Fat cells make a hormone called leptin which allows t-cells to be made.
If you have no fat cells then leptin disappears because it is the adipocytes or fat cells that make it.
In detail using poor mice studies…
‘In this review, we will characterize the effects of leptin on innate and adaptive immune cells, with a particular focus on CD4+ T cells, which are known to be highly leptin responsive’
The Role of the Adipokine Leptin in Immune Cell Function in Health and Disease
https://www.frontiersin.org/articles/10.3389/fimmu.2020.622468/full
If you don’t have enough fat cells or body fat you may have less leptin to help t-cell production.
“Nutritional deprivation suppresses immune function. The cloning of the obese gene and identification of its protein product leptin has provided fundamental insight into the hypothalamic regulation of body weight.
Circulating levels of this adipocyte derived hormone are proportional to fat mass but maybe lowered rapidly by fasting or increased by inflammatory mediators.
The impaired T-cell immunity of mice now known to be defective in leptin (ob/ob)4 or its receptor (db/db) has never been explained.
Impaired cell-mediated immunity and reduced levels of leptin are both features of low body weight in humans.
Indeed, malnutrition predisposes to death from infectious diseases.
We report here that leptin has a specific effect on T lymphocyte responses, differentially regulating the proliferation of naive and memory T cells.
Leptin increased Th1 and suppressed Th2 cytokine production.
Administration of leptin to mice reversed the immunosuppressive effects of acute starvation.
Our findings suggest a new role for leptin in linking nutritional status to cognate cellular immune function, and provide a molecular mechanism to account for the immune dysfunction observed in starvation.”
Leptin modulates the T-cell immune response and reverses starvation-induced immunosuppression
http://life.nthu.edu.tw/~b861662/leptin.pdf
There’s a hormone mimic on the market now called Metreleptin or Myalept.
Anorexics get immune failure from not having enough fats cells to make their leptin so this drug can replace leptin and restores their t-cell immune function back to normal levels.
“Our data show that metreleptin administration, in doses that normalize circulating leptin levels, induces transcriptional changes, activates intracellular signaling pathways, and restores CD4(+) T-cell counts.
Thus, metreleptin may prove to be a safe and effective therapy for selective CD4(+) T-cell immune reconstitution in hypoleptinemic states such as tuberculosis and HIV infection in which CD4(+) T cells are reduced.”
Selective capacity of metreleptin administration to reconstitute CD4+ T-cell number in females with acquired hypoleptinemia.
http://www.ncbi.nlm.nih.gov/pubmed/23382191
Gastric cells also release leptin so if you don’t get hungry or eat then leptin won’t be made in the gut and there will be no t-cells via the gastric mechanism, so much of this is about eating…
“Leptin is a hormone that plays a central role in the regulation of food intake and energy expenditure.
Originally discovered in mature white adipocytes, it was subsequently isolated from the gastric mucosa. This tissue contains a large number of epithelial endocrine and exocrine cells secreting leptin in the blood stream and in the gastric lumen, respectively.”
Leptin secretion by white adipose tissue and gastric mucosa.
http://www.ncbi.nlm.nih.gov/pubmed/17149693
You also don’t want to be too obese or diabetic as opposed to skinny because then you can get ‘leptin resistance’ which is similar in some ways to ‘insulin resistance’.
Leptin resistance leads to less t-cells to do the work of opening up our arteries, immune failure also results, and this is seen in diabetics who get arterial collapse, sepsis and gangrene at the end stage.
This is the effect of leptin resistance in obese children and the effect on their t-cells when given leptin.
“Leptin deficiency was associated with reduced numbers of circulating CD4+ T cells and impaired T cell proliferation and cytokine release, all of which were reversed by recombinant human leptin administration.”
Beneficial effects of leptin on obesity, T cell hyporesponsiveness, and neuroendocrine/metabolic dysfunction of human congenital leptin deficiency
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC150795/
These fat and t-cell studies are from heart research papers if you wish to learn more.
Immunometabolism: CD4+ T cell activation by adipocytes in obesity
http://www.nature.com/nri/journal/v13/n4/pdf/InBrief.pdf?WT.ec_id=NRI-201304
Fats are key to immune activation.
“All identified fatty acids were able to individually enhance T-cell proliferation.
These data indicate that adipocytes can modulate CD4(+) T-cell function through the release of lipids.
Remarkably, free fatty acids were the most prominent modulators of T-cell proliferation, possibly leading to an accumulation of these cells in adipose tissue.”
