Association of the IL-10 receptor A536G (S138G) loss-of-function variant with multiple sclerosis in Tunisian patients.

Interleukin-10 (IL-10), a potent anti-inflammatory T-cell cytokine, has been shown to be a regulatory cytokine that is associated with disease remission in multiple sclerosis (MS) and exerts its activity through its cognate cell surface receptor complex, IL-10 receptor 1 (IL-10R1) and IL-10R2. The purpose of this study was to investigate the IL-10R1 S138G loss-of-function polymorphism (A536G: rs3135932) for possible influence on susceptibility and outcome of MS in Tunisian patients. A total of 103 Tunisian MS patients and 160 control subjects were studied. Genomic DNA samples were extracted from leukocytes and used to investigate S138G polymorphism in IL-10R1 gene by multiplex allele-specific polymerase chain reaction. Associations between G allele [odds ratio (OR) = 5.57; 95% confidence intervals (CI) = 3.26-9.54; p = 10-7 ], GG genotypes [OR = 10.41; 95% CI = 2.28-47.58; p = 0.0007] and AG genotype [OR = 4.14; 95% CI = 2.16-7.93; p = 0.000016] with the risk development of MS were found. In contrast, the AA genotype seemed to be associated with protection against MS [OR = 0.17; 95% CI = 0.09-0.30; p = 10-7 ]. No association was found between S138G SNP and clinical features or disease activity of MS patients. In conclusion, our results suggest that S138G loss-of-function polymorphism of the IL-10R1 may be important risk factor in increasing susceptibility to MS.

Cytokine and cellular responses to human herpesvirus-6B in patients with B-acute lymphoblastic leukemia.

Primary infection with human herpesvirus-6 (HHV-6), is followed by its lifelong persistence in the host. Most T-cell responses to HHV-6 have been characterized using peripheral blood from healthy adults; however, the role of HHV-6 infection in immune modulation has not been elucidated for some diseases. Therefore, in this study the immune response to HHV-6 infection in patients with B-acute lymphoblastic leukemia (B-ALL) was analyzed. HHV-6 load was quantified in blood samples taken at the time of diagnosis of leukemia and on remission. The same concentrations of anti- and pro-inflammatory cytokines (IL-4, IL-1, IL-6, IL-8, IL-12p70, IL-17a, TNF-α and IFN-γ) were detected in plasma samples from 20 patients with and 20 without detectable HHV-6 virus loads in blood. Characterization of T-cell responses to HHV-6 showed low specific T-cells frequencies of 2.08% and 1.46% in patients with and without detectable viral loads, respectively. IFN-γ-producing T cells were detected in 0.03%-0.23% and in 0%-0.2% of CD4+T cells, respectively. Strong production of IL-6 was detected in medium supernatants of challenged T-cells whatever the HHV-6 status of the patients (973.51 ± 210.06 versus 825.70 ± 210.81 pg/mL). However, concentrations of TNF-α and IFN-γ were low. Thus, no association between plasma concentrations of cytokines and detection of HHV-6 in blood was identified, suggesting that HHV-6 is not strongly associated with development of B-ALL. The low viral loads detected may correspond with latently infected cells. Alternatively, HHV-6B specific immune responses may be below the detection threshold of the assays used.

Glucomannan's protective effect on the virulence of Vibrio splendidus in pacific oyster.

We examine the effect of Glucomannan, extracted from Candida utilis yeast, on immune parameters and resistance to Vibrio splendidus of Crassostreagigas. Our results showed that Glucomannan was a successful anti-adhesive molecule; it exhibited a stronger inhibitory effect on adhesion of Vibrio splendidus in infected Crassostreagigas. Vibrio splendidus viable cells number declined after incubation with Glucomannan. Furthermore, the Glucomannan diet showed higher activity to trigger the immune response against bacteria. Glucomannan applications, in biological control of seafood associated pathogens can be an alternative solution, providing consumer with a product of good quality owing to the use of 40 non-toxic compounds. Based on our results, Glucomannan could be used as a bio-protective culture in oyster's depuration to prevent Vibrio splendidus growth.

Quantitative analysis of human herpesvirus-6 and human cytomegalovirus in blood and saliva from patients with acute leukemia.

