Biology subjects

Guzman, C. A.

Publications and source records attributed to Guzman, C. A..

3 recordsLinked to original sources

bioRxiv2021

Itaconate and derivatives reduce interferon responses and inflammation in influenza A infection

Itaconate has recently emerged as a metabolite with immunomodulatory properties. We evaluated effects of endogenous itaconate and exogenous itaconate, dimethyl-, and 4-octyl-itaconate on host responses to influenza A virus infection. Infection induced ACOD1 (the enzyme catalyzing itaconate synthesis) mRNA in monocytes and macrophages, which correlated with viral replication and was abrogated by itaconate treatment. Pulmonary inflammation and weight loss were greater in Acod1-/- than wild-type mice, and ectopic synthesis of itaconate in human epithelial cells reduced infection-induced inflammation. The compounds induced different recruitment programs in infected human macrophages, and transcriptome profiling revealed that they reversed infection-triggered interferon responses and modulated inflammation in cell lines, PBMC, and lung tissue. Single-cell RNA sequencing of PBMC revealed that infection induced ACOD1 exclusively in monocytes, whereas treatment silenced IFN-responses in monocytes, lymphocytes, and NK cells. Viral replication did not increase under treatment despite the dramatically repressed IFN responses, but 4-octyl itaconate inhibited viral transcription in PBMC. The results reveal dramatic reprogramming of host responses by itaconate and derivatives and their potential as adjunct treatments for hyperinflammation in viral infection.

immunology↗

bioRxiv2020

MTX-COVAB, a human-derived antibody with potent neutralizing activity against SARS-CoV-2 infection in vitro and in a hamster model of COVID-19

Fast track microfluidic screening of the antibody repertoires of 12 convalescent COVID-19 donors comprising 2.8mio antibodies yielded MTX-COVAB, a human-derived monoclonal antibody with low picomolar neutralization IC50 of SARS-CoV-2. COVAB neutralization potency is on par with the Regeneron cocktail as demonstrated in a comparative neutralization assay. MTX-COVAB shows strong efficacy in vivo and binds to all currently identified clinically relevant variants of SARS-CoV-2. MTX-COVAB completes GMP manufacturing by the end of this year and will be tested in the clinic in March 2021.

immunology↗

bioRxiv2019

Transcriptomic analysis of native versus cultured human and mouse dorsal root ganglia focused on pharmacological targets

Dorsal root ganglion (DRG) neurons detect sensory inputs and are crucial for pain processing. They are often studied in vitro as dissociated cell cultures with the assumption that this reasonably represents in vivo conditions. However, to our knowledge, no study has ever directly compared genome-wide transcriptomes of DRG tissue in vivo versus in vitro, or between different labs and culturing protocols. We extracted bilateral lumbar DRG from C57BL6/J mice and human organ donors, and acutely froze one side and processed the other side as a dissociated cell culture, which was then maintained in vitro for 4 days. RNA was extracted and sequenced using the NextSeq Illumina platform. Comparing native to cultured human or mouse DRG, we found that the overall expression level of many ion channels and GPCRs specifically expressed in neurons is markedly lower in culture, but still expressed. This suggests that most pharmacological targets expressed in vivo are present in culture conditions. However, there are changes in expression levels for these genes. The reduced relative expression for neuronal genes in human DRG cultures is likely accounted for by increased expression of genes in fibroblast-like and other proliferating cells, consistent with the mitotic status of many cells in these cultures. We did find a subset of genes that are typically neuronally expressed, increased in human and mouse DRG cultures, including genes associated with nerve injury and/or inflammation in preclinical models such as BDNF, MMP9, GAL, and ATF3. We also found a striking upregulation of a number of inflammation-associated genes in DRG cultures, although many were different between mouse and human. Our findings suggest an injury-like phenotype in DRG cultures that has important implications for the use of this model system for pain drug discovery.

neuroscience↗