Adipocyte-derived lipids modulate CD4+ T-cell function.
http://www.ncbi.nlm.nih.gov/pubmed/23504601
This also explains why perfectly healthy people can have low t-cells, people into extreme exercise and fitness are quite at risk of getting low t-cell counts because they have hardly any fat cells to make leptin and often avoid fatty foods.
“Prolonged strenuous exercise is followed by a temporary functional immune impairment.”
Strenuous exercise decreases the percentage of type 1 T cells in the circulation
http://www.jappl.org/content/91/4/1708.full
Here’s a comment years ago from a friend called in the US after I raised this subject.
“I read a study about drug abusers, when they go off their drugs, their CD4 go low – why is that if body is cleansing and getting healthier without drugs?
I know about one guy – very heavy drug abuser – he has no place on his skin where …to inject his drugs! 10 years with heroin. He is poz for 10 years and has CD4 about 700-900 all the time. AIDS doctors never prescribed him any ARV because his CD4 is high.
Another my poz friend was a professional sportsman athlete, very healthy, not even alcohol, no smoking, training all the time. 7 years ago he got HIV+ and his CD4 were very low right away – AIDS doctor prescribed him ARV right away. He had very bad side effects, but he never felt any symptoms of “AIDS” before that with his low CD4.”
I will write further on diabetes and heart health elsewhere but it is also good to get the concept that higher t-cells and white blood cells are needed to remove fat from our arteries.
Hence the immune system is responding to the need to open arteries as well as remove excess fat if there is too much, white blood cells remove cholesterol clogging.
Everything is about balance.
This article from Medical News Today gives the concept that being lean can lower white blood cells that also react to pathogens.
“The researchers found that, after controlling for age, men who were most physically fit had the lowest levels of groups of white blood cells. Combining the groups of white blood cells created a measure of total white blood cell count, which is used as a marker for inflammatory activity. High total white blood cell counts have also been associated with illness and death from coronary heart disease. High levels of white blood cells were associated with higher levels of body fat as measured by body-mass index”
Effects Of Fatness And Fitness On White Blood Cell Counts
https://www.medicalnewstoday.com/articles/126469#2
Now this is important to note for HIV+ people on antiretroviral drugs.
The level of CD4 T-cells in people on anti-retrovirals (ARV’s) went up far more if they were fat.
It means your body mass is more important to raise t-cells than the drugs.
“BMI predicts CD4+ T-lymphocyte gains in men started on ART.”
CD4+ T-Lymphocyte Recovery in HIV-Infected Men with Viral Suppression on Antiretroviral Therapy
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3342850/
Again, this recent study showed low leptin was the key factor that affected t-cells in people on HAART.
“Serum leptin levels were significantly higher in patients with high CD4 counts than in patients with low CD4 counts”
And they concluded that HAART wasn’t helping leptin levels or t-cells.
“Conclusion: Serum leptin level was higher in HIV patients with high CD4 count and correlated with fasting serum insulin and HOMA-IR, thereby indicating that HAART treatment could lead to decreased levels of leptin in HIV patients, which might lead to impaired immunological recovery.”
Relationship between Leptin Levels and Suppressed CD4 Counts in HIV Patients
The use of antiretrovirals to raise t-cells was always questionable from the beginning because people may have had a small rise in t-cells on ARV’s, but they died at the same rate from poisoning, especially with the AZT dose between 1987 and the mid 90’s before the new HAART formulas for AIDS drugs lowered the dose.
“The results of Concorde do not encourage the early use of zidovudine in symptom-free HIV-infected adults. They also call into question the uncritical use of CD4 cell counts as a surrogate endpoint for assessment of benefit from long-term antiretroviral therapy.”
Concorde: MRC/ANRS randomised double-blind controlled trial of immediate and deferred zidovudine in symptom-free HIV infection 1994
http://www.thelancet.com/journals/lancet/article/PIIS0140-6736(94)90006-X/abstract
If HIV+ perhaps ask your doctor about measuring leptin levels and trying out Myalept instead of HAART.
Myalept
The main understanding is that our fat cells stimulate immune cells partly to prevent fat clogging in our arteries and to stimulate new arterial growth.
That immune stimulation by fat cells can also help with infections.
There are studies that also say too much leptin causes inflammation and heart disease, leptin also reduces paraoxonase enzymes which lowers bad cholesterol so too much leptin and high t-cells can also cause problems.
Fat is an essential part of our diet, just too much can be a problem and cholesterol is not a problem as it helps nerve signalling and much more, oxidised or ‘rusted’ cholesterol from a diet lacking good nutrients is the cause of heart inflammation.
Some fat in the diet with these food types is a good guide to balancing extra fat while remaining healthy.
