TLR9 signalling activation via direct ligation and its functional consequences in CD4 + T cells.

CpG Oligodeoxynucleotides (ODNs) are established TLR9 ligands; however, their functional responses in CD4+ T cells are believed to be independent of TLR9 and MyD88. We studied ligand-receptor interactions of ODN 2216 and TLR9 in human CD4+ T cells and assessed their consequences in terms of TLR9 signalling and cell phenotype. We demonstrated that the uptake of ODN 2216, a synthetic TLR9 agonist, is controlled by TLR9 signalling molecules and results in an increase in the expression of TLR9 signalling molecules, regulated via a feedback mechanism. Next, the uptake of ODN 2216 resulted in TLR9 signalling dependent but MyD88 independent increase in expression of TGF-ß. Finally, ODN 2216 treated CD4+ T cells showed an anti-inflammatory phenotype that was similar to Th3 type of regulatory T cells. These Th3-like cells were able to suppress the proliferation of untreated CD4+ T cells. Collectively, our results demonstrate a direct and interdependent relationship between ODN 2216 uptake and TLR9 signalling in CD4+ T cells. Our findings thus pave the way for future research to explore direct modulation of adaptive immune cells, using innate immune ligands, to subvert exaggerated inflammatory responses.

Direct Engagement of TLR9 Ligand with T Helper Cells Leads to Cell Proliferation & Up-regulation of Cytokines.

PURPOSE: Toll like receptor (TLR) engagement is primarily a function of the innate immune cells. The purpose of the study was to assess direct uptake of ODN 2216 in T helper cells and effects on cell proliferation and cytokine expression. METHODS: We isolated CD4+ CD25- T helper cells by magnetic sorting and studied the uptake of ODN 2216 using flow cytometry and confocal microscopy. We then studied the effect of ODN 2216 engagement on cell proliferation and cytokine expression using flow cytometry and gene expression of TLR9 signaling genes using real time RT-PCR. RESULTS: We made a chance observation that purified T helper cells from healthy individuals consistently bind to the TLR9 ligand ODN 2216. In PBMCs, on the other hand, 98% of monocytes preferentially bound to ODN 2216 FITC, indicating that they competed with the lymphocytes. We confirmed intracellular localization of ODN 2216 FITC as well as intracellular expression of TLR9 in Thelper cells. Furthermore, ODN 2216 FITC was also co-localized with the lysosomal membrane associated protein 1. The uptake of TLR9 ligand culminated in cellular proliferation, up-regulation of cytokines and increased mRNA expression of TLR9 and IRF7 in T helper cells, in the absence of antigen presenting cells. ODN 2216 uptake was inhibited by promethazine as well as by TLR9 antagonist. CONCLUSIONS: Our results show a direct engagement of TLR9 ligand in T helper cells and suggest involvement of TLR9 signalling in CD4+T cells, which may envisage novel targets for TLR inhibitors.

Serial Serum Immunoglobulin G (IgG) Trough Levels in Patients with X-linked Agammaglobulinemia on Replacement Therapy with Intravenous Immunoglobulin: Its Correlation with Infections in Indian Children.

Patients with primary antibody deficiency (PAD) are being increasingly diagnosed in the developing world. However, care of these children continues to remain suboptimal due to financial and social constraints. Immunoglobulin (Ig) trough level is an important predicting factor for infections in children on replacement immunoglobulin therapy. There are no data on this aspect from the developing world. Therefore, we studied serial immunoglobulin G (IgG) trough levels in 14 children with X-linked agammaglobulinemia (XLA) receiving replacement intravenous immunoglobulin (IVIG). Infections during the course of enrolment were documented prospectively. Mean age at the time of diagnosis was 5.1 years (range 2-11 years). Mean time from onset of symptoms and initiation of therapy was 3.3 years. Two children had established chronic lung disease prior to enrolment. Total numbers of major and minor infections were 7 and 40, respectively. At a mean dose of 414 mg/kg/month of IVIG, mean trough IgG level was 435 mg/dl. Median IgG trough levels during the episodes of major and minor infections were 244 and 335 mg/dl, respectively. An escalation in IVIG dose of 100 mg/kg produced an increase in serum IgG levels by 53.6 mg/dl. Median trough IgG level of 354 mg/dl was found to be protective with 64% sensitivity and 75% specificity. A median dose of 397 mg/kg was required to keep children free of infections. Despite financial constraints and several challenges in the context of a developing country, children with XLA have good outcome on replacement immunoglobulin therapy. Furthermore, mean biological trough IgG levels are much lower than reported in for Western patients; however, studies involving larger number of subjects are required in future to draw firm conclusions.

