Mari Luomala

Improved immunogenicity of oral D x RRV reassortant rotavirus vaccine by Lactobacillus casei GG

In a search for new strategies to improve oral vaccination, the effect of orally administered Lactobacillus casei strain GG (LGG) in conjunction with D x RRV rhesus-human reassortant live oral rotavirus vaccine was tested in 2-5-month-old infants. Infants who received LGG showed an increased response with regard to rotavirus-specific IgM secreting cells, measured using an ELISPOT technique, on day 8 after vaccination. In infants receiving LGG or placebo, respectively, a rotavirus IgM seroconversion was detected in 26/27 (96%), versus 23/27 (85%) cases (p = 0.15) and rotavirus IgA seroconversion was detected in 26/28 (93%) versus 20/27 (74%) cases (p = 0.05). These findings suggest that LGG has an immunostimulating effect on oral rotavirus vaccination. The clinical significance of LGG-enhanced immune responses to oral vaccines should be further evaluated.

Promoter polymorphism of IL-10 and severity of multiple sclerosis

Functional polymorphisms of the genes for interleukin‐10 (IL‐10; promoter position −1082), chemokine receptor‐5 (CCR5 32 bp deletion), tumor necrous factor‐α (TNFα promoter position −308) and cytotoxic T‐lymphocyte antigen‐4 (CTLA‐4 exon 1 position 49) were investigated for possible influence on susceptibility and outcome of multiple sclerosis (MS). The polymorphisms were typed by polymerase chain reaction based methods or by direct sequencing in MS patients (n = 93–116) and controls (n = 109–400). The studied genes were not associated with MS susceptibility. Patients were classified as suffering from a mild/moderate [Expanded Disability Status Scale (EDSS) 0–5.5] or severe (EDSS 6–8.0) form of MS. The AG genotype of IL‐10 proved to be protective against severe MS in all patients (OR = 0.32, P = 0.010), the effect being increased over the years (10 years; OR = 0.33, P = 0.043, 15 years; OR = 0.21, P = 0.025 or 20 years; OR = 0.14, P = 0.026). Our results suggest that differential production of IL‐10 might be a factor in the severity of MS.

A study of interleukin-1 cluster genes in susceptibility to and severity of multiple sclerosis

In this explorative study, interleukin-1 (IL-1) receptor antagonist (IL-1RA; polymorphism of variable number of tandem repeats: VNTR), IL-1alpha (-889), IL-1beta (-511) and IL-1beta (+3953) polymorphisms were studied in relation to susceptibility to and severity of multiple sclerosis (MS), in 93 MS patients and 400 normal controls. No associations were found for any polymorphisms, alone or in combination. However, in our MS cohort, females were found to be IL-1RA allele 2 carriers more frequently than males (33/49 vs. 16/44, p = 0.0028). Using a cohort of 109 controls, IL-1RA allele 2 carriers were more frequently women with MS than control women (33/49 vs. 23/43, odds ratio (OR) = 2.19, 95% confidence interval (CI) 1.02-4.72, p = 0.043, P(C) = ns). The data suggest that the IL-1 cluster genes make no major contribution to MS, but the tentative association between IL-1RA allele 2 and susceptibility of MS in women warrants further studies.

Increase in CCR5 Δ32/Δ32 genotype in multiple sclerosis

Chemokines and their receptors participate in the development of multiple sclerosis (MS) by guiding immune cells into the brain tissue. A CCR5 Δ32 deletion mutation abolishes functional CCR5 on the cell surface and may reduce cell entry into the lesion sites. To analyse the significance of this mutation in MS, we compared the frequencies of CCR5 genotype in peripheral blood mononuclear cells from 89 MS patients and 119 healthy controls. The CCR5 genotype was further compared with the CCR5 RNA and surface protein expression in 48 MS patients and their controls. In all MS patients, the Δ32/32 genotype was found with 6.7% frequency, whereas it was present only in 0.8% of the controls (6/89 vs 1/119, P = 0.01). Specifically, the Δ32/Δ32 genotype was increased (11.5%, P = 0.05) among primary progressive MS patients, whereas it was present only in 4.8% in other MS subtypes and only in 0.8% of the controls. The amount of CCR5 protein on CD4+ cells analysed in 48 MS patients (nine primary progressive MS, 18 secondary progressive MS, 21 relapsing–remitting MS) and 13 controls decreased with genotype, being 8.9% in wt/wt, 7.7% in wt/Δ32 and 4.3% in Δ32/Δ32. CCR5 surface expression analysed on these 48 MS patients and 13 controls was significantly decreased in Δ32/Δ32 MS patients as compared with that in wt/wt genotype individuals (P = 0.004). The significantly increased number of Δ32/Δ32 individuals among our MS patients suggests that this genotype could contribute as a general risk factor for MS. However, neither the levels of RNA or surface protein correlated with MS subtype, neurological disability as expressed by expanded disability status scale, or disease progression index. Our results suggest that the lack of CCR5 does not protect from MS, but rather it may predispose to the chronic course of the disease. This would further imply that in view of the redundancy in the chemokine system, CCR5 ligands must be assumed to function through other closely related chemokine receptors.

