Killer T cells: How badly Omikron gets infected depends a lot on these men. So it’s time to get to know

In the meantime, enough data has been collected to prove that the novel coronavirus variant Omikron can undermine some of the defense mechanisms that made up immune bodies. But this is not the full story. How far Omicron will hit—and we’re talking about how susceptible we are to disease—depends largely on our immune system’s best killer: killer T cells. So it’s time to get to know these guys.

T cells or T lymphocytes are immune cells, and they can be divided into four main groups: helper T cells, inhibitory T cells, memory T cells, and cytotoxic T cells also known as Killer T Silen. It’s the last we’ll talk about. Killer T cells are not known for their grace. When these immune killers encounter a cell hijacked by a virus, their first instinct is to wreak havoc. Killer T punches holes in the infected cell and injects toxins to destroy it from within. the cell dies In an amazing and terrifying way, as well as the virus particles inside.

The carnage described above can make the difference between a person with a mild infection and a serious one. And that’s exactly what experts now hope will happen to vaccinated people whose antibodies may falter omicron, the variant of the new Corona virus spreading all over the world. Killer T cells alone cannot completely prevent infection, so we still need the other strategies we use to keep the virus at bay. But killer T cells, bolstered by a vaccine or previous infection, can help maintain resilience against hospitalizations and deaths, providing a safety net that could avert some of the worst effects of the coronavirus.

Killer T’s aggressive style of action has serious benefits

Enough preliminary data has been collected to show that Omikron can undermine some of the defense mechanisms that have built fortified bodies. The variant’s thorny protein – the molecular key the virus uses to open cells – contains more than 30 mutations compared to the original SARS-CoV-2. Last week, several teams of scientists, as well as Pfizer, released early lab data suggesting that these modifications could make the variant up to 41 times better at bypassing neutralizing antibodies produced by vaccines. In the real body, this can make it easier for Omikron to initiate an infection.

But infection does not always guarantee serious illness. Nor is neutralizing antibodies the only defense the immune system can mobilize. Killer T cells are different, and their violent mode of action has serious advantages: they learn different and different aspects of the virus from antibodies, and fighting them with mutations is much more difficult. Although the protection of T cells against Omikron can be slightly reduced according to quite a few immunologists, it is not something we should really worry about.

When the antibodies fail, the killer T cells overwhelm

Antibodies are powerful but simple. Having been eliminated by the B cells, they spend their days roaming the body, trying to find a super-specific anatomical piece of the pathogen. When they do, some of them – neutralizing agents – can cling so tightly that the virus cannot interact with or invade cells. Antibodies can prevent infection on their own; The rest of the immune system never needs to intervene.

However, this ideal scenario is not always achieved. After a vaccination or infection, antibody levels rise — but then slowly but steadily begin to fall, giving pathogens more opportunities to slip past. Neutralizing antibodies can also be easily deceived by mutations. Once held tight, they slipped. So viruses have time and mutations on their side: infection becomes easier when the antibodies are gone and the viruses mutate. Once the pathogen makes its way into the cell, the relevant parts of it are no longer visible to the antibodies, so they linger past.

But when the antibodies fail, the killer T cells take over. The reason they are all there is to eliminate infected cells – not the floating viruses. As a sign of distress, infected cells can cut into some of the virus they need to produce and show the distorted pieces on the outside. These scissors are rudimentary yet effective: For killer T cells, they’re like a red rag for a bull.

Another trick up your sleeve

All of this makes it difficult for the virus to evade T-cell responses. SARS-CoV-2 would have to change much of its physiology to successfully mask itself – something the virus may not be able to achieve without compromising its ability to penetrate our cells.

Even if the coronavirus somehow gets a major transformation, it will have to outpace another trick: Thanks to the genetic aberration, the infected cells of different people will display different pieces of the virus in front of the T cells. Which means that a version of the virus that evades killer T cells in one person can still be completely destroyed in the next. In this way, killer T cells can prevent the spread of infection within and between the body.

To be honest, we don’t have the full picture of Omikron yet. However, what is known so far looks promising. The new data shows that most of the viral fragments that killer T cells trained to recognize, including those in the spike protein, are still perfectly conserved on Omikron, with a few exceptions. As a result, about 95 percent of T cells in previously infected people will still reach their target; Among the two vaccinated, that would be 86 percent.

Start flying with booster

So there’s likely to be a decline in the extent to which killer T cells can detect Omikron, but not a significant decrease. It is in line with what the researchers observed with other variants of SARS-CoV-2. Omikron is anomaly, and scientists still have to test how well the T cells perform against the variant – but more importantly, much of the T-cell response must remain functional – meaning that the immune system’s ability to control the spread of the virus will still be preserved. .

Killer T cells become even more important when the antibodies don’t work properly. Cellular infection can begin to spread at a rapid pace, but T cells can come to install the pathogen in place, usually within a few days. This quick defense can stop the progression of the disease and possibly slow its transmission; It also buys the remaining time from the immune system to regulate itself. The B cells, having awakened from their sleep, will begin to produce more antibodies to replace the faded ones. Another group of T cells, called helper T cells, will arrive to help coordinate the rest of the immune response. Getting a booster can also start this process.

Soon it will stop

All of this will likely mean that more people who have been vaccinated can become infected with Omicron as the world continues its battle to contain the highly contagious delta. But vaccinated people are likely to have a much lower risk of serious illness than their unvaccinated peers, a pattern that early South African studies seem to fit in. This is consistent with the gradual way in which immune protection tends to wear off: Defenses against infection – usually neutralizing antibodies – fail first. But protection from serious illness and death is the last thing that goes; To achieve those very dangerous results, viruses must remain in the body and frequently frustrate the many defenders the immune system throws their way.

But the vaccine-trained T cells are not expected to last forever. Too many people around the world remain unvaccinated, giving the virus much greater opportunities to mutate. SARS-CoV-2 can eventually learn to trick killer T cells.

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