We report a fast (less than 3 h) and cost-effective melting temperature assay method for the detection of single-nucleotide polymorphisms in the MBL2 gene. The protocol, which is based on the Corbett Rotor Gene real time PCR platform and SYBR Green I chemistry, yielded, in the cohorts studied, sensitive (100%) and specific (100%) PCR amplification without the use of costly fluorophore-labeled probes or post-PCR manipulation. At the end of the PCR, the dissociation protocol included a slow heating from 60 degrees to 95 degrees C in 0.2 degrees C steps, with an 8-s interval between steps. Melting curve profiles were obtained using the dissociation software of the Rotor Gene-3000 apparatus. Samples were analyzed in duplicate and in different PCR runs to test the reproducibility of this technique. No supplementary data handling is required to determine the MBL2 genotype. MBL2 genotyping performed on a cohort of 164 HIV-1-positive Brazilian children and 150 healthy controls, matched for age and sex and ethnic origin, yielded reproducible results confirmed by direct sequencing of the amplicon performed in blind. The three MBL2 variants (Arg52Cys, Gly54Asp, Gly57Glu) were grouped together and called allele 0, while the combination of three wild-type alleles was called allele A. The frequency of the A/A homozygotes was significantly higher among healthy controls (0.68) than in HIV-infected children (0.55; P = 0.0234) and the frequency of MBL2 0/0 homozygotes was higher among HIV-1-infected children than healthy controls (P = 0.0296). The 0 allele was significantly more frequent among the 164 HIV-1-infected children (0.29) than among the 150 healthy controls (0.18; P = 0.0032). Our data confirm the association between the presence of the mutated MBL2 allele (allele 0) and HIV-1 infection in perinatally exposed children. Our results are in agreement with the literature data which indicate that the presence of the allele 0 confers a relative risk of 1.37 for HIV-1 infection through vertical transmission.

Mannose binding lectin (MBL) is a pathogen pattern recognition protein involved in antimicrobial activities. Variation in MBL2 gene has been extensively implicated in differential outcomes of infectious diseases in studies conducted outside Africa, but virtually very little is known on the role of this candidate gene in the African continent. We investigated human genetic variations in MBL2 in a Zimbabwean pediatric population and their putative associations with HIV infection in perinatally exposed children. One hundred and four children aged 7 to 9 years comprising 68 perinatally exposed to HIV (32 who were born infected and 36 who were uninfected) and 36 unexposed controls were recruited. DNA samples were genotyped for MBL2 polymorphisms using PCR-RFLP and sequencing. HIV infected children had markedly variable and significantly lower mean height (p=0.03) and weight (p=0.005) when compared to the uninfected children. Using all samples, frequencies for MBL2 genetic variants for the Zimbabwean population were calculated. Twelve single nucleotide polymorphisms were observed and minor alleles occurred with the following frequencies: -550C>G (G: 0.02), -435G>A (A: 0.08), -428A>C (C: 0.39), -394A>G (A: 0.39), -328AGAGAA ins/del (AGAGAA ins: 0.44), -245G>A (A: 0.05), -221C>G (C: 0.12), -111A>T (T: 0.10), -70C>T (C: 0.46), +4C>T (C: 0.45), novel -595G>A (A: 0.02), and 170G>A (0.24). We found that the MBL2 +4T variant displayed a trend for association with reduced risk of HIV transmission from mother-to-child but the remaining vast majority of the genetic markers did not show a significant association. We conclude (1) the MBL2 gene is highly polymorphic in the Zimbabwean population, and (2) MBL2 genetic variation does not appear to play a major role in influencing the risk of mother-to-child HIV transmission in our study sample. These observations contest the hitherto significant role of this candidate gene for HIV transmission from mother-to-child in non-African populations and thus, further speak to the limits of extrapolating genomic association studies directly to the African populations from studies conducted elsewhere. It is hoped that more OMICS research in a diverse set of African countries can shed further light on the putative role (or the lack thereof ) of this candidate gene in HIV transmission in the continent, a major global health burden in Africa.

