Exposure to Mimivirus Collagen Promotes Arthritis

Abstract

b Collagens, the most abundant proteins in animals, also occur in some recently described nucleocytoplasmic large DNA viruses such as Mimiviridae, which replicate in amoebae. To clarify the impact of viral collagens on the immune response of animals exposed to Mimiviridae, we have investigated the localization of collagens in Acanthamoeba polyphaga mimivirus particles and the response of mice to immunization with mimivirus particles. Using protein biotinylation, we have first shown that viral collagen encoded by open reading frame L71 is present at the surface of mimivirus particles. Exposure to mimivirus collagens elicited the production of anti-collagen antibodies in DBA/1 mice immunized intradermally with mimivirus protein extracts. This antibody response also targeted mouse collagen type II and was accompanied by T-cell reactivity to collagen and joint inflammation, as observed in collagen-induced arthritis following immunization of mice with bovine collagen type II. The broad distribution of nucleocytoplasmic large DNA viruses in the environment suggests that humans are constantly exposed to such large virus particles. A survey of blood sera from healthy human subjects and from rheumatoid arthritis patients indeed demonstrated that 30% of healthy-subject and 36% of rheumatoid arthritis sera recognized the major mimivirus capsid protein L425. Moreover, whereas 6% of healthy-subject sera recognized the mimivirus collagen protein L71, 22% of rheumatoid arthritis sera were positive for mimivirus L71. Accordingly, our study shows that environmental exposure to mimivirus represents a risk factor in triggering autoimmunity to collagens.

Reef invertebrate viromics: diversity, host specificity and functional capacity

“…). Collagen producing genes have been identified in nucleocytoplasmic large DNA viruses and as a structural component of the external capsids of mimiviruses (Shah et al ., ), although none of the contigs containing collagen genes from this study were assigned to Mimiviridae (Supporting Information Table S7). While collagen is one of the most ubiquitous proteins produced in multicellular animals, it is also one of the main structural components, which give form and structure to sponges (Simpson, ).…”

Your Garden Hose: A Potential Health Risk Due to Legionella spp. Growth Facilitated by Free-Living Amoebae

“…7 Legionellosis (Legionella infection) alone accounts for 29% of all reported disease outbreaks from drinking water in the United States since it became a reportable disease in 2001. The elderly are most at risk, and, together with nontuberculosis mycobacterial infections that require hospitalizations, legionellosis cases account for the majority of hospital costs associated with drinking water disease.…”

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“…The Mimivirus replicates in amoeba which is the best known natural host, and has also been isolated from a patient with pneumonia . It has also been suggested to be a risk factor in triggering autoimmunity to collagens . Mimiviruses detected by HMMER in this study were not detected by BLAST and they are only distantly related to any known virus and thus, there is no previous epidemiological knowledge for these viruses.…”

“…31 It has also been suggested to be a risk factor in triggering autoimmunity to collagens. 32 Mimiviruses detected by HMMER in this study were not detected by BLAST and they are only distantly related to any known virus and thus, there is no previous epidemiological knowledge for these viruses. The fact that some new Mimi and Poxviruses were detected in the control specimens suggests that some of the new viruses may be environmental viruses.…”