Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
Multicenter Study
. 2018 Mar 1;141(3):786-796.
doi: 10.1093/brain/awx372.

Multiple sclerosis risk variants alter expression of co-stimulatory genes in B cells

Ide Smets  1   2 , Barnaby Fiddes  3 , Josselyn E Garcia-Perez  4   5 , Di He  3 , Klara Mallants  1 , Wenjia Liao  3 , James Dooley  4   5 , George Wang  3 , Stephanie Humblet-Baron  4   5 , Bénédicte Dubois  1   2 , Alastair Compston  3 , Joanne Jones  3 , Alasdair Coles  3 , Adrian Liston  4   5 , Maria Ban  3 , An Goris  1 , Stephen Sawcer  3
Affiliations
Multicenter Study

Multiple sclerosis risk variants alter expression of co-stimulatory genes in B cells

Ide Smets et al. Brain. .

Abstract

The increasing evidence supporting a role for B cells in the pathogenesis of multiple sclerosis prompted us to investigate the influence of known susceptibility variants on the surface expression of co-stimulatory molecules in these cells. Using flow cytometry we measured surface expression of CD40 and CD86 in B cells from 68 patients and 162 healthy controls that were genotyped for the multiple sclerosis associated single nucleotide polymorphisms (SNPs) rs4810485, which maps within the CD40 gene, and rs9282641, which maps within the CD86 gene. We found that carrying the risk allele rs4810485*T lowered the cell-surface expression of CD40 in all tested B cell subtypes (in total B cells P ≤ 5.10 × 10-5 in patients and ≤4.09 × 10-6 in controls), while carrying the risk allele rs9282641*G increased the expression of CD86, with this effect primarily seen in the naïve B cell subset (P = 0.048 in patients and 5.38 × 10-5 in controls). In concordance with these results, analysis of RNA expression demonstrated that the risk allele rs4810485*T resulted in lower total CD40 expression (P = 0.057) but with an increased proportion of alternative splice-forms leading to decoy receptors (P = 4.00 × 10-7). Finally, we also observed that the risk allele rs4810485*T was associated with decreased levels of interleukin-10 (P = 0.020), which is considered to have an immunoregulatory function downstream of CD40. Given the importance of these co-stimulatory molecules in determining the immune reaction that appears in response to antigen our data suggest that B cells might have an important antigen presentation and immunoregulatory role in the pathogenesis of multiple sclerosis.

PubMed Disclaimer

Figures

Figure 1
Figure 1
Association of the CD40 SNP rs4810485 with B cell surface expression of CD40 in healthy controls (n = 135). MFI ratio of CD40 on CD40-positive cells by genotype is depicted for (A) B cells, (B) naïve B cells, (C) non-switched memory B cells and (D) class-switched memory B cells in the G/G (n = 70), G/T (n = 34) and T/T (n = 12) genotype group. Box-whisker plots represent median, quartiles and 1.5× interquartile range (IQR). rs4810485*T is the multiple sclerosis risk allele. P-value is given for a linear regression of CD40 MFI in function of the number of T alleles.
Figure 2
Figure 2
Association of the CD40 SNP rs4810485 with B cell surface expression of CD40 in multiple sclerosis patients (n = 66). MFI of CD40 by genotype is depicted for (A) B cells, (B) transitional B cells, (C) naïve B cells, (D) non-switched memory B cells, (E) class-switched memory B cells, and (F) plasmablasts in the G/G (n = 34), G/T (n = 25) and T/T (n = 7) genotype group. Box-whisker plots represent median, quartiles and 1.5× IQR. rs4810485*T is the multiple sclerosis risk allele. P-value is given for a linear regression of CD40 MFI in function of the number of T alleles including batch as covariate.
Figure 3
Figure 3
Association of the CD86 SNP rs9282641 with B cell surface expression of CD86 in healthy controls (n = 135). Percentage of CD86-positive cells by genotype is depicted for (A) B cells, (B) naïve B cells, (C) non-switched memory B cells and (D) class-switched memory B cells in the A/A (n = 14), A/G (n = 47) and G/G (n = 74) genotype group. Box-whisker plots represent median, quartiles and 1.5× IQR. rs9282641*G is the multiple sclerosis risk allele. P-value is given for a linear regression of per cent CD86-positive in function of the number of G alleles.
Figure 4
Figure 4
Association of the CD86 SNP rs9282641 with B cell surface expression of CD86 in untreated multiple sclerosis patients (n = 67). Percentage of CD86-positive cells by genotype is depicted for (A) B cells, (B) transitional B cells, (C) naïve B cells, (D) non-switched memory B cells, (E) class-switched memory B cells and (F) plasmablasts in the A/G (n = 14) and G/G (n = 53) genotype group. Box-whisker plots represent median, quartiles and 1.5× IQR. rs9282641*G is the multiple sclerosis risk allele. P-value is given for a linear regression of per cent CD86-positive in function of the number of G alleles with batch as covariate.
Figure 5
Figure 5
Association of the CD40 SNP rs4810485 with total CD40 and CD40 alternative splice forms in untreated multiple sclerosis patients (n = 65). Genotype specific (A) relative quantity of total CD40 expression (spanning exons 1–2) versus housekeeping gene and relative quantity of alternative CD40 splice-forms lacking (B) exon 5, (C) exons 5–6 and (D) exon 6 compared to relative quantity of total CD40 expression in the G/G (n = 34), G/T (n = 25) and T/T (n = 6) genotype group. Box-whisker plots represent median, quartiles and 1.5× IQR. rs4810485*T is the multiple sclerosis risk allele. P-value is given for a linear regression of CD40 expression levels in function of the number of T alleles.
Figure 6
Figure 6
Association of the CD40 SNP rs4810485 with serum IL-10 levels in untreated multiple sclerosis patients (n = 66). IL-10 levels are measured in the G/G (n = 34), G/T (n = 25) and T/T (n = 7) genotype group. Box-whisker plots represent median, quartiles and 1.5× IQR. rs4810485*T is the multiple sclerosis risk allele. P-value is given for a linear regression of IL-10 levels in function of the number of T alleles.
See this image and copyright information in PMC

References

    1. Boon L, Brok HP, Bauer J, Ortiz-Buijsse A, Schellekens MM, Ramdien-Murli S, et al. Prevention of experimental autoimmune encephalomyelitis in the common marmoset (Callithrix jacchus) using a chimeric antagonist monoclonal antibody against human CD40 is associated with altered B cell responses. J Immunol 2001; 167: 2942–9. - PubMed
    1. Carr EJ, Dooley J, Garcia-Perez JE, Lagou V, Lee JC, Wouters C, et al. The cellular composition of the human immune system is maintained in multiple stable equilibriums shaped by age and cohabitation. Nat Immunol 2016; 417: 461–8. - PMC - PubMed
    1. Comabella M, Canto E, Nurtdinov R, Rio J, Villar LM, Picon C, et al. MRI phenotypes with high neurodegeneration are associated with peripheral blood B-cell changes. Hum Mol Genet 2016; 25: 308–16. - PubMed
    1. Dendrou CA, Fugger L, Friese MA. Immunopathology of multiple sclerosis. Nat Rev Immunol 2015; 15: 545–58. - PubMed
    1. Dooley J, Pauwels I, Franckaert D, Smets I, Garcia-Perez JE, Hilven K, et al. Immunological profiles of multiple sclerosis treatments reveal shared early B cell alterations. Neurol Neuroimmunol Neuroinflamm 2016; 3: e240. - PMC - PubMed

Publication types