BACKGROUND

Malignant B-cell clones are affected by both acquired genetic alterations and by inherited genetic variations changing the inflammatory tumour microenvironment.

METHODS

We investigated 50 inflammatory response gene polymorphisms in 355 B-cell non-Hodgkin's lymphoma (B-NHL) samples encompassing 216 diffuse large B cell lymphoma (DLBCL) and 139 follicular lymphoma (FL) and 307 controls. The effect of single genes and haplotypes were investigated and gene-expression analysis was applied for selected genes. Since interaction between risk genes can have a large impact on phenotype, two-way gene-gene interaction analysis was included.

RESULTS

We found inherited SNPs in genes critical for inflammatory pathways; TLR9, IL4, TAP2, IL2RA, FCGR2A, TNFA, IL10RB, GALNT12, IL12A and IL1B were significantly associated with disease risk and SELE, IL1RN, TNFA, TAP2, MBL2, IL5, CX3CR1, CHI3L1 and IL12A were, associated with overall survival (OS) in specific diagnostic entities of B-NHL. We discovered noteworthy interactions between DLBCL risk alleles on IL10 and IL4RA and FL risk alleles on IL4RA and IL4. In relation to OS, a highly significant interaction was observed in DLBCL for IL4RA (rs1805010) * IL10 (rs1800890) (HR = 0.11 (0.02-0.50)). Finally, we explored the expression of risk genes from the gene-gene interaction analysis in normal B-cell subtypes showing a different expression of IL4RA, IL10, IL10RB genes supporting a pathogenetic effect of these interactions in the germinal center.

CONCLUSIONS

The present findings support the importance of inflammatory genes in B-cell lymphomas. We found association between polymorphic sites in inflammatory response genes and risk as well as outcome in B-NHL and suggest an effect of gene-gene interactions during the stepwise oncogenesis.

OBJECTIVE

To assess the association between single nucleotide polymorphisms (SNPs) of mannose-binding lectin 2 gene (MBL2) (rs1800450, rs1800451 and rs11003125) and protein kinase C-beta 1 gene (PRKC beta 1) (rs3700106, rs2575390) with diabetic macroangiopathy in northern Chinese Han population.

METHODS

The samples have included 318 type 2 diabetes mellitus (T2DM) patients and 448 normoglycemic controls. The five SNPs were determined by a Multiplex SnaPshot method. Biochemical indices such as fasting plasma-glucose, triglyceride and total cholesterol were also measured. Linkage disequilibrium and haplotype analysis were carried out for all samples using Haploview 4.2. Additive model was applied to assess the effect of interaction between SNPs and environment factors on macrovascular complications.

RESULTS

Genotypic frequencies of rs11003125 have differed significantly between the controls and patients with coronary heart disease and peripheral vascular disease (P=0.024 and 0.004, respectively). The allele frequency of rs11003125 was also statistically significant between the two groups (P=0.014 and 0.001, respectively). Compared with patients without macrovascular complications, the allele frequency of rs11003125 was significantly different in patients with peripheral vascular disease (P=0.031). No significant differences were found between the distribution of the genotype frequency and allele frequencies of other variants. Haplotype analysis indicated that, compared with controls and patients without macrovascular complications, individuals with G allele of rs1800450 and C allele of rs11003125 had a higher risk for macrovascular complications.

CONCLUSIONS

The rs11003125 polymorphism located in the promoter region of MBL2 gene is associated with macrovascular complications of T2DM in northern Chinese Han population. G allele of rs1800450 and C allele of rs11003125 may be risk factors for macrovascular complications. There were additive interactive effects for rs11003125 polymorphism (GC+CC) and hypertension, diabetic nephropathy, diabetic neuropathy and diabetic retinopathy on macrovascular complications.

