scholarly journals Hepatitis B Surface Antigen Vector Delivers Protective Cytotoxic T-Lymphocyte Responses to Disease-Relevant Foreign Epitopes

2006 ◽  
Vol 80 (8) ◽  
pp. 3975-3984 ◽  
Author(s):  
Wai-Ping Woo ◽  
Tracy Doan ◽  
Karen A. Herd ◽  
Hans-Jürgen Netter ◽  
Robert W. Tindle

ABSTRACT Although hepatitis B surface antigen (HBsAg) per se is highly immunogenic, its use as a vector for the delivery of foreign cytotoxic T-lymphocyte (CTL) epitopes has met with little success because of constraints on HBsAg stability and secretion imposed by the insertion of foreign sequence into critical hydrophobic/amphipathic regions. Using a strategy entailing deletion of DNA encoding HBsAg-specific CTL epitopes and replacement with DNA encoding foreign CTL epitopes, we have derived chimeric HBsAg DNA immunogens which elicited effector and memory CTL responses in vitro, and pathogen- and tumor-protective responses in vivo, when the chimeric HBsAg DNAs were used to immunize mice. We further show that HBsAg DNA recombinant for both respiratory syncytial virus and human papillomavirus CTL epitopes elicited simultaneous responses to both pathogens. These data demonstrate the efficacy of HBsAg DNA as a vector for the delivery of disease-relevant protective CTL responses. They also suggest the applicability of the approach of deriving chimeric HBsAg DNA immunogens simultaneously encoding protective CTL epitopes for multiple diseases. The DNAs we tested formed chimeric HBsAg virus-like particles (VLPs). Thus, our results have implications for the development of vaccination strategies using either chimeric HBsAg DNA or VLP vaccines. HBsAg is the globally administered vaccine for hepatitis B virus infection, inviting its usage as a vector for the delivery of immunogens from other diseases.

Virology ◽  
2005 ◽  
Vol 333 (2) ◽  
pp. 293-300 ◽  
Author(s):  
Masanori Isogawa ◽  
Kazuhiro Kakimi ◽  
Hiroyuki Kamamoto ◽  
Ulrike Protzer ◽  
Francis V. Chisari

2001 ◽  
Vol 193 (1) ◽  
pp. 73-88 ◽  
Author(s):  
Jan H. Kessler ◽  
Nico J. Beekman ◽  
Sandra A. Bres-Vloemans ◽  
Pauline Verdijk ◽  
Peter A. van Veelen ◽  
...  

We report the efficient identification of four human histocompatibility leukocyte antigen (HLA)-A*0201–presented cytotoxic T lymphocyte (CTL) epitopes in the tumor-associated antigen PRAME using an improved “reverse immunology” strategy. Next to motif-based HLA-A*0201 binding prediction and actual binding and stability assays, analysis of in vitro proteasome-mediated digestions of polypeptides encompassing candidate epitopes was incorporated in the epitope prediction procedure. Proteasome cleavage pattern analysis, in particular determination of correct COOH-terminal cleavage of the putative epitope, allows a far more accurate and selective prediction of CTL epitopes. Only 4 of 19 high affinity HLA-A*0201 binding peptides (21%) were found to be efficiently generated by the proteasome in vitro. This approach avoids laborious CTL response inductions against high affinity binding peptides that are not processed and limits the number of peptides to be assayed for binding. CTL clones induced against the four identified epitopes (VLDGLDVLL, PRA100–108; SLYSFPEPEA, PRA142–151; ALYVDSLFFL, PRA300–309; and SLLQHLIGL, PRA425–433) lysed melanoma, renal cell carcinoma, lung carcinoma, and mammary carcinoma cell lines expressing PRAME and HLA-A*0201. This indicates that these epitopes are expressed on cancer cells of diverse histologic origin, making them attractive targets for immunotherapy of cancer.


2006 ◽  
Vol 13 (7) ◽  
pp. 733-739 ◽  
Author(s):  
Zhijun Wang ◽  
Li Xiang ◽  
Junjie Shao ◽  
Zhenghong Yuan

ABSTRACT In this article, the immunogenicity of tRNA and the recognition of tRNA by Toll-like receptors (TLRs) are analyzed. Analyses of the effects of different tRNAAla(UGC) fragments (tRNAAla1-76 [corresponding to positions 1 through 76], tRNAAla26-76, tRNAAla40-76, tRNAAla62-76, tRNAAla1-70, tRNAAla26-70, tRNAAla40-70, and tRNAAla62-70) on the immune responses of hepatitis B surface antigen (HBsAg) were performed with BALB/c mice. Results show that tRNAAla1-76, tRNAAla26-76, tRNAAla40-76, and tRNAAla62-76 adjuvants not only induced stronger T helper (Th) 1 immune responses but also cytotoxic-T-lymphocyte (CTL) responses relative to tRNAAla1-70, tRNAAla26-70, tRNAAla40-70, and tRNAAla62-70 adjuvants in HBsAg immunization. A deletion of the D loop (tRNAAla26-76), anticodon loop (tRNAAla40-76), or TψC (tRNAAla62-76) loop of tRNAAla(UGC) does not significantly decrease the adjuvant characteristic of tRNAAla(UGC). However a deletion of the 3′-end CCACCA sequence (tRNAAla1-70, tRNAAla26-70, tRNAAla40-70, and tRNAAla62-70) of tRNAAla(UGC) significantly decreased the adjuvant characteristic in Th1 and CTL immune responses. Moreover, the recognitions of different tRNAAla(UGC) fragments by TLR3, TLR7, TLR8, and TLR9 were analyzed. Results show that a deletion of the 3′ CCACCA sequence of tRNAAla(UGC) significantly decreased the recognition by TLR3. We concluded that the 3′ CCACCA sequence of tRNAAla(UGC) is the important motif to induce Th1 and CTL responses and this motif can be effectively recognized by TLR3.


