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DQB1*0602 rather than DRB1*1501 confers susceptibility to multiple sclerosis-like disease induced by proteolipid protein (PLP).

Kaushansky N, Altmann DM, David CS, Lassmann H, Ben-Nun A - J Neuroinflammation (2012)

Bottom Line: Due to strong linkage disequilibrium in HLA-II region, it has been hard to establish precisely whether the functionally relevant effect derives from the DRB1*1501, DQA1*0102-DQB1*0602, or DRB5*0101 loci of HLA-DR15 haplotype, their combinations, or their epistatic interactions.Moreover, that DQB1*0602, but not DRB1*1501, determines disease-susceptibility to PLP in HLA-transgenics, suggests a potential differential, functional role for DQB1*0602 as a predisposing allele in MS.This, together with previously demonstrated disease-susceptibility to MBP and MOG in DRB1*1501-transgenics, also suggests a differential role for DRB1*1501 and DQB1*0602 depending on target antigen and imply a potential complex 'genotype/target antigen/phenotype' relationship in MS heterogeneity.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Immunology, The Weizmann Institute of Science, Rehovot, Israel.

ABSTRACT

Background: Multiple sclerosis (MS) is associated with pathogenic autoimmunity primarily focused on major CNS-myelin target antigens including myelin basic protein (MBP), proteolipidprotein (PLP), myelin oligodendrocyte protein (MOG). MS is a complex trait whereby the HLA genes, particularly class-II genes of HLA-DR15 haplotype, dominate the genetic contribution to disease-risk. Due to strong linkage disequilibrium in HLA-II region, it has been hard to establish precisely whether the functionally relevant effect derives from the DRB1*1501, DQA1*0102-DQB1*0602, or DRB5*0101 loci of HLA-DR15 haplotype, their combinations, or their epistatic interactions. Nevertheless, most genetic studies have indicated DRB1*1501 as a primary risk factor in MS. Here, we used 'HLA-humanized' mice to discern the potential relative contribution of DRB1*1501 and DQB1*0602 alleles to susceptibility to "humanized" MS-like disease induced by PLP, one of the most prominent and encephalitogenic target-antigens implicated in human MS.

Methods: The HLA-DRB1*1501- and HLA-DQB1*0602-Tg mice (MHC-II(-/-)), and control non-HLA-DR15-relevant-Tg mice were immunized with a set of overlapping PLP peptides or with recombinant soluble PLP for induction of "humanized" MS-like disease, as well as for ex-vivo analysis of immunogenic/immunodominant HLA-restricted T-cell epitopes and associated cytokine secretion profile.

Results: PLP autoimmunity in both HLA-DR15-Tg mice was focused on 139-151 and 175-194 epitopes. Strikingly, however, the HLA-DRB1*1501-transgenics were refractory to disease induction by any of the overlapping PLP peptides, while HLA-DQB1*0602 transgenics were susceptible to disease induction by PLP139-151 and PLP175-194 peptides. Although both transgenics responded to both peptides, the PLP139-151- and PLP175-194-reactive T-cells were directed to Th1/Th17 phenotype in DQB1*0602-Tg mice and towards Th2 in DRB1*1501-Tg mice.

Conclusions: While genome studies map a strong MS susceptibility effect to the region of DRB1*1501, our findings offer a rationale for potential involvement of pathogenic DQ6-associated autoimmunity in MS. Moreover, that DQB1*0602, but not DRB1*1501, determines disease-susceptibility to PLP in HLA-transgenics, suggests a potential differential, functional role for DQB1*0602 as a predisposing allele in MS. This, together with previously demonstrated disease-susceptibility to MBP and MOG in DRB1*1501-transgenics, also suggests a differential role for DRB1*1501 and DQB1*0602 depending on target antigen and imply a potential complex 'genotype/target antigen/phenotype' relationship in MS heterogeneity.

