The plant virus, cowpea mosaic virus (CPMV), is increasingly being used as a nanoparticle platform for multivalent display of peptides. A growing variety of applications have employed the CPMV display technology including vaccines, antiviral therapeutics, nanoblock chemistry, and materials science. CPMV chimeras can be inexpensively produced from experimentally infected cowpea plants and are completely stable at 37 degrees C and low pH, suggesting that they could be used as edible or mucosally-delivered vaccines or therapeutics. However, the fate of CPMV particles in vivo, or following delivery via the oral route, is unknown. To address this question, we examined CPMV in vitro and in vivo. CPMV was shown to be stable under simulated gastric conditions in vitro. The pattern of localization of CPMV particles to mouse tissues following oral or intravenous dosing was then determined. For several days following oral or intravenous inoculation, CPMV was found in a wide variety of tissues throughout the body, including the spleen, kidney, liver, lung, stomach, small intestine, lymph nodes, brain, and bone marrow. CPMV particles were detected after cardiac perfusion, suggesting that the particles entered the tissues. This pattern was confirmed using methods to specifically detect the viral capsid proteins and the internal viral RNA. The stability of CPMV virions in the gastrointestinal tract followed by their systemic dissemination supports their use as orally bioavailable nanoparticles.

The measles virus (MV) P gene encodes three proteins: the P protein and two nonstructural proteins, C and V. Because the functions of both the C and V protein are unknown, we used MV C (C-) and V (V-) deletion recombinants generated by the MV reverse genetics system (F. Radecke, P. Spielhofer, H. Schnieder, K. Kaelin, M. Huber, C. Dotsch, G. Christiansen, and M. A. Billeter 1995. EMBO J. 14, 5773-5784). Compared to parental vaccine strain, Edmonston (Ed) MV, both had normal growth and cytopathic effects in Vero cells and showed similar growth kinetics in human neuroblastoma SK-N-MC cells and in primary mouse neurons expressing the MV receptor, CD46. However, in vivo, using YAC-CD46 transgenic mice as a model for MV induced CNS disease (M. B. A. Oldstone, H. Lewicki, D. Thomas, A. Tishon, S. Dales, J. Patterson, M. Manchester, D. Homann, D. Naniche, and A. Holz 1999. Cell 98, 629-640), C- and V- viruses differed markedly from wt Ed(V(+)C(+)) virus. Newborn mice inoculated with as little as 10(3) PFU of Ed strain became ill and died after 10-15 days. In contrast, those inoculated with 10(3) or 10(4) PFU of MV C- or MV V- showed significantly fewer and milder clinical symptoms and had a lower mortality. A total of 10(5) PFU V- virus were required to kill most YAC-CD46 mice, and less than half (44%) were killed with a corresponding dose of MV C-. Immunohistochemical staining for MV antigens showed similar extents of spread for MV C- and MV Ed but restricted spread for MV V- throughout the brain. Viral load and transcription were markedly reduced for V- but not for C-. Multiple cytokines and chemokines were equivalently upregulated for all three viruses. Therefore, MV C and V proteins encode virulence functions in vivo and likely operate via separate mechanisms.

Successful postexposure treatment for inhalation anthrax is thought to include neutralization of anthrax toxin. The soluble anthrax toxin receptor/tumor endothelial marker 8 and capillary morphogenesis protein 2 (sATR/TEM8 and sCMG2, respectively) receptor decoys bind to anthrax toxin protective antigen (PA) and compete with cellular receptors for binding. Here, we show that, in a tissue-culture model of intoxication, sCMG2 is a 11.4-fold more potent antitoxin than sATR/TEM8 and that this increased activity corresponds to an approximately 1000-fold higher PA-binding affinity. Stoichiometric concentrations of sCMG2 protect rats against lethal toxin challenge, making sCMG2 one of the most effective anthrax antitoxins described to date.

Chagas disease (CD) is a parasitic disease caused by Trypanosoma cruzi protozoa, presenting with cardiomyopathy, megaesophagus, and/or megacolon. To determine the mechanisms of gastrointestinal (GI) CD tissue tropism, we systematically characterized the spatial localization of infection-induced metabolic and microbiome alterations, in a mouse model of CD. Notably, the impact of the transition between acute and persistent infection differed between tissue sites, with sustained large-scale effects of infection in the esophagus and large intestine, providing a potential mechanism for the tropism of CD within the GI tract. Infection affected acylcarnitine metabolism; carnitine supplementation prevented acute-stage CD mortality without affecting parasite burden by mitigating infection-induced metabolic disturbances and reducing cardiac strain. Overall, results identified a previously-unknown mechanism of disease tolerance in CD, with potential for new therapeutic regimen development. More broadly, results highlight the potential of spatially resolved metabolomics to provide insight into disease pathogenesis and infectious disease drug development.