1980 ◽  
Vol 152 (6) ◽  
pp. 1805-1810 ◽  
Author(s):  
J P Lake ◽  
M E Andrew ◽  
C W Pierce ◽  
T J Braciale

The in vitro secondary cytotoxic T lymphocyte (CTL) response to Sendai virus-treated stimulator cells by primed spleen cells from thymus gland-grafted nude mice was examined. BALB/c (H-2d) nude mice grafted with allogeneic C57BL/10 (H-2b) thymus glands developed CTL responses directed exclusively to Sendai virus-infected H-2d target cells. (C57BL/6 X BALB/c)F1 nude mice grafted with thymus glands of either parent developed CTL responses preferentially against infected target cells expressing the MHC antigens present in the parental thymus graft, but also had detectable activity for infected target cells of the parental haplotype not expressed in the thymus. These results provide evidence against the concept that self recognition by MHC-restricted CTL is directed exclusively by the MCH type of the thymus.


Blood ◽  
2001 ◽  
Vol 97 (6) ◽  
pp. 1776-1786 ◽  
Author(s):  
Corinna La Rosa ◽  
Radhika Krishnan ◽  
Susan Markel ◽  
Jonathan P. Schneck ◽  
Richard Houghten ◽  
...  

The pp65495-503 cytotoxic T-lymphocyte (CTL) epitope from cytomegalovirus (CMV) is universally recognized among CMV+ individuals who express an allele of the human leukocyte antigen A (HLA-A*0201). The relative binding affinity of the epitope to HLA-A*0201 is moderate, and its increased activity might prove beneficial in its use as a CTL epitope vaccine. A new approach to enhance the activity of T-cell epitopes is the use of positional scanning synthetic combinatorial libraries (PS-SCLs). Using a nonamer PS-SCL, the pp65495-503 epitope was modified after screening a CMV-specific T-cell clone (TCC) (3-3F4) from which the native peptide sequence was derived. Two peptides with amino acid substitutions at P1, P3, P7, and P8 are between 103 and 104 more active than the native epitope. Although the native CTL epitope terminates as a free acid, both tetrasubstituted peptides only function as CTL epitopes when the carboxyl terminus is amidated. Selective substitution of the native sequence based on PS-SCL screening results identified 3 amidated monosubstituted and disubstituted peptides that are better recognized than the native epitope by TCCs from a cohort expressing HLA-A*0201. In vitro stimulation of peripheral blood mononuclear cells with each of the peptide epitope analogs stimulated memory CTLs, which recognized CMV-infected targets among a high percentage of CMV+ individuals. Binding studies of peptide analogs with HLA-Ig (immunoglobulin) dimers and 2 different TCCs correlated with in vitro lysis results. These data suggest that increasing the activity of CTL epitopes while maintaining broad recognition is possible, which holds promise for vaccine development in infectious disease and cancer.


1994 ◽  
Vol 28 (9) ◽  
pp. 1014-1017
Author(s):  
Christine A. Lindsay ◽  
Ken Dang ◽  
James M. Adams ◽  
Ching Nan Ou ◽  
Carol J. Baker

OBJECTIVE: To determine in vitro the compatibility of reconstituted intravenous immunoglobulin (IVIG) (Gammagard, Baxter-Hyland) with five different neonatal and pediatric intravenous solutions in Viaflex polyvinyl chloride bags. DESIGN: In vitro compatibility study. INTERVENTIONS: Samples were taken at time=0, 10, 30, 60, 90, and 120 minutes and at 4, 8, 12, and 24 hours and assayed for total immunoglobulin G content and antibodies to hepatitis B surface antigen. Type III group B Streptococcus (GBS) and opsonic activity for type III GBS were analyzed at time=0, 60, and 120 minutes and 12 and 24 hours. All results were compared with those from pure IVIG. RESULTS: Our results demonstrate that mixing IVIG with intravenous solutions commonly used in the care of premature infants (dextrose 5% in water [D5W], D15W, D5W/NaCl 0.225%, and total parenteral nutrition [TPN]) does not significantly alter total immunoglobulin G concentrations or concentration of antibodies to hepatitis B surface antigen or type III GBS. As well, the in vitro functional activity for type III GBS of the IVIG, when mixed with these solutions for up to 24 hours, remained intact. An apparent decrease in bactericidal killing was seen with the IVIG/central TPN mixture. This apparent decrease was found to be an artifact of the high concentration of glucose (20 percent) in the solution. CONCLUSIONS: We propose that Gammagard may be mixed with these solutions through Y-site connections without loss of antibody content or functional activity of the IVIG.


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