Tag Archives: immune system

Delta-9-tetrahydrocannabinol alleviates inflammation by modulating immune responses in LPS-induced murine inflammation model

Posted on by

Delta-9-THC reduced inflammatory immune signaling across human immune cells and a mouse model of systemic inflammation. In LPS-stimulated cells, THC markedly suppressed type I interferon-related genes and pro-inflammatory cytokines including IL-1β and TNF-α, while also reducing immune-cell activation markers.

The effects extended beyond isolated cells. In mice exposed to systemic inflammation, THC reduced activation of splenic myeloid cells and T cells. Brain analysis also showed reduced neuroinflammatory signaling, including lower expression of inflammatory mediators, while pathways associated with neurogenesis, synaptic plasticity and neuronal function were enriched.

Importantly, the researchers describe THC’s effects as modulation rather than indiscriminate immune suppression, concluding that THC appears to dampen excessive inflammatory signaling while influencing cellular stress-adaptation pathways. They say these findings support further investigation of cannabinoid signaling in chronic inflammatory, neuroimmune and neurodegenerative disorders.

“Introduction: Δ9-Tetrahydrocannabinol (THC), the primary psychoactive component of cannabis, has been reported to modulate immune responses; however, its effects on complex innate immune signaling pathways and inflammation remain incompletely understood. Here, we investigated the immunomodulatory effects of THC on lipopolysaccharide (LPS)-induced inflammation across cellular and in vivo models.

Methods: We integrated transcriptomic, cellular, and in vivo approaches to characterize the effects of THC on innate immune activation. Human THP-1 monocytic cells were treated with THC in the presence or absence of LPS, followed by transcriptomic and gene expression analyses to evaluate inflammatory, type I interferon, unfolded protein response (UPR), and autophagy pathways. Findings were validated in primary human monocytes by assessing immune activation markers. The effects of chronic THC exposure were further evaluated in a murine model of systemic inflammation by examining splenic myeloid and T-cell activation. RNA sequencing of brain tissue was performed to assess the effects of THC on neuroinflammatory and neuronal pathways.

Results: THC induced a stress-adaptive transcriptional program in THP-1 cells, characterized by upregulation of genes associated with the UPR and autophagy pathways. In contrast, THC markedly suppressed LPS-induced type I interferon-stimulated genes (ISGs) and pro-inflammatory cytokines, including IL-1β and TNF-α. In primary human monocytes, THC significantly reduced the expression of activation markers CD80, CD83, and CD209. Consistent with these findings, chronic THC exposure attenuated the activation of splenic myeloid and T cells in mice subjected to systemic inflammation. Brain transcriptomic analysis further demonstrated reduced expression of neuroinflammatory pathways following THC exposure, accompanied by enrichment of pathways associated with neurogenesis and synaptic plasticity.

Discussion: Our findings demonstrate that THC exerts broad immunomodulatory effects characterized by suppression of inflammatory and type I interferon responses while promoting cellular stress-adaptation pathways. These effects were observed across human monocytic cells, primary monocytes, and peripheral immune populations in vivo, and were accompanied by reduced neuroinflammatory signaling and increased neuronal plasticity-associated pathways in the brain. Together, these findings provide mechanistic insight into the immunomodulatory actions of THC and support further investigation of cannabinoid signaling as a potential regulator of chronic inflammatory and neuroimmune disorders.”

https://pubmed.ncbi.nlm.nih.gov/42818626

“Chronic THC exposure reduces LPS-induced immune activation in vivo.”

https://www.frontiersin.org/journals/immunology/articles/10.3389/fimmu.2026.1856131/full

Need this THC study explained? thcXplained.com

(+)-Trans-Cannabidiol Is an Agonist at Human CB2 Receptors

Posted on by

A new 2026 study reports that (+)-trans-cannabidiol [(+)-CBD] acts as an agonist at human CB2 cannabinoid receptors, activating a major receptor of the endocannabinoid system involved in immune and inflammatory signaling.

Researchers found that (+)-CBD produced a strong, concentration-dependent CB2 response, reaching roughly 90% of the maximum effect produced by the reference cannabinoid agonist CP55940. Additional testing indicated that the compound acts through the receptor’s primary, or orthosteric, binding site.

