Transcription of signal-3 cytokines, IL-12 and IFN alpha beta, coincides with the timing of CD8 alpha beta up-regulation during viral infection of common carp (Cyprinus carpio L).
Mammalian naïve CD8+ T cells are activated by antigen (signal 1) and CD28 costimulation (signal 2) to undergo several rounds of cell division, but programming for survival, effector function and memory requires a third signal that can be provided by IL-12 and/or type I interferons. Functional studies indicate that the route of antigen presentation and costimulation are conserved from fish to mammals. However, the potential of IL-12 and IFN alpha beta to act as signal-3 cytokines in infections inducing a CTL response has not been examined in fish. We report the cloning of CD8 alpha and CD8 beta homologues, each present in duplicate copies and of two TCR-C alpha isoforms in European common carp. The identification of (cytotoxic) T cell marker sequences and the availability of sequences coding for the signal-3 cytokines in the same fish species, allowed us to investigate by RT-qPCR their kinetics of gene expression during viral and parasitic infection. Our results show that transcription of signal-3 cytokines occurred concomitantly with CD8 alpha beta up-regulation exclusively at 4 days post-primary viral infection. No regulation of IL-12 and IFN alpha beta was observed after parasitic infection. Our data provide evidences for an evolutionary conservation of function for IL-12 and IFN alpha beta to act as third signal during CTL activation. In addition, we suggest that a CD8 alpha 2/beta1 and a p35p40b association could be the preferred combinations for the formation of a functional CD8 co-receptor and an IL-12p70 heterodimer during viral infection. The relevance of our findings to future vaccination strategies in fish is discussed.
Forlenza
Maria
M
Department of Animal Sciences, Cell Biology and Immunology Group, Wageningen Institute of Animal Sciences, Wageningen University, PO Box 338, 6700 AH, Wageningen, The Netherlands.
de Carvalho Dias
João D A
JD
Veselý
Tomas
T
Pokorová
Dagmar
D
Savelkoul
Huub F J
HF
Wiegertjes
Geert F
GF
D000595:Amino Acid Sequence; D000818:Animals; D017951:Antigen Presentation; D018106:CD28 Antigens / Q000276:immunology; D016827:CD8 Antigens / Q000096:biosynthesis* / Q000235:genetics; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology; D002347:Carps / Q000276:immunology* / Q000469:parasitology / Q000821:virology; D003001:Cloning, Molecular; D019143:Evolution, Molecular; D018628:Gene Dosage; D016898:Interferon-alpha / Q000235:genetics / Q000276:immunology*; D016899:Interferon-beta / Q000235:genetics / Q000276:immunology*; D018664:Interleukin-12 / Q000235:genetics / Q000276:immunology*; D008969:Molecular Sequence Data; D011529:Protozoan Infections, Animal / Q000276:immunology; D011948:Receptors, Antigen, T-Cell / Q000276:immunology; D016693:Receptors, Antigen, T-Cell, alpha-beta / Q000235:genetics / Q000276:immunology; D018353:Rhabdoviridae Infections / Q000276:immunology / Q000662:veterinary; D015398:Signal Transduction; D014158:Transcription, Genetic; D014345:Trypanosoma; D015854:Up-Regulation; D018116:Vesiculovirus
D018106:CD28 Antigens; D016827:CD8 Antigens; C067361:CD8 receptor; C431698:CD8alpha antigen; C477867:CD8beta antigen; D016898:Interferon-alpha; D011948:Receptors, Antigen, T-Cell; D016693:Receptors, Antigen, T-Cell, alpha-beta; D018664:Interleukin-12; D016899:Interferon-beta