Biology subjects

Herrera, B. B.

Publications and source records attributed to Herrera, B. B..

8 recordsLinked to original sources

bioRxiv2026

CXCL10-driven STAT3 signaling programs pathogenic CD4+ T cell responses and limits antiviral immunity during arthritogenic alphavirus infection

Arthritogenic alphaviruses, including onyong nyong (ONNV), chikungunya virus (CHIKV), and Mayaro (MAYV) viruses, cause acute and chronic inflammatory joint disease, with disease severity and resolution influenced by host age. The immunological mechanisms governing persistent inflammation remain incompletely defined. In an age-stratified murine model we show that ONNV infection induced elevated Cxcl10 expression and viral persistence in infected tissues, accompanied by preferential accumulation of CD4+ T cells and limited recruitment of CD8+ T cells. This was associated with skewed T cell differentiation, characterized by increased STAT3 phosphorylation and ROR{gamma}t expression. Infection with CHIKV and MAYV recapitulated these features, supporting a conserved CXCL10-driven pathogenic program across arthritogenic alphaviruses. Perturbation of this axis reduced CD4+ T cell accumulation, altered T cell differentiation states, and decreased tissue viral burden. Thus, we show that a CXCL10-biased immune response is highly proinflammatory but poorly effective in mediating viral clearance, thus setting the stage for chronic disease.

immunology↗

bioRxiv2026

Age-dependent PD-1 induction restricts IL-2-driven effector T cell responses during La Crosse virus infection in mice

Age is a major determinant of disease severity following La Crosse virus (LACV) infection, yet the immunological mechanisms underlying heightened susceptibility in children remains poorly defined. Here, we show that acute LACV infection in weanling mice induces T cell dysfunction characterized by early PD-1 upregulation and impaired effector differentiation despite evidence of activation. This state is associated with reduced IL-2-dependent STAT5 signaling, indicating a failure to respond to available cytokine cues. Although regulatory T cells expand and exhibit elevated CD25 expression, their depletion increases IL-2 levels without restoring antiviral T cell responses or viral control. In contrast, PD-1 blockade partially restores T cell activation, and combined PD-1 blockade with CD25 targeting enables robust effector differentiation and improved viral control. These findings demonstrate that checkpoint signaling limits T cell responsiveness to IL-2, uncoupling activation from differentiation and driving age-dependent susceptibility to LACV infection.

immunology↗

bioRxiv2025

Pre-existing YFV-17D immunity mediates T cell cross-protection against DENV-2 infection

Widespread yellow fever virus (YFV) immunity in Sub-Saharan Africa may mitigate orthoflavivirus outbreaks. Here, we investigate whether pre-existing YFV-17D immunity confers cross-protection against dengue virus serotype 2 (DENV-2) in a murine model. IFNAR1-/- mice immunized with YFV-17D exhibited significantly reduced DENV-2 viremia, weight loss, and disease severity, with improved survival compared to YFV-naive controls. Mechanistic studies revealed that cross-protection was mediated by heterologous T cell responses rather than cross-neutralizing antibodies. Depletion of T cells in YFV-17D-immune mice prior to DENV-2 challenge resulted in increased viremia, weight loss, and disease severity, underscoring the protective role of YFV-17D-elicited T cell immunity. Furthermore, YFV-17D-specific T cells displayed cytotoxicity against DENV NS3- and NS5-pulsed cells, demonstrating their functional role in viral control. These findings highlight the critical contribution of heterologous T cell immunity in YFV-17D-mediated protection against DENV-2 and suggest that vaccines designed to elicit T cell responses could enhance cross-protection against orthoflavivirus infections.

immunology↗

bioRxiv2025

Immunodominant structural proteins Gc and N drive T cell-mediated protection against La Crosse virus

