Identification of a T-helper cell epitope on the rotavirus VP6 protein.
In this work, we have studied the T-helper (Th)-cell response against rotavirus, in a mouse model. Adult BALB/c mice were inoculated parenterally with porcine rotavirus YM, and the Th-cell response from spleen cells against the virus and two overlapping fragments of the major capsid protein VP6 (VP6(1-192) and VP6(171-397)) were evaluated in vitro. The Th cells recognized the YM virus and the two protein fragments, suggesting that there are at least two Th-cell epitopes on the VP6 molecule. To study the specificity of Th cells against VP6 at the clonal level, we established two Th-cell hybridomas cross-reactive for the VP6 protein of rotavirus strains YM and SA11. Both hybridomas recognized the VP6(171-397) polypeptide, and a synthetic peptide comprising the amino acids 289 to 302 (RLSFQLVRPPNMTP) of YM VP6 in the context of the major histocompatibility complex class II IEd molecule. The Th-cell hybridomas recognized rotavirus VP6 in a highly cross-reactive fashion, since they could be stimulated by eight different strains of rotavirus, including the murine rotavirus EDIM, that represent five G serotypes and at least two subgroups. The amino acid sequence of the VP6 epitope is highly conserved in most group A rotavirus strains sequenced so far. On the other hand, it was found that Th cells specific for the VP6 epitope may constitute an important proportion of the total polyclonal Th-cell response against rotavirus YM in spleen cells. These results demonstrate that VP6 can be a target for highly cross-reactive Th cells.
Baños
D M
DM
Departamento de Genética y Fisiología Molecular, Instituto de Biotecnología, UNAM, Cuernavaca, Morelos, México.
Lopez
S
S
Arias
C F
CF
Esquivel
F R
FR
D000818:Animals; D000956:Antigens, Viral / Q000276:immunology*; D002213:Capsid / Q000276:immunology*; D036022:Capsid Proteins; D002460:Cell Line; D003429:Cross Reactions; D018984:Epitopes, T-Lymphocyte / Q000276:immunology*; D005260:Female; D006825:Hybridomas; D051379:Mice; D008807:Mice, Inbred BALB C; D012401:Rotavirus / Q000276:immunology*; D013154:Spleen / Q000166:cytology / Q000276:immunology; D013552:Swine / Q000821:virology; D006377:T-Lymphocytes, Helper-Inducer / Q000276:immunology*
D000956:Antigens, Viral; D036022:Capsid Proteins; D018984:Epitopes, T-Lymphocyte; C061332:VP6 protein, Rotavirus