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Richardson, R. A.

Publications and source records attributed to Richardson, R. A..

3 recordsLinked to original sources
bioRxiv2024

Delay of innate immune responses following influenza B virus infection affects the development of robust antibody response in ferrets

Due to its natural influenza susceptibility, clinical signs, transmission, and similar sialic acid residue distribution, the ferret is the primary animal model for human influenza research. Antibodies generated following infection of ferrets with human influenza viruses are used in surveillance to detect antigenic drift and cross-reactivity with vaccine viruses and circulating strains. Inoculation of ferrets, with over 1500 human clinical influenza isolates (1998-2019) resulted in lower antibody responses (HI<1:160) to 86% (387/448) influenza B viruses (IBV) compared to 2.7% (30/1094) influenza A viruses (IAV). In this directed analysis, we show that the immune responses in ferrets inoculated with IBV (B/Victoria or B/Yamagata lineage) were delayed and reduced compared to IAV (A/H1pdm09 or A/H3N2). Analysis of innate gene expression in the ferret upper respiratory tract and peripheral blood indicated that IAV generated a strong inflammatory response, including an early activation of the interferon (IFN) response; whereas IBV elicited a delayed and reduced response. Serum levels of cytokines, chemokines, and IFNs were all much higher following IAV-infection than IBV-infection in ferrets. Pro-Inflammatory (MCP-1, MIP-1B, TNFA), IFN (IFNB, IFNG), TH1/TH2 (IP-10, IL-2), and T-effector (IL-12p40) proteins were significantly higher in sera of IAV-infected than IBV-infected ferrets over twenty-eight days following challenge. Serum levels of Type-I/II/III IFNs were detected following IAV-infection throughout the 28-day period and Type-III IFN was only detected by day 28 for IBV. An early increase in IFN-lambda levels corresponded to gene expression following IAV-infection. Reduced innate immune responses detected following IBV-infection reflected the subsequent delayed and reduced serum antibodies. Differences in serum antibody responses by IBV were not observed in antibody secreting cells in the spleen or peripheral blood. These findings help in understanding the antibody responses in humans following IBV vaccination or infection and consideration of potential addition of innate immunomodulators to overcome low responses. AUTHOR SUMMARYThe ferret is the primary animal model for human influenza research. Using a ferret model, we studied the differences in both innate and adaptive immune responses following infection with influenza A and B viruses. Antibodies generated following infection of ferrets is used for surveillance assays to detect antigenic drift and cross-reactivity with vaccine viruses and circulating influenza strains. Influenza A virus (IAV) infection of ferrets to generate these reagents resulted in a strong antibody response, but Influenza B virus (IBV) infection generated weak antibody responses. In this study using influenza-infected ferrets, we found that IAV resulted in an early activation of the interferon and pro-inflammatory response, whereas IBV showed a delay and reduction in these responses. Serum levels of interferons and other cytokines or chemokines were much higher in ferrets following IAV infection. These reduced innate responses were reflected the subsequent delayed and reduced antibody responses to IBV in the sera. These findings may help in understanding low antibody responses in humans following influenza B vaccination and infection and may warrant the use of innate immunomodulators to overcome these weak responses.

microbiology↗
bioRxiv2022

Unbiased proteomic and forward genetic screens reveal that mechanosensitive ion channel MSL10 functions at ER-plasma membrane contact sites in Arabidopsis thaliana

Mechanosensitive (MS) ion channels are an evolutionarily conserved way for cells to sense mechanical forces and transduce them into ionic signals. The channel properties of Arabidopsis thaliana MscS-Like (MSL)10 have been well studied, but how MSL10 signals remains largely unknown. To uncover signaling partners of MSL10, we employed both a proteomic screen and a forward genetic screen; both unexpectedly implicated ER-plasma membrane contact sites (EPCSs) in MSL10 function. The proteomic screen revealed that MSL10 associates with multiple proteins associated with EPCSs. Of these, only VAMP-associated proteins (VAP)27-1 and VAP27-3 interacted directly with MSL10. The forward genetic screen, for suppressors of a gain-of-function MSL10 allele (msl10-3G, MSL10S640L), identified mutations in the synaptotagmin (SYT)5 and SYT7 genes. We also found that EPCSs were expanded in leaves of msl10-3G plants compared to the wild type. Taken together, these results indicate that MSL10 can be found at EPCSs and functions there, providing a new cell-level framework for understanding MSL10 signaling. In addition, placing a mechanosensory protein at EPCS provides new insight into the function and regulation of this type of subcellular compartment.

plant biology↗
bioRxiv2020

Regulation of Vacuole Morphology by PIEZO Channels in Spreading Earth Moss

The perception of mechanical force is a fundamental property of most, if not all cells. PIEZO channels are plasma membrane-embedded mechanosensitive calcium channels that play diverse and essential roles in mechanobiological processes in animals1,2. PIEZO channel homologs are found in plants3,4, but their role(s) in the green lineage are almost completely unknown. Plants and animals diverged approximately 1.5 billion years ago, independently evolved multicellularity, and have vastly different cellular mechanics5. Here, we investigate PIEZO channel function in the moss Physcomitrium patens, a representative of one of the first land plant lineages. PpPIEZO1 and PpPIEZO2 were redundantly required for normal growth, size, and shape of tip-growing caulonema cells. Both were localized to vacuolar membranes and facilitated the release of calcium into the cytosol in response to hypoosmotic shock. Loss-of-function ({Delta}Pppiezo1/2) and gain-of-function (PpPIEZO2-R2508K and -R2508H) mutants revealed a role for moss PIEZO homologs in regulating vacuole morphology. Our work here shows that plant and animal PIEZO homologs have diverged in both subcellular localization and in function, likely co-opted to serve different needs in each lineage. The plant homologs of PIEZO channels thus provide a compelling lens through which to study plant mechanobiology and the evolution of mechanoperceptive strategies in multicellular eukaryotes.

plant biology↗