Effects of 1α,25 Dihydroxyvitamin D3 on Pro-inflammatory Cytokines of Palmitic Acid Treated Thp-1 Cells

The level of saturated fatty acids, such as palmitic acid (PA), correlates with chronic inflammation in obese and metabolic syndrome patients. However, low level of vitamin D₃ is observed in those conditions. The aim of this study is to investigate effects of 1α,25(OH)₂ D₃ on PA-treated THP-1 cells. Using quantitative real-time polymerase chain reaction, we measure mRNA expression of pro-inflammatory cytokines: TNF-α, Interleukin (IL)-1β, IL-6, and chemokine IL-8 under PA and 1α,25(OH)₂ D₃ influence. PA, at all concentrations (25-100 μM), enhanced LPS stimulatory effect on those mRNA expression compared to LPS-treated and -untreated cells. Combination with 1α,25(OH)₂ D₃ increased cytokine expression at high (10^-6 M) and high-normal (10^-8 M) concentrations compared to PA + LPS and LPS alone, both for 2 and 24 h. However, low-normal (10^-10 M) and low (10^-12 M) levels of 1α,25(OH)₂ D₃ could not enhance PA effect, but mRNA expression of pro-inflammatory cytokine was higher than LPS-treated cells. Upstream pathway of 1α,25(OH)₂ D₃ , which is cholecalciferol, also gave the similar result. Further, inhibition of calcium pathway does not play a role in this mechanism. Thus, these findings support pro-inflammatory effect of PA and vitamin D₃ on innate immune response, especially on fat-induced inflammation.

PRACTICAL APPLICATION

The effect of vitamin D₃ on chronic inflammation in obesity is uncertain. This study shows an in vitro possibility that vitamin D₃ could exaggerate inflammation when combined with high SFAs. The idea of using vitamin D₃ supplement to modulate inflammation in fat-related inflammation needs further refined experiments before its clinical application.

HLA-DRB1 and HLA-DQB1 Are Associated with Adult-Onset Immunodeficiency with Acquired Anti-Interferon-Gamma Autoantibodies

Recently a newly identified clinical syndrome of disseminated non-tuberculous mycobacterial diseases (with or without other opportunistic infections in adult patients who were previously healthy, has been recognized in association with an acquired autoantibody to interferon-gamma. This syndrome is emerging as an important cause of morbidity and mortality, especially among people of Asian descent. Trigger for the production of this autoantibody remains unknown, but genetic factors are strongly suspected to be involved. We compared HLA genotyping between 32 patients with this clinical syndrome, and 38 controls. We found that this clinical syndrome was associated with very limited allele polymorphism, with HLA-DRB1 and DQB1 alleles, especially HLA-DRB1*15:01, DRB1*16:02, DQB1*05:01 and DQB1*05:02. Odds ratio of DRB1*15:01, DRB1*16:02, DQB1*05:01 and DQB1*05:02 were 7.03 (95% CI, 2.18–22.69, P<0.0001, 9.06 (95% CI, 2.79–29.46, P<0.0001), 6.68 (95% CI, 2.29–19.52, P = 0.0004), and 6.64 (95% CI, 2.30–19.20, P = 0.0004), respectively. Further investigation is warranted to provide better understanding on pathogenesis of this association.

Cryptococcal osteomyelitis in a child with a novel compound mutation of the IL12RB1 gene

The IL-12p40/IL-12Rbeta1 and IFN-gammaR1/IFN-gammaR2/STAT1 signaling pathways are important for clearing intracellular bacteria. Genetic defects within these pathways are associated with increased susceptibility to intracellular pathogens. Among these, IL-12Rbeta1 deficiency is the most common defect and leads to infections with Salmonella and Mycobacterium spp. We report a child who presented with Cryptococcal osteomyelitis and history of disseminated Mycobacterial infection and recurrent Salmonella septicemia. Flow cytometry showed defective expression of IL-12Rbeta1. Mutation analysis revealed a novel compound heterozygous mutation of IL12RB1, c.625C>T, p.Q209X was found in exon 7 on the paternal allele and c.710delC, p.P237HfsX5 was found in exon 8 on the maternal allele. As these mutations each result in a stop codon before the last spliceable exon, the transcripts likely underwent nonsense mediated decay, leading to a lack of IL12Rbeta1 expression on the cell surface and eradicating signaling via the IL12 signaling pathway.

The immunogenicity and safety of pneumococcal conjugate vaccine in human immunodeficiency virus-infected Thai children

BACKGROUND

HIV-infected children have high risk of invasive pneumococcal disease (IPD) despite receiving highly active antiretroviral therapy (HAART). This study aimed to determine the immunogenicity and safety of a 7-valent pneumococcal conjugate vaccine (PCV-7) in Thai HIV-infected children compared to HIV-exposed uninfected children.