Primer extension reaction (PEXT) is the most widely used approach to genotyping of single nucleotide polymorphisms (SNP). It is based on the high accuracy of nucleotide incorporation by the DNA polymerase. We propose a dual-analyte bio/chemiluminometric method for the simultaneous detection of the PEXT reaction products of the normal and mutant allele in a high sample-throughput format. PCR-amplified DNA fragments that span the SNP of interest are subjected to two PEXT reactions using normal and mutant primers in the presence of digoxigenin-dUTP and biotin-dUTP. Both primers contain a d(A)30 segment at the 5'-end but differ in the final nucleotide at the 3'-end. Under optimized conditions only the primer that is perfectly complementary with the interrogated DNA will be extended by DNA polymerase and lead to a digoxigenin- or biotin-labeled product. The products of the PEXT reactions are mixed, denatured, and captured in microtiter wells through hybridization with immobilized oligo(dT) strands. Detection is performed by adding a mixture of antidigoxigenin-alkaline phosphatase (ALP) conjugate and a streptavidin-aequorin conjugate. The flash-type bioluminescent reaction of aequorin is triggered by the addition of Ca2+. ALP is then measured by adding the appropriate chemiluminogenic substrate. The method was evaluated by genotyping two SNPs of the human mannose-binding lectin gene (MBL2) and one SNP of the cytochrome P450 gene CYP2D6. Patient genotypes showed 100% concordance with direct DNA sequencing data.

OBJECTIVE

To investigate whether the mannose-binding-lectin 2 (MBL2) gene was associated with type 2 diabetes in the populations living the northern part of China.

METHODS

The study involved 318 type 2 diabetic patients and 448 normoglycemic controls. The variances of rs1800450, rs1800451 and rs11003125 were determined by the Multiplex SNaPshot method. Fasting blood-glucose, triglyceride and total cholesterol were also measured. All of these results were analyzed by logistic regression method. Linkage disequilibrium and Haplotype measures were computed in all samples using Haploview.

RESULTS

There seemed no mutation on rs1800451 while the rs1800450 and rs11003125 polymorphism was consistent with Hardy-Weinberg expectations in both the case and the control groups. Genotypes and allele frequencies of rs1800450 as well as rs11003125 were observed (P = 0.006, P = 0.003) and (P = 0.010, P = 0.004), respectively. Data from logistic regression analysis revealed that factors as overweight, abdominal obesity, hypercholesterolemia, GG genotype frequencies of Exon1 rs1800450 polymorphism as well as (GC + CC) genotype frequencies of rs11003125 polymorphism in MBL2 conferred increased risks for type 2 diabetes. Haplotype analyses of the two SNPs (rs1800450, rs11003125) revealed similar effects as compared with the single SNP associations. Only haplotype constructed from GC alleles conferred increased trends for type 2 diabetes (OR = 2.21, 95%CI: 1.47 - 3.33, P = 0.000).

CONCLUSIONS

Our result suggested that the Exon1 rs1800450 polymorphism and promoter region rs11003125 polymorphism in MBL2 gene were both associated with type 2 diabetes in the Chinese population living in the northern areas of China. The G allele of rs1800450 and C allele of rs11003125 might be the risk factors of type 2 diabetes.

OBJECTIVE

Systemic lupus erythematosus (SLE) is a prototypical autoimmune disease characterized by production of autoantibodies. Mannose binding lectin (MBL) is an important element of the innate defense system. t0 he present study was undertaken to determine whether variant alleles in MBL2 gene were associated with disease severity in SLE patients.

METHODS

The MBL alleles [-550, -221, +4, Codon 52, Codon 54 and Codon 57] were studied by PCR- RFLP (restriction fragment length polymorphism) method in 100 SLE patients fulfilling ACR (American College of Rheumatology) criteria along with 100 healthy controls. SLE disease activity was evaluated using SLE Disease Activity Index (SLEDAI) score.

RESULTS

Homozygosity for MBL variant allele (O/O) was observed in 24 per cent of the SLE patients compared to 16 per cent of the normal controls, while no difference was found for heterozygosity (A/O) (37 vs 35%). A significant difference was reported in incidence of double heterozygosity for mutant allele B and D (B/D) among SLE patients as against control group ( p = 0.015). MBL genotypes did not show any association with renal involvement.

