An Immunconjugate Vaccine Alters Distribution and Reduces the Antinociceptive, Behavioral and Physiological Effects of Fentanyl in Male and Female Rats
by Colin N. Haile, Miah D. Baker, Sergio A. Sanchez, Carlos A. Lopez Arteaga, Anantha L., Duddupudi, Gregory D. Cuny , Elizabeth B. Norton, Thomas R. Kosten, and Therese A. Kosten
Department of Psychology & TIMES, University of Houston, Houston, TX 77204, USA
Department of Pharmacological & Pharmaceutical Sciences, University of Houston, Houston, TX 77204, USA
Department of Microbiology & Immunology, Tulane University School of Medicine, New Orleans, LA 70112, USA
Menninger Department of Psychiatry, Baylor College of Medicine, Houston, TX 77030, USA
The Michael E DeBakey Veteran’s Affairs Medical Center, Houston, TX 77030, USA
Academic Editor: Teijo Saari
Pharmaceutics 2022, 14(11), 2290;
https://doi.org/10.3390/pharmaceutics14112290Received: 31 August 2022 / Revised: 13 October 2022 / Accepted: 18 October 2022 / Published: 26 October 2022
Abstract
Fentanyl (FEN) is a potent synthetic opioid associated with increasing incidence of opioid use disorder (OUD) and fatal opioid overdose. Vaccine immunotherapy for FEN-associated disorders may be a viable therapeutic strategy. Here, we expand and confirm our previous study in mice showing immunological and antinociception efficacy of our FEN vaccine administered with the adjuvant dmLT. In this study, immunized male and female rats produced significant levels of anti-FEN antibodies that were highly effective at neutralizing FEN–induced antinociception in the tail flick assay and hot plate assays. The vaccine also decreased FEN brain levels following drug administration. Immunization blocked FEN-induced, but not morphine-induced, rate-disrupting effects on schedule-controlled responding. Vaccination prevented decreases on physiological measures (oxygen saturation, heart rate) and reduction in overall activity following FEN administration in male rats. The impact of FEN on these measures was greater in unvaccinated male rats compared to unvaccinated female rats. Cross-reactivity assays showed anti-FEN antibodies bound to FEN and sufentanil but not to morphine, methadone, buprenorphine, or oxycodone. These data support further clinical development of this vaccine to address OUD in humans.
3. Results
3.1. Anti-FEN Antibody Levels
Anti-FEN IgG antibody levels over ten weeks are shown in Figure 1B. ANOVA yielded significant main effects for Sex (F(1, 28) = 8.604, p < 0.01) and Time (F(3, 84) = 13.85, p < 0.0001) and a significant Sex X Time interaction (F(3, 84) = 10.37, p < 0.0001). For male rats, post hoc multiple comparisons revealed significant differences in anti-FEN IgG antibody levels between 4 and 6 (p < 0.01), 8 (p < 0.01), and 10 (p < 0.05) weeks. For female rats, post hoc multiple comparisons revealed a significant difference in antibody levels between weeks 4 and 6 (p < 0.05). Between group comparisons revealed a highly significant difference in antibody concentrations for male rats compared to female rats at weeks 8 (p < 0.0001) and 10 (p < 0.01). Overall, anti-FEN IgG antibody levels increased over time compared to baseline in male rats and were greater than levels in female rats.
3.3. Fentanyl Brain Levels
Figure 2E and Figure 3E show brain levels of FEN following a high dose administration. ANOVA revealed significant main effects for Vaccine status (F(1, 54) = 599.90, p < 0.001) and Sex (F(1, 54) = 10.70, p < 0.005) and their interaction (F(1, 54) = 4.53, p < 0.05). Post hoc multiple comparisons revealed significant differences between vaccine groups of both sexes (p’s < 0.01–0.0001). As expected, greater amounts of FEN were present in the brains of unvaccinated male and female rats compared to vaccinated rats of either sex. Interestingly, female unvaccinated rats had higher brain FEN levels compared to male unvaccinated rats (p < 0.01).
4. Discussion
The present study expands upon our previous results by further characterizing our anti-FEN vaccine in male and female Sprague Dawley rats. We find that the FEN-CRM+dmLT vaccine: (1) produces anti-FEN antibodies that are long-lasting; (2) blocks FEN-induced nociception in the tail flick and hotplate assays; (3) leads to lower FEN brain levels following FEN administration 20-weeks after initial vaccination; (4) blocks the rate-disrupting effects of FEN, but not MOR, on schedule-controlled responding; (5) protects against FEN-induced decreases in oxygen saturation, heart rate, and activity levels in male rats and decreases in heart rate in female rats; and (6) generates anti-FEN antibodies that bind specifically to FEN and not to other opioids. Additionally, we report on several sex differences in response to the vaccine or to FEN. These findings include: (1) greater anti-FEN antibody levels in male rats compared to female rats across weeks; (2) a more pronounced FEN-induced antinociception in male rats in the tail flick test; (3) greater penetration of FEN into the brain in female rats; and (4) greater FEN-induced decreases on oxygen saturation and heart rate in male rats compared to female rats. These data show our FEN-CRM conjugate vaccine coupled with the adjuvant dmLT can produce anti-FEN antibodies that eliminate the behavioral and physiological effects of FEN. The vaccine formulation includes CRM197, a carrier protein in vaccines already FDA-approved, and GMP-grade dmLT, that has proven safe and effective in many clinical trials [45]. This is the first report to show the effectiveness of this vaccine formulation in male and female rats that extend our previous findings in mice [26] and are consistent with other vaccine studies targeting opioids [22,23,24,25,42,46,47].
Complete Article:
https://www.mdpi.com/1999-4923/14/11/2290/htm