The findings show that different molecular forms of cannabidiol can interact with cannabinoid receptors in very different ways. The researchers conclude that (+)-CBD may deserve further study in CB2-sensitive disease states, adding another layer to our understanding of how cannabinoid chemistry can influence the human endocannabinoid system.

“(-)-trans-Cannabidiol ((-)-CBD) is a principal phytocannabinoid from Cannabis sativa. (-)-CBD has complex pharmacology but is a relatively weak inhibitor of CB1 and CB2 receptor signaling. Cannabidiol has two chiral centres and thus four stereoisomers. (+)-trans-CBD ((+)-CBD) has a higher affinity than (-)-CBD at CB1 and CB2, but its pharmacodynamic effects at these receptors are incompletely described.

We examined the activity of (+)-CBD at human CB1 and CB2 receptors using a fluorescence-based assay of membrane potential in AtT20 cells stably expressing CB1 or CB2 receptors.

(+)-CBD produced a rapid, concentration-dependent hyperpolarization in CB2-expressing cells (pEC50 6.63 ± 0.08) with a maximal effect 90% of the response to CP55940. The CB2 response was blocked by pertussis toxin pretreatment and competitively inhibited by the CB2 antagonist AM630 (Schild slope 1.1 ± 0.1). (+)-CBD was a low-efficacy, low-potency CB1 agonist and inhibited somatostatin-receptor effects at high concentrations (10-30 μM). (+)-CBD had no effect on the membrane potential of AtT20 wild-type cells. In silico modeling of ligand interactions with CB2 indicated that (+)-CBD but not (-)-CBD formed an H-bond with Ser285, a residue crucial for agonist activation of CB2.

Our data suggests (+)-CBD acted as a CB2 agonist via the orthosteric binding site on the receptor. Synthetic CBD, including (+)-CBD, has previously been administered in clinical trials, presumably without consideration of its potential CB2 agonist activity.

Given the relative safety of (-)-CBD in people, (+)-CBD may be a useful drug to explore CB2-sensitive disease states.”

https://pubmed.ncbi.nlm.nih.gov/42745361

“This study emphasizes the importance of understanding the molecular actions of the enantiomers of chiral cannabinoids. Although the safety of (+)-CBD cannot simply be assumed to be the same as (−)-CBD, the identification of (+)-CBD as a robust CB2 agonist suggests that (+)-CBD may be worth exploring as a therapeutic agent in chronic inflammatory conditions or other diseases where CB2 activation may prove beneficial.”

https://bpspubs.onlinelibrary.wiley.com/doi/10.1002/prp2.70325

Δ9-Tetrahydrocannabinol treatment impairs CD8+ T cell differentiation into interferon gamma-competent CD45RO+ cells

Posted on by

New research published in The Journal of Pharmacology and Experimental Therapeutics shows that Δ9-tetrahydrocannabinol (THC) can alter the development of CD8+ T cells involved in inflammatory immune responses. Researchers found that THC reduced secretion of interferon gamma (IFNγ), interleukin-2 (IL-2), and tumor necrosis factor alpha (TNFα), three signaling molecules involved in immune activation and inflammation.

Rather than simply preventing cells from producing IFNγ, THC appeared to change how the T cells developed. THC reduced the differentiation of CD8+ T cells into mature CD45RO+ cells capable of secreting IFNγ. A selective CB2 receptor agonist produced similar effects, suggesting that activation of the cannabinoid CB2 receptor may play an important role in THC’s immune-modulating activity.

The researchers examined these effects partly because IFNγ-producing CD8+ T cells contribute to persistent neuroinflammation associated with HIV-associated neurocognitive disorders. They concluded that reducing CD8+ T-cell-derived IFNγ in the central nervous system may potentially improve cognitive outcomes during HIV infection, while noting that the findings may also have relevance to other inflammatory diseases involving IFNγ-producing CD8+ T cells.

“Chronic human immunodeficiency virus (HIV) infection results in a persistent state of neuroinflammation, even with combined antiretroviral therapy. Neuroinflammation contributes to pathology termed HIV-associated neurocognitive disorder, which is exacerbated by interferon gamma (IFNγ)-producing CD8+ T cells in the central nervous system.

