Publications

Human T-lymphotropic virus type 1 (HTLV-1) infection presents a wide clinical spectrum ranging from lifelong asymptomatic carriage to severe inflammatory neurodegeneration (HAM/TSP) or adult T-cell leukemia/lymphoma (ATLL). Although IgG responses contribute to viral control and immunopathology, the extent to which HTLV-1 clinical outcomes shape pathogen-derived IgG repertoires remains unclear. In this study, we applied a high-density infectious-disease epitope microarray containing 4,345 linear epitopes from viral, bacterial, parasitic, and fungal pathogens to profile IgG responses in healthy controls (HCs), asymptomatic carriers (ACs), HAM/TSP patients, and ATLL patients. Signal intensities were quantified in arbitrary units, and recognized epitopes were evaluated using similarity clustering (80% identity threshold) to assess repertoire structure. HTLV-1–infected individuals exhibited extensive remodeling of humoral immunity, with marked differences in the breadth and intensity of IgG recognition across clinical groups. HAM/TSP patients displayed broad and high-magnitude responses consistent with chronic inflammation and heightened Th1 activation, whereas ATLL patients recognized the largest number of epitopes but with distinct patterns indicative of altered B-cell regulation. Enhanced IgG responses to Mycobacterium tuberculosis, Strongyloides stercoralis, Toxoplasma gondii, and Plasmodium species were consistent with known co-infection susceptibilities in HTLV-1. Epitope similarity analysis revealed hundreds of low-redundancy clusters across all groups, arguing against simple linear cross-reactivity and suggesting phenotype-specific reshaping of B-cell selection and idiotypic networks. These findings demonstrate that HTLV-1 infection produces distinct, clinically dependent IgG epitope signatures across multiple pathogen classes, with potential relevance for understanding HTLV-1 pathogenesis and informing future studies integrating epitope mapping with B-cell repertoire analysis.

Immunity to previously encountered viruses can alter response to unrelated pathogens. We reasoned that similar mechanism may also involve SARS-CoV-2 and thereby affect the specificity and the quality of the immune response against the virus. Here, we employed high-throughput next generation phage display method to explore the link between antibody immune response to previously encountered antigens and spike (S) glycoprotein. By profiling the antibody response in COVID-19 naïve individuals with a diverse clinical history (including cardiovascular, neurological, or oncological diseases), we identified 15 highly antigenic epitopes on spike protein that showed cross-reactivity with antigens of seasonal, persistent, latent or chronic infections from common human viruses. We observed varying degrees of cross-reactivity of different viral antigens with S in an epitope-specific manner. The data show that pre-existing SARS-CoV-2 S1 and S2 cross-reactive serum antibody is readily detectable in pre-pandemic cohort. In the severe COVID-19 cases, we found differential antibody response to the 15 defined antigenic and cross-reactive epitopes on spike. We also noted that despite the high mutation rates of Omicron (B.1.1.529) variants of SARS-CoV-2, some of the epitopes overlapped with the described mutations. Finally, we propose that the resolved epitopes on spike if targeted by re-called antibody response from SARS-CoV-2 infections or vaccinations can function in chronically ill COVID-19 naïve/unvaccinated individuals as immunogenic targets to boost antibodies augmenting the chronic conditions. Understanding the relationships between prior antigen exposure at the antibody epitope level and the immune response to subsequent infections with viruses from a different strain is paramount to guiding strategies to exit the COVID-19 pandemic.

Introduction Peptides (B-cell epitopes) have broad applications in disease diagnosis and surveillance of pathogen exposure. In this framework, we present a pilot study to design and produce a peptide microarray for the integrated surveillance of neglected tropical diseases. The peptide microarray was evaluated against peptides derived from Ascaris lumbricoides, Necator americanus, Schistosoma haematobium, Schistosoma mansoni, Trichuris trichiura, Bacillus anthracis, Mycobacterium leprae, Wuchereria bancrofti, Rabies lyssavirus, Chlamydia trachomatis and Trypanosoma brucei. Methods S. haematobium was diagnosed using the urine filtration technique. S. mansoni, A. lumbricoides, N. americanus and T. trichiura were diagnosed using the Kato Katz and formal ether concentration techniques. Immunogenic peptides were retrieved from the Tackling Infection to Benefit Africa infectious diseases epitope microarray. Further peptides were predicted using ABCpred. IgG and IgM reactivity against the derived peptides were evaluated using peptide microarray multiplex immunoassays. Positive response was defined as fluorescence intensity ≥ 500 fluorescence units. Immunodominant peptides were identified using color-coded heat maps and bar graphs reflecting the obtained fluorescence signal intensities. Receiver Operating Characteristic analysis and Mann-Whitney-U test were performed to determine the diagnostic validity of the peptides. Results Species-specific responses with at least one peptide derived from each NTD pathogen were observed. The reactive peptides included; for S. haematobium, XP_035588858.1-206-220 and XP_035588858.1-206-220 immunodominant for IgG and IgM respectively, for S. mansoni, P20287.1-58-72 immunodominant for both antibodies and for T. trichiura, CDW52482.1-326-340 immunodominant for IgG and CDW57769.1-2017-2031 and CDW57769.1-1518-1532 immunodominant for IgM. According to ROC analysis most of the peptides selected were inaccurate; with AUC < 0.5. Some peptides had AUC values ranging from 0.5 to 0.5875 for both IgM and IgG suggesting no discrimination. Conclusion Multiplex peptide microarrays are a valuable tool for integrated NTDs surveillance and for screening parasites exposure in endemic areas. Species sero-reactivity observed in the study maybe indicative of exposure to the different NTDs parasites. However, although peptides with the least cross reactivity were selected there is need to validate the sero-reactivity with recombinant antigens and immune-blotting techniques such as western blotting.