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Mapping immunogenic DR15- and DQ6-associated PLP T-cell epitopes by immunization with individual overlapping peptides spanning hΔPLP. HLA-DRB1*1501-Tg, HLA-DQB1*0602-Tg and HLA-DRB1*1502-Tg (as control HLA-Tg line) mice were immunized (s.c.) each with an individual peptide (derived from native hPLP) of the overlapping peptides spanning hΔPLP. Ten days later, the primed LNC of immunized mice were analyzed ex-vivo for recall proliferative response to the immunizing peptide (0.5 - 5 μg/ml). Results expressed as stimulation index (S.I., mean cpm of antigen containing cultures/mean c.p.m of medium-containing cultures) are from one experiment with pooled draining LNC from two mice immunized with each individual peptide. Results are representative of three independent experiments.
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Figure 2: Mapping immunogenic DR15- and DQ6-associated PLP T-cell epitopes by immunization with individual overlapping peptides spanning hΔPLP. HLA-DRB1*1501-Tg, HLA-DQB1*0602-Tg and HLA-DRB1*1502-Tg (as control HLA-Tg line) mice were immunized (s.c.) each with an individual peptide (derived from native hPLP) of the overlapping peptides spanning hΔPLP. Ten days later, the primed LNC of immunized mice were analyzed ex-vivo for recall proliferative response to the immunizing peptide (0.5 - 5 μg/ml). Results expressed as stimulation index (S.I., mean cpm of antigen containing cultures/mean c.p.m of medium-containing cultures) are from one experiment with pooled draining LNC from two mice immunized with each individual peptide. Results are representative of three independent experiments.

Mentions: To define HLA-DR15 haplotype-related immunogenic epitopes of human PLP, DRB1*1501- and DQB1*0602-Tg mice were immunized with each of the individual overlapping peptides spanning the aqueous-soluble recombinant hΔPLP [Δ, deleted of hydrophobic (transmembrane) domains] (listed in Table 1). Ten days later, the primed LNC were analyzed ex-vivo for a recall proliferative response to variable concentrations of the immunizing peptide. As shown in Figure 2A, the phPLP30-51, 139-151, 175-194, 185-206, and 206-226 peptides that elicit a significant T-cell response in DRB1*1501-Tg mice are likely to contain DRB1*1501-presented immunogenic eitopes, with phPLP175-194, 185-206, and 206-226 eliciting the strongest DRB1*1501-associated T-cell response. In the DQB1*0602-Tg mice, T-cell responses were seen in response to peptides phPLP30-51, 139-151, 175-194, 215-235, and 257-276 (Figure 2B), with responses to phPLP30-51, 139-151, 175-194, and 257-276 being about equally strong, although the responses to phPLP30-51 and phPLP257-276 were larger.


DQB1*0602 rather than DRB1*1501 confers susceptibility to multiple sclerosis-like disease induced by proteolipid protein (PLP).

Kaushansky N, Altmann DM, David CS, Lassmann H, Ben-Nun A - J Neuroinflammation (2012)

Mapping immunogenic DR15- and DQ6-associated PLP T-cell epitopes by immunization with individual overlapping peptides spanning hΔPLP. HLA-DRB1*1501-Tg, HLA-DQB1*0602-Tg and HLA-DRB1*1502-Tg (as control HLA-Tg line) mice were immunized (s.c.) each with an individual peptide (derived from native hPLP) of the overlapping peptides spanning hΔPLP. Ten days later, the primed LNC of immunized mice were analyzed ex-vivo for recall proliferative response to the immunizing peptide (0.5 - 5 μg/ml). Results expressed as stimulation index (S.I., mean cpm of antigen containing cultures/mean c.p.m of medium-containing cultures) are from one experiment with pooled draining LNC from two mice immunized with each individual peptide. Results are representative of three independent experiments.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3344688&req=5

Figure 2: Mapping immunogenic DR15- and DQ6-associated PLP T-cell epitopes by immunization with individual overlapping peptides spanning hΔPLP. HLA-DRB1*1501-Tg, HLA-DQB1*0602-Tg and HLA-DRB1*1502-Tg (as control HLA-Tg line) mice were immunized (s.c.) each with an individual peptide (derived from native hPLP) of the overlapping peptides spanning hΔPLP. Ten days later, the primed LNC of immunized mice were analyzed ex-vivo for recall proliferative response to the immunizing peptide (0.5 - 5 μg/ml). Results expressed as stimulation index (S.I., mean cpm of antigen containing cultures/mean c.p.m of medium-containing cultures) are from one experiment with pooled draining LNC from two mice immunized with each individual peptide. Results are representative of three independent experiments.
Mentions: To define HLA-DR15 haplotype-related immunogenic epitopes of human PLP, DRB1*1501- and DQB1*0602-Tg mice were immunized with each of the individual overlapping peptides spanning the aqueous-soluble recombinant hΔPLP [Δ, deleted of hydrophobic (transmembrane) domains] (listed in Table 1). Ten days later, the primed LNC were analyzed ex-vivo for a recall proliferative response to variable concentrations of the immunizing peptide. As shown in Figure 2A, the phPLP30-51, 139-151, 175-194, 185-206, and 206-226 peptides that elicit a significant T-cell response in DRB1*1501-Tg mice are likely to contain DRB1*1501-presented immunogenic eitopes, with phPLP175-194, 185-206, and 206-226 eliciting the strongest DRB1*1501-associated T-cell response. In the DQB1*0602-Tg mice, T-cell responses were seen in response to peptides phPLP30-51, 139-151, 175-194, 215-235, and 257-276 (Figure 2B), with responses to phPLP30-51, 139-151, 175-194, and 257-276 being about equally strong, although the responses to phPLP30-51 and phPLP257-276 were larger.