‘The types of food that raise paraoxonase enzymes are featured in the Mediterranean diet and this can partly explain why the Mediterranean diet is so beneficial for heart disease.
Foods that can be used on a daily basis would include pomegranate juice, possibly the most potent of the foods, ‘Vitamin C and vitamin E, quercetin, red wine polyphenols, green tea extracts, grape seed extracts, freeze-dried blueberries, gallic acid and ellagic acid from berries, taurine foods, acai berries, olive oil and moderate alcohol consumption….’
Paraoxonase Enzymes, Pesticides, Cholesterol and the Mediterranean Diet
This article from 2013 in South Africa should also point out the problem in labelling starving people as having low t-cells and AIDS.
It should never have been ignored, immense money has been spent for decades on questionable drug therapies while people starve.
‘A five-year study by the University of Cape Town’s African Food Security Unit Network has exposed a food crisis that constitutes a “death sentence” for many and which the government has labelled as “serious”.
It found that, in Johannesburg, 43% of the poor faced starvation and malnutrition. Researchers believe the figure could be higher.
According to the UN Food and Agricultural Organisation, 870 million people worldwide are chronically undernourished, 234million of them living in sub-Saharan Africa.
The plight of the hungry was highlighted in 2011 when four children, aged between two and nine, died in a farmer’s field as they began an 18km walk in search of their mother and food in Verdwaal, North Wes It was later discovered that they had not eaten for more than a week.
The Department of Agriculture, Forestry and Fisheries last week revealed that 12million South Africans are “food insecure”.
12 Million Going To Bed Hungry in SA (the story has gone)
https://www.algoafm.co.za/kaycee-rossouw/more-than-12million-south-africans-will-go-to-bed-hungry
We spend 21 billion yearly at least for HIV testing and drugs while presently 160 million people are in famine and 800 million don’t eat enough.
30 million people have starved to death since COVID in 2020.
In April 2020 governments around the world gave 8 billion to COVAX for COVID injections while that year the World Food Program failed to raise funds and immediately the 160 million in famine were put on food rations.
It seems a poor show when drug companies make hundreds of billions of dollars.
The effects of locking down 4 billion people living on a few dollars a day gave the results below.
Never take food and having some fat on our bodies for granted.
By Action Against Hunger
1 December 2021
Dear world leaders,
It is over six months since the UN warned that famine risk is soaring globally. We — a group of 120 NGOs from around the world — are at a loss that since then the crisis has only worsened. There has been a 370% rise in people experiencing catastrophic levels of hunger since April and now a staggering 45 million people are at extreme risk — on the brink of famine. These numbers do not tell the whole story. Behind them are people suffering immensely from a crisis that we can prevent. What will it take for this situation to change?
The promises of the G7’s Famine Prevention Compact issued in May have not yet been met. It is clear that, since then, the situation has only deteriorated. Grand gestures do not fill empty stomachs. As the UN Secretary General has recently alerted, less than half the funding needed to stave off famine in six countries of highest concern (Burkina Faso, Ethiopia, Southern Madagascar, north-east Nigeria, South Sudan, Yemen) has been received to date. Meanwhile, some Humanitarian Response Plans (HRPs) are less than 20% funded.
The number of people at risk, and associated costs, are escalating, rising from $6.6bn needed to support 41 million people at risk of famine a few months ago, to $7bn needed to feed the 45 million people at risk across 43 countries, now. As basic food needs go unmet, humanitarian crises are escalating. One in 33 people worldwide are now in need of humanitarian assistance and one in ten people has malnutrition. The gap between needs and humanitarian funding is stark in some of the most vulnerable regions.
Conflict, the climate crisis, economic shocks and the ongoing Covid-19 pandemic are set to push more people into crisis level hunger and malnutrition in 2022. Conflict in particular is escalating globally, forcing families to flee their homes and lose their livelihoods. The hunger and malnutrition this is causing disproportionately affects women and girls putting them at increased risk of extreme hunger and gender-based violence.
In conflict settings, supporting peacebuilding and conflict prevention is also crucial. Further, it is time that political commitments made to uphold international law, safeguard people’s human rights and secure access to aid are acted upon. All parties to a conflict must facilitate humanitarian access, protect civilians and desist from using starvation as a method of warfare. Obstacles, such as sanctions and access denial, to humanitarian action are severely compounding a crisis that cannot be healed with money alone.
We have watched the number of people in need rise in 2021. We call on World Leaders to take the urgent action desperately needed now to reverse this trend in 2022.’
Famine action letter
https://reliefweb.int/report/world/famine-action-letter
Other links to AIDS history.