PMID- 19725947
OWN - NLM
STAT- MEDLINE
DCOM- 20091209
LR  - 20211020
IS  - 1745-6150 (Electronic)
IS  - 1745-6150 (Linking)
VI  - 4
DP  - 2009 Sep 2
TI  - Hypothesis for heritable, anti-viral immunity in crustaceans and insects.
PG  - 32
LID - 10.1186/1745-6150-4-32 [doi]
AB  - BACKGROUND: It is known that crustaceans and insects can persistently carry one 
      or more viral pathogens at low levels, without signs of disease. They may 
      transmit them to their offspring or to naive individuals, often with lethal 
      consequences. The underlying molecular mechanisms have not been elucidated, but 
      the process has been called viral accommodation. Since tolerance to one virus 
      does not confer tolerance to another, tolerance is pathogen-specific, so the 
      requirement for a specific pathogen response mechanism (memory) was included in 
      the original viral accommodation concept. Later, it was hypothesized that 
      specific responses were based on the presence of viruses in persistent 
      infections. However, recent developments suggest that specific responses may be 
      based on viral sequences inserted into the host genome. PRESENTATION OF THE 
      HYPOTHESIS: Non-retroviral fragments of both RNA and DNA viruses have been found 
      in insect and crustacean genomes. In addition, reverse-transcriptase (RT) and 
      integrase (IN) sequences are also common in their genomes. It is hypothesized 
      that shrimp and other arthropods use these RT to recognize "foreign" mRNA of both 
      RNA and DNA viruses and use the integrases (IN) to randomly insert short cDNA 
      sequences into their genomes. By chance, some of these sequences result in 
      production of immunospecific RNA (imRNA) capable of stimulating RNAi that 
      suppresses viral propagation. Individuals with protective inserts would pass 
      these on to the next generation, together with similar protective inserts for 
      other viruses that could be amalgamated rapidly in individual offspring by random 
      assortment of chromosomes. The most successful individuals would be 
      environmentally selected from billions of offspring. CONCLUSION: This hypothesis 
      for immunity based on an imRNA generation mechanism fits with the general 
      principle of invertebrate immunity based on a non-host, "pattern recognition" 
      process. If proven correct, understanding the process would allow directed 
      preparation of vaccines for selection of crustacean and insect lines applicable 
      in commercial production species (e.g., shrimp and bees) or in control of 
      insect-borne diseases. Arising from a natural host mechanism, the resulting 
      animals would not be artificially, genetically modified (GMO).
FAU - Flegel, Timothy W
AU  - Flegel TW
AD  - Center of Excellence for Shrimp Molecular Biology and Biotechnology (Centex 
      Shrimp), Mahidol University, Rama 6 Road, Bangkok 10400, Thailand. 
      sctwf@mahidol.ac.th
LA  - eng
PT  - Journal Article
DEP - 20090902
PL  - England
TA  - Biol Direct
JT  - Biology direct
JID - 101258412
RN  - EC 2.7.7.- (Integrases)
RN  - EC 2.7.7.49 (RNA-Directed DNA Polymerase)
SB  - IM
EIN - Biol Direct. 2009;4. doi:10.1186/1745-6150-4-36
MH  - Animals
MH  - Crustacea/genetics/*immunology/*virology
MH  - Genome/genetics
MH  - Immunity/*immunology
MH  - Inheritance Patterns/*immunology
MH  - Insecta/genetics/*immunology/*virology
MH  - Integrases/metabolism
MH  - *Models, Immunological
MH  - RNA-Directed DNA Polymerase/metabolism
MH  - Retroviridae/enzymology
MH  - Virus Diseases/genetics/immunology
PMC - PMC2757015
EDAT- 2009/09/04 06:00
MHDA- 2009/12/16 06:00
PMCR- 2009/09/02
CRDT- 2009/09/04 06:00
PHST- 2009/08/22 00:00 [received]
PHST- 2009/09/02 00:00 [accepted]
PHST- 2009/09/04 06:00 [entrez]
PHST- 2009/09/04 06:00 [pubmed]
PHST- 2009/12/16 06:00 [medline]
PHST- 2009/09/02 00:00 [pmc-release]
AID - 1745-6150-4-32 [pii]
AID - 10.1186/1745-6150-4-32 [doi]
PST - epublish
SO  - Biol Direct. 2009 Sep 2;4:32. doi: 10.1186/1745-6150-4-32.