Journal: medRxiv

Article Title: A Trypanosoma cruzi Trans-Sialidase Peptide Demonstrates High Serological Prevalence Among Infected Populations Across Endemic Regions of Latin America

doi: 10.1101/2025.01.22.25320967

Figure Lengend Snippet: Phage library displays the proteome of T. cruzi in 47-aa peptides with a 19-aa step size on the capsid of T7 phage. The library includes all coding regions of the proteome and splice variants. We performed the PhIP-seq assay by incubating the phage library with human plasma, followed by immunoprecipitation of antibodies in the sample and enrichment of antibody-bound phage through lysis in E. coli . We performed two rounds of enrichment and then sequenced the enriched phage to obtain the identity of the immunoprecipitated peptides.

Article Snippet: An anti- T. cruzi IgG BLI method was developed using a commercial T. cruzi Chimeric Chagas Multi-Antigen (MACH; Jena Biosciences).

Techniques: Immunoprecipitation, Lysis

Journal: medRxiv

Article Title: A Trypanosoma cruzi Trans-Sialidase Peptide Demonstrates High Serological Prevalence Among Infected Populations Across Endemic Regions of Latin America

doi: 10.1101/2025.01.22.25320967

Figure Lengend Snippet: ( A , B ) Heatmap of z-score enrichment over seronegative controls in the (A) blood donor (BD) specimens (n=64 seropositive, n=26 seronegative) and the (B) cardiac biomarker (CBM) specimens (n=114, seropositive; n=18, seronegative; n=95, healthy controls) for seroreactive peptides (rows) with >15% seropositivity within each cohort. Peptides are sorted by protein name and samples are sorted by patient region of origin (n=10, Central America [yellow]; n=13, Mexico [blue]; n=12, South America [light green]; n=1, USA [pink]; n=28, unknown [green]) (A), or cardiac disease stage (n=14 stage A seronegative [magenta]; n=6 stage B seronegative [orange]; n=38 stage A seropositive [magenta]; n=46 stage B seropositive [orange]; n=7 stage C seropositive [light green]; n=23 stage D seropositive [blue]) (B). Protein groups with well-characterized antigens are indicated by labels (Surface antigen, Surface antigen 2 (CA-2); NSP-like, Nucleoporin NSP1-like C-terminal domain-containing protein; MASP, Mucin-associated surface protein; Mucin, TcMUCII; MAP, Microtubule-associated protein; CCP, Calpain-like cysteine peptidase; 60S, 40S, ribosomal subunit proteins). ( C ) Breadth of antibody reactivity, shown as the number of seroreactive peptides in each person. The dotted red line and number signify the median number of seroreactive peptides in BD and CBM specimen sets. Samples are grouped by geographic region (BD specimens) and heart disease stage (CBM specimens). ( D ) Number of peptides identified as seroreactive in this study that are part of proteins expressed in specific stages of the T. cruzi life cycle (Tryp = trypomastigote; Ama = amastigote; Meta = metacyclic trypomastigote; Epi = epimastigote; Multiple = protein is expressed in trypomastigote, amastigote, and/or metacyclic trypomastigote stages). Stage expression analysis shows seroreactive peptides in every host-interfacing lifecycle stage. Stage-specific expression is based on the ‘Life cycle proteome (Brazil)’ data set from TriTrypDB. Gene IDs for stage-specific proteins were mapped onto the gene IDs that corresponded to seroreactive peptides. ( E , F ) Selected known seroreactive antigens are captured by T. cruzi PhIP-seq. Neg. is seronegative specimens from the respective specimen sets; Pos. is seropositive specimens from the respective cohorts; NYBC is NYBC US controls. Antibody reactivity to two known antigens (E) Ag2, a nucleoporin protein, and (F) TCE, a 60S ribosomal subunit protein are plotted as reads per 100,000 (RPK). The dotted red line signifies the RPK that corresponds to a z-score cutoff of 5 in the seronegative population of each cohort.

Article Snippet: An anti- T. cruzi IgG BLI method was developed using a commercial T. cruzi Chimeric Chagas Multi-Antigen (MACH; Jena Biosciences).

Techniques: Biomarker Assay, Expressing

Journal: medRxiv

Article Title: A Trypanosoma cruzi Trans-Sialidase Peptide Demonstrates High Serological Prevalence Among Infected Populations Across Endemic Regions of Latin America

doi: 10.1101/2025.01.22.25320967

Figure Lengend Snippet: ( A ) Anti-trans-sialidase peptide antibody reactivity is plotted as RPK. The dotted red line signifies the RPK that corresponds to a z-score cutoff of 5 in the seronegative population of each cohort. ( B ) Trans-sialidase reactivity orthogonal validation using a split-luciferase binding assay (SLBA). Reactivity was tested against four seropositive blood donor specimens and five seronegative US healthy control specimens. ( C ) Alanine-scanning mutagenesis in 10-aa windows (highlighted in red) across the entire trans-sialidase antigenic fragment demonstrates the seroreactive epitope in Chagas disease. Values are normalized antibody indices and represent the averages of five seropositive blood donor specimens.

Article Snippet: An anti- T. cruzi IgG BLI method was developed using a commercial T. cruzi Chimeric Chagas Multi-Antigen (MACH; Jena Biosciences).

Techniques: Luciferase, Binding Assay, Control, Mutagenesis

Journal: medRxiv

Article Title: A Trypanosoma cruzi Trans-Sialidase Peptide Demonstrates High Serological Prevalence Among Infected Populations Across Endemic Regions of Latin America

doi: 10.1101/2025.01.22.25320967

Figure Lengend Snippet: Recombinant antigens in current FDA-cleared serology tests include Ag 1, Ag 2, Ag 13, Ag 30, Ag 36 ( , ), shed acute phase antigen (SAPA) , KMP-11 , TcD and TcE ( , ). Note, TcD contains the same antigenic epitope as Ag 13. ( A ) Heatmap of z-score enrichment over seronegative controls in the seropositive blood donor (BD) specimens (n=64). Each antigen motif was derived using Multiple EM for Motif Elicitation (MEME) and then scored against the entire T. cruzi PhIP-seq proteome. The maximum z-score across all peptides with significant sequence matches to a given antigen motif was plotted for each sample and each antigen. ( B ) Percent of samples enriched ( z-score ≥5) for each antigen in BD and cardiac biomarker (CBM) specimen sets.

Article Snippet: An anti- T. cruzi IgG BLI method was developed using a commercial T. cruzi Chimeric Chagas Multi-Antigen (MACH; Jena Biosciences).

Techniques: Recombinant, Derivative Assay, Sequencing, Biomarker Assay