Human herpesvirus-6 (HHV-6) and human cytomegalovirus (HCMV) DNAs were quantified by real-time PCR assays in blood and saliva obtained from 50 patients with acute leukemia at the time of diagnosis (50 of each matrix), aplasia (65 of each matrix), remission (55 of each matrix), and relapse (20 of each matrix) to evaluate which biological matrix was more suitable to identify a viral reactivation, search for a possible link between HHV-6 and HCMV reactivations, and evaluate the relations between viral loads and count of different leukocyte types in blood. The median HHV-6 loads were 136; 219; 226, and 75 copies/million cells in blood at diagnosis, aplasia, remission and relapse, respectively. The HCMV loads were 193 and 317 copies/million cells in blood at diagnosis and remission. In the saliva samples, the HHV-6 loads were 22,165; 15,238; 30,214, and 17,454 copies/million cells at diagnosis, aplasia, remission, and relapse, respectively. The HCMV loads were 8,991; 1,461; 2,980, and 4,283 copies/million cells at diagnosis, aplasia, remission, and relapse, respectively. The HHV-6 load in the blood was correlated to the counts of polymorphonuclear leukocytes (R(2) = 0.5; P < 0.0001) and lymphocytes (R(2) = 0.4; P = 0.001) and was not correlated to the monocyte counts (R(2) = 0.07; P = 0.7). Saliva appears to be a more sensitive biological matrix than whole blood in the detection of HHV-6 or HCMV reactivations. The HHV-6 and HCMV reactivations were linked only in saliva.

Evaluation of the implication of KIR2DL2 receptor in multiple sclerosis and herpesvirus susceptibility.

To evaluate the possible effect of cell immunoglobulin-like receptors (KIRs) on viral infection in multiple sclerosis (MS) patients, we performed genotyping of KIR2DL2 and his HLA-C1 ligand and we analyzed the presence of all eight human herpesviruses (HHVs) in 60 MS patients and 112 healthy controls. Significantly higher frequencies were found for KIR2DL2 enhanced in the presence of its ligand HLA-C1 in MS patients. Moreover, a significant association was observed between an increase in HHV risk of infection in KIR2DL2 and HLA-C1 positive patient. Our results confirm a possible effect of KIR2DL2 on viral infection susceptibility in MS patients.

Prevalence of human herpesvirus U94/REP antibodies and DNA in Tunisian multiple sclerosis patients.

Human herpesvirus 6 (HHV-6) has been linked to the pathogenesis of multiple sclerosis (MS). Based on antibody detection and quantitative HHV-6 polymerase chain reaction assay, this study aimed to analyze the possible association between infection with HHV-6 and MS. A total of 131 serum samples were analyzed by ELISA for the presence of specific antibodies to HHV-6 latency-associated U94/REP protein: 68 serum samples from 60 MS patients (20 in relapse and 48 in remission phase) and 63 serum samples from 63 healthy controls. Real-time quantitative PCR for HHV-6 U94/rep DNA was also performed in total blood of MS patients and healthy controls. The serological analysis by ELISA showed that MS patients had increased prevalence and titers of anti-U94/REP immunoglobulins in comparison with control group (seroprevalence 51.47 % versus 28.57 % and mean titer of positive samples 1:248 versus 1:110; p=0.0005), with significant difference between relapse and remission phases. HHV-6 DNA was detected in 4 of 60 MS patients (6.66 %) and in 2 of 63 healthy controls (3.17 %), confirming previous data of prevalence obtained by qualitative nested PCR. However, viral load was higher in MS patients compared to controls, and differences were statistically significant (p=0.02). The results show that, in spite of the low presence of HHV-6 DNA in peripheral blood, MS patients have increased prevalence and titer of IgGs reacting with HHV-6 latency-associated U94/REP protein.

Identification of human herpesviruses 1 to 8 in Tunisian multiple sclerosis patients and healthy blood donors.

Members of the human Herpesviridae family are candidates for representing the macroenvironmental factors associated with multiple sclerosis (MS) pathogenesis. To verify the possible role of human herpesviruses (HHVs) as triggering or aggravating factors in relapsing-remitting multiple sclerosis clinical outcome, we studied the prevalence of all eight human herpesviruses in whole blood samples collected from 51 MS patients and from 51 healthy controls. The presence of DNA of herpes simplex virus type 1 (HSV-1) and type 2 (HSV-2), varicella zoster virus (VZV), Epstein-Barr virus (EBV), human cytomegalovirus (HCMV), human herpesvirus 6 (HHV-6), human herpesvirus 7 (HHV-7) and human herpesvirus 8 (HHV-8) was searched by specific nested polymerase chain reaction. HHVs were significantly more prevalent in the blood of MS patients than in those of the controls (P < 10(-4)). HSV-1, HSV-2, HCMV and HHV-8 were negative in both MS patients and controls samples. In MS patients, EBV, HHV-7, HHV-6 and VZV were detected in 31.3%, 33.3%, 5.8% and 7.8% of samples, respectively, compared with 3.9%, 9.8%, 1.96% and 1.96%, respectively, of samples from controls. We found a statistically significant difference only for EBV DNA and for HHV-7 DNA prevalence (P < 0.001 and P = 0.03). Although these results indicate lack of apparent association in terms of gender, type of diagnosis, symptoms, disease score and ß interferon treatment between EBV or HHV-7 to MS among Tunisian patients, heterogeneity related to genetic polymorphism as well as geographical distribution of the disease and of pathogens may be of significance.