Anti-human immunodeficiency virus (HIV) broadly neutralizing antibodies (bNAbs) offer a promising approach for the treatment of HIV-1. The current paradigm for antibody therapy involves passive antibody transfer, requiring regular delivery of bNAbs in treating chronic diseases such as HIV-1. An alternative strategy is to use AAV-mediated gene transfer to enable in vivo production of desirable anti-HIV-1 antibodies. In this study, we investigated two sets of triple combinations of AAV9-vectors encoding different bNAbs: N6, 10E8, 10-1074 (CombiMab1), and VRC07-523, PGDM1400, 10-1074 (CombiMab2). We used CBAxC57Bl and C57BL/6 mouse models to characterize rAAV-induced antibody expression and to evaluate the neutralization capacity of mouse sera against a global panel of HIV-1 viral strains. rAAV9-mediated IgG expression varied between bNAb clones and mouse strains, with C57BL/6 mice exhibiting higher bNAb titers following rAAV delivery. Although CombiMab2 treatment elicited a higher IgG titer than CombiMab1, both combinations resulted in neutralization of all the viral strains from the global HIV-1 panel. Our data highlight the potential of AAV vectors as a long-term option for HIV-1 therapy.

INTRODUCTION. Despite existing treatment methods, complete eradication of human immunodeficiency virus (HIV) infection remains an unattainable goal due to the high variability of HIV type 1 (HIV-1). HIV infection necessitates life-long administration of antiretroviral medicinal products, which cause serious adverse drug reactions. The development of gene therapy products based on adeno-associated virus (AAV) vectors encoding broadly neutralising antibodies represents a promising direction for creating long-term therapies capable of countering a wide range of viral variants.AIM. This study aimed to evaluate the protective efficacy of CombiMab-2, a medicinal product consisting of a combination of three AAV vectors (AAV9-VRC07-523, AAV9-10-1074, and AAV9-PGDM1400) encoding broadly neutralising antibodies against HIV-1, in a humanised mouse model.MATERIALS AND METHODS. The study used an HIV infection model based on immunodeficient B-NDG mice humanised with human CD4⁺ lymphocytes (1.5×10⁷ cells per animal) from a leukoconcentrate of a healthy donor. The experiment used two groups of mice, including a control group (3 animals) receiving saline solution and an experimental group (5 animals) receiving CombiMab-2. The medicinal product was administered into different muscles as three separate components six weeks prior to infection. The CCR5-tropic HIV-1 strain was obtained by transfecting HEK293FT cells with the pNL4-3(AD8) plasmid encoding the full-length virus. The authors monitored viral loads in the plasma of animals by reverse transcription polymerase chain reaction and CD4⁺ lymphocyte counts in the peripheral blood of animals by flow cytometry for four weeks after infection.RESULTS. Six weeks after CombiMab-2 administration, the levels of broadly neutralising antibodies in the serum of humanised mice ranged from 0.17 μg/mL to 4.0 μg/mL. In the control group, the viral load reached 10⁵ copies/mL one week after HIV-1 infection and continued to rise over the next three weeks. In the treatment group, infection developed only in one mouse, which had the lowest antibody titre before infection. No viral load was detected in the remaining mice of the treatment group, which indicated that the medicinal product was effective if serum concentrations of broadly neutralising antibodies reached 0.5 μg/mL or higher.CONCLUSIONS. The tested medicinal product based on three AAV vectors (AAV9-VRC07-523, AAV9-10-1074, and AAV9-PGDM1400) exhibits protective activity against HIV-1 in humanised mice. The presented data allow the authors to consider CombiMab-2 as a promising antiviral agent that can serve as a basis for further pharmaceutical development.

Introduction. Over the past several decades, the study of mutations associated with motor neuron disease has led to the development of a number of transgenic animal models of motor neuron disease. One of the causes of the familial form of this disorder is mutations in the gene encoding Cu/Zn superoxide dismutase 1. The B6SJL-Tg (SOD1*G93A) mouse strain expresses a mutant form of human superoxide dismutase 1. Aim of study. To assess motor functions, dynamics of survival, and morphological changes in the spinal cord of transgenic B6SJL-Tg (SOD1*G93A) mice. Material and methods. In total, 31 animals have been studied. Starting from the age of 22 weeks, once every two weeks, the “open field” and “beam walking” motor tests were performed. The morphological changes in the spinal cord were evaluated at intermediate (26–35 weeks) and late stages (40–45 weeks). Neuronal proteins NeuN and PGP9.5, gliofibrillar protein, cyclonucleotide phosphatase (a marker of oligodendroglia) and a marker protein of microglia IBA1 were detected by immunohistochemistry; antibodies MTC02 to the outer membrane protein were used to detect mitochondria. Results. Motor problems appeared at the age of 24–26 weeks and steadily progressed; one could see consistent paresis of the hindlimbs, then the forelimbs, which was accompanied by general hypotrophy of the animals. There was a greater variability in the timing of symptom onset and life expectancy in males compared to females. The neurodegenerative process with damage to motor neurons was accompanied by the activation of micro- and astroglia. A sharp decrease in immunoreactivity to the mitochondrial marker MTC02 was found. Conclusion. The obtained results demonstrate new details of the development of a complex of motor and pathomorphological changes characteristic of motor neuron disease in B6SJL-Tg (SOD1*G93A) mice. Clarification of the fine dynamics of the neurodegenerative process in these animals is of great importance for monitoring the course of the disease during preclinical trials of new drugs and methods of gene therapy.

This study investigated the protective efficacy of two distinct combinations of three recombinant adeno-associated virus serotype 9 (rAAV9) vectors encoding broadly neutralizing antibodies against HIV-1—CombiMab-1 and CombiMab-2—in mice humanized with primary CD4⁺ T-lymphocytes. We demonstrated that mice preventively treated with CombiMab-1 or CombiMab-2 did not develop viremia and maintained human CD4+ T-lymphocyte counts following viral challenge, in contrast to control animals. These results demonstrate the significant protective capacity of CombiMab-1 and CombiMab-2 against HIV-1 challenge.