Interaction between ESR1 and HLA-DR2 may contribute to the development of MS in women

Estrogen hormones modulate immune cell functions and influence immune response.1 The two-fold risk of MS in women as compared with men may be caused by the effects of estrogens, mostly exhibited through nuclear receptors. Expression of estrogen receptor 1 (ESR1) has been identified in cells of the immune system1 and, thus, genetic variability of ESR1 may play a role in the development of MS. In this explorative study, we investigated whether variants of the ESR1 Pvu II polymorphism are associated with MS, especially in women, and whether the human leukocyte antigen (HLA)-DR2 allele, which has consistently been shown to be linked with the disease, influences this association. Ninety-seven patients with clinically definitive MS according to Poser’s criteria (mean age 45.9 ± 10.0 years, range 24 to 78 years; 53 women, 44 men) and 100 healthy adults (mean age 45.7 ± 10.3 years, range 23 to 78 years; 58 women, 42 men) were genotyped. The ESR1 Pvu II restriction fragment length polymorphism, marked with P (restriction site absent) and p (present), was identified as described earlier. …

The combination of HLA-DR1 and HLA-DR53 protects against MS

The DRB1/3/4/5 loci from 97 patients with MS and 100 normal control subjects were analyzed. DRB1*15 increased the risk of MS (OR = 4.2, p < 0.0001), whereas DR1 decreased the risk (OR = 0.30, pc = 0.005). In analyses of the DR1 risk in relation to DR51, DR52, and DR53 alleles, DR1 in combination with DR53 was found to have the strongest protective effect against MS in all subjects (OR = 0.05, p < 0.0001) and in DRB1*15-negative subjects (OR = 0.09, pc = 0.026). DR53 may be an important allele or haplotype, acting together with DR1 to protect against MS.

Suppression of immune system genes by methylprednisolone in exacerbations of multiple sclerosis. Preliminary results.

Abstract.Acute relapses of multiple sclerosis (MS) are treated with intravenous methylprednisolone (IVMP), which speeds recovery from exacerbation. It is known that IVMP suppresses the immunological activation which occurs during an acute attack of MS. However, the specific target genes affected by this therapy remain obscure. A cDNA microarray for 448 genes was used to identify the target genes in IVMP therapy. Total RNA was isolated from peripheral blood mononuclear cells derived from six MS patients immediately before and after completion of therapy. IVMP significantly reduced mRNA levels for T-cell-specific transcription factor 7 (p=0.02), T-cell-specific protein-tyrosine kinase (p=0.02), T-cell surface glycoprotein CD5 (p=0.05) and interferon-stimulated gene factor 3 gamma subunit (p=0.04). Significantly increased expression was found for eosinophil-derived neurotoxin (p=0.05). The suppression of expression of genes associated with T-cell differentiation and antigen-specific T-cell activation detected in this study may contribute to the beneficial effect of MP in relapses of MS.

Plasminogen activator inhibitor 1 gene and risk of MS in women.

Article abstract In view of the potential importance of the proteolytic mechanisms in the evolution of MS lesions, the authors studied the 4G/5G promoter polymorphism of the plasminogen activator inhibitor 1 (PAI-1) gene in the susceptibility of MS. The 5G5G genotype was associated with MS in women at an odds ratio of 2.3 (95% confidence interval, 1.04 to 5.23). The genotype seems to be a low producer of PAI-1, suggesting that reduced capacity for proteinase inhibition may be involved in the etiopathogenesis of MS in women.

Effects of oxidized low- and high-density lipoproteins on gene expression of human macrophages.

Objective. Oxidized low‐density lipoprotein (ox‐LDL) is a major factor in foam cell formation, whereas the role of oxidized high‐density lipoprotein (ox‐HDL) in this process is not known. The objective of the present study was to examine the effects of ox‐LDL and ox‐HDL on the gene expression of cultured human macrophages. Material and methods. Gene expression of human macrophages was studied after incubation for 1 day and 3 days with native and oxidized LDL and HDL using cDNA expression array. Expression of granulocyte‐macrophage colony‐stimulating factor 1, which was constantly up‐regulated by ox‐LDL and down‐regulated by ox‐HDL after 1‐ and 3 days of incubation in cDNA microarray experiments, was verified by quantitative reverse transcriptase‐polymerase chain reaction (RT‐PCR). Results. Genes that showed altered expression were divided into six groups; 1) lipid metabolism, 2) inflammation, growth and hemostasis, 3) matrix metalloproteinases and tissue inhibitors of matrix metalloproteinases, 4) enzymes, 5) structural and binding proteins and 6) annexins. Conclusions. The microarray method was found to be applicable in analyzing changes in gene expression induced by oxidized lipoproteins in cultured human macrophages. Our results reflect different functional roles of ox‐LDL and ox‐HDL in foam cell formation.

Plasma-soluble CD40 is related to cholesterol metabolism in patients with moderate hypercholesterolemia.

Objectives. CD40 is a marker of immunological activation and is expressed in the atherosclerotic lesions. We studied whether CD40 and cholesterol synthesis pathways are associated with each other. Design. Forty-three subjects were randomly assigned to receive either simvastatin (n = 14), atorvastatin (n = 15), or placebo (n = 14) for eight weeks. Plasma samples were obtained before and at the end of the follow-up. sCD40 levels were measured in duplicate using an enzyme-linked immunosorbent assay. Cholesterol, its precursor lathosterol, the plant sterols campesterol and sitosterol as well as 27-hydroxycholesterol were quantified by gas-liquid chromatography-mass spectrometry. Results. sCD40 was inversely correlated with the lathosterol to cholesterol ratio (r = − 0.47, p = 0.002), an indicator of cholesterol synthesis rate, as well as apolipoprotein A–I (r = − 0.38, p = 0.01) in addition to being directly correlated with 27-hydroxycholesterol (r = 0.40, p = 0.008). In multivariate linear regression analysis these three predictors explained 37% of the total variability of sCD40 levels. Simvastatin or atorvastatin treatment had no significant effect on sCD40 levels. Conclusion. These results indirectly suggest that sCD40 concentrations are related to cellular cholesterol levels. This may be a novel indication for the relationship between immunological processes and cholesterol metabolism.