T-helper and humoral responses to Puumala hantavirus nucleocapsid protein: identification of T-helper epitopes in a mouse model.
Puumala hantavirus (PUUV) is a rodent-borne agent causing nephropathia epidemica in humans, a milder form of haemorrhagic fever with renal syndrome occurring in Fennoscandia, central Europe and western Russia. In this study we characterized the immunogenicity of an E. coli-expressed nucleocapsid (N) protein of PUUV (strain Kazan-E6) in inbred mice (BALB/c, CBA and C57/BL6). The recombinant N (rN) protein raised PUUV-specific antibodies in all three tested murine haplotypes, and all IgG subclasses were detected. Epitope mapping using peptides spanning the N protein revealed that the B-cell recognition sites were mainly located at the amino-terminal part of the protein. Proliferative T-helper (Th) lymphocyte responses were detected in all haplotypes after a single immunization with rN. Several Th-recognition sites, spanning amino acids 6-27, 96-117, 211-232 and 256-277, were identified using overlapping peptides. Peptides representing the identified sites could also prime Th-lymphocytes to proliferate in response to recall with rN protein, thereby confirming the authenticity of the identified sites. The rN-primed Th-lymphocytes produced predominantly interleukin (IL)-2 and gamma interferon, together with lower levels of IL-4 and IL-6, indicating a mixed Th1/Th2 response.
de Carvalho Nicacio
Cristina
C
Microbiology and Tumor Biology Center, Karolinska Institutet, S-171 77 Stockholm, Sweden1.
Sällberg
Matti
M
Division of Clinical Virology, F68, Oral Microbiology, F88, and Basic Oral Sciences, F59, Huddinge University Hospital, S-141 86 Huddinge, Sweden2.
Hultgren
Catharina
C
Division of Clinical Virology, F68, Oral Microbiology, F88, and Basic Oral Sciences, F59, Huddinge University Hospital, S-141 86 Huddinge, Sweden2.
Lundkvist
Åke
Å
Swedish Institute for Infectious Disease Control, S-171 82 Stockholm, Sweden3.|Microbiology and Tumor Biology Center, Karolinska Institutet, S-171 77 Stockholm, Sweden1.
D000595:Amino Acid Sequence; D000818:Animals; D000917:Antibody Formation; D004195:Disease Models, Animal; D018604:Epitope Mapping; D000939:Epitopes / Q000032:analysis*; D006476:Orthohantavirus / Q000235:genetics / Q000276:immunology*; D018778:Hantavirus Infections / Q000097:blood; D007111:Immunity, Cellular; D007371:Interferon-gamma / Q000032:analysis; D007376:Interleukin-2 / Q000032:analysis; D015847:Interleukin-4 / Q000032:analysis; D015850:Interleukin-6 / Q000032:analysis; D008213:Lymphocyte Activation; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D008808:Mice, Inbred CBA; D008969:Molecular Sequence Data; D019590:Nucleocapsid Proteins / Q000235:genetics / Q000276:immunology*; D011994:Recombinant Proteins / Q000276:immunology; D006377:T-Lymphocytes, Helper-Inducer / Q000276:immunology*
D000939:Epitopes; D007376:Interleukin-2; D015850:Interleukin-6; D019590:Nucleocapsid Proteins; D011994:Recombinant Proteins; D015847:Interleukin-4; D007371:Interferon-gamma