Biology subjects

Collins, P. L.

Publications and source records attributed to Collins, P. L..

3 recordsLinked to original sources

bioRxiv2024

ERK5 Signaling is Required for Type III IFN-mediated Mucosal Antiviral Responses

Type III interferons (IFN{lambda}) are innate immune cytokines that limit viral replication and coordinate tissue repair through the induction of interferon stimulated genes (ISGs). This response must be tightly regulated to avoid excessive responses that result in the disruption of tissue barrier integrity or inefficient responses that allow for pathogen escape. Here we examine the contribution of Mitogen Activated Protein Kinase (MAPK) signaling on IFN{lambda}-mediated antiviral activity. We find that extracellular-signal-regulated kinase 5 (ERK5), a poorly characterized member of the conventional MAPK family, potentiates the antiviral efficacy of IFN{lambda}. Chemical inhibition and genetic targeting of ERK5 during IFN{lambda} treatment of cells results in a decrease in ISG induction and impaired control of viral infections. This decrease in IFN{lambda} antiviral efficacy in the absence of ERK5 kinase activity corresponded to lowered STAT1 phosphorylation, revealing a noncanonical role for ERK5 in STAT1 activation downstream of IFN{lambda}. In contrast, type I IFN antiviral signaling is largely resistant to ERK5 modulation. Altogether, we identify ERK5 as a potentiator of STAT1 activation, ISG expression, and antiviral activity following type III IFN stimulation. SIGNIFICANCERegulation of type III interferons (IFN{lambda}) at mucosal barriers in response infection to mitigate viral replication and support barrier integrity. The specific mechanistic requirements for MAPK signaling to sustain IFN{lambda}-mediated gene expression have remained elusive. Amongt the least characterized members of the MAPK family, the role of ERK5 in regulating host inflammatory responses has been hampered by off-target effects of kinase inhibitors. Here, we combine pharmacological and genetic approaches to specifically demonstrate that ERK5 promotes antiviral immunity in epithelial cells. Mechanistically, ERK5 enhances the activation of STAT1 in response to IFN stimulation to augment the transcription of IFN-stimulated genes. Our work demonstrates that therapeutic modulation of MAPK and IFN signaling pathway co-integration could distinguish between the protective and deleterious outcomes of IFN expression. One-sentence summaryERK5 potentiates IFN lambda responses.

immunology↗

bioRxiv2023

Pathogenic CD8 T cell responses are driven by neutrophil-mediated hypoxia in cutaneous leishmaniasis.

Cutaneous leishmaniasis caused by Leishmania parasites exhibits a wide range of clinical manifestations. Although parasites influence disease severity, cytolytic CD8 T cell responses mediate disease. While these responses originate in the lymph node, we find that expression of the cytolytic effector molecule granzyme B is restricted to lesional CD8 T cells in Leishmania- infected mice, suggesting that local cues within inflamed skin induce cytolytic function. Expression of Blimp-1 (Prdm1), a transcription factor necessary for cytolytic CD8 T cell differentiation, is driven by hypoxia within the inflamed skin. Hypoxia is further enhanced by the recruitment of neutrophils that consume oxygen to produce reactive oxygen species, ultimately increasing granzyme B expression in CD8 T cells. Importantly, lesions from cutaneous leishmaniasis patients exhibit hypoxia transcription signatures that correlate with the presence of neutrophils. Thus, targeting hypoxia-driven signals that support local differentiation of cytolytic CD8 T cells may improve the prognosis for patients with cutaneous leishmaniasis, as well as other inflammatory skin diseases where cytolytic CD8 T cells contribute to pathogenesis.

immunology↗

bioRxiv2022

Aiolos modulates the TFH and CD4-CTL differentiation programs via reciprocal regulation of the Zfp831/TCF-1/Bcl-6 axis and CD25

Effective immunity to influenza virus and other respiratory viruses requires the generation of CD4+ T cell subsets that coordinate multiple aspects of the immune response. These subsets include T follicular helper (TFH) and T helper 1 (TH1) cells, which promote humoral and cell-mediated responses, respectively. A third population, CD4+ cytotoxic T lymphocytes (CD4-CTLs) facilitates clearance of infection via mechanisms normally associated with CD8+ T cells. Here, we identify the transcription factor Aiolos as a regulator of TFH and CD4-CTL responses. We demonstrate that Aiolos deficiency compromises TFH differentiation and antibody production during influenza virus infection. Conversely, we find that CD4+ T cells acquire a cytotoxic-like program in the absence of Aiolos, including increased expression of the CTL-associated transcription factors Eomes and Blimp-1. We further show that while Aiolos positively regulates the TFH transcriptional regulators Zfp831, TCF-1 and Bcl-6, it also directly represses expression of IL-2R and IL-2/STAT5-driven expression of the cytotoxic gene program. Thus, our findings identify Aiolos as a pivotal regulator of TFH and CD4-CTL differentiation and highlight its potential as a target for manipulating CD4+ T cell humoral and cytotoxic responses.

immunology↗