2025 in review: Six impactful research studies using PEPperPRINT’s peptide microarray technology

In 2025, peptide microarrays continued to shape immunology research, with scientists using PEPperPRINT’s technology to better understand disease mechanisms and uncover promising biomarkers. It was also a milestone year for the field: PEPperPRINT introduced its new cLIFT technology, expanding peptide microarray capailities to study new applications, such as how post-translational modifications affect antibody binding.  

From fresh insights into the COVID-19 immune response to new findings related to Sudden Infant Death Syndrome (SIDS), recent publications highlight how precise epitope mapping is becoming indispensable in both basic research and clinical diagnostics.

1. CRP under fire: Autoantibodies target inflammation’s key regulator in lupus

Overview: C-reactive protein (CRP) is a key player in innate immunity, long used as a biomarker for inflammation. In systemic lupus erythematosus (SLE), CRP levels are paradoxically low despite chronic inflammation. This study explored a novel hypothesis: that autoantibodies against full-length CRP (flCRP) might interfere with CRP’s immune-regulatory functions. The authors demonstrated that SLE patients produce IgG autoantibodies that specifically recognize conformational and linear epitopes of native CRP, not just its denatured or fragmented forms. These antibodies were associated with reduced neutrophil-mediated efferocytosis, impaired classical complement activation, and increased disease activity.

Why this matters: This study reshapes our understanding of CRP in SLE, not simply as a bystander or diagnostic marker, but as a target of autoimmunity with functional consequences. The identification of pathogenic anti-CRP antibodies reveals a mechanism by which CRP's protective roles in apoptotic cell clearance and immune regulation are neutralized in lupus. Clinically, this offers a new biomarker to stratify patients and a potential therapeutic target, e.g., using CRP-mimetic peptides or anti-idiotypic antibodies to neutralize pathogenic anti-CRP activity. It also explains long-observed discrepancies between inflammation and CRP levels in lupus patients.

How peptide microarrays were used: PEPperPRINT’s custom peptide microarrays were central to mapping the epitope specificity of anti-CRP antibodies in SLE: the arrays displayed overlapping 15-mer peptides spanning the full CRP sequence, allowing high-resolution B-cell epitope analysis, and sera from SLE patients and healthy donors were screened for IgG binding using fluorescent secondary antibodies. Patients with high anti-CRP peptide reactivity showed reduced neutrophil phagocytosis and impaired complement C3 activation, supporting the idea that these autoantibodies are functionally disruptive.

Reference: Karlsson, Jesper, et al. "Mapping autoantibody targets of full-length C-reactive protein in systemic lupus erythematosus: importance for neutrophil function and classical complement activation." Frontiers in Immunology 16 (2025): 1578372. https://doi.org/10.3389/fimmu.2025.1578372

2. Unmasking hepatitis C: How peptide signatures reveal new paths for CD8+ T‑cell immunotherapy

Overview: This study focused on identifying CD8+ T-cell epitopes in Hepatitis C Virus (HCV) that are restricted to the HLA-A*02:01 allele, one of the most common class I MHC molecules globally. The goal was to uncover conserved and immunogenic peptide signatures across all seven HCV genotypes, to aid in the design of broad-spectrum, T-cell-based vaccines. Using a combination of in silico prediction, immunogenicity modeling, cytokine profiling, and in vitro validation, the researchers mapped a library of 615 predicted HLA-A*02:01-binding peptides. They assessed proteasomal cleavage, TAP transport, and cytokine induction potential to classify these peptides and then evaluated their reactivity using real CD8+ T cells.

Why this matters: HCV remains a global health burden with persistent infections often leading to liver cirrhosis and cancer. While antiviral therapies exist, they are costly and not accessible worldwide. A preventive or therapeutic vaccine based on conserved T-cell epitopes would offer a cost-effective solution. This study brings valuable insight into the structural and immunological patterns of HCV-derived peptides that are most likely to trigger robust CD8+ T cell responses. It highlights the importance of epitope immunodominance, cytokine bias (Th1/Th2), and structural motifs, and it offers a rational strategy for next-generation vaccine design applicable to highly variable viruses like HCV.

How peptide microarrays were used: PEPperPRINT’s custom peptide microarrays were used to empirically validate the predicted immunogenic peptides. These arrays enabled high-throughput screening of synthetic peptides for HLA-A*02:01 binding and T cell reactivity. The microarray results helped differentiate peptides with high, medium, or low immunogenic potential and were cross-validated against predicted cytokine profiles, such as IFN-γ induction (Th1) versus IL-4 (Th2). The precision and throughput of the PEPperPRINT platform allowed the researchers to narrow down an initial large peptide library to a focused list of high-confidence vaccine candidates with broad HLA coverage and cross-genotype conservation. 

