r/Virology

I transduced A549 lung cancer cell line with a lentivirus expressing a gene of interest. 48 h post-transduction, I infected the cells with flu for another 48 h before submitted to flow cytometry. Compared to the non lentivirus-transduced control, the %flu infected cells are significantly lowered, say reduced by 60-70%, which is not ideal.

Is the lentivirus competing with flu in terms of infecting the cells? If yes, does increasing the time between lentivirus and flu infection helps? Say when the lentivirus has been degraded, then I infect the cells with flu, there shouldn't be any competition.

Or are there any other factors? Thanks!

Biological Mechanisms of Rabies Incubation

In nature, the rabies virus (Lyssavirus rabies) already possesses a highly variable and often prolonged incubation period compared to many other acute viral infections. In humans, the incubation period typically ranges from 1 to 3 months, but documented cases range from less than a week to more than a year.

Several naturally occurring biological factors influence the length of this incubation period:

Anatomical Entry Point: Rabies is a neurotropic virus that travels via retrograde axoplasmic transport through the peripheral nervous system to the central nervous system (CNS). Exposures that occur further from the brain (such as on the foot or hand) generally result in longer incubation periods than exposures on the face or neck, due to the physical distance the virus must travel along axons.

Viral Load and Inoculum Size: The quantity of virus introduced during an exposure impacts the speed at which it establishes a persistent presence in local tissue before entering peripheral nerves.

Tissue Interacting and Replication: Before entering the nervous system, the virus may replicate at low levels in muscle tissue at the bite site. During this phase, it can remain relatively undetected by the host immune system because it does not trigger a widespread inflammatory response.

Immune Evasion: The rabies virus glycoprotein and matrix proteins play roles in evading host innate immune responses, allowing the virus to persist in peripheral tissues or neural paths without triggering rapid clearance.

Biosafety Standards

Research involving the handling, isolation, or propagation of wild-type rabies virus requires Biosafety Level 2 (BSL-2) or Biosafety Level 3 (BSL-3) containment depending on the specific strain, concentration, and procedures being performed. Work involving genetic modification of viral pathogens is strictly regulated under international biosafety frameworks to manage biological risks and prevent accidental release or severe health outcomes

Is possible to have long term rabies