Respiratory syncytial virus recombinant F protein (residues 255-278) induces a helper T cell type 1 immune response in mice.
We have developed and evaluated an immunodominant respiratory syncytial virus (RSV) F antigen in a mouse model. The antigenic region corresponding to amino acids 255-278 of the RSV F protein was cloned into a vector containing the ctxA(2)B gene of cholera toxin (CT). The recombinant protein was expressed in Escherichia coli and analyzed on sodium dodecyl sulfate-polyacrylamide gels. The purified protein was evaluated by immunoblot and ganglioside GM(1) enzyme-linked immunosorbent assay to confirm the expression of the RSV F protein and to correct association of the recombinant protein to form a holotoxin-like chimera, respectively. We hypothesized that genetic fusion of modified CT-based adjuvant with RSV F immunodominant epitopes (rRF-255) would induce protective humoral and cellular immune responses in mice. Intranasal immunization of mice with rRF-255 overall induced higher concentrations of anti-RSV F-specific antibodies in both serum and saliva as compared with mice immunized intranasally with RSV or phosphate-buffered saline (PBS). Antibody isotype analysis (IgA, IgG1, IgG2a, and IgG2b) was also performed. The predominant IgG2a antibody isotype response in combination with cytokine analysis of helper T cell type 1 (interferon-gamma, interleukin [IL]-2, IL-12 p70, and tumor necrosis factor-alpha) and helper T cell type 2 (IL-4 and IL-10) responses revealed that rRF-255 antigen induces a prominent helper T cell type 1 immune response in mice. The rRF-255 antigen also induced serum neutralizing antibodies in immunized mice. Analysis of RSV load in lungs showed that rRF-255 immunization provided significant protection compared with PBS control animals.
Singh
Shree R
SR
Department of Mathematics and Science, Alabama State University, Montgomery, Alabama 36101, USA. ssingh@alasu.edu
Dennis
Vida A
VA
Carter
Christina L
CL
Pillai
Shreekumar R
SR
Moore
Eddie G
EG
D000276:Adjuvants, Immunologic; D000818:Animals; D000914:Antibodies, Viral / Q000096:biosynthesis; D002460:Cell Line; D002772:Cholera Toxin / Q000235:genetics / Q000276:immunology* / Q000378:metabolism; D016207:Cytokines / Q000378:metabolism; D005260:Female; D016056:Immunodominant Epitopes; D051379:Mice; D008807:Mice, Inbred BALB C; D011993:Recombinant Fusion Proteins / Q000276:immunology / Q000302:isolation & purification / Q000378:metabolism; D018357:Respiratory Syncytial Virus Infections / Q000276:immunology* / Q000821:virology; D012136:Respiratory Syncytial Viruses / Q000235:genetics / Q000276:immunology*; D018417:Th1 Cells / Q000276:immunology* / Q000378:metabolism; D014760:Viral Fusion Proteins / Q000737:chemistry / Q000235:genetics / Q000276:immunology*; D019562:Viral Load
D000276:Adjuvants, Immunologic; D000914:Antibodies, Viral; D016207:Cytokines; D016056:Immunodominant Epitopes; D011993:Recombinant Fusion Proteins; D014760:Viral Fusion Proteins; D002772:Cholera Toxin