The effects of low level laser therapy on both HIV‐1 infected and uninfected TZM‐bl cells

Abstract

Human immunodeficiency virus (HIV-1) infection remains a major health problem despite the use of highly active antiretroviral therapy (HAART), which has greatly reduced mortality rates. Due to the unavailability of an effective vaccine and treatment that would completely eradicate the virus in infected individuals, the quest for new therapies continues. Low level laser therapy (LLLT) involves the exposure of cells to low levels of red or infrared light. LLLT has been widely used in different medical conditions, but not in HIV-1 infection. This study aimed to determine the effects of LLLT on HIV-1 infected and uninfected TZM-bl cells. Both infected and uninfected cells were irradiated at a wavelength of 660 nm with different fluences from 2 J/cm to 10 J/cm . Changes in cellular responses were assessed using cell morphology, viability, proliferation, cytotoxicity and luciferase activity assays. Upon data analysis, uninfected irradiated cells showed no changes in cell morphology, viability, proliferation and cytotoxicity, while the infected irradiated cells did. In addition, laser irradiation reduced luciferase activity in infected cells. Finally, laser irradiation had no inhibitory effect in uninfected cells, whereas it induced cell damage in a dose dependent manner in infected cells.

The combination of low level laser therapy and efavirenz drastically reduces HIV infection in TZM-bl cells

“…The notably high levels of luciferase activity as shown by RLUs in the presence of HIV was a clear indication that TZM-bl cells are permissive to HIV infection and the ZM53 virus used was infectious. An observation similar to the one made in a previous [ 45 ], showed that irradiation caused reduction in HIV infection as seen in [ Fig. 6 ].…”

Photobiomodulation of freshly isolated human adipose tissue-derived stromal vascular fraction cells by pulsed light-emitting diodes for direct clinical application

“…Further, we analysed the cytotoxic impact of our single LLLT dose on SVF cells showing no difference between untreated cells and cells undergoing LLLT. Lugongolo, Manoto, Ombinda‐Lemboumba, Maaza, & Mthunzi‐Kufa, made an interesting observation after application of laser irradiation to infected (HIV‐1) and uninfected cells, demonstrating no inhibitory effect on uninfected cells but induced cell damage in the HIV‐1 infected cells in a dose‐dependent manner (Lugongolo et al, ). Another study was performed using the effect of photobiomodulation on endothelial cells where the LDH release was decreased and the viability increased after red and near‐infrared laser treatment (Franco et al, ).…”

Viral inactivation by light

“…3.4 J/cm 2 M13 bacteriophage, Murine cytomegalovirus Log (pfu): 5 for M13 bacteriophage at 1 h of laser exposure time [ 31 ] Blue Femtosecond laser (400 nm). 20 mJ/pulse M13 bacteriophages Log 10 (Loud reduction): 5.8 ± 0.3 and 2.9 ± 0.15 at 15 and 2 min, respectively [ 32 ] Blue laser (408 nm), Low-power ultrashort pulse (USP), 150 mW Murine Norovirus > 3 log10 inactivation at 3 h [ 33 ] Red Laser, LLLT (660 nm), 2–10 J/cm 2 , 626 s HIV-1 Luciferase activity: Reduction in infected cells (8 J/cm 2 ) and no inhibitory effect in uninfected cells [ 34 ] Infrared Femtosecond laser (800 nm), 4 μW, 10 ms HIV-1 Luciferase activity: Two-fold reduction with Radiation and Raltegravir for 30 min [ 35 ] …”