La Crosse virus (LACV) is a major cause of pediatric encephalitis in the U.S., primarily affecting children under 16 years. Despite severe morbidity and potential mortality risks, no vaccines or antivirals exist. Murine models recapitulate human susceptibility patterns, with weanling mice (3 weeks old) succumbing to disease while adults ([≥]8 weeks old) exhibit resistance. We characterized the T cell responses underlying this difference. Adult mice mounted robust CD4+ and CD8+ T cell responses by 6 days post-infection (dpi), with sustained IFN-{gamma}, granzyme B, IL-2, and TNF- production. These T cells expanded significantly and exhibited in vivo cytotoxicity against cells pulsed with LACV glycoprotein (Gc) and nucleocapsid (N) antigens. In contrast, weanlings showed weak T cell responses and 100% mortality by 7 dpi. Immunization with LFn-LACV-Gc and -N improved T cell cytotoxicity and survival in weanlings, highlighting their potential as vaccines. These findings inform strategies to mitigate LACV-induced encephalitis in children.

immunology↗

bioRxiv2025

Development of an RT-RPA assay for La Crosse virus detection provides insights into age-dependent neuroinvasion in mice

BackgroundLa Crosse virus (LACV) is a mosquito-borne arbovirus responsible for pediatric encephalitis in North America, predominantly affecting children under 16 years. Early and accurate diagnosis is critical to reducing morbidity in this vulnerable population. However, existing molecular and serological methods are limited in sensitivity, specificity, and accessibility. MethodsTo address these limitations, we developed a reverse transcription recombinase polymerase amplification (RT-RPA) assay for LACV detection. Primers targeting the divergent M segment of the LACV genome were designed and screened for optimal performance. The assays analytical sensitivity was evaluated through serial dilutions of LACV RNA prior to reverse transcription, while specificity was assessed using reverse transcribed RNA from related or geographically relevant arboviruses. We further adapted the RT-RPA test into a lateral flow assay (LFA) format for potential point-of-care use. Additionally, we employed a murine model to explore the age-dependent dynamics of LACV neuroinvasion and clearance, with the virus detected using RT-RPA and reverse transcription quantitative polymerase change reaction (RT-qPCR). ResultsPrimer screening identified an optimal primer pair that amplified LACV cDNA within 20 minutes at 39{degrees}C, with a limit of detection (LOD) of 100 copies. The assay demonstrated high specificity, with no amplification of related or other geographically relevant arboviruses. Integration of the RT-RPA test into an LFA format preserved the LOD and specificity, enabling visual detection via test strips. In the murine model, weanling mice exhibited LACV neuroinvasion as early as 4 days post-infection (dpi), with sustained detection between 5-7 dpi. In adult mice, neuroinvasion was first detected at 5 dpi, plateauing between 6-10 dpi, and cleared entirely by 20 dpi in surviving animals. ConclusionsThis study establishes the RT-RPA assay as an efficient, specific, and sensitive diagnostic platform for LACV, with potential for adaptation into field-deployable LFA tests. Moreover, our findings provide valuable insights into the age-dependent dynamics of LACV neuroinvasion and clearance, informing future diagnostic and therapeutic strategies.

microbiology↗

bioRxiv2024

Development of RT-RPA-based point-of-care tests for epidemic arthritogenic alphaviruses

Chikungunya (CHIKV), onyong-nyong (ONNV), and Mayaro (MAYV) viruses are transmitted by mosquitoes and known to cause a debilitating arthritogenic syndrome. These alphaviruses have emerged and re-emerged, leading to outbreaks in tropical and subtropical regions of Asia, South America, and Africa. Despite their prevalence, there persists a critical gap in the availability of sensitive and virus-specific point-of-care (POC) diagnostics. Traditional immunoglobulin-based tests such as enzyme-linked immunosorbent assay (ELISAs) often yield cross-reactive results due to the close genetic relationship between these viruses. Molecular diagnostics such as quantitative polymerase chain reaction (qPCR) offer high sensitivity but are limited by the need for specialized laboratory equipment. Recombinase polymerase amplification (RPA), an isothermal amplification method, is a promising alternative to qPCR, providing rapid results with minimal equipment requirements. Here, we report the development and validation of three virus-specific RPA-based POC tests for CHIKV, ONNV, and MAYV. These tests demonstrated both speed and sensitivity, capable of detecting 10 viral copies within 20 minutes of amplification, without exhibiting cross-reactivity. Furthermore, we evaluated the clinical potential of these tests using serum and tissue samples from CHIKV, ONNV, and MAYV-infected mice, as well as CHIKV-infected human patients. We demonstrate that the RPA amplicons derived from the patient samples can be sequenced, enabling cost-effective molecular epidemiological studies. Our findings highlight the significance of these rapid and specific POC diagnostics in improving the early detection and management of these arboviral infections.