CONCLUSIONS

In this study from western India, MBL gene polymorphism showed an influence as a possible risk factor for susceptibility to SLE, but had no direct effect on disease characteristics. Further studies need to be done on a larger number of SLE patients in different regions of the country.

BACKGROUND

Serious infections are common in patients undergoing autologous stem cell transplantation (ASCT) mainly because of the effects of immunosuppression. The innate immune system plays an important role in the defense against different infections. Mannose binding lectin (MBL) is a central molecule of the innate immune system. There are several promoter polymorphisms and structural variants of the MBL2 gene that encodes for this protein. These variants produce low levels of MBL and have been associated with an increased risk for infections.

METHODS

Prospective cohort study. The incidence, severity of infections and mortality in 72 consecutive patients with hematologic diseases who underwent ASCT between February 2006 and June 2008 in a tertiary referral center were analyzed according to their MBL2 genotype. INNO-LiPA MBL2 was used for MBL2 gene amplification and genotyping. Relative risks (RR) (IC95%) as measure of association were calculated. Multivariate analysis was performed using logistic regression.

RESULTS

A statistically significant higher number of fungal infections was found in patients with MBL2 variants causing low MBL levels (21.1%versus1.9%, p=0.016). In this MBL2 variant group infection was more frequently the cause of mortality than in the MBL2 wild-type group (p=0.05). Although not statistically significant, there was a higher incidence of major infections in the MBL2 variant group as well as a higher number of infections caused by gram-positive bacteria.

CONCLUSIONS

Low-producer MBL2 genotypes were associated with an increased number of fungal infections in ASCT patients, which would suggest that MBL has a protective role against such infections. ASCT patients with MBL2 variant genotypes are more likely to die as a result of an infection.

Human mannose-binding lectin (MBL) is encoded by the MBL2 gene and is a key player in innate immunity. However, the mechanism of the transcriptional regulation of MBL2 is largely unknown. The peroxisome proliferator-activated receptors (PPARs) are ligand-activated transcription factors that play an important role in a number of biological responses, including lipid homeostasis, immune function and adipogenesis. In this study, we showed that PPARα and PPARγ up-regulate the expression of human MBL2. Using a luciferase assay, electrophoretic mobility-shift assay and chromatin immunoprecipitation assay, we demonstrated that PPARs regulate the expression of human MBL2 via the peroxisome proliferator responsive element (PPRE). On the other hand, MBL2 mRNA expression was not affected by the PPARα ligand both in vivo in rat liver and in vitro in rat H4IIE hepatoma cells. Thus, there is a species difference in regulation of MBL2 gene expression by PPARs between humans and rodents. We also show that the species differences in response to PPAR could be due in part to sequence-specific differences in the PPRE in the promoter region of MBL2. These results indicate that human, but not rat, MBL2 expression is regulated by PPARs via a PPRE.

OBJECTIVE

To detect the serum level of mannose binding lectin (MBL) and its genovariation in systemic lupus erythematosus (SLE) patients and to investigate the role of MBL in the pathogenesis of SLE.

METHODS

ELISA was used to measure the serum MBL level of 40 SLE patients and 30 healthy blood donors. Tm genotyping method was used for the first timer in China. Primers and specific fluorophore-labelled hybridization probes for the exon 1 and promoter regions of MBL gene were designed based on the haplotype MBL2(*) LXPA (GenBank X15422). The genotyping of MBL in these two groups were performed using real-time PCR through Light Cycler Instrument.

RESULTS

(1) The serum MBL of the SLE patients was 107.2 microg/L, significantly lower than that of the healthy blood donors (290.2 microg/L, P = 0.0002). (2) MBL mutation in exon 1 region was mainly at codon 54, with a mutation rate of 37.1% in the SLE group, significantly higher than that of the control group (13.3%, p = 0.049). (3) Polymorphisms of H/L in MBL gene were present in both SLE patients and controls, and there was no difference in the L allele frequency between the two groups. (4) The serum MBL level of the SLE patients with MBL mutation in codon 54 was 49.8 microg/L, significantly lower than that of the SLE patients without MBL mutation in codon 54 (141.7 microg/L, P = 0.000 27). The SLE disease activity index (SLEDAI) of the SLE patients with MBL mutation in codon 54 was 7.44, significantly lower than that of the SLE patients without MBL mutation in codon 54 (12.87, P = 0.0029). A negative correlation was observed between SLEDAI score and serum MBL (r = -0.48).