Many people living with HIV self-report using Cannabis sativa to mitigate symptoms of chronic infection and side effects of treatment. C. sativa is composed of various phytocannabinoids, including Δ9-tetrahydrocannbinol (THC), which possesses immune-modulating properties.

This study aims to determine whether C. sativa use by people living with HIV, and specifically THC, affects IFNγ secretion by CD8+ T cells.

We found that HIV status does not influence T cell IFNγ responses, and C sativa use modestly reduces the average secretion of IFNγ by CD8+ T cells from HIV+ donors. Treatment of CD8+ T cells with THC and the selective cannabinoid receptor 2 agonist, JWH-015, reduced T-cell cytokine secretion, with THC eliciting greater suppression than cannabidiol.

These results suggest that THC treatment does not directly impair IFNγ gene expression or protein production, as determined by polymerase chain reaction and flow cytometry. However, THC treatment impaired CD8+ T cell differentiation into IFNγ-competent CD45RO+ cells.

These studies are of clinical relevance because reduction of CD8+ T-cell-derived IFNγ in the central nervous system may improve cognitive outcomes during HIV infection. Furthermore, these findings may be generalizable to other inflammatory diseases in which IFNγ-producing CD8+ T cells have been implicated.

SIGNIFICANCE STATEMENT: Δ9-Tetrahydrocannbinol (THC) treatment reduces CD8+ T cell interferon gamma (IFNγ) secretion isolated from HIV- and HIV+ individuals. THC and the selective cannabinoid receptor 2 agonist, JWH-015, both reduced CD8+ T cell secretion of IFNγ, interleukin 2, and tumor necrosis factor α, suggesting the involvement of cannabinoid receptor 2. Although THC treatment does not suppress IFNγ mRNA or protein levels, it reduces the number of IFNγ-secreting cells by impairing CD8+ T-cell differentiation into IFNγ-competent CD45RO+ cells.”

https://pubmed.ncbi.nlm.nih.gov/42748512

https://jpet.aspetjournals.org/article/S0022-3565(26)01210-3/abstract

Need this THC study explained? thcXplained.com

Delta-8-tetrahydrocannabinol ameliorates murine autoimmune hepatitis and is associated with epigenetic modulation of immune responses

Posted on by

A new 2026 study published in International Immunopharmacology found that delta-8-tetrahydrocannabinol (Δ8-THC) significantly reduced autoimmune hepatitis in mice while altering the immune responses responsible for liver inflammation. Researchers found that Δ8-THC reduced inflammatory immune cells and helped preserve immune cells involved in protecting the liver.

The researchers also uncovered a possible mechanism. Δ8-THC increased two microRNAs, miR-100-5p and miR-199a-3p, which suppressed mTOR signaling and shifted CD4+ T-cell development away from inflammatory Th1 and Th17 cells and toward regulatory T cells that help control excessive immune activity.

The authors concluded that Δ8-THC showed both hepatoprotective and anti-inflammatory activity and highlighted its potential therapeutic value for autoimmune and inflammatory disorders. The study adds new evidence that cannabinoids may influence disease not only by reducing inflammation, but by changing the molecular and epigenetic pathways that regulate immune responses.

“Aim of the study: Cannabinoids have gained attention for their ability to modulate immune responses and suppress inflammation. However, the effect of Δ8-THC, a minor cannabinoid found in Cannabis, has not been explored in autoimmune hepatitis. To address knowledge gap, the present study aimed to investigate the hepatoprotective and immunoregulatory properties of Δ8-THC in experimental autoimmune hepatitis and to identify molecular and epigenetic mechanisms underlying its immunoregulatory effects.

Methods: miRNA sequencing and flow cytometric analysis were performed using hepatic immune cells from female C57BL/6 mice treated with ConA (12.5 mg/kg, i.v.) and Δ8-THC (20 mg/kg, i.p.). Differential miRNA expressions were analyzed using the edgeR, and miRNA targets were predicted using Ingenuity Pathway Analysis. Target gene expression was validated by qRT-PCR and Western blot. Functional assays including miRNA mimic/inhibitor transfection and CD4+ T-cell differentiation were performed to validate target gene regulation by miRNAs and its role in CD4+ T-cell differentiation.