microbiology↗

bioRxiv2024

Age-specific dynamics of neutralizing antibodies, cytokines, and chemokines in response to La Crosse virus infection in mice

La Crosse virus (LACV) is a primary cause of pediatric arboviral encephalitis in the United States, particularly affecting children aged 16 years or younger. This age-related susceptibility extends to murine models, where weanling mice (3 weeks old) succumb to LACV infection, while adults ([≥]6 weeks old) demonstrate resistance. Despite its clinical relevance, the host immune response to LACV is not fully understood. In this study, we investigated the roles of neutralizing antibodies (nAbs), cytokines, and chemokines in weanling and adult mice following infection with 5x105 plaque forming units (PFU) of LACV. We observed significant age-related differences in viral titers and survival. Weanling mice demonstrated early disease onset with elevated peripheral viremia, but passive transfer of adult serum, confirmed to have nAbs, to naive weanlings prior to infection completely rescued them from death. Cytokine and chemokine profiling revealed distinct kinetics and age-specific immune responses. Adult mice had increased Th1 cytokines, Th9/Th17/Th22/Treg cytokines, and many chemokines. In contrast, weanlings had higher Th2 cytokines, correlating with symptoms onset. Flow cytometry and intracellular cytokine staining further demonstrated that weanling mice produced higher levels of IL-4 by CD4+ and CD8+ T cells compared to adults, regardless of infection status. Conversely, LACV-infected adult mice had increased IFN-{gamma} production by CD8+ T cells compared to uninfected adults. Finally, adoptive transfer of splenocytes from immune adult mice to naive weanlings delayed neurological symptoms and improved survival, highlighting the protective role of immune adult cells against LACV. In conclusion, this study links nAbs and cytokine and chemokine responses to protective immunity in adult mice, contrasting with the pathogenesis seen in weanlings. These findings underscore the importance of further research into innate and adaptive immune mechanisms in LACV infection.

microbiology↗

bioRxiv2018

T cell responses to nonstructural protein 3 distinguish infections by Dengue and Zika viruses

The 2015-16 Zika virus (ZIKV) epidemic in the Americas and the Caribbean demonstrates that clinical assays to detect, distinguish, and characterize immune responses to flaviviral infections are needed. ZIKV and dengue virus (DENV) are mosquito-transmitted flaviviruses sharing overlapping geographical distribution and have significant sequence similarity that can increase the potential for antibody and T cell cross-reaction. Using nonstructural protein 1-based enzyme-linked immunosorbent assays (ELISAs), we determine the serostatus of individuals living in a DENV- and ZIKV-endemic region in Brazil, identifying individuals with primary DENV (pDENV) and ZIKV (pZIKV), ZIKV with primary DENV (ZIKVwpDENV), and secondary DENV (sDENV) infections; pDENV and pZIKV were further confirmed by neutralization tests. Development of an enzyme-linked immunospot (ELISPOT) assay for DENV and ZIKV structural and nonstructural (NS) protein antigens enables us to distinguish infections by these viruses based on T cells and to characterize those responses. We find that IFN-{gamma} and TNF- T cell responses to NS3 differentiates DENV and ZIKV infections with 94% sensitivity and 92% specificity. In general, we also show that pDENV and sDENV cases and pZIKV and ZIKVwpDENV cases elicit similar T cell response patterns, and that HIV-infected individuals have T cell responses that are lower in magnitude compared to HIV-negative individuals. These results have important implications for DENV and ZIKV diagnostic and vaccine development and provide critical insights into the T cell response in individuals with multiple flaviviral infections.

microbiology↗