Cytomegalovirus Antigenic Mimicry of Human Alloreactive Peptides: A Potential Trigger for Graft versus Host Disease

The association between human cytomegalovirus (hCMV) reactivation and the development of graft-versus-host-disease (GVHD) has been observed in stem cell transplantation (SCT). Seventy seven SCT donor-recipient pairs (DRP) (HLA matched unrelated donor (MUD), n=50; matched related donor (MRD), n=27) underwent whole exome sequencing to identify single nucleotide polymorphisms (SNPs) generating alloreactive peptide libraries for each DRP (9-mer peptide-HLA complexes); Human CMV CROSS (Cross-Reactive Open Source Sequence) Database was compiled from NCBI; HLA class I binding affinity for each DRPs HLA was calculated by NetMHCpan 2.8 and hCMV- derived 9-mers algorithmically compared to the alloreactive peptide-HLA complex libraries. Short consecutive (6 or greater) amino acid (AA) sequence homology matching hCMV to recipient peptides was considered for HLA-bound-peptide (IC50<500 nM) cross reactivity. Of the 70,686 hCMV 9-mers contained within the hCMV CROSS database, 29,658.8 +/- 9038.5 were found to match MRD DRP alloreactive peptides and 52,910.2 +/- 16121.8 matched MUD DRP peptides (Student's T-test, p<0.001). In silico analysis revealed multiple high affinity, immunogenic CMV-Human peptide matches (IC50<500 nM) expressed in GVHD-affected tissue-specific manner (proteins expressed at 10 RPKM or greater). hCMV+GVHD was found in 18 patients, 13 developing hCMV viremia before GVHD onset with a subset analysis of 7 instances of hCMV viremia prior to acute GVHD onset (n=3), chronic GVHD (n=2) and acute + chronic GVHD (n=2) indicating cross reactive peptide expression within affected organs. We propose that based on our analysis and preliminary clinical correlations that hCMV immune cross-reactivity may cause antigenic mimicry of human alloreactive peptides triggering GVHD.Comment: Pre-submission manuscript, 4 tables, 5 figures, 2 supplements & 2 Appendices-available upon request from first autho

Practitioners\u27 perspectives on preparing for and delivering remote psychological support in Nepal, Perú and the United States during COVID-19

INTRODUCTION: The COVID-19 pandemic has propelled a global paradigm shift in how psychological support is delivered. Remote delivery, through phone and video calls, is now commonplace around the world. However, most adoption of remote delivery methods is occurring without any formal training to ensure safe and effective care. OBJECTIVE: The purpose of this applied qualitative study was to determine practitioners\u27 experiences of rapidly adapting to deliver psychological support remotely during COVID-19. DESIGN: We used a pragmatic paradigm and applied approach to gain perspectives related to the feasibility and perceived usefulness of synchronous remote psychological support, including views on how practitioners can be prepared. METHODS: Key informant interviews were conducted remotely with 27 specialist and non-specialist practitioners in Nepal, Perú and the USA. Interviewees were identified through purposeful sampling. Data were analysed using framework analysis. RESULTS: Respondents revealed three key themes: (i) Remote delivery of psychological support raises unique safety concerns and interference with care, (ii) Remote delivery enhances skills and expands opportunities for delivery of psychological support to new populations, and (iii) New training approaches are needed to prepare specialist and non-specialist practitioners to deliver psychological support remotely. CONCLUSIONS: Remote psychological support is feasible and useful for practitioners, including non-specialists, in diverse global settings. Simulated remote role plays may be a scalable method for ensuring competency in safe and effective remotely-delivered care

Sequence homology between HLA-bound cytomegalovirus and human peptides: A potential trigger for alloreactivity.