Results: Δ8-THC markedly suppressed ConA-induced autoimmune hepatitis by restoring immune homeostasis within the liver through suppression of inflammatory monocytes, neutrophils, and natural killer cells, and preservation of tolerogenic Kupffer cells. In addition, Δ8-THC reshaped the hepatic lymphoid compartment, diminishing inflammatory CD4+ T-cell responses while favoring regulatory T-cell expansion. These effects were associated with the preservation of miR-100-5p and miR-199a-3p expression in the liver, whereas both miRNAs were markedly downregulated following ConA treatment. mTOR, a central regulator of T-cell differentiation, was identified as a target of these miRNAs. Consistent with these findings, Δ8-THC reduced mTOR expression and upregulated hepatoprotective miRNAs in both in vivo and in vitro models. Functional analyses with miRNA overexpression and inhibition approaches verified the direct regulation of mTOR by these miRNAs in T cells and RAW 264.7 cells. In naïve CD4+ T cells, miRNA gain- and loss-of-function experiments demonstrated that miR-100-5p/miR-199a-3p-mediated suppression of mTOR promotes regulatory T-cell differentiation while limiting Th1 and Th17 polarization.

Conclusion: Our results identify Δ8-THC as a promising hepatoprotective and anti-inflammatory compound that ameliorates ConA-induced autoimmune hepatitis by influencing CD4+ T-cell differentiation potentially through the miR-100-5p/miR-199a-3p-mTOR axis, highlighting its potential therapeutic value in autoimmune and inflammatory disorders.”

https://pubmed.ncbi.nlm.nih.gov/42753324

“In conclusion, our findings suggest that Δ8-THC can mitigate ConA-induced hepatitis, potentially through epigenetic regulation involving microRNAs. Specifically, Δ8-THC improved liver function and reduced systemic and intrahepatic inflammation in ConA-exposed mice. These effects were associated with increased expression of miR-100-5p and miR-199a-3p in the liver, suggesting that these miRNAs may regulate mTOR signaling and contribute to the suppression of proinflammatory responses and promotion of anti-inflammatory pathways. Functional studies supported the involvement of these miRNAs in the regulation of mTOR signaling, CD4+ T-cell differentiation, and inflammatory responses.”

https://www.sciencedirect.com/science/article/pii/S1567576926012518?via%3Dihub

Brain’s own cannabis compound protects against inflammation

Posted on by

“Some clinical studies have indicated that marijuana or its active cannabinoid ingredient alleviates symptoms of the inflammatory disease multiple sclerosis (MS). Also, researchers have found that the brain’s natural “endocannabinoids” are released after brain injury and are believed to alleviate neuronal damage. However, scientists have not understood how such substances act within the brain’s own immune system.

 Now, experiments by Oliver Ullrich and colleagues have pinpointed how one of the brain’s endocannabinoids protects neurons from inflammation after such damage. They say their studies could lead to new drugs to treat the inflammation and brain degeneration from MS or other such disorders.

In an article in the January 5, 2006, issue of Neuron, the researchers reported experiments showing how the endocannabinoid anandamide (AEA) protects brain cells from inflammation. Such a role in the brain’s immune system is distinct from cannabinoids’ effects on neuronal signaling that produce the behavioral effects of marijuana.”

http://www.bio-medicine.org/biology-news/Brains-own-cannabis-compound-protects-against-inflammation-2810-1/

The role of cannabinoid system on immune modulation: therapeutic implications on CNS inflammation.

Posted on by

Abstract

“There is a growing amount of evidence suggesting that cannabinoids may be neuroprotective in CNS inflammatory conditions. Advances in the understanding of the physiology and pharmacology of the cannabinoid system have increased the interest of cannabinoids as potential therapeutic targets. Cannabinoid receptors and their endogenous ligands, the endocannabinoids, have been detected in cells of the immune system, as well as in brain glial cells. In the present review it is summarized the effects of cannabinoids on immune reactivity and on the regulation of neuroinflammatory processes associated with brain disorders with special attention to chronic inflammatory demyelinating diseases such as multiple sclerosis.”

http://www.ncbi.nlm.nih.gov/pubmed/16026313

Cannabinoids and the immune system: potential for the treatment of inflammatory diseases?