METHODS

A prospective study was conducted among children 2 months to 9 years. The number of PCV-7 doses depended upon age and HIV status; 2-6 months of age: 3 doses; 7-23 months of age: 2 doses; HIV-infected child ≥24 months: 2 doses and HIV-exposed child ≥24 months: 1 dose. Serotype-specific pneumococcal IgG antibody concentrations were measured at baseline and 28 days after complete vaccination. The primary end point was the proportion of children who achieved serotype-specific IgG antibody concentration at a cut off level ≥0.35 μg/mL. Secondary end points were a 4-fold increase in serotype-specific IgG antibody, rates of adverse events and predictors for seroconversion among HIV-infected children.

RESULTS

Fifty-nine HIV-infected and 30 HIV-exposed children were enrolled. The median (IQR) age was 97 (67-111) and 61 months (51-73), respectively (p<0.001). Among HIV-infected children, current and nadir CD4 counts were 1,079 cell/mm(3) and 461 cell/mm(3), respectively. The proportion of children who achieved pneumococcal IgG ≥0.35 μg/mL was in the range of 85-98% in HIV-infected and 83-100% in HIV-exposed children depending on serotype. The lowest response was to serotype 6B in both groups. The 4-fold increase in serotype-specific IgG concentrations was similar between HIV-infected and HIV-exposed groups, except for serotype 9V (p=0.027). HIV-infected children who had a history of AIDS had a lower antibody response to serotype 23F (p=0.025). Seven (12%) HIV-infected children had a grade 3 local reaction.

CONCLUSION

PCV-7 is highly immunogenic and safe among HIV-infected children treated with HAART. The use of the pneumococcal conjugate vaccine among HIV-infected children is encouraged in order to prevent IPD.

A novel mutation of the IL12RB1 gene in a child with nocardiosis, recurrent salmonellosis and neurofibromatosis type I: first case report from Thailand

Genetic defects of interleukin (IL)-12/23-and interferon (IFN)-gamma-mediated immunity can cause increased susceptibility to intracellular microbes. Among these defects, a mutation of the gene encoding the IL-12 receptor beta1 (IL-12Rbeta1) is the most common worldwide. A 12-year old Thai boy with pre-existing neurofibromatosis type 1 (NF1) was evaluated for primary immunodeficiency after a history of tuberculous lymphadenitis, recurrent Salmonella infections and nocardiosis. Flow cytometry of phytohemagglutinin (PHA)-stimulated peripheral blood mononuclear cells (PBMCs) revealed a defect in the IL-12Rbeta1 surface expression. A genetic study showed a novel nonsense homozygous mutation of the IL12RB1 gene in exon 4 (402C > A), confirming the diagnosis of IL-12Rbeta1 deficiency. This is the first case report of a primary IL-12Rbeta1 deficiency in Thailand with the interesting finding of a coexisting NF1.

Association between ADAM33 polymorphisms and asthma in a Thai population

ADAM33 (A Disintegrin And Metalloprotease 33) is an asthma susceptibility gene found across several human populations. However, no information on ADAM33 exists for Thai population. The objective of this study was to determine the association, if any, between ADAM33 polymorphisms and asthma in Thai subjects. Genotyping revealed 8 single nucleotide polymorphisms (SNPs) within the 3' region of the ADAM33 gene among 200 asthmatics and 100 control subjects. Asthmatic subjects were further sub-categorized into high and low severity groups. Multiple genetic model statistic tests for single-marker and haplotype association were carried out. Differences in allele frequencies at the SNPs rs528557/S2, rs598418 and rs44707/ST+4 in asthmatics were statistically significant compared to controls. The SNP rs528557/S2 could also be linked to the low severity group and the SNPs rs598418 and rs44707/ST+4 with the high severity group. Two-SNP haplotype analysis at the SNPs rs528557/S2 and rs598418 revealed a significant association with asthma. This study in a Thai population confirmed a positive association between ADAM33 polymorphisms and asthma susceptibility.

A novel mutation of the CYBB gene resulting in severe form of X-linked chronic granulomatous disease

We evaluated a boy who had multiple Salmonella septicemia, Aspergillus pneumonia and brain abscesses. His nitroblue tetrazolium (NBT) test was reportedly abnormal. The dihydrorhodamine (DHR) flow cytometry assay was compatible with typical X-linked chronic granulomatous disease (X-CGD). CYBB analysis revealed a novel complex mutation atggacg --> ttca in exon 12 (base pairs 1532-1538). As a result, 3 amino acids Tyr 511, Gly 512 and Arg 513 were deleted and replaced by 2 amino acids, Phe and Gln. The DHR and mutation analysis of his mother showed normal DHR pattern and no mutations in exon 12 of CYBB gene. In conclusion, any children with multiple Salmonella and Aspergillus infection should be suspected of CGD. NBT test, DHR assay and gene analysis are helpful toolsto confirm the diagnosis e v en i n the case of de novo mutation.