X-linked agammaglobulinemia: Twenty years of single-center experience from North West India.

BACKGROUND: X-linked agammaglobulinemia (XLA) is an X-linked genetic defect in maturation of B lymphocytes that results in the absence of B lymphocytes in the peripheral blood and profound hypogammaglobulinemia. It is caused by a mutation in the BTK gene located on the X chromosome. There are no large series describing XLA from the developing world. OBJECTIVE: To analyze the clinical features, immunologic and genetic characteristics, and outcomes of 36 patients with XLA diagnosed and managed for a period of 2 decades. METHODS: Diagnosis of XLA was made on the basis of presence of BTK gene mutation or marked reduction of B lymphocytes in peripheral blood with a family history of an affected male relative. The diagnosis was confirmed by genetic mutation studies in 28 patients with 25 unique mutations in the BTK gene. RESULTS: There was a significant delay in diagnosis in most of the patients. The mean (SD) delay in the diagnosis was 4.2 (3.5) years. Point mutations were the most common mutations detected, accounting for 68% of all mutations. Deletions and insertions were also seen in a few cases. Four of the mutations are novel mutations that have not been previously reported. Seven of the 36 patients (19%) were dead at the time of analysis in the present cohort. The mean survival was 137 months (95% confidence interval, 13-163 months). CONCLUSION: The present study is perhaps the largest series of patients with XLA from any developing country so far.

Cytokeratin (CK5, CK8, CK14) expression and presence of progenitor stem cells in human fetal thymuses.

The aim of the current study was to observe the expression of cytokeratins in human fetal thymuses. Specific cytokeratin markers in adult humans and mice have been well described but there has been little similar work on human fetuses. We also aimed to see whether progenitor stem cells that could be harvested to treat various immunodeficiency disorders are present in fetal thymic tissue. Thymuses obtained from 30 aborted human fetuses (12 to 31 weeks) were examined immunohistochemically to investigate changes in cytokeratin expression in the epithelial cells (TEC) at various gestational ages. Before 16 weeks of gestation, cortical (cTEC) and medullary (mTEC) TEC exhibited homogenous staining for cytokeratins CK8 and CK5. After 16 weeks there was differential staining, with cTEC positive for CK8 and mTEC for CK5 and CK14. Interestingly, both CK5 + CK8+ progenitor stem cells were present in the fetal thymic cortex at all gestational ages, with a relatively high number from 12 to 16 weeks. Cytokeratin expression in fetal thymuses was quite different from that in the adult thymus owing to the presence of undifferentiated progenitor stem cells in fetal thymic stroma along with differentiated TEC. The best time to harvest these progenitor stem cells from fetal thymic stroma in order to treat various immune deficiency disorders appears to be 12-16 weeks. Clin. Anat. 29:711-717, 2016. © 2016 Wiley Periodicals, Inc.

Chronic granulomatous disease: two decades of experience from a tertiary care centre in North West India.

Chronic granulomatous disease (CGD) results from an inherited defect in the phagocytic cells of the immune system. It is a genetically heterogenous disease caused by defects in one of the five major subunits of the nicotinamide adenine dinucleotide phosphate (NADPH) oxidase complex. There is a paucity of data from India on CGD. We herein describe the clinical features in 17 children with CGD from a single tertiary referral center in India. A detailed analysis of the clinical features, laboratory investigations and outcome of 17 children 7 with X-linked (XL) and 10 with autosomal recessive (AR) form was performed. Diagnosis of CGD was based on an abnormal granulocyte oxidative burst evaluated by either Nitroblue Tetrazolium (NBT) test or flow cytometry based Dihyrorhodamine 123 assay or both. The molecular diagnosis was confirmed by genetic mutation analysis in 13 cases. The mean age at diagnosis and the age at onset of symptoms was significantly lower in children diagnosed with XL- CGD compared those with AR disease. Mutations were detected in CYBB gene in 6 patients with XL-CGD and NCF-1 gene mutations were observed in 7 cases of AR- CGD. The course and outcome of the disease was much worse in children diagnosed with X-linked form of disease compared to AR forms of the disease; 4/7 (57%) children with X-CGD were dead at the time of data analysis. This is one of the largest series on chronic granulomatous disease from any developing country.

