#cd4 cells

[bpod-bpod]

Help for Helpers

As sadly revealed by the coronavirus pandemic, reduced immunity makes elderly people more vulnerable to infectious diseases, but it also means they respond less strongly to vaccines. Following vaccination, dendritic cells that have encountered a foreign antigen [molecule from the pathogen] travel to our lymph nodes, where they activate antibody-producing B cells to multiply in germinal centres , with assistance from T helper cells. In older lymph nodes, reduced stimulation from dendritic cells after vaccination leads to the formation of fewer of these essential T cells (pictured, in green, in lymph nodes from young (top) and old mice (below)), generating a weaker response overall. Yet researchers found a way to overcome these defects in immune activity, by applying the drug imiquimod at the vaccination site. Currently used in creams to treat genital warts and some skin cancers, imiquimod boosted T cell numbers in older mice, raising the possibility that age-related declines in immunity can be corrected.

Written by Emmanuelle Briolat

Image adapted from work by Marisa Stebegg and Alexandre Bignon, and colleagues

Laboratory of Lymphocyte Signalling and Development, Babraham Institute, Cambridge, UK

Image copyright held by the original authors

Research published in eLife, March 2020

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[mrchillmrfluffy]

The T-Cell T-shirt

Show your moral support to anyone who has any kind of immunodeficiency, such as HIV/AIDS. This t-shirt helps you spread the love and care and tell them that if you could, you would give them your t-cells to help their t-cell count up. The text is in Purple to support Spirit Day and the cell pictured drawing the blue heart is what a T-cell actually looks like.

A share of the earnings from this t-shirt (and all of our t-shirts) will be donated to a charity organisation. More information in our Foundation section.

Role of CD4 T-Cells in HIV Infection One of the conundrums of HIV infection is that the very cells meant to initiate an immune defense are the same ones targeted for infection by HIV. As a retrovirus, HIV needs to infect certain "host" cells in order to make copies of itself. CD4 cells are the prime targets for this in the course of an infection. During infection, HIV attaches to these helper cells, emptying its genetic material within so that the host's genetic coding can be altered to produce other HIV virions. In doing so, the host CD4 cell is killed, and its ability to trigger an immune defense is to gradually deplete to such a point as to leave the body open to opportunistic infections. The dynamics of an HIV are such that "killer" CD8 T-cells are increasingly left blind in an advancing infection and eventually become unable to cope with the growing population of HIV (as measured by the viral load). If left untreated, the immune system will, in all but rare cases, completely collapse (or become compromised).

As they are "killed" CD4 T-cell count can get very low in patients with HIV.

[mtatva-blog]

HIV Infection and its Different Stages

HIV Infection and its Different Stages

HIV infection advances to the f stage if not treated, overwhelming your immune system and getting worse over time. By using HIV medicines (called Antiretroviral Therapy or ART) consistently, you can prevent HIV from progressing to AIDS. ART helps control the virus so that you can live a longer, healthier life and reduce the risk of transmitting HIV to others. Three Stages of HIV Infection The…

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[odishasamaya-blog]

Research: A low priced printer to track HIV patients' health

http://odishasamaya.com/news/health/research-a-low-priced-printer-to-track-hiv-patients-health/60648

Washington: US researchers have patented a low-cost printer that helps HIV patients living in low-resource settings track the health of their cells.

Patients with HIV are encouraged to participate in regular checkups to keep track of their . In high resource settings, devices known as flow cytometers complete the tests by analysing the blood.

    Border researchers patent new low-cost printer that tracks HIV         patients’ health

As a solution to this, Thomas Boland, a Professor of metallurgical, materials and biomedical engineering at University of Texas has created a less expensive, battery-powered health monitoring tool for use in third world countries. The portable device works by helping clinicians count the number of CD4 cells — cells that are attacked by HIV — in the body. After drawing a patient’s blood, clinicians mix in magnetic microscale beads that latch on to CD4 cells in the blood. The mixture is then placed in an inkjet printer that’s been modified to print out cells instead of ink. Rather than printing vertically onto a sheet of paper, the cells are shot out horizontally onto a magnetised microscopic slide.

CD4 cells in the blood automatically attach to the slide, while other cells that do not need to be counted dribble down into an excess container. Doctors can then look at the slide through a microscope to count the number of CD4 cells on it. That number is inserted into an equation that calculates the total number of CD4 cells in the individual’s body. The procedure takes as little as 20 minutes, resulting in ultra-quick results. The printer will help doctors and patients in low-resource settings who do not have access to flow cytometers. The next step in the process is to license the technology to a company that is willing to help get it in the market.

[pozmagazine]

Treatment News: Starving HIV of Sugar Halts Virus’s Replication

It’s simple, say PLOS researchers: HIV requires considerable sugar stores to replicate in CD4 cells and simply cannot copy itself once its sugar supply has been cut off. The scientists are now working to develop a new way to block the way CD4 cells open their sugar stores to the virus, essentially trying to starve HIV to death.

[pozmagazine]

The First Year of HIV Infection: A Window of Opportunity

Heads up: People who start HIV treatment within a year of contracting the virus have a better chance of refurbishing their immune systems than those whose treatment is delayed past that point. (Click here for an overview)

It’s pretty exciting that we’re nearing the point where we can get HIV-positive patients back to the point where they are immunologically similar to HIV-uninfected people….

[hivforum]

I came across a discussion about CD4 and CD4% disparities. While they didn't say, I assumed they were discussing those not on meds yet. The discussion was about someone with a CD4 of 500-800, for example, but a CD4% in the 20's. Some were saying a CD4% of 25 would be expected to have an absolute in the 300's. So, they were saying the labs can "lie," and be giving a false story to the state of the immune system. This had me thinking about those living where they still have CD4 requirements.

This is an good question that I should have answered earlier—my apologies.

It’s true that there is a typical correlation between CD4 count and CD4 percent. For example, a CD4 count of 200 generally corresponds with a CD4 percent of 14%, and someone is defined as having AIDS if either the absolute count or percent are lower than those thresholds.

However, like all biological phenomena, this is just an average. It’s not unusual to be an outlier in either direction: you can have a high CD4 count with a lower CD4 percent, or vice versa.

Conditions (e.g. some infections) or drugs (e.g. Bactrim) that lower your white blood cell count or lymphocyte count will also lower your absolute CD4 count but will not affect your CD4 percent. On the other hand, your CD4 count may be unusually high—and out of proportion to your CD4 percent—if you’ve had your spleen removed or if you’re also infected with HTLV-I. But by far the most common reason for CD4 count/percentage disparity is just normal variation.

These disparities raise the obvious question: Which number should you believe? Many years ago, I wrote a paper showing that in the Moore Clinic database at Johns Hopkins, the CD4 percent added little useful information (in terms of predicting the risk of opportunistic infections) above and beyond the information you got from the absolute count. However, other studies have suggested that the CD4 percent is sometimes a more reliable indicator of immune function than the CD4 count. Also, the percent is less variable than the count, so it can be helpful when your CD4 count is fluctuating or inconsistent with previous values. Knowing that the CD4 percent is stable is reassuring in those cases.

Fortunately, I would like to think that we’re moving into a “post-CD4 era,” in which people are diagnosed early, start effective treatment while they still have high baseline CD4 counts, and maintain undetectable viral loads. In such cases, no one should care about either the CD4 count or percent. When things go that way, continued CD4 monitoring is now considered “optional” in the U.S. treatment guidelines.