The complete nucleotide sequence of two human T-cell leukaemia type III (HTLV-III) proviral DNAs each have four long open reading frames, the first two corresponding to the gag and pol genes. The fourth open reading frame encodes two functional polypeptides, a large precursor of the major envelope glycoprotein and a smaller protein derived from the 3'-terminus long open reading frame analogous to the long open reading frame (lor) product of HTLV-I and -II.
It is generally believed that the gag gene product of human immunodeficiency virus type 1 (HIV-1) is processed into several core proteins by a virus-specific protease. We used deletion mutation analysis to study the role of HIV-specific protease in the processing of core proteins and its requirement for viral infectivity. Several mutant genomes with deletions in the protease gene were constructed. A mammalian cell line, COS-M6, transfected with the wild-type viral genome was shown to produce virions containing processed core proteins, while COS-M6 cells transfected with two mutated genomes could express only the core protein precursor, Pr56gag. The wild-type transfectant produced infectious virus; both transfectants expressing the mutated genomes also produced virions, and one of them still retained reverse transcriptase activity. However, the mutant viral particles were devoid of infectivity. Virions with a distinct central core and an electron-dense nucleoid budded out from the plasma membrane of COS-M6 cells transfected with the wild-type genome. In contrast, noninfectious virions that budded either into cytoplasmic vacuoles or out from the plasma membrane of COS-M6 cells transfected with mutant genomes contained ring-shaped nucleoids. These results indicate that the HIV-1 protease plays a role not only in the maturation of the core proteins but also in the assembly of the virus and thus is required for viral infectivity.
By analogy to other retroviruses, the major envelope glycoprotein, gpl20, of human T-lymphotropic virus type III (HTLV-Ill) is a probable target for neutralizing antibody. This antigen has been purified from H9 cells chronically infected with the HTLV-IllB prototype strain. Several goats immunized with the gpl20 produced antibodies that neutralized infection of H9 cells by the homologous virus isolate. These same sera failed to neutralize the divergent HTLV-IllRF isolate. Individuals infected with HTLV-11I commonly develop antibodies to gpl20 that could be isolated by using the gpl20 antigen coupled to an immunoadsorbent resin. The antibody fraction that bound tightly to such a resin was found to neutralize the IIIB but not the RF isolate in a similar fashion as the goat anti-gpl20 sera. However, the nonbinding fraction (effluent) from the resin also contained neutralizing activity that was able to block infection by both virus isolates with similar efficacy. Human antibodies to the other virus envelope gene product, the transmembrane gp4l, were also affinity purified by utilizing the recombinant peptide 121, but these failed to influence infection by either virus isolate.
The PedsQL 3.2 Diabetes Module Diabetes Symptoms and Diabetes Management Summary Scores demonstrated excellent measurement properties and may be useful as standardized patient-reported outcomes of diabetes symptoms and diabetes management in clinical research, clinical trials, and practice in children, adolescents, and young adults with type 1 diabetes.
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