Reference: Correa-Dias, Laura Cardoso, et al. "HCV immunodominant peptide mapping reveals unique HLA-A* 02-restricted signatures: insights for CD8+ T-cell-based vaccines and immunotherapies." Immunogenetics 77.1 (2025): 13. https://doi.org/10.1007/s00251-025-01370-2

3. A tumor-binding antibody with cross-reactivity to viral antigens 

Overview: This study explores a fascinating instance of molecular mimicry in cancer immunology. Researchers previously identified an autoantibody targeting complement factor H (CFH) in non-small cell lung cancer (NSCLC) patients that correlated with favorable prognosis. A recombinant human monoclonal antibody named GT103, cloned from these autoantibodies, was found to promote tumor cell lysis and an antitumor immune microenvironment. This research investigates whether such antibodies might originate from previous viral infections due to sequence similarity between tumor and viral epitopes.

Why this matters: This study highlights how the immune system can repurpose its memory (originally formed in response to viruses) toward recognizing tumor antigens. If antibodies like GT103 arise from such mimicry, this offers a potential explanation for some naturally occurring antitumor immune responses. Furthermore, this insight opens up new opportunities for therapeutic development by identifying viral mimic epitopes that can prime or boost antitumor immunity through vaccination or passive antibody therapy. Understanding these mechanisms deepens our grasp of cancer immunosurveillance and may explain why certain patients generate protective autoantibodies against tumors. It also suggests that viral exposure history might influence individual cancer risk and immune responsiveness.

How peptide microarrays were used: To investigate cross-reactivity, the study employed the PEPperCHIP^® Infectious Disease Epitope Microarray from PEPperPRINT, containing 4,345 linear B-cell epitopes derived from 196 different pathogens. GT103 was incubated with the array, and binding was quantified using dual-channel fluorescence scanning. This approach allowed the researchers to determine which viral epitopes were most strongly recognized by GT103. According to the peptide-binding results, the top hits included peptides from HERV-K pol protein, measles hemagglutinin, Hepatitis C virus, and Toxoplasma gondii. Although GT103 bound these peptides with lower affinity than to its native CFH epitope, the study provides strong evidence for antibody cross-reactivity due to conserved amino acid motifs.

Reference: Campa, Michael J., et al. "A tumor-binding antibody with cross-reactivity to viral antigens." Cancer Immunology, Immunotherapy 74.4 (2025): 126. https://doi.org/10.1007/s00262-025-03975-8

4. Anti-TRPV2 autoantibody linked to Sudden Infant Death Syndrome

Overview: This study investigated the role of autoantibodies in Sudden Infant Death Syndrome (SIDS), the unexplained death of an infant under one year of age. Researchers identified a strong association between SIDS and circulating autoantibodies targeting the TRPV2 (transient receptor potential vanilloid 2) channel, a cardiac ion channel involved in calcium transport and intercellular communication. TRPV2 autoantibodies were significantly more frequent in SIDS cases than in accidental suffocation deaths or healthy controls. In animal models, maternal immunization against TRPV2 resulted in the transplacental transfer of these autoantibodies to pups, leading to a significantly increased risk of early postnatal death. Mechanistic investigations showed that TRPV2 autoantibodies impaired ion channel function, disrupted myocardial signaling, and reduced survival, strongly suggesting a causal role in SIDS pathogenesis.

Why this matters: Despite decades of research, the biological underpinnings of SIDS remain elusive. This study is the first to implicate a specific autoantibody (anti-TRPV2) as a potential causal factor in SIDS, offering a major breakthrough in the field. If validated in larger cohorts, this autoantibody could serve as the first biomarker to identify infants at risk for SIDS and distinguish biological causes from accidental deaths. Moreover, it presents a novel therapeutic target for early intervention, such as autoantibody screening or neutralization strategies in at-risk populations.

How peptide microarrays were used: PEPperPRINT’s peptide microarray platform was central to this discovery. Researchers screened serum samples from infants who died of SIDS, accidental suffocation, and healthy controls against 100 extracellular epitope sequences from cardiac ion channels. The arrays revealed a distinct IgG response against a specific TRPV2 peptide, which mapped precisely to the channel’s extracellular pore turret, a critical region for channel activation. According to the study, the array allowed detailed immunosignature heat maps to be generated and compared across groups. Only anti-TRPV2 antibodies were significantly associated with SIDS (P = 0.028 vs. controls), and logistic regression modeling estimated a 71% accuracy for this marker.

