Humoral and Mucosal Antibody Response to RSV Structural Proteins in RSV-Infected Adult Hematopoietic Cell Transplant (HCT) Recipients

Respiratory syncytial virus (RSV) is an important cause of lower respiratory tract infection in infants, the elderly, and immunocompromised patients. RSV antibodies play a role in preventing reinfection and in clearance of RSV, but data regarding the levels of viral protein-specific antibodies elicited and their contribution to patient recovery from RSV-induced disease are limited. We prospectively enrolled a cohort of RSV-infected adult hematopoietic cell transplant (HCT) recipients (n = 40). Serum and nasal-wash samples were obtained at enrollment (acute samples) and convalescence (convalescent samples). We measured (1) humoral IgG and mucosal IgA binding antibody levels to multiple RSV proteins (F, G, N, P, and M2-1) by Western blot (WB); (2) neutralizing antibody (Nt Ab) titers by microneutralization assay; and (3) palivizumab-like antibody (PLA) concentrations by an ELISA-based competitive binding assay developed in the lab. Finally, we tested for correlations between protein-specific antibody levels and duration of viral shedding (normal: cleared in <14 days and delayed: cleared ≥14 days), as well as RSV/A and RSV/B subtypes. Convalescent sera from HCT recipients had significantly higher levels of anti-RSV antibodies to all 5 RSV structural proteins assayed (G, F, N, P, M2-1), higher Nt Abs to both RSV subtypes, and higher serum PLAs than at enrollment. Significantly higher levels of mucosal antibodies to 3 RSV structural proteins (G, N, and M2-1) were observed in the convalescent nasal wash versus acute nasal wash. Normal viral clearance group had significantly higher levels of serum IgG antibodies to F, N, and P viral proteins, higher Nt Ab to both RSV subtypes, and higher PLA, as well as higher levels of mucosal IgA antibodies to G and M2-1 viral proteins, and higher Nt Ab to both RSV subtypes compared to delayed viral clearance group. Normal RSV clearance was associated with higher IgG serum antibody levels to F and P viral proteins, and PLAs in convalescent serum (p < 0.05). Finally, overall antibody levels in RSV/A- and/B-infected HCT recipients were not significantly different. In summary, specific humoral and mucosal RSV antibodies are associated with viral clearance in HCT recipients naturally infected with RSV. In contrast to the humoral response, the F surface glycoprotein was not a major target of mucosal immunity. Our findings have implications for antigen selection in the development of RSV vaccines.

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Nasal Wash Cytokine Concentrations in Pediatric Allogeneic Hematopoietic Cell Transplant Recipients with Respiratory Viral Infections

10.1164/ajrccm-conference.2019.199.1_meetingabstracts.a5214 ◽

2019 ◽

Author(s):

T. Flerlage ◽

A. Souquette ◽

E.K. Allen ◽

J. Wolf ◽

G. Maron ◽

...

Keyword(s):

Viral Infections ◽

Hematopoietic Cell ◽

Cell Transplant ◽

Transplant Recipients ◽

Hematopoietic Cell Transplant ◽

Nasal Wash ◽

Allogeneic Hematopoietic Cell Transplant ◽

Respiratory Viral Infections

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Antigenic Fingerprinting of Respiratory Syncytial Virus (RSV)-A–Infected Hematopoietic Cell Transplant Recipients Reveals Importance of Mucosal Anti–RSV G Antibodies in Control of RSV Infection in Humans

The Journal of Infectious Diseases ◽

10.1093/infdis/jiz608 ◽

2019 ◽

Vol 221 (4) ◽

pp. 636-646 ◽

Cited By ~ 3

Author(s):

Sandra Fuentes ◽

Megan Hahn ◽

Katarina Chilcote ◽

Roy F Chemaly ◽

Dimpy P Shah ◽

...

