ABSTRACT
To explore the association between T-cell receptor beta variable (TCR BV) complementarity determining region 3 (CDR3) spectratyping and CMV activation in the recipients of allogeneic hematopoietic stem cell transplantation (HSCT).Fluorescence quantitative PCR melting curve analysis was used to sequence 24 TCR BV families in 7 HSCT recipients and 3 healthy controls. CMV-pp65 antigenemia was measured by immunohistochemical staining. Plasma IgM specific for CMV was identified using ELISA. Relationship between TCR BV families and CMV activation was statistically analyzed.Twenty-four TCR BV families were expressed in 3 healthy controls, while TCR BV CDR3 sequencing results in 7 recipients turned out to be BV9, BV11, BV17, BV20 and so on. Amino acid sequence features were as follows:TCR BV9 contained "QVRGGTDTQ", TCR BV11 contained "VATDEQ" and "LGDEQ", TCR BV17 contained "IGQGNTEA", and TCR BV20 contained "VGLAANEQ". Five recipients suffered from pp65 antigenemia in 3 month after transplantation, and pp65-positive cells ranged from 2 to 15 per 5×10white blood cells. Three recipients were CMV-IgM positive. No significant differences were found in TCR BV families between pp65-positive recipients and pp65-negative recipients (all>0.05). But there was statistically significant difference in frequency of TCR BV11 between CMV-IgM negative recipients and CMV-IgM positive recipients (<0.05).T cell immune response was characterized by special TCR BV CDR3 spectratyping in HSCT recipients, and TCR BV11 expression may be associated with CMV activation.
Subject(s)
Humans , Amino Acid Sequence , Complementarity Determining Regions , Genetics , Allergy and Immunology , Cytomegalovirus , Genetics , Allergy and Immunology , Cytomegalovirus Infections , Genetics , Genotype , Hematopoietic Stem Cell Transplantation , Lymphocyte Activation , Genetics , Phosphoproteins , Polymerase Chain Reaction , Polymorphism, Genetic , Allergy and Immunology , Receptors, Antigen, T-Cell, alpha-beta , Genetics , Allergy and Immunology , Spleen , T-Lymphocytes , Allergy and Immunology , Virology , Viral Matrix ProteinsABSTRACT
Human cytomegalovirus glycoprotein B (gB) represents a target for diagnosis and treatment in view of the role it plays in virus entry and spread. Nevertheless, to our knowledge, rare detection of a gB antigen has been reported in transplant patients and limited information is available about diagnostic gB monoclonal antibodies (mAbs). Our aim was to develop gB mAbs with diagnostic potential. Hydrophilic gB peptides (ST: amino acids 27-40, SH: amino acids 81-94) of favorable immunogenicity were synthesized and used to immunize BALB/c mice. Two mAbs, named ZJU-FH6 and ZJU-FE6, were generated by the hybridoma technique and limited serial dilution and then characterized by indirect ELISA, Western blotting, immunoprecipitation, and immunohistochemical staining. The mAbs displayed high titers of specific binding affinities for the ST and SH synthetic peptides at an mAb dilution of 1:60,000 and 1:240,000, respectively. Western blotting and immunoprecipitation indicated that these mAbs recognized both denatured and native gB of the Towne and AD169 strains. The mAbs, when used as the primary antibody, showed positive staining in cells infected with both Towne and AD169 strains. The mAbs were then tested on patients submitted to allogeneic hematopoietic stem cell transplantation. The gB antigen positivity rates of the patients tested using ZJU-FH6 and ZJU-FE6 were 62.0 and 63.0%, respectively. The gB antigen showed a significant correlation with the level of pp65 antigen in peripheral blood leukocytes. In conclusion, two potential diagnostic gB mAbs were developed and were shown to be capable of recognizing gB in peripheral blood leukocytes in a reliable manner.