Chronic diarrhea and abnormal serum immunoglobulin levels: a case report

A 15-year-old Thai boy with multiple episodes of chronic diarrhea caused by giardiasis with hypogammaglobulin M and IgG4 subclass deficiency (but normal antibody response to rabies vaccine) is reported. Immune status follow-up is necessary for a definite diagnosis and proper management.

Recurrent Campylobacter lari bacteremia in X-linked agammaglobulinemia: a case report and review

X-linked agammaglobulinemia (XLA) is a primary immune deficiency disease with a B-cell defect. We present the first XLA patient who had recurrent Campylobacter lari bacteremia. High dose intravenous immunoglobulin combined with azithromycin once per week, and a complete avoidance of bacterial reservoirs may be helpful for the prevention of C. lari bacteremia.

The phosphorylation of phospholipase C-gamma1, Raf-1, MEK, and ERK1/2 induced by a conserved retroviral peptide

A synthetic 17-amino acid peptide (CKS-17) homologous to a highly conserved region of human and animal retroviral transmembrane proteins has been found to exhibit suppressive properties for numerous immune functions. It has been shown that CKS-17 causes an imbalance of human types 1 and 2 cytokines and inhibition of the immune responses of lymphocytes, monocytes, and macrophages. CKS-17 induced increased intracellular levels of cAMP, which plays an important role in regulation of cytokine biosynthesis. In this study, using a Jurkat T-cell line and Western blot analysis, CKS-17 induced phosphorylation of PLC-gamma1, Raf-1, MEK and ERK1/2. Using a PLC selective inhibitor U73122 or PLC-gamma1-deficient Jurkat cell line, phosphorylation induced by CKS-17 of ERK1/2, PLC-gamma1, or Raf-1, respectively, were undetectable or significantly reduced. Reintroduction of PLC-gamma1 into the PLC-gamma1-deficient Jurkat cells restored the phosphorylation of ERK1/2 and PLC-gamma1 induced by CKS-17. Further, pretreatment of Jurkat cells with PKC inhibitors blocks the phosphorylation of Raf-1, MEK, and ERK1/2 induced by CKS-17. These results indicate that CKS-17 induces the PLC-gamma1-PKC-Raf-1-MEK-ERK1/2 signaling pathway.

Chronic rhinosinusitis and recurrent nasal polyps in two children with IgG subclass deficiency and review of the literature

Chronic rhinosinusitis (CRS) is a chronic inflammatory disorder of mucosa of the nose and the paranasal sinuses. Two major forms of CRS can be differentiated; CRS with nasal polyps (CRSwNP) and CRS without nasal polyps (CRSsNP). The pathophysiology and etiology of nasal polyps (NPs) are partly understood. IgG subclass deficiency was shown to be associated with an increased susceptibility to infections. However the association between NPs and IgG subclass deficiency has never been reported.

OBJECTIVES

To report two cases of recalcitrant CRS and recurrent NPs with IgG subclass deficiency.

CASE REPORT

Two children (6 and 8 year-old boys) were referred to the Pediatric Allergy/Immunology Clinic, Siriraj Hospital due to a prolonged history of CRS and recurrent NPs. Both of them were treated with aggressive medical (topical and systemic corticosteroids, antibiotics, leukotriene antagonist, nasal irrigation) as well as surgical therapy, without significant improvement. Immunologic investigation in both patients showed that IgG, IgA, and IgM level were normal. IgG subclasses level in patient No. 1 were IgG1 1,235 (280-1120) mg/dl (79%), IgG2 235 (30-630) mg/dl (23.5%), IgG3 27.3 (40-250) mg/dl (1.74%), and IgG4 92.4 (11-620) mg/dl (5.9%). IgG subclasses level in patient No. 2 were IgG1 1,139 (280-1120) mg/dl (82.5%), IgG2 170 (30-630) mg/dl (12.3%), IgG3 5.6 (40-250) mg/dl (0.4%), IgG4 65.7 (11-620) mg/dl (4.8%). The diagnosis of CRS and recurrent NPs with IgG3 subclass deficiency in the first patient and IgG2/IgG3 subclass deficiency in the second patient were made. Patient No. 1 was given monthly IVIG therapy for the total of 7 courses and medications were gradually tapered. Currently, the patient is doing well after the cessation of IVIG therapy for 3 months. Patient No. 2 denied the IVIG treatment and was lost to follow up.