Posted on by

Abstract

“Since the discovery of the cannabinoid receptors and their endogenous ligands, significant advances have been made in studying the physiological function of the endocannabinoid system. The presence of cannabinoid receptors on cells of the immune system and anecdotal and historical evidence suggesting that cannabis use has potent immuno-modulatory effects, has led to research directed at understanding the function and role of these receptors within the context of immunological cellular function. Studies from chronic cannabis smokers have provided much of the evidence for immunomodulatory effects of cannabis in humans, and animal and in vitro studies of immune cells such as T cells and macrophages have also provided important evidence. Cannabinoids can modulate both the function and secretion of cytokines from immune cells. Therefore, cannabinoids may be considered for treatment of inflammatory disease. This review article will highlight recent research on cannabinoids and how they interact with the immune system and also their potential use as therapeutic agents for a number of inflammatory disorders.”

http://www.ncbi.nlm.nih.gov/pubmed/16023222

The cannabinoid system and immune modulation

Posted on by

Figure 1.

“Studies on the effects of marijuana smoking have evolved into the discovery and description of the endocannabinoid system. To date, this system is composed of two receptors, CB1 and CB2, and endogenous ligands including anandamide, 2-arachidonoyl glycerol, and others. CB1 receptors and ligands are found in the brain as well as immune and other peripheral tissues. Conversely, CB2 receptors and ligands are found primarily in the periphery, especially in immune cells. Cannabinoid receptors are G protein-coupled receptors, and they have been linked to signaling pathways and gene activities in common with this receptor family. In addition, cannabinoids have been shown to modulate a variety of immune cell functions in humans and animals and more recently, have been shown to modulate T helper cell development, chemotaxis, and tumor development. Many of these drug effects occur through cannabinoid receptor signaling mechanisms and the modulation of cytokines and other gene products.

It appears the immunocannabinoid system is involved in regulating the brain-immune axis and might be exploited in future therapies for chronic diseases and immune deficiency.”

“The medicinal uses of marijuana were described centuries ago for diseases such as asthma, migraine, pain, convulsions, and anxiety (reviewed in ref.). More recently, emphasis has been placed on marijuana’s putative, beneficial effects on appetite, glaucoma, spasticity in multiple sclerosis, pain, and inflammation.

Recent experimental evidence supports marijuana’s therapeutic potential in some of these maladies.

The active plant ingredients in marijuana belong to the C21-cannabinoid compounds including the primary psychoactive compound, Δ9-tetrahydrocannabinol (THC). This cannabinoid along with others such as Δ8-THC, cannabidiol, and cannabinol, as well as chemical analogs, have been extensively studied over the years for their biological and therapeutic properties. Some of the properties of these agents have included effects on immunity ranging from suppression of resistance to infection to enhancement of IL-1 production by macrophages. These early studies about the immunomodulating effects of these drugs have been the subject of previous overviews and will not be reviewed here. Instead, we will briefly summarize the general features of the cannabinoid system and review recent findings on the structure and function of the cannabinoid system components in the immune system. For convenience, we will refer to this as the “immunocannabinoid” system.

CANNABINOID SYSTEM

Marijuana cannabinoids, analogs, and endocannabinoids”

https://jlb.onlinelibrary.wiley.com/doi/full/10.1189/jlb.0303101?sid=nlm%3Apubmed

Cannabinoids and the immune system.

Posted on by

“The effect of cannabimimetic agents on the function of immune cells such as T and B lymphocytes, natural killer cells and macrophages has been extensively studied over the past several decades using human and animal paradigms involving whole animal models as well as tissue culture systems.

From this work, it can be concluded that these drugs have subtle yet complex effects on immune cell function and that some of the drug activity is mediated by cannabinoid receptors expressed on the various immune cell subtypes.

However, the overall role of the cannabinoid system of receptors and ligands in human health and disease is still unclear and requires extensive elucidation.

Further studies will define the precise structure and function of the putative immunocannabinoid system, the potential therapeutic usefulness of these drugs in chronic diseases such as acquired immune deficiency syndrome and multiple sclerosis, the effects of these agents on tumour growth and induction of apoptosis, and the potential anti-inflammatory and proinflammatory properties of cannabimimetic compounds.

It is likely that the cannabinoid system, along with other neuroimmune systems, has a subtle but significant role in the regulation of immunity and that this role can eventually be exploited in the management of human disease.”