Immune to addiction: how immunotherapies can be used to combat methamphetamine addiction

A conjugate vaccine strategy that induces protective immunity against arecoline

Betel-quid chewing addiction is the leading cause of oral submucous fibrosis and oral cancer, resulting in significant socio-economic burdens. Vaccination may serve as a promising potential remedy to mitigate the abuse and combat accidental overdose of betel nut. Hapten design is the crucial factor to the development of arecoline vaccine that determines the efficacy of a candidate vaccine. Herein, we reported that two kinds of novel arecoline-based haptens were synthesized and conjugated to Bovine Serum Albumin (BSA) to generate immunogens, which generated antibodies with high affinity for arecoline but reduced binding for guvacoline and no affinity for arecaidine or guvacine. Notably, vaccination with Arec-N-BSA, which via the N-position on the tetrahydropyridine ring (tertiary amine group), led to a higher antibody affinity compared to Arec-CONH-BSA, blunted analgesia and attenuated hypothermia for arecoline.

The Neurobiology of Methamphetamine Addiction and the Potential to Reduce Misuse Through Conjugate Vaccines Targeting Toll-Like Receptor 4

The methamphetamine epidemic continues to worsen each year and has contributed to more overdose deaths than opioids. Methamphetamine was listed in the top ten lethal drugs in 2021 in the United States. The drug has been shown to cause health problems such as addiction and neurological and behavioral changes. One possible solution to address this crisis is through vaccinations. Vaccinations consist of injecting a controlled substance with the goal of creating compound-specific antibodies. Although still early in development, vaccinations have been found to improve withdrawal symptoms and decrease drug-seeking behavior with minimal health side effects in rodent studies. This paper provides an overview of the clinical presentation and neurobiology of methamphetamine addiction and drug-seeking behaviors. The responses and adverse effects of conjugate vaccines IXTv-100 with adjuvant glucopyranosyl lipid A administered in oil-water stable emulsion and tetanus-toxoid conjugated to succinyl-methamphetamine adsorbed on aluminum hydroxide combined with adjuvant E6020 are examined.

Development of Methamphetamine Conjugated Vaccine through Hapten Design: In Vitro and In Vivo Characterization

BACKGROUND

Methamphetamine (METH) substance-use disorder is an ever-growing global health issue with no effective treatment. Anti-METH vaccines are under investigation as an alternative to existing psychological interventions. This platform has made significant progress over past decades mainly in preclinical stages, and efforts to develop an anti-METH vaccine with a high antibody response are of utmost importance.

METHODOLOGY

A novel conjugated anti-METH vaccine was developed using METH HCl as the starting material for the design of hapten, a peptide linker consisting of five lysines and five glycines, and finally immunogenic carrier mannan, which is novel to this platform. All the chemical reaction steps were confirmed by several analytical techniques, and the immunogenicity of the developed vaccine was investigated in a mouse model.

RESULTS

Thin-layer chromatography and gas chromatography confirmed the reaction between METH and peptide linker. UV, NMR and color tests were used to confirm the presence of the aldehyde groups in oxidized mannan (OM). The final conjugated vaccine was confirmed by UV and LC-MS. The stability of mannan, the METH hapten, and the final vaccine was evaluated by UV and LC-MS and demonstrated satisfactory stability over 3 months in various storage conditions. Animal studies supported the immunogenicity of the novel vaccine.

CONCLUSIONS

We successfully developed and characterized a novel METH vaccine in vitro and in vivo. The present study findings are encouraging and will form the basis of further exploration to assess its effectiveness to prevent METH addiction in preclinical models.

Tryptophan and Substance Abuse: Mechanisms and Impact

Addiction, the continuous misuse of addictive material, causes long-term dysfunction in the neurological system. It substantially affects the control strength of reward, memory, and motivation. Addictive substances (alcohol, marijuana, caffeine, heroin, methamphetamine (METH), and nicotine) are highly active central nervous stimulants. Addiction leads to severe health issues, including cardiovascular diseases, serious infections, and pulmonary/dental diseases. Drug dependence may result in unfavorable cognitive impairments that can continue during abstinence and negatively influence recovery performance. Although addiction is a critical global health challenge with numerous consequences and complications, currently, there are no efficient options for treating drug addiction, particularly METH. Currently, novel treatment approaches such as psychological contingency management, cognitive behavioral therapy, and motivational enhancement strategies are of great interest. Herein, we evaluate the devastating impacts of different addictive substances/drugs on users' mental health and the role of tryptophan in alleviating unfavorable side effects. The tryptophan metabolites in the mammalian brain and their potential to treat compulsive abuse of addictive substances are investigated by assessing the functional effects of addictive substances on tryptophan. Future perspectives on developing promising modalities to treat addiction and the role of tryptophan and its metabolites to alleviate drug dependency are discussed.