Reference: Maguy, Ange, et al. "Anti-TRPV2 Autoantibody Linked to Sudden Infant Death Syndrome." Circulation 152.1 (2025): 81-84. https://doi.org/10.1161/CIRCULATIONAHA.125.073748

5. Preclinical characterization of a CGRP-targeting vaccine for migraine prevention

Overview: This study presents a novel approach to migraine prevention through the development of an active immunotherapy targeting calcitonin gene-related peptide (CGRP), a neuropeptide central to migraine pathophysiology. Unlike monoclonal antibodies that passively neutralize CGRP, this strategy uses a peptide-based immunogen to elicit a durable, endogenous immune response capable of producing CGRP-neutralizing antibodies. The findings of this study support the feasibility of using an active immunization approach to replace or supplement existing monoclonal antibody therapies for migraine.

Why this matters: Monoclonal antibodies targeting CGRP or its receptor have transformed the landscape of migraine prevention, yet they come with high costs, require frequent dosing, and can elicit anti-drug immune responses that limit long-term efficacy. This study introduces a vaccine-like therapy that may overcome these limitations by enabling the body to generate its own antibodies against CGRP. The potential benefits are substantial: longer-lasting protection with fewer injections, reduced manufacturing costs, and improved global accessibility.

How peptide microarrays were used: To evaluate the immunospecificity of the vaccine-induced antibodies, the research team employed PEPperPRINT’s peptide microarray platform. These high-density arrays were critical in confirming that the immune response elicited by the CGRP-targeting immunogens was both specific and restricted to the intended epitope region. The microarrays provided high-resolution epitope mapping, revealing that the dominant antibody response was directed at the immunizing epitope in the C-terminal domain of CGRP, an area critical for receptor interaction and biologic function. This specificity assessment was essential in validating the immunogen design and ensuring that the vaccine would not interfere with other physiological systems. 

Reference: Boyd, Justin D., et al. "Preclinical characterization of an active immunotherapy targeting calcitonin gene-related peptide." Communications Medicine 5.1 (2025): 145.
https://doi.org/10.1038/s43856-025-00870-2 

6. Decoding COVID-19 immunity: Epitope signatures across viral variants and clinical trajectories

Overview: In this study, researchers undertook an in-depth analysis of the IgG-mediated humoral immune response in COVID-19 patients with divergent disease trajectories using a whole-proteome peptide microarray. The study aimed to capture both the breadth and specificity of immune responses in patients progressing to severe disease, those recovering from severe infection, and SARS-CoV-2-naïve individuals. A key finding was that recovered patients demonstrated a broader and more diverse antibody response – especially toward spike and nonstructural proteins (nsp2, nsp3, nsp5, and nsp13) – than patients who deteriorated to severe disease. Additionally, mutations in several variants (e.g., G142D, L452R, N501Y) were shown to either enhance or diminish antibody binding, offering a molecular explanation for altered vaccine and infection outcomes in emerging strains.

Why this matters: The study addresses a central question in COVID-19 immunology: what differentiates protective antibody responses from pathological or insufficient ones? By linking the evolution of antibody reactivity to disease outcomes and variant-specific mutations, this work provides insight into which epitopes contribute to recovery and which may be linked to immune evasion. One major implication lies in vaccine and diagnostic development. Furthermore, the immune system’s differential recognition of wild-type vs. mutated peptides reinforces the need for dynamic vaccine design that can keep pace with evolving SARS-CoV-2 variants. This could have broad implications for pandemic preparedness and for tailoring booster formulations that avoid antigenic escape.

How peptide microarrays were used: The PEPperCHIP^® SARS-CoV-2 Whole Proteome Microarray was at the heart of this study’s methodology. Each chip contained 5,347 peptides covering the complete SARS-CoV-2 proteome, from structural (S, N, M, E) to nonstructural (nsp1-16) and accessory proteins (orf3a, orf6, orf7a, orf8). Critically, the array also included peptides with mutations from major variants, such as Alpha, Beta, Delta, Gamma, and Omicron. Patient plasma samples were incubated on individual microarray slides, allowing the team to quantify IgG binding intensity at the single-epitope level. Through this process, the researchers observed that nsp3 showed the highest number of immunoreactive epitopes overall, while spike protein epitopes were more likely to be unique to SARS-CoV-2, making them optimal diagnostic and vaccine targets. 

Reference: Bihani, Surbhi, et al. "Investigation of Immunoreactivity Profiles and Epitope Landscape in Divergent COVID-19 Trajectories and SARS-CoV-2 Variants." Journal of Proteome Research 24.2 (2025): 762-776.
https://doi.org/10.1021/acs.jproteome.4c00791 

How peptide microarrays can support your research

The studies highlighted in this article demonstrate the broad potential of PEPperPRINT’s peptide microarray technology to drive forward impactful research across a wide range of fields, from infectious diseases to cancer therapy. These breakthroughs not only showcase the versatility and precision of the platform but also highlight the real-world applications that can improve diagnostics and treatments globally.

If you’re looking to explore how peptide microarrays can advance your own research or would like to learn more about our technology, we invite you to get in touch with PEPperPRINT. Together, we can make a meaningful impact on global health and scientific progress.