Cellular immune response induced by dna immunization of mice with drug resistant integrases of hiv-1 clade a offers partial protection against growth and metastatic activity of integrase-expressing adenocarcinoma cells

Funding Information: Funding: Experiments were supported by the grants of the Russian Science Fund 15-15-30039, Russian Fund for Basic Research 20-04-01034, Latvian Science Fund LZP 2018-2-03-08, and EU-ROPARTNER project “Strengthening and spreading international partnership activities of the Faculty of Biology and Environmental Protection of University of Lodz, Poland, for interdisciplinary research and innovation”. Mobility and method acquisition were supported by Swedish institute PI project 19806/2016TP, and Horizon 2020 project VACTRAIN#692293. MI and BW were supported by Horizon 2020 grant EAVI contract N68113. Funding Information: Experiments were supported by the grants of the Russian Science Fund 15-15-30039, Russian Fund for Basic Research 20-04-01034, Latvian Science Fund LZP 2018-2-03-08, and EU-ROPARTNER project ?Strengthening and spreading international partnership activities of the Faculty of Biology and Environmental Protection of University of Lodz, Poland, for interdisciplinary research and innovation?. Mobility and method acquisition were supported by Swedish institute PI project 19806/2016TP, and Horizon 2020 project VACTRAIN#692293. MI and BW were supported by Horizon 2020 grant EAVI contract N68113. Publisher Copyright: © 2021 by the authors. Licensee MDPI, Basel, Switzerland.Therapeutic DNA-vaccination against drug-resistant HIV-1 may hinder emergence and spread of drug-resistant HIV-1, allowing for longer successful antiretroviral treatment (ART) up-to relief of ART. We designed DNA-vaccines against drug-resistant HIV-1 based on consensus clade A integrase (IN) resistant to raltegravir: IN_in_r1 (L74M/E92Q/V151I/N155H/G163R) or IN_in_r2 (E138K/G140S/Q148K) carrying D64V abrogating IN activity. INs, overexpressed in mammalian cells from synthetic genes, were assessed for stability, route of proteolytic degradation, and ability to induce oxidative stress. Both were found safe in immunotoxicity tests in mice, with no inherent carcinogenicity: their expression did not enhance tumorigenic or metastatic potential of adenocarcinoma 4T1 cells. DNA-immunization of mice with INs induced potent multicytokine T-cell response mainly against aa 209–239, and moderate IgG response cross-recognizing diverse IN variants. DNA-immunization with IN_in_r1 protected 60% of mice from challenge with 4Tlluc2 cells expressing non-mutated IN, while DNA-immunization with IN_in_r2 protected only 20% of mice, although tumor cells expressed IN matching the immunogen. Tumor size inversely correlated with IN-specific IFN-γ/IL-2 T-cell response. IN-expressing tumors displayed compromised metastatic activity restricted to lungs with reduced metastases size. Protective potential of IN immunogens relied on their immunogenicity for CD8+ T-cells, dependent on proteasomal processing and low level of oxidative stress.publishersversionPeer reviewe

Both ATM and DNA-PK Are the Main Regulators of HIV-1 Post-Integrational DNA Repair

The integration of a DNA copy of an HIV-1 RNA genome into the host genome, carried out by the viral enzyme integrase, results in the formation of single-stranded gaps in cellular DNA that must be repaired. Here, we have analyzed the involvement of the PI3K kinases, ATM, ATR, and DNA-PKcs, which are important players in the DNA damage response (DDR) in HIV-1 post-integrational DNA repair (PIR). The participation of the DNA-PK complex in HIV-1 PIR has been previously shown, and the formation of a complex between the viral integrase and the DNA-PK subunit, Ku70, has been found to be crucial for efficient PIR. Now, we have shown that the inhibition of both DNA-PKcs and ATM, but not ATR, significantly reduces PIR efficiency. The activation of both kinases is a sequential process, where one kinase, being activated, activates the other, and it occurs simultaneously with the integration of viral DNA. This fact suggests that the activation of both kinases triggers PIR. Most interestingly, the activation of not only DNA-PKcs, but also ATM depends on the complex formation between integrase and Ku70. The elucidation of the interactions between viruses and DDR is important both for understanding the modulation of host cell functions by these pathogens and for developing new approaches to combat viral infections