Immunotherapies for the Treatment of Drug Addiction

Substance use disorders (SUD) are a serious public health concern globally. Existing treatment platforms suffer from a lack of effectiveness. The development of immunotherapies against these substances of abuse for both prophylactic and therapeutic use has gained tremendous importance as an alternative and/or supplementary to existing therapies. Significant development has been made in this area over the last few decades. Herein, we highlight the vaccine and other biologics development strategies, preclinical, clinical updates along with challenges and future directions. Articles were searched in PubMed, ClinicalTrial.gov, and google electronic databases relevant to development, preclinical, clinical trials of nicotine, cocaine, methamphetamine, and opioid vaccines. Various new emerging vaccine development strategies for SUD were also identified through this search and discussed. A good number of vaccine candidates demonstrated promising results in preclinical and clinical phases and support the concept of developing a vaccine for SUD. However, there have been no ultimate success as yet, and there remain some challenges with a massive push to take more candidates to clinical trials for further evaluation to break the bottleneck.

Methamphetamine Induces Systemic Inflammation and Anxiety: The Role of the Gut–Immune–Brain Axis

Methamphetamine (METH) is a highly addictive drug abused by millions of users worldwide, thus becoming a global health concern with limited management options. The inefficiency of existing treatment methods has driven research into understanding the mechanisms underlying METH-induced disorders and finding effective treatments. This study aims to understand the complex interactions of the gastrointestinal–immune–nervous systems following an acute METH dose administration as one of the potential underlying molecular mechanisms concentrating on the impact of METH abuse on gut permeability. Findings showed a decreased expression of tight junction proteins ZO-1 and EpCAm in intestinal tissue and the presence of FABP-1 in sera of METH treated mice suggests intestinal wall disruption. The increased presence of CD45+ immune cells in the intestinal wall further confirms gut wall inflammation/disruption. In the brain, the expression of inflammatory markers Ccl2, Cxcl1, IL-1β, TMEM119, and the presence of albumin were higher in METH mice compared to shams, suggesting METH-induced blood–brain barrier disruption. In the spleen, cellular and gene changes are also noted. In addition, mice treated with an acute dose of METH showed anxious behavior in dark and light, open field, and elevated maze tests compared to sham controls. The findings on METH-induced inflammation and anxiety may provide opportunities to develop effective treatments for METH addiction in the future.

Development and characterization of a novel conjugated methamphetamine vaccine

BACKGROUND

Methamphetamine (METH) addiction is a major public health concern globally with limited management options. The development of a METH vaccine through hapten design has received significant attention as a promising platform for the potential treatment of METH addiction and overdose, however there is yet to be a successful candidate in human trials.

RESEARCH DESIGN AND METHODS

In this study, we developed a novel conjugated METH vaccine using oxidized mannan (a polymannose) as an immunogenic carrier. A METH hapten was synthesized by using amphetamine and conjugated to mannan with a (Lysine-Glycine-Lysine-Glycine-lysine-Glycine-Lysine-Glycine-Lysine-Glycine) (KG)₅ peptide linker.

RESULTS

The reaction between amphetamine and (KG)₅, oxidation of mannan, and conjugation of amphetamine-(KG)₅ with oxidized mannan were confirmed by color tests, Fourier-transform infrared spectroscopy, gas and liquid chromatography mass spectrometry, thin-layer chromatography, and ultraviolet spectrophotometer. Additionally, the ability of the vaccine to generate antibodies was confirmed in C57BL/6 mice.

CONCLUSIONS

The successful development and characterization of the METH-mannan conjugate vaccine, provides a potential therapeutic intervention to curb METH substance use disorders. Each step of vaccine development was characterized to aid in future research on these vaccines, and the immunogenicity shown in the animal models supports future evaluation of the approach. Future studies of the conjugated METH vaccine should evaluate the efficacy in animal models of acute and chronic METH to pave the way for human studies.