CONCLUSIONS

Mutation occurring in MBL exon 1 region at codon 54 may be a predisposing factor of the pathogenesis of SLE. Serum MBL may be a potential biomarker of disease activity in SLE patients.

Mannose-binding lectin (MBL) is a protein critical in activating complement. Patients with wild-type and variant mbl2 genotypes have high or low concentrations of MBL protein, which is known to increase susceptibility to transplant rejection or infection, respectively. Our objective was to determine mbl2 genotype frequencies in future solid organ transplant recipients in order to optimize their induction and maintenance immunosuppressive therapies, and to provide MBL reference data for this unique population. We genotyped 1687 patients, and concurrently measured protein in 807 of them, during 2010-2011. Frequencies of the structural allele SNPs in our population were similar to those of other studied populations; however, Black patients with the same intermediate and deficient mbl2 genotypes as Caucasians produced significantly lower levels of MBL protein; therefore, within this population more genotypes should be considered MBL-deficient. Overall, the most critical parameter in determining serum MBL protein concentration was genotype, which was independent of other factors including ethnicity, gender, or diseased native organ type.

Progressive visceral leishmaniasis (VL) is fatal if not treated; yet, most infections with the causative agents are asymptomatic. We hypothesized that genetic factors contribute to this variable response to infection. The mannose-binding lectin 2 gene (MBL2) is a candidate that merits examination in the context of VL because it enhances infection with intracellular pathogens. Four functional MBL2 polymorphisms at codons 52, 54, 57 and in the promoter at the -221 position (X/Y) are known to be associated with the outcome of several diseases. The aim of the present study was to investigate whether these functional variants were associated with VL in Moroccan children. Here, we genotyped polymorphisms by sequencing and PCR-RFLP in 112 individuals with VL, 97 asymptomatic subjects and 42 healthy individuals who had no evidence of present or past infection. Regression analysis showed no significant association between polymorphisms in exon 1 genotypes and outcome of infection with Leishmania infantum. However, the genotype XY in -221 conferred a protective role against VL in our study population with a significant difference (OR=0.291; CI [0.158-0.538]; p=0.0006). Subjects with YY genotypes in -221 had a higher risk to developing VL. We concluded that MBL2 polymorphism at the -221 promoter region plays a protective role in L. infantum infection.

Severe asthma is problematic and its pathogenesis poorly understood. Fungal sensitization is common, and many patients with severe asthma with fungal sensitization (SAFS), used to denote this subgroup of asthma, respond to antifungal therapy. We have investigated 325 haplotype-tagging SNPs in 22 candidate genes previously associated with aspergillosis in patients with SAFS, with comparisons in atopic asthmatics and healthy control patients, of whom 47 SAFS, 279 healthy and 152 atopic asthmatic subjects were genotyped successfully. Significant associations with SAFS compared with atopic asthma included Toll-like receptor 3 (TLR3) (p = .009), TLR9 (p = .025), C-type lectin domain family seven member A (dectin-1) (p = .043), interleukin-10 (IL-10) (p = .0010), mannose-binding lectin (MBL2) (p = .007), CC-chemokine ligand 2 (CCL2) (2 SNPs, p = .025 and .041), CCL17 (p = .002), plasminogen (p = .049) and adenosine A2a receptor (p = .024). These associations differ from those found in ABPA in asthma, indicative of contrasting disease processes. Additional and broader genetic association studies in SAFS, combined with experimental work, are likely to contribute to our understanding of different phenotypes of problematic asthma.

