Priming of cytotoxic T lymphocytes by five heat-aggregated antigens in vivo: conditions, efficiency, and relation to antibody responses.
Mice were immunized i.p. with soluble or heat-denatured protein antigens [ovalbumin, beta-galactosidase, or recombinant E7 protein of human papilloma virus type 16 (HBV)]. Heat-denatured (100 degrees C) preparations of these proteins were able to induce cytotoxic T lymphocytes (CTL) that recognize cells expressing the respective genes, whereas native protein was either inefficient or required up to 30-fold higher doses. If the heat-treated proteins were separated into aggregated and soluble fractions by ultracentrifugation, only the aggregated fractions were able to induce specific CTL; this is probably because of the easier access to one of the major histocompatibility complex class I loading pathways for exogenous antigen. Addition of the adjuvant aluminium hydroxide (alum) to aggregated proteins abolished their ability to induce CTL; thus, a condition leading to a strong antibody response appeared to inhibit CTL induction. Interestingly, immunization with heat-denatured ovalbumin plus alum increased the IgM/IgG1 ratio compared to immunization with native ovalbumin and alum. Immunization of B6 mice transgenic for an HLA-A2/H-2K(b) hybrid gene with heat-denatured, recombinant HPV 16-E7 protein induced D(b)-restricted CTL specific for the peptide 49-57 of E7, indicating that this epitope is immunodominant over any A2-restricted E7 epitope in these mice. A whole influenza virus preparation heated to 100 degrees C or even autoclaved was still able to induce virus-specific CTL and BALB/c spleen cells heated to 100 degrees C could still cross-prime minor H-specific CTL in B6 mice, although with lower efficiency than fresh spleen cells. Thus, aggregated proteins can be considered as components for future vaccines.
Speidel
K
K
Department of Tumorvirus Immunology, German Cancer Research Center (DKFZ), Heidelberg, Germany.
Osen
W
W
Faath
S
S
Hilgert
I
I
Obst
R
R
Braspenning
J
J
Momburg
F
F
Hämmerling
G J
GJ
Rammensee
H G
HG
D000818:Animals; D000917:Antibody Formation; D000956:Antigens, Viral / Q000276:immunology; D006183:H-2 Antigens / Q000276:immunology; D006358:Hot Temperature; D007111:Immunity, Cellular; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D009856:Oncogene Proteins, Viral / Q000276:immunology; D010047:Ovalbumin / Q000737:chemistry / Q000276:immunology*; D027383:Papillomaviridae / Q000737:chemistry / Q000276:immunology*; D050725:Papillomavirus E7 Proteins; D011489:Protein Denaturation; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology*; D014612:Vaccines / Q000276:immunology; D001616:beta-Galactosidase / Q000737:chemistry / Q000276:immunology*
D000956:Antigens, Viral; D006183:H-2 Antigens; D009856:Oncogene Proteins, Viral; D050725:Papillomavirus E7 Proteins; D014612:Vaccines; C059731:oncogene protein E7, Human papillomavirus type 16; D010047:Ovalbumin; D001616:beta-Galactosidase