J-LEAPS vaccines initiate murine Th1 responses by activating dendritic cells

• Published in: Vaccine 2010-08, Vol.28 (34), p.5533-5542
• Main Authors: Taylor, P.R, Koski, G.K, Paustian, C.C, Bailey, E, Cohen, P.A, Moore, F.B.-G, Zimmerman, D.H, Rosenthal, K.S
• Format: Article
• Language: English
• Subjects: Adoptive Transfer; Allergy and Immunology; Amino acids; Animals; Antigen Presentation; Applied microbiology; Binding sites; Biological and medical sciences; Bone marrow; Cells, Cultured; Dendritic cells; Dendritic Cells - immunology; Epitopes, T-Lymphocyte - immunology; Female; Fundamental and applied biological sciences. Psychology; gag Gene Products, Human Immunodeficiency Virus - immunology; Herpes Simplex - immunology; Herpes Simplex - prevention & control; Herpes simplex virus 1; Herpesvirus 1, Human - immunology; HIV; HSV; Human immunodeficiency virus; IL12; Immune system; Immunization; Interferon-gamma - immunology; Interleukin-12 - immunology; LEAPS; Ligands; Lymphocytes; Mice; Mice, Inbred A; Mice, Inbred C57BL; Microbiology; Miscellaneous; Peptides; Proteins; Studies; T cell receptors; Th1; Th1 Cells - immunology; Vaccines; Vaccines, antisera, therapeutical immunoglobulins and monoclonal antibodies (general aspects); Viral Envelope Proteins - immunology; Viral Vaccines - immunology; Virology
• ISSN: 0264-410X; 1873-2518
• DOI: 10.1016/j.vaccine.2010.06.043

Abstract The Ligand Epitope Antigen Presentation System (LEAPS) converts a peptide containing a T cell epitope as small as 8 amino acids into an immunogen and directs the nature of the subsequent response. Tandem synthesis of the J peptide (a peptide from the beta-2-microglobulin) with peptides of 15 or 30 amino acids from HSV-1 or HIV made them immunogenic and promoted Th1 immune responses. Immunization of A/J or C57BL/6 mice with J-LEAPS heteroconjugates containing an epitope from the HSV-1 glycoprotein D (JgD) or an epitope from the HIV gag protein (JH) emulsified with Seppic ISA51 induced increased levels of IL-12p70 by day 3 and increased levels of interferon gamma (IFN-gamma) on days 10 and 24. Interestingly, levels of IL-10, TNF-alpha, and IL-6 did not change. Neither the H nor the gD peptides alone elicited responses and only weak responses followed immunization with the J peptide. Bone marrow (BM) cells became CD86 and CD11c positive within 48 h of treatment with JgD or JH. JH or JgD treatment promoted IL-12p70 production and expression of CD8 denoting the maturation and activation of a subclass of myeloid DCs. Pure cultures of immature myeloid DCs also responded to JgD treatment, forming clusters, developing dendrites, and producing IL-12p70 within 24 h. The JH or JgD treated bone marrow cells (JgD-DC) were necessary and sufficient to activate splenic T cells to produce IFN-gamma and the JgD-DC provided an antigen specific booster response to T cells from JgD immunized mice. Adoptive transfer of JgD-DC was also sufficient to initiate protective antigen specific immunity from lethal challenge with HSV-1. The J-LEAPS vaccines appear to act as an adjuvant and immunogen on DC precursors in a unique manner to promote activation and maturation into IL-12p70 producing DCs which then can initiate sufficient Th1 immune responses to elicit protection without production of acute phase cytokines.