Bottom Line: Due to strong linkage disequilibrium in HLA-II region, it has been hard to establish precisely whether the functionally relevant effect derives from the DRB1*1501, DQA1*0102-DQB1*0602, or DRB5*0101 loci of HLA-DR15 haplotype, their combinations, or their epistatic interactions.Moreover, that DQB1*0602, but not DRB1*1501, determines disease-susceptibility to PLP in HLA-transgenics, suggests a potential differential, functional role for DQB1*0602 as a predisposing allele in MS.This, together with previously demonstrated disease-susceptibility to MBP and MOG in DRB1*1501-transgenics, also suggests a differential role for DRB1*1501 and DQB1*0602 depending on target antigen and imply a potential complex 'genotype/target antigen/phenotype' relationship in MS heterogeneity.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Immunology, The Weizmann Institute of Science, Rehovot, Israel.

ABSTRACT

Background: Multiple sclerosis (MS) is associated with pathogenic autoimmunity primarily focused on major CNS-myelin target antigens including myelin basic protein (MBP), proteolipidprotein (PLP), myelin oligodendrocyte protein (MOG). MS is a complex trait whereby the HLA genes, particularly class-II genes of HLA-DR15 haplotype, dominate the genetic contribution to disease-risk. Due to strong linkage disequilibrium in HLA-II region, it has been hard to establish precisely whether the functionally relevant effect derives from the DRB1*1501, DQA1*0102-DQB1*0602, or DRB5*0101 loci of HLA-DR15 haplotype, their combinations, or their epistatic interactions. Nevertheless, most genetic studies have indicated DRB1*1501 as a primary risk factor in MS. Here, we used 'HLA-humanized' mice to discern the potential relative contribution of DRB1*1501 and DQB1*0602 alleles to susceptibility to "humanized" MS-like disease induced by PLP, one of the most prominent and encephalitogenic target-antigens implicated in human MS.

Methods: The HLA-DRB1*1501- and HLA-DQB1*0602-Tg mice (MHC-II(-/-)), and control non-HLA-DR15-relevant-Tg mice were immunized with a set of overlapping PLP peptides or with recombinant soluble PLP for induction of "humanized" MS-like disease, as well as for ex-vivo analysis of immunogenic/immunodominant HLA-restricted T-cell epitopes and associated cytokine secretion profile.

Results: PLP autoimmunity in both HLA-DR15-Tg mice was focused on 139-151 and 175-194 epitopes. Strikingly, however, the HLA-DRB1*1501-transgenics were refractory to disease induction by any of the overlapping PLP peptides, while HLA-DQB1*0602 transgenics were susceptible to disease induction by PLP139-151 and PLP175-194 peptides. Although both transgenics responded to both peptides, the PLP139-151- and PLP175-194-reactive T-cells were directed to Th1/Th17 phenotype in DQB1*0602-Tg mice and towards Th2 in DRB1*1501-Tg mice.

Conclusions: While genome studies map a strong MS susceptibility effect to the region of DRB1*1501, our findings offer a rationale for potential involvement of pathogenic DQ6-associated autoimmunity in MS. Moreover, that DQB1*0602, but not DRB1*1501, determines disease-susceptibility to PLP in HLA-transgenics, suggests a potential differential, functional role for DQB1*0602 as a predisposing allele in MS. This, together with previously demonstrated disease-susceptibility to MBP and MOG in DRB1*1501-transgenics, also suggests a differential role for DRB1*1501 and DQB1*0602 depending on target antigen and imply a potential complex 'genotype/target antigen/phenotype' relationship in MS heterogeneity.

Show MeSH
Related in: MedlinePlus