Keyword(s):

Respiratory Syncytial Virus ◽

Hematopoietic Cell ◽

Cell Transplant ◽

Upper Respiratory Tract ◽

Hematopoietic Cell Transplant ◽

Nasal Wash ◽

Rsv Infection ◽

Antibody Repertoires ◽

Syncytial Virus ◽

Paired Serum

Abstract Background Respiratory syncytial virus (RSV) infection causes significant morbidity in hematopoietic cell transplant (HCT) recipients. However, antibody responses that correlate with recovery from RSV disease are not fully understood. Methods In this study, antibody repertoire in paired serum and nasal wash samples from acutely RSV-A–infected HCT recipients who recovered early (<14 days of RSV shedding) were compared with late-recovered patients (≥14 days of shedding) using gene fragment phage display libraries and surface plasmon resonance. Results Anti-F serum responses were similar between these 2 groups for antibody repertoires, neutralization titers, anti-F binding antibodies (prefusion and postfusion proteins), antibody avidity, and binding to specific antigenic sites. In contrast, nasal washes from early-recovered individuals demonstrated higher binding to F peptide containing p27. While the serum RSV G antibody repertoires in the 2 groups were similar, the strongest difference between early-recovered and late-recovered patients was observed in the titers of nasal wash antibodies, especially binding to the central conserved domain. Most importantly, a significantly higher antibody affinity to RSV G was observed in nasal washes from early-recovered individuals compared with late-recovered HCT recipients. Conclusions These findings highlight the importance of mucosal antibodies in resolution of RSV-A infection in the upper respiratory tract.

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Antibody Response to the Furin Cleavable Twenty-Seven Amino Acid Peptide (p27) of the Fusion Protein in Respiratory Syncytial Virus (RSV) Infected Adult Hematopoietic Cell Transplant (HCT) Recipients

Vaccines ◽

10.3390/vaccines8020192 ◽

2020 ◽

Vol 8 (2) ◽

pp. 192 ◽

Cited By ~ 1

Author(s):

Xunyan Ye ◽

Wanderson Cabral de Rezende ◽

Obinna Patrick Iwuchukwu ◽

Vasanthi Avadhanula ◽

Laura L. Ferlic-Stark ◽

...

Keyword(s):

Respiratory Syncytial Virus ◽

Cell Transplant ◽

Hematopoietic Cell Transplant ◽

Nasal Wash ◽

Amino Acid Peptide ◽

Mucosal Antibody ◽

Infected Adult ◽

Rsv Infection ◽

Syncytial Virus ◽

Mucosal Igg

Background: Cleavage of the inactive precursor fusion protein (F0) of respiratory syncytial virus (RSV) at two furin-recognition sites is required for membrane fusion activity, and the cleavage releases the twenty-seven amino acid peptide (p27). However, a recent study shows that p27 was an immunodominant epitope in RSV infected children, indicating that p27 was recognized as an immunogen. In the present study, we investigated the immunogenicity of p27 in an immunocompromised population of adults by measuring serum and mucosal antibody responses to p27 in samples from adult hematopoietic cell transplant (HCT) recipients. Methods: We prospectively enrolled a cohort of RSV infected HCT recipients. Serum and nasal-wash samples were obtained within the first week of RSV infection (acute) and 3 to 5 weeks post-infection (convalescent). We quantified the serum and mucosal IgG and IgA anti-p27 antibodies by a RSV/A p27 peptide enzyme-linked immunosorbent assay (ELISA) and serum and mucosal p27 like antibodies (P27LA) by a p27 competitive antibody (P27CA) assay. Results: The lower limit of detection for the ELISA and P27CA assays was 0.2 and 50 ng/mL, respectively with no cross-reaction detected with a panel of monoclonal antibodies targeting pre-fusion and post-fusion antigenic sites. P27 antibodies were detected at nanogram concentration in sera and nasal washes in the majority of RSV infected HCT recipients. However, there was no significant difference in the geometric mean antibody concentrations between the acute and convalescent sera (except for serum P27LA), between HCT recipients who shed RSV <14 days and ≥14 days, as well as between RSV/A and RSV/B infected HCT recipients. In addition, approximately 30% of HCT recipients had a 4-fold or greater decrease in mucosal IgG and IgA anti-p27 antibodies during viral clearance. Conclusion: In conclusion, in RSV naturally infected adult HCT recipients, the antibodies against p27 were detectable in both serum and nasal wash samples with higher concentration in serum than that in nasal washes. However, nearly 30% of RSV infected HCT recipients had a significant decrease in their mucosal anti-p27 antibody, suggesting that IgG and IgA anti-p27 antibodies were binding to either free viruses or RSV infected cells containing p27, and that anti-p27 antibodies in the respiratory tract were part of the mucosal antibody response in controlling RSV infection.

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