CONCLUSION

We reported two cases of recalcitrant CRS and recurrent NPs in children. Immunologic work up revealed IgG subclass deficiency. The treatment with monthly IVIG improved CRS and NPs in treated patient which brought up the possibility of association between NPs and IgG subclass deficiency. Further study on the direct role of IVIG in NPs will be needed in the future.

A retroviral-derived peptide phosphorylates protein kinase D/protein kinase Cmu involving phospholipase C and protein kinase C

CKS-17, a synthetic peptide representing a unique amino acid motif which is highly conserved in retroviral transmembrane proteins and other immunoregulatory proteins, induces selective immunomodulatory functions, both in vitro and in vivo, and activates intracellular signaling molecules such as cAMP and extracellular signal-regulated kinases. In the present study, using Jurkat T-cells, we report that CKS-17 phosphorylates protein kinase D (PKD)/protein kinase C (PKC) mu. Total cell extracts from CKS-17-stimulated Jurkat cells were immunoblotted with an anti-phospho-PKCmu antibody. The results show that CKS-17 significantly phosphorylates PKD/PKCmu in a dose- and time-dependent manner. Treatment of cells with the PKC inhibitors GF 109203X and Ro 31-8220, which do not act directly on PKD/PKCmu, attenuates CKS-17-induced phosphorylation of PKD/PKCmu. In contrast, the selective protein kinase A inhibitor H-89 does not reverse the action of CKS-17. Furthermore, a phospholipase C (PLC) selective inhibitor, U-73122, completely blocks the phosphorylation of PKD/PKCmu by CKS-17 while a negative control U-73343 does not. In addition, substitution of lysine for arginine residues in the CKS-17 sequence completely abrogates the ability of CKS-17 to phosphorylate PKD/PKCmu. These results clearly indicate that CKS-17 phosphorylates PKD/PKCmu through a PLC- and PKC-dependent mechanism and that arginine residues play an essential role in this activity of CKS-17, presenting a novel modality of the retroviral peptide CKS-17 and molecular interaction of this compound with target cells.

A retroviral-derived immunosuppressive peptide activates mitogen-activated protein kinases

The highly conserved region within the retroviral transmembrane envelope proteins has been implicated in a number of retrovirus-associated mechanisms of immunosuppression. CKS-17, a synthetic peptide representing the prototypic sequence of the immunosuppressive domain, has been found to suppress numerous immune functions, disregulate cytokines, and elevate intracellular cAMP. In this report we show that using a human monocytic cell line THP-1, CKS-17 activates mitogen-activated protein (MAP) kinases extracellular signal-regulated kinase 1 and 2 (ERK1/2). Kinetic studies show that CKS-17 induces an acute increase of ERK1/2 activity followed by a rapid decrease and then a second sustained increase of ERK1/2. CKS-17 also activates MAP kinase/ERK kinase (MEK) with a similar induction pattern. Mutant THP-1 cells isolated in our laboratory, in which CKS-17 exclusively fails to activate cAMP, did not show the transient decrease of CKS-17-induced ERK1/2 phosphorylation. Pretreatment of THP-1 cells or mutant THP-1 cells with cAMP analog or forskolin followed by treatment with CKS-17 showed no activation of MEK or ERK1/2. These results indicate that CKS-17 activates the MEK/ERK cascade and that there is a cross-talk between CKS-17-mediated MEK/ERK cascade and cAMP in that the MEK/ERK cascade is negatively regulated by cAMP. These data present a novel molecular mechanism(s) by this highly conserved retroviral immunosuppressive component.

Detection of Burkholderia pseudomallei DNA in patients with septicemic melioidosis

Septicemic melioidosis is the most severe form of melioidosis, which is caused by Burkholderia pseudomallei. It is endemic in Southeast Asia and is the leading cause of death from community-acquired septicemia in northeast Thailand. A major factor that contributes to the high mortality is the delay in isolation and identification of the causative organism. More than half of the patients die within the first 2 days after hospital admission, before bacterial cultures become positive. The present study was undertaken to develop a rapid diagnostic method for identification of this organism. A nested PCR system that amplified a part of 16S rRNA gene that was highly specific to B. pseudomallei was developed. This system was able to detect as few as two bacteria present in the PCR. DNAs from all 30 clinical isolates of B. pseudomallei and none of the other bacteria tested were amplified. The described PCR system has been employed for the detection of the organism in clinical specimens, including buffy coat and pus from internal organs. The detection of B. pseudomallei in buffy coat specimens by PCR was shown to be comparable to the detection of bacteria from blood cultures in septicemic melioidosis cases.