MicroRNAs (miRNAs), a subgroup of small noncoding RNAs, play critical roles in tumor growth and metastasis. Accumulating evidence shows that the dysregulation of miRNAs is associated with the progression of hepatocellular carcinoma (HCC). However, the molecular mechanism by which miR-942-3p contributes to HCC remains undocumented. The association between miR-942-3p expression and the clinicopathological characteristics in HCC patients was analyzed by The Cancer Genome Atlas data set. The targets of miR-942-3p were identified by bioinformatic analysis and dual luciferase report assay. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and Transwell assays were performed to assess the functional role of miR-942-3p in HCC cells. Consequently, we found that miR-942-3p expression level was elevated in HCC tissues and cell lines as compared with the normal tissues and was associated with the pathological stage and tumor node metastasis (TNM) stage, acting as an independent prognostic factor of poor survival in patients with HCC. Ectopic expression of miR-942-3p enhanced the proliferation and invasive potential of HCC cells, but inhibition of miR-942-3p expression had the opposite effects. Mannose-binding lectin 2 (MBL2) was further identified as a direct target of miR-942-3p and possessed a negative correlation with miR-942-3p expression and unfavorable survival in patients with HCC. Restoration of MBL2 inhibited the progression of HCC cells and attenuated the tumor-promoting effects induced by miR-942-3p. In conclusion, miR-942-3p may act as an oncogenic factor in HCC cells by targeting MBL2 and provide a potential marker for patients with HCC.

BACKGROUND

Preterm premature rupture of membranes (PPROM) is the leading identifiable cause of preterm birth, a complication that is more common in African Americans. Attempts to identify genetic loci associated with preterm birth using genome-wide association studies (GWAS) have only been successful with large numbers of cases and controls, and there has yet to be a convincing genetic association to explain racial/ethnic disparities. Indeed, the search for ancestry-specific variants associated with preterm birth has led to the conclusion that spontaneous preterm birth could be the consequence of multiple rare variants. The hypothesis that preterm birth is due to rare genetic variants that would go undetected in standard GWAS has been explored in the present study. The detection and validation of these rare variants present challenges because of the low allele frequency. However, some success in the identification of fetal loci/genes associated with preterm birth using whole genome sequencing and whole exome sequencing (WES) has recently been reported. While encouraging, this is currently an expensive technology, and methods to leverage the sequencing data to quickly identify and cost-effectively validate variants are needed.

METHODS

We developed a WES data analysis strategy based on neonatal genomic DNA from PPROM cases and term controls that was unencumbered by preselection of candidate genes, and capable of identifying variants in African Americans worthy of focused evaluation to establish statistically significant associations.

RESULTS

We describe this approach and the identification of damaging nonsense variants of African ancestry in the DEFB1 and MBL2 genes that encode anti-microbial proteins that presumably defend the fetal membranes from infectious agents. Our approach also enabled us to rule out a likely contribution of a predicted damaging nonsense variant in the METTL7B gene.

CONCLUSIONS

Our findings support the notion that multiple rare population-specific variants in the fetal genome contribute to preterm birth associated with PPROM.

A purification protocol that comprised ion exchange chromatography on DEAE-cellulose, affinity chromatography on Affi-gel blue gel, ion exchange chromatography on SP-Sepharose, and gel filtration by FPLC on Superdex 75 was complied to isolate two trypsin inhibitors from Phaseolus vulgaris cv "White Cloud Bean". Both trypsin inhibitors exhibited a molecular mass of 16 kDa and reduced the activity of trypsin with an IC(50) value of about 0.6 microM. Dithiothreitol attenuated the trypsin inhibitory activity, signifying that an intact disulfide bond is indispensable to the activity. [Methyl-(3)H] thymidine incorporation by leukemia L1210 cells was inhibited with an IC(50) value of 28.8 microM and 21.5 microM, respectively. They were lacking in activity toward lymphoma MBL2 cells and inhibitory effect on HIV-1 reverse transcriptase and fungal growth when tested up to 100 microM.

BACKGROUND

Mannose-binding lectin (MBL) and toll-like receptors (TLRs) are important components of the innate immune system. We assessed the susceptibility of children with genetic variants in these factors to respiratory infections, rhinovirus infections and acute otitis media.

