Limits...
Active immunization with human interleukin-15 induces neutralizing antibodies in non-human primates

View Article: PubMed Central - PubMed

ABSTRACT

Background: Interleukin-15 is an immunostimulatory cytokine overexpressed in several autoimmune and inflammatory diseases such as Rheumatoid Arthritis, psoriasis and ulcerative colitis; thus, inhibition of IL-15-induced signaling could be clinically beneficial in these disorders. Our approach to neutralize IL-15 consisted in active immunization with structurally modified human IL-15 (mhIL-15) with the aim to induce neutralizing antibodies against native IL-15. In the present study, we characterized the antibody response in Macaca fascicularis, non-human primates that were immunized with a vaccine candidate containing mhIL-15 in Aluminum hydroxide (Alum), Montanide and Incomplete Freund’s Adjuvant.

Results: Immunization with mhIL-15 elicited a specific antibodies response that neutralized native IL-15-dependent biologic activity in a CTLL-2 cell proliferation assay. The highest neutralizing response was obtained in macaques immunized with mhIL-15 adjuvanted in Alum. This response, which was shown to be transient, also inhibited the activity of simian IL-15 and did not affect the human IL-2-induced proliferation of CTLL-2 cells. Also, in a pool of synovial fluid cells from two Rheumatoid Arthritis patients, the immune sera slightly inhibited TNF-α secretion. Finally, it was observed that this vaccine candidate neither affect animal behavior, clinical status, blood biochemistry nor the percentage of IL-15-dependent cell populations, specifically CD56+ NK and CD8+ T cells.

Conclusion: Our results indicate that vaccination with mhIL-15 induced neutralizing antibodies to native IL-15 in non-human primates. Based on this fact, we propose that this vaccine candidate could be potentially beneficial for treatment of diseases where IL-15 overexpression is associated with their pathogenesis.

No MeSH data available.


Effect of serum on TNF-α production mediated by IL-15 in synovial cells from RA patients. Synovial fluid cells were incubated with serum (fixed dilution 1:1000), or with 60 ng/ml of IL-15, or a combination of both. After incubation, supernatants were collected and levels of human TNF-α were quantified by ELISA. The tested serum corresponds to one animal from the Alum group and was taken 15 days after the third immunization
© Copyright Policy - OpenAccess
Related In: Results  -  Collection

License 1 - License 2
getmorefigures.php?uid=PMC5036325&req=5

Fig7: Effect of serum on TNF-α production mediated by IL-15 in synovial cells from RA patients. Synovial fluid cells were incubated with serum (fixed dilution 1:1000), or with 60 ng/ml of IL-15, or a combination of both. After incubation, supernatants were collected and levels of human TNF-α were quantified by ELISA. The tested serum corresponds to one animal from the Alum group and was taken 15 days after the third immunization

Mentions: In order to assess activity of sera from immunized monkeys on other IL-15-induced biological functions, we measured effects on TNF-α secretion of one serum from Alum group corresponding to 15 days after the third immunization. For this purpose, we determined levels of IL-15 in synovial fluids from patients with RA [38] and we selected 2 patients with high concentration of this cytokine (≥25 pg/mL). In this experiment, we found that serum from an animal immunized with mhIL-15 in Alum inhibited TNF-α secretion induced by exogenous IL-15 in synovial cells. Additionally, this serum diminished significantly (p 0.05) the baseline levels of TNF-α secreted by these cells (Fig. 7).Fig. 7


Active immunization with human interleukin-15 induces neutralizing antibodies in non-human primates
Effect of serum on TNF-α production mediated by IL-15 in synovial cells from RA patients. Synovial fluid cells were incubated with serum (fixed dilution 1:1000), or with 60 ng/ml of IL-15, or a combination of both. After incubation, supernatants were collected and levels of human TNF-α were quantified by ELISA. The tested serum corresponds to one animal from the Alum group and was taken 15 days after the third immunization
© Copyright Policy - OpenAccess
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC5036325&req=5

Fig7: Effect of serum on TNF-α production mediated by IL-15 in synovial cells from RA patients. Synovial fluid cells were incubated with serum (fixed dilution 1:1000), or with 60 ng/ml of IL-15, or a combination of both. After incubation, supernatants were collected and levels of human TNF-α were quantified by ELISA. The tested serum corresponds to one animal from the Alum group and was taken 15 days after the third immunization
Mentions: In order to assess activity of sera from immunized monkeys on other IL-15-induced biological functions, we measured effects on TNF-α secretion of one serum from Alum group corresponding to 15 days after the third immunization. For this purpose, we determined levels of IL-15 in synovial fluids from patients with RA [38] and we selected 2 patients with high concentration of this cytokine (≥25 pg/mL). In this experiment, we found that serum from an animal immunized with mhIL-15 in Alum inhibited TNF-α secretion induced by exogenous IL-15 in synovial cells. Additionally, this serum diminished significantly (p 0.05) the baseline levels of TNF-α secreted by these cells (Fig. 7).Fig. 7

View Article: PubMed Central - PubMed

ABSTRACT

Background: Interleukin-15 is an immunostimulatory cytokine overexpressed in several autoimmune and inflammatory diseases such as Rheumatoid Arthritis, psoriasis and ulcerative colitis; thus, inhibition of IL-15-induced signaling could be clinically beneficial in these disorders. Our approach to neutralize IL-15 consisted in active immunization with structurally modified human IL-15 (mhIL-15) with the aim to induce neutralizing antibodies against native IL-15. In the present study, we characterized the antibody response in Macaca fascicularis, non-human primates that were immunized with a vaccine candidate containing mhIL-15 in Aluminum hydroxide (Alum), Montanide and Incomplete Freund’s Adjuvant.

Results: Immunization with mhIL-15 elicited a specific antibodies response that neutralized native IL-15-dependent biologic activity in a CTLL-2 cell proliferation assay. The highest neutralizing response was obtained in macaques immunized with mhIL-15 adjuvanted in Alum. This response, which was shown to be transient, also inhibited the activity of simian IL-15 and did not affect the human IL-2-induced proliferation of CTLL-2 cells. Also, in a pool of synovial fluid cells from two Rheumatoid Arthritis patients, the immune sera slightly inhibited TNF-α secretion. Finally, it was observed that this vaccine candidate neither affect animal behavior, clinical status, blood biochemistry nor the percentage of IL-15-dependent cell populations, specifically CD56+ NK and CD8+ T cells.

Conclusion: Our results indicate that vaccination with mhIL-15 induced neutralizing antibodies to native IL-15 in non-human primates. Based on this fact, we propose that this vaccine candidate could be potentially beneficial for treatment of diseases where IL-15 overexpression is associated with their pathogenesis.

No MeSH data available.