Parenteral Vaccine Adjuvants Elicit Humoral Immune Responses in Cynomolgus Macaques

Researchers from the United States have found that parenteral vaccine adjuvants can promote systemic and mucosal HIV-1 peptide-specific humoral immune responses in cynomolgus macaques. The study aimed to evaluate the ability of adjuvants to augment peptide-specific immune responses. The findings suggest that parenteral vaccine administration in combination with the appropriate adjuvant formulation can elicit vaccine-specific humoral immune responses in both systemic and mucosal compartments.

Key Takeaways:

• Parenteral vaccine adjuvants, such as RC529-SE/rhGM-CSF, rhIL-1alpha/rhGM-CSF, and CT-E29H, promoted peptide-specific immune responses in cynomolgus macaques.
• The adjuvant combination of RC529-SE/rhGM-CSF elicited the highest peak anti-peptide IgG geometric mean titer in serum (1:32,768 at week 25).
• Measurable SHIV neutralizing antibody responses were detectable in only one macaque immunized i.m. with peptide formulated with RC529-SE/rhGM-CSF.
• The study found that while i.n. immunization with peptide in combination with CT-E29H failed to elicit measurable antibody responses at nasal or genital mucosal surfaces, i.n. immunization with peptide in combination with rhIL-1alpha/rhGM-CSF did elicit antibody responses at the nasal and genital mucosa.
• The results suggest that parenteral vaccine administration in combination with the appropriate adjuvant formulation can elicit vaccine-specific humoral immune responses in both systemic and mucosal compartments.

Statistics:

• 1:32,768: the peak anti-peptide IgG geometric mean titer in serum elicited by the RC529-SE/rhGM-CSF adjuvant combination at week 25.
• 1:1,217: the peak anti-peptide IgG geometric mean titer in serum elicited by the rhIL-1alpha/rhGM-CSF adjuvant combination at week 10.
• 1:256: the peak anti-peptide IgG geometric mean titer in serum elicited by the CT-E29H adjuvant combination at week 25.
• 1 macaque: the number of animals immunized i.m. with peptide formulated with RC529-SE/rhGM-CSF that showed measurable SHIV neutralizing antibody responses.

Sources:

• Vaccine (A comparative evaluation of nasal and parenteral vaccine adjuvants to elicit systemic and mucosal HIV-1 peptide-specific humoral immune responses in cynomolgus macaques. Vaccine, 2004;22(27-28):3774-3788).
• Contact: Herman F. Staats, Department of Pathology, Human Vaccine Institute, Duke University Medical Center, Box 3712, Durham, NC 27710, USA. E-mail: hfs@acpub.duke.edu.