Human cytomegalovirus (hCMV) reactivation may often coincide with the development of graft-versus-host-disease (GVHD) in stem cell transplantation (SCT). Seventy seven SCT donor-recipient pairs (DRP) (HLA matched unrelated donor (MUD), n = 50; matched related donor (MRD), n = 27) underwent whole exome sequencing to identify single nucleotide polymorphisms (SNPs) generating alloreactive peptide libraries for each DRP (9-mer peptide-HLA complexes); Human CMV CROSS (Cross-Reactive Open Source Sequence) database was compiled from NCBI; HLA class I binding affinity for each DRPs HLA was calculated by NetMHCpan 2.8 and hCMV- derived 9-mers algorithmically compared to the alloreactive peptide-HLA complex libraries. Short consecutive (≥6) amino acid (AA) sequence homology matching hCMV to recipient peptides was considered for HLA-bound-peptide (IC5

HCMV cross-reactivity potential of 77 SCT DRP from whole exome sequencing data using sliding window match analysis.

<p>HCMV cross-reactivity potential of 77 SCT DRP from whole exome sequencing data using sliding window match analysis.</p

GVHD tissue-specific immunogenic CMV peptide matches, CMV reactivation before GVHD patients.

<p>Patient-specific process of cross comparison along with the source genes, IC50 values to indicate inverse binding affinity and GVHD organ specific tissue involvement. *Note: Twelve patients with CMV reactivation/infection before GVHD onset exhibited previously identified immunogenic CMV peptide matches with gene expression specific to the tissues affected by GVHD (above); The filter of immunogenicity provides a connection to T cell reactivity shown <i>in vitro</i> to the listed CMV genes in a separate patient population [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0178763#pone.0178763.ref036" target="_blank">36</a>]; Patient 79 with muscle/fascia GVHD showed no muscle-specific previously <i>known immunogenic</i> CMV peptide matches but still had three relevant CMV peptide matches expressed in the skeletal muscle (not shown); Tissues in parentheses were also affected by GVHD but without immunogenic matches/expression by patient; Patients 67 and 71 experienced <i>de novo</i> CMV infection; All 13 patients exhibited multiple CMV peptide matches with unknown immunogenicity.</p

Bioinformatic pipeline of the alloreactive peptide library comparison with the CMV proteome.

<p>A determination of the potential for Pro-GVHD DRP cross-reactivity upon CMV reactivation correlated with GVHD-tissue specific distribution of peptides & immunogenicity.</p

Human-CMV short sequence homology in GVHD tissue specific peptide and gene distribution from GTEx analysis (n = 18).

<p>GVHD incidence denotes the specific organs affected in each patient; Peptides, lists the number of unique peptide-HLA complexes matched between human and CMV peptide library; the column, <i>Genes</i> lists the source genes for the aforementioned peptides; <i>GVHD tissue specific peptides</i> lists the number of peptides which bind HLA with an IC50 <500nM, and are expressed in tissues affected by GVHD; <i>GVHD tissue gene expression</i> denotes the number of genes expressed at an RPKM >10 corresponding to the GVHD tissue specific peptides. Note: *- All patients with an asterisk following their numeric representation experienced CMV reactivation prior to GVHD (except Patients 67 and 71, <i>de novo</i> CMV infected) and patients without an asterisk experienced GVHD prior to CMV reactivation. **- human peptides may have overlapping areas of homology yielding a higher number of matches. Immunogenic CMV genes in this context refer to the genes associated with HCMV ORF-specific CD8+ T memory cell responses measured in frequency among CMV seropositive patients previously [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0178763#pone.0178763.ref036" target="_blank">36</a>].</p

CMV- Human match analysis per DRP (IC50 <500 nM) by donor type according to continuous amino acid sequence homology (one standard deviation from the mean value).

<p>CMV- Human match analysis per DRP (IC50 <500 nM) by donor type according to continuous amino acid sequence homology (one standard deviation from the mean value).</p

Matrix depicting T cell clonal cross-reactivity between CMVp-HLA and mHA-HLA.

<p>*-indicates response of the alloreactive T cell clone to a viral pathogen peptide,bound to the same HLA as the mHA and vice versa. For example, TC₁ recognizes, mHA₁ HLA + CMVp₂HLA, TC_1CMV recognizes, mHA₁ HLA + CMVp₁ HLA, and so on.</p

Matrix depicting the T cell clonal interaction with mHA-HLA.

<p>Matrix depicting the T cell clonal interaction with mHA-HLA.</p