Novel adjuvant for immunization against tuberculosis: DNA vaccine expressing Mycobacterium tuberculosis antigen 85A and interleukin-15 fusion product elicits strong immune responses in mice.

Abstract

OBJECTIVES:

To investigate the potential of interleukin (IL)-15 as a novel adjuvant for Mycobacterium tuberculosis (Mtb) antigen 85A (Ag85A) vaccine.

RESULTS:

C57BL/6 mice were intramuscularly immunized three times with a plasmid expressing the Ag85A-IL-15 fusion protein (pcDNA3.1-Ag85A-IL-15), with the empty pcDNA3.1 vector and the pcDNA3.1-Ag85A as control. Mice vaccinated with pcDNA3.1-Ag85A-IL-15 generated more secretory IgA (sIgA) into their lung (209 ± 21 μg/ml) and acquired an enhanced serum IgG response to Ag85A. IgG2a/IgG1 ratios were upregulated, natural killer cell activity was augmented and Ag85A-specific splenic T cell proliferation was enhanced in these mice as well. Vaccination with pcDNA3.1-Ag85A-IL-15 promoted the polarization of CD4+ T cells towards a Th1 type in the spleen, and significantly upregulated the serum level of interferon (IFN)-γ (458 ± 98 pg/ml), a typical Th1 cytokine. IFN-γ-expressing CD8+ cells were also increased in the spleen after pcDNA3.1-Ag85A-IL-15 immunization.

CONCLUSIONS:

A superior immune type I response in mice vaccinated with plasmid Ag85A-IL-15 has been achieved.

• Authors: Li Sun, Quan Yuan, Tianhua Xu, Li Yao, Jiangmin Feng, Jianfei Ma, Lining Wang, Changlong Lv, Danan Wang
• Journal: Biotechnology letters (Biotechnol Lett) Vol. 39 Issue 8 Pg. 1159-1166 (Aug 2017) ISSN: 1573-6776 [Electronic] Netherlands
• PMID: 28470626 (Publication Type: Journal Article)

Chemical References

• Adjuvants, Immunologic
• Antigens, Bacterial
• Recombinant Fusion Proteins
• Tuberculosis Vaccines
• Vaccines, DNA
• Interferon-gamma
• Acyltransferases
• antigen 85A, Mycobacterium tuberculosis

Topics

• Acyltransferases (chemistry, genetics, immunology)
• Adjuvants, Immunologic (chemistry, genetics)
• Animals
• Antigens, Bacterial (chemistry, genetics, immunology)
• Bronchoalveolar Lavage Fluid (cytology)
• Cells, Cultured
• Cloning, Molecular
• HEK293 Cells
• Humans
• Interferon-gamma (chemistry, genetics, immunology)
• Mice
• Mice, Inbred C57BL
• Plasmids
• Recombinant Fusion Proteins (chemistry, genetics, immunology)
• Spleen (cytology)
• Tuberculosis
• Tuberculosis Vaccines (chemistry, genetics, immunology)
• Vaccines, DNA (chemistry, genetics, immunology)