and the Spumaretrovirinae [41], distinguished on the basis of their biologic features. The Orthoretrovirinae subfamily encloses six genera (alpha-, beta-, delta-, epsilon- and gamma-retroviruses and lentiviruses), consisting of simple and complex viruses according to the coding domains present in their genome; of note, five out of the six genera display oncogenic properties [42]. The coding domains gag, pol, pro and env are present in all retroviruses and preside to the synthesis of core and envelope proteins and enzymes. Additional domains, generated by alternative splicing, are present in complex retroviruses, and code for regulatory proteins, like Tat and Rev, whose role is to enhance viral gene expression [43].