title: Molecular differences between the divergent responses of ovalbumin-specific CD4 T cells to alum-precipitated ovalbumin compared to ovalbumin expressed by Salmonella.
abstract: CD4 T helper (Th) cell differentiation defined by in vitro cytokine-directed culture systems leaves major gaps in our knowledge of the mechanisms driving divergent Th differentiation. This is evident from our analysis of the response of mouse ovalbumin-specific CD4 T cells to different forms of ovalbumin that induce markedly distinct responses in vivo. We show that live attenuated ovalbumin-expressing Salmonella (SalOVA) induce Th1-associated T-bet and IFN-gamma. Conversely, alum-precipitated ovalbumin (alumOVA) induces the Th2-associated GATA-3 and IL-4. The early diversity occurring within these CD4 T cells isolated 3 days after immunization was assessed using real-time RT-PCR microfluidic cards designed with 384 selected genes. The technique was validated both at the population and single cell levels at different stages of the responses, showing beta2-microglobulin to be a more stably expressed reference mRNA than either beta-actin or 18S RNA. SalOVA was then shown selectively to induce the OVA-specific CD4 T cells to produce many chemokines and pro-inflammatory cytokines, contrasting with alumOVA-induced cells that only produced a few Th2-associated cytokines. Several cytokines and features associated with follicular helper functions were induced in the OVA-specific CD4 T cells by both antigens. Finally, IL-17RB is strongly associated with OVA-specific CD4 T cells responding to alumOVA, suggesting that alum may promote Th2 immune response through a role for the IL-25/IL-17RB pathway.
authors.affiliation: MRC Centre for Immune Regulation, University of Birmingham, Medical School, Birmingham, UK. k.serre@bham.ac.uk
authors.forename: Karine
authors.initials: K
authors.lastname: Serre
authors.forename: Elodie
authors.initials: E
authors.lastname: Mohr
authors.forename: Kai-Michael
authors.initials: KM
authors.lastname: Toellner
authors.forename: Adam F
authors.initials: AF
authors.lastname: Cunningham
authors.forename: Samuel
authors.initials: S
authors.lastname: Granjeaud
authors.forename: Roger
authors.initials: R
authors.lastname: Bird
authors.forename: Ian C M
authors.initials: IC
authors.lastname: MacLennan
mesh_terms: D000534:Alum Compounds / Q000494:pharmacology*; D000818:Animals; D015496:CD4-Positive T-Lymphocytes / Q000187:drug effects / Q000276:immunology / Q000378:metabolism*; D002454:Cell Differentiation / Q000187:drug effects / Q000235:genetics / Q000276:immunology; D020869:Gene Expression Profiling; D005786:Gene Expression Regulation / Q000276:immunology; D007114:Immunization; D047468:Immunoprecipitation; D007371:Interferon-gamma / Q000378:metabolism; D015847:Interleukin-4 / Q000378:metabolism; D051379:Mice; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D020411:Oligonucleotide Array Sequence Analysis; D010047:Ovalbumin / Q000187:drug effects / Q000276:immunology* / Q000378:metabolism*; D012475:Salmonella / Q000276:immunology* / Q000378:metabolism; D012480:Salmonella Infections / Q000235:genetics / Q000276:immunology / Q000378:metabolism / Q000628:therapy; D018417:Th1 Cells / Q000276:immunology / Q000378:metabolism / Q000502:physiology; D018418:Th2 Cells / Q000276:immunology / Q000378:metabolism / Q000502:physiology
chemical_list: D000534:Alum Compounds; D015847:Interleukin-4; C041524:aluminum sulfate; D007371:Interferon-gamma; D010047:Ovalbumin