METHODS

In a prospective cohort study, blood samples from 381 Finnish children were analyzed for polymorphisms in MBL2 at codons 52, 54 and 57, TLR2 Arg753Gln, TLR3 Leu412Phe, TLR4 Asp299Gly, TLR7 Gln11Leu and TLR8 Leu651Leu. Children were followed up for respiratory infections until 24 months of age with daily diaries. Polymerase chain reaction and antigen tests were used for detection of respiratory viruses from nasal swabs.

RESULTS

Children with MBL variant genotype had a mean of 59 days with symptoms of respiratory infection per year, compared with 49 days in those with wild-type (P = 0.01). TLR8 polymorphisms were associated with an increased risk and TLR7 polymorphisms with a decreased risk of recurrent rhinovirus infections (P = 0.02 for both). TLR2 polymorphisms were associated with recurrent acute otitis media (P = 0.02). MBL polymorphisms were associated with an increased and TLR7 polymorphisms with a decreased risk of rhinovirus-associated acute otitis media (P = 0.03 and P = 0.006, respectively).

CONCLUSIONS

Genetic polymorphisms in MBL and TLRs promote susceptibility to or protection against respiratory infections. In addition to environmental factors, genetic variations may explain why some children are more prone to respiratory infections.

Complement is activated during Shiga toxin-producing Escherichia coli-associated hemolytic uremic syndrome (STEC-HUS). There is evidence of complement activation via the alternative pathway in STEC-HUS patients as well as from in vivo and in vitro models. Ozaki et al. demonstrate activation of the mannose-binding lectin (MBL) pathway in Shiga toxin-treated mice expressing human MBL2, but lacking murine Mbls. Treatment with anti-human MBL2 antibody was protective, suggesting that MBL pathway activation also contributes to Shiga toxin-mediated renal injury.

Immature immune system in neonates is considered a risk factor for neonatal infections and sepsis. Mannose-binding lectin (MBL) is one of the innate immune system components that could recognize a wide variety of pathogens and initiate an immune response against them. Objectives of this study were to assess the correlation between serum level of MBL and MBL2 gene polymorphism and incidence of neonatal sepsis. Isolation of bacteria from neonatal blood culture was carried out by conventional methods then, serum level of MBL was measured by ELISA and MBL2 gene polymorphism was determined by PCR-RFLP. Out of 50 neonates with sepsis enrolled in this study, 44 (88%) neonates had MBL deficiency and 6 (12%) had normal serum level with a very high statistically significant difference (P=0.00001). Genotype BB was more frequent in neonatal sepsis (56%) followed by genotype AB (32%) then genotype AA (12%) and it was more prevalent in preterm (63.2%) than in full term (33.3%) with a high statistically significant difference (P=0.001). Patients with BB genotype had the lowest MBL level in serum compared to other genotypes with a very high significant difference (P=0.001). In conclusion, low serum level of MBL and genotype BB might be significantly associated with development of sepsis among neonates.

Oral Lichen Planus (OLP) is an oral inflammatory condition, mediated by host immune system reaction, presenting basal membrane damages with inflammatory lesions in the mouth and/or skin. In this study, the role of functional polymorphisms in the MBL2 gene, encoding for Mannose-Binding Protein C (MBP-C), a member of the innate immune response and an acute-phase protein able to activate the complement cascade, was investigated to assess a possible association with OLP susceptibility in Italian patients. Two variations at the promoter region (called H/L and X/Y) and three at the first exon (at codon 52, 54, and 57) of the MBL2 gene were analyzed in 69 OLP patients and 244 healthy controls from northeastern Italy. Considering the polymorphisms singularly, the MBL2 X allele and C/T genotype of the D allele (correlated with low MBP-C expression) were associated with susceptibility to develop OLP. Moreover, when taking into account MBL2 combined genotypes, more OLP patients were deficient MBP-C producers than not deficient, who were more represented among healthy controls. MBL2 combined genotypes, responsible for deficient MBP-C production, are associated with an increased risk of developing OLP.