Antimicrobial peptide LL37, Niacinamide and SARS-CoV-2

Vitamin D works for more than you think

This is part of the small series of stating the obvious. This is by no measure a “dig” into the researchers doing the much-needed work to prove that a simplistic, natural approach will bear positive results. The last one was about Vitamin C, and Vitamin D.

Breaking news ! Vitamin C works to prevent SARS-CoV-2 infection

Niacinamide enhances cathelicidin mediated SARS-CoV-2 membrane disruption

As the writing on the wall is ever so more evident for anyone with a shred of common sense, or in the case of scientists with a little spark of honesty left, many scientists are looking into alternative interventions to deal with SARS-CoV-2 since vaccine escape is now undeniable, and won’t change anytime soon.

Here the authors found that LL37 (which I will explain later in this piece) an Antimicrobial peptide (peptides are the building blocks for proteins in a simplistic description) has the capacity to neutralize SARS-CoV-2 and when you said neutralization is increased by using Niacinamide, another form of Vitamin B3. It is like the chill sister of Niacin (flush).

These results are consistent with reports that LL37, a cationic peptide, can execute its antimicrobial activity by attacking the negatively charged membrane of pathogens. Enveloped viruses such as coronavirus that assemble virions by budding off from the endoplasmic reticulum membrane have a negatively charged membrane due to a higher content of phosphatidylserine (PS). To mimic the membrane composition of a generic coronavirus, we prepared three different vesicles in which PS composition was varied according to the published range of ER-derived virions15. We observed that increasing the percentage of PS resulted in an increase in the negative surface charge on the vesicles, which was neutralized by the presence of LL37. These results suggest that the positively charged peptide can coat the outer leaflet of the bilayer by electrostatic interactions. To determine the consequence of the interaction of LL37 with the vesicles, we assayed whether membrane integrity was compromised. Using a fluorescence resonance energy transfer (FRET) based membrane disruption assay, we observed a reduction in FRET when vesicles were treated with LL37. These results indicate that LL37 is more effective in interacting with and disrupting membranes with a higher negative charge. Previous reports have also indicated that disruption of vesicle membranes by positively charged polymers leads to vesicle clumping.

The researchers go through many steps to pin down the exact pathway in which LL37 directly binds and neutralizes the virus. The results suggest that a positively charged peptide can coat part of the layer of the virus via “cell magnetism” (crude simplification). The result at the end of this part of their experiments indicated LL37 is more effective at interacting with higher negative charged membranes. They go on to discuss the different levels of LL37 between infected and uninfected patients, in which symptomatic individuals had on average 3 times less LL37 than their asymptomatic counterparts. A similar trend was found between symptomatic and asymptomatic infected individuals.

Since lower levels of LL37 are associated with the symptomatic COVID-19 patient group, we speculated that increasing the level of LL37 or enhancing the activity of the existing LL37 might serve as a potential means of combating SARSCoV-2 infection. One method of enhancing the activity of LL37 is to decrease its inherent self-aggregation and thereby increase its bioavailability. A common approach to prevent aggregation is through the use of a hydrotrope such as niacinamide (vitamin B3). It is a generally regarded as safe (GRAS) substance used to increase the solubility, and therefore the activity, of various drugs. Indeed, we observed that LL37 supplemented with niacinamide exhibited an enhanced potency against infection by different variants of SARS-CoV-2. To understand the mechanism of LL37 interaction with lipid membranes in the presence of niacinamide, we used atomistic molecular dynamics (MD) simulations. Our simulations support the hydrotropic solubilisation of LL37 by an aqueous solution of niacinamide. We found that niacinamide transiently associated with mainly the hydrophobic and non-polar residues of LL37 by both aromatic-π and van der Waals interactions. These predominantly included phenylalanine (Phe5, Phe6, Phe17 and Phe27) and isoleucine (Ile20 and Ile24) residues , which mediates LL-37’s self-aggregation and therefore reduced activity. Our simulations suggest that encapsulating of aggregation prone residues of LL37 by niacinamide would likely improve the bioavailability of the peptide.

Consistent with simulation predictions, we observed that membrane disruption of liposomes by LL37 was enhanced in combination with niacinamide, while niacinamide by itself was not antiviral. To test whether the effect of niacinamide can be reproduced with naturally produced AMPs, we analyzed its effect on AMPs that are highly secreted in saliva and from the skin . We found that human saliva exhibits antiviral activity against SARS-CoV-2, which can be potentiated upon supplementation with niacinamide. Likewise, we also observed that skin scrubs supplemented with niacinamide exhibited antiviral activity. Our body naturally synthesizes niacinamide, but interestingly, the biosynthetic pathways and precursor leading to niacinamide production are downregulated in symptomatic COVID-19 patients. Thus, exogenous supplementation of niacinamide in symptomatic patients may potentiate the activity of naturally produced AMPs from the body’s epithelial.

