Anti-HIV type 1 Polyclonal antibody

This study was aimed at formulating Lopinavir loaded Vitamin E-TPGS micelles to enhance its oral bioavailability. Lopinavir is an HIV-1 protease inhibitor with low aqueous solubility leading to poor oral bioavailability and thus frequent dosing. Drug loaded micelles were fabricated using thin film hydration technique and optimized by two-factor five-level central composite design. For this purpose independent variables selected were TPGS to drug ratio and rotational speed of rotary evaporator, whereas dependent variables chosen were particle size and % entrapment efficiency. The effect of an independent variable on the dependent variable was studied by generating a quadratic polynomial model. Results of in vitro characterization showed that prepared lopinavir micelles exhibited particle size 91.71 nm, polydispersity index 0.129, zeta potential -24.8 mV, entrapment efficiency 99.36 +/- 1.06% and drug loading 20.83 +/- 1.23%. Results of DSC and P-XRD evaluation revealed that drugs were successfully encapsulated inside the Vitamin E-TPGS micelles. In vitro release studies displayed enhancement in drug dissolution as a result of its loading into micelles. TEM images showed that micelles were spherical. On oral administration of lopinavir micelles; the relative bioavailability was boosted by 3.17 folds compared to lopinavir suspensions. Thus, we can conclude that TPGS based micelles possess the prodigious potential to overcome the challenges of current HAART therapy.

HIV-1 often acquires drug-resistant mutations in spite of the benefits of antiretroviral therapy (ART). HIV-1 integrase (IN) is essential for the concerted integration of HIV-1 DNA into the host genome. IN further contributes to HIV-1 RNA binding, which is required for HIV-1 maturation. Non-catalytic-site integrase inhibitors (NCINIs) have been developed as allosteric IN inhibitors, which perform anti HIV-1 activity by a multimodal mode of action such as inhibition of the IN-lens epithelium-derived growth factor (LEDGF)/p75 interaction in the early stage and disruption of functional IN multimerization in the late stage of HIV-1 replication. Here, we show that IN undergoes an adaptable conformational change to escape from NCINIs. We observed that NCINI-resistant HIV-1 variants have accumulated 4 amino acid mutations by passage 26 (P26) in the IN-encoding region. We employed highperformance liquid chromatography (HPLC), thermal stability assays, and X-ray crystallographic analysis to show that some amino acid mutations affect the stability and/or dimerization interface of the IN catalytic core domains (CCDs), potentially resulting in the severely decreased multimerization of full-length IN proteins (IN undermultimerization). This undermultimerized IN via NCINI-related mutations was stabilized by HIV-1 RNA and restored to the same level as that of wild-type HIV-1 in viral particles. Recombinant HIV-1 clones with IN undermultimerization propagated similarly to wild-type HIV-1. Our study revealed that HIV-1 can eventually counteract NCINI-induced IN overmultimerization by IN undermultimerization as one of the escape mechanisms. Our findings provide information on the understanding of IN multimerization with or without HIV-1 RNA and may influence the development of anti HIV-1 strategies. IMPORTANCE Understanding the mechanism of HIV-1 resistance to anti-HIV-1 drugs could lead to the development of novel drugs with increased efficiency, resulting in more effective ART. ART composed of more potent and long-acting anti-HIV-1 drugs can greatly improve drug adherence and also provide HIV-1 prevention such as pre exposure prophylaxis. NCINIs with a multimodal mode of action exert potent anti HIV-1 effects through IN overmultimerization during HIV-1 maturation. However, HIV-1 can acquire some mutations that cause IN undermultimerization to alleviate NCINI-induced IN overmultimerization. This undermultimerized IN was efficiently stabilized by HIV-1 RNA and restored to the same level as that of wild-type HIV-1. Our findings revealed that HIV-1 eventually acquires such a conformational escape reaction to overcome the unique NCINI actions. The investigation into drug-resistant mutations associated with HIV-1 protein multimerization may facilitate the elucidation of its molecular mechanism and functional multimerization, allowing us to develop more potent anti-HIV-1 drugs and unique treatment strategies.