Authors conclude that either increasing the levels of LL37 (we are about to see this), or increasing the effectiveness of the LL37 already inside you might be a potential form of combating a SARS-CoV-2 infection. They describe how finicky LL37 is and a way to make it “more stable” is by simply supplementing Niacinamide. Niacinamide on its own doesn’t have an antiviral effect, put inside our bodies it can potentiate our antiviral defense system.

And they also note that the metabolic pathways in our bodies to produce Niacinamide are downregulated in symptomatic patients. The closing remark of the paper is that LL37 has the potential to neutralize SARS-CoV-2 and this effect is potentiated by Niacinamide. And supplementing both or boosting our own production of the peptide with Niacinamide supplementation is a potent method to block viral transmission and limit viral load.

Upregulating Human Cathelicidin Antimicrobial Peptide LL-37 Expression May Prevent Severe COVID-19 Inflammatory Responses and Reduce Microthrombosis

The paper above goes into great detail on many aspects of SARS-CoV-2 infection, NETosis and Thrombosis, Vasoconstriction, the direct effects of LL-37 on these, LL-37 and diabetes, and the Nervous system. While not the topic in this post I will just put that part below the image.

Since the macaque model of COVID-19 has shown elevated levels in the brain of alpha-synuclein plaques, the role of alpha-synuclein production (if any) in common brain-fog and the attendant possible long-term impacts of COVID-19 is of interest (138). Similarly, since the brain has some of the highest levels of LL-37 expression (144) and LL-37 has previously been shown to suppress alpha-synuclein amyloid formation in cell culture, the impact of cathelicidin induction in addressing these sequelae deserves further investigation (145). We hypothesize enhanced LL-37 expression may address some consequences of COVID-19 by inhibiting alpha-synuclein aggregation and oligomer-induced cell damage and preventing infection of astrocytes as shown in Figure 4. Alpha synuclein plaques are associated with progression of Parkinson’s disease and LL-37 may also serve as a mechanism to reduce progression of the disease in COVID-19 patients. Vitamin D3, an up regulator of LL-37, has been hinted as helpful in addressing Parkinson’s in COVID-19 patients due to its super-promoter activity of Nrf2-KEAP, which promotes protective antioxidant and Ca2+ production and may work in conjunction with the potentially protective effect of LL-37 (146).

LL-37 may also provide a role in preventing pericyte dysregulation and astrocyte dysfunction through binding the S1 domain of SARS-CoV-2 and cloaking ACE-2 receptors (20). CRAMP has been shown to have antimicrobial activity in astrocytes of mice models responding to bacterial supernatants, demonstrating the co-location of cathelidin and astrocytes in response to pathogens (147). LL-37 may also prepare astrocytes for infection by gearing them into a pro-inflammatory state with upregulated IL-1β and IL-6, but this inflammatory state must be reduced upon infection to prevent chronic inflammation and disease (144). Research into the impacts of LL-37 in various cell lines of the brain post infection should also be conducted as a dual effect of LL-37 as pro-inflammatory in early infection but anti-inflammatory in cells that have encountered a pathogen has been previously noted (148).

The upregulation of LL37 alone can help many beneficial effects besides the neutralizing aspect we discussed above, it has a direct inhibitory effect on the most concerning long-term issues with a SARS-CoV-2 infection, especially when the S1 is around (I will cover the next few days). And also protects from neurological diseases set off by SARS-CoV-2 from progressing.

So how do we make our bodies produce more LL37 ?

Vitamin D… lol. But there are other possible ways.

Curcumin can help induce the gene so you produce more LL37, and Resveratrol (it is in my list of supplements btw) induces the expression of LL37 by a novel mechanism. And the best for last. And it has the best cost/benefit. Exercise.

In summary, when infected with SARS-CoV-2 or a few other respiratory pathogens, taking Vitamin D in its active form and Niacinamide will help your body not only produce but potentialize the effects of the peptide LL37. You can also take resveratrol daily for the many benefits it provides besides the one mentioned in the image above and another reason I recommend it. As a closing remark, you can also buy LL37 as a peptide supplement, it is slightly expensive between 60 to 90 dollars, but I don’t see WHY would you do it unless you really need it, stick to simpler options unless in a severe enough situation.

Massive appreciation to all supporters here and on Kofi !!!