Study of spatial relationship of phrenic nerves with cardiac structures relevant to electrophysiologic interventions.

BACKGROUND: Pulmonary vein (PV) isolation with catheter ablation in treating atrial fibrillation carries the risk of injury to phrenic nerve (PN). Left PN (LPN) stimulation continues to be one of the common complications of transvenous left ventricular lead placement during cardiac resynchronization therapy (CRT). METHODS AND RESULTS: In 30 formalin-fixed cadavers, spatial relationship of PNs with PV ostia, left atrial appendage (LAA), and cardiac veins was observed. Segmental location of LPN and cardiac vein crossover was also noted. Right and left PNs coursed abutting the ostium of right superior and left superior PVs in five (16.6%) and one (3.33%) cases, respectively. LPN coursed along the lateral surface of LAA in 20 (66.66%) cases and behind LAA in one (3.33%) case. Out of 18 (60%) cases having two cardiac veins draining free wall of left ventricle (LV) and suitable for CRT lead placement, both cardiac veins were crossed by LPN in two (6.66%) cases. LPN-cardiac vein crossover was located in midlateral segment in 10 (33.3%) cases; mid posterolateral segment in five (16.7%) cases; apical lateral segment and apical posterolateral segment in three (10.0%) cases each. CONCLUSION: PN is highly susceptible to either injury during catheter ablation or stimulation with LV pacing in certain critical locations. Detailed knowledge of spatial relationship of PNs with cardiac structures could help minimize inadvertent complications during these transcatheter electrophysiological procedures.

Hyper-IgE syndrome with a novel STAT3 mutation-a single center study from India.

BACKGROUND: Hyper IgE syndrome (HIES) is a rare primary immunodeficiency disorder characterized by the triad of elevated IgE and eosinophilia, eczema and recurrent skin and pulmonary infections. Mutation in the STAT3 gene accounts for majority of the autosomal dominant and sporadic forms of HIES. OBJECTIVE: To report clinical and molecular analyses of patients with Hyper IgE syndrome from a single tertiary care center in India. METHODS: Four patients with suspected HIES were studied. Flowcytometry for T(H)17 cell numbers and phosphoSTAT3, and STAT3 gene sequencing were performed. RESULTS: T(H)17 cells were significantly reduced. Mutations were found in the DNA-binding domain in three and a mutation in the transactivation domain in one patient. One of the mutations detected was a novel mutation (g54792 c.1018A> C p.K340Q) in the DNA binding domain. Mycobacterial infection, which is usually not commonly associated with HIES was found in two of our cases, one with a cutaneous abscess in the shoulder, and the other with BCG site reactivation. CONCLUSIONS: A novel mutation in the STAT3 is reported. Mycobacterial infections can be seen in the spectrum of HIES related infections.

Ophthalmologic profile of patients with systemic sclerosis.

PURPOSE: To study the ophthalmologic manifestations of systemic sclerosis (SSc) and its correlation with autoantibody profile. METHODS: A cross-sectional study on 200 eyes of 100 consecutive adult patients diagnosed with SSc was performed at a tertiary care center in Northern India. The examination of ocular adnexa, anterior segment, and posterior segment with slit-lamp biomicroscopy, tear film break-up time (TBUT), Schirmer's II test, and choroidal thickness measurement by swept-source ocular coherence tomography was done. Autoantibody profile was available for 85 patients, and its statistical association with the ocular examination findings was analyzed. RESULTS: In total, 100 patients (93 females and 7 males) were included. The mean age was 45.11 ± 11.68 years, and the mean disease duration was 6.93 ± 3.68 years. Meibomian gland disease was more commonly found in patients with the diffuse subtype of SSc (P = 0.037). Choroidal thickness was increased in 34% and decreased in 7% (reference range = 307 ± 79 mm) patients. Reduced TBUT, meibomian gland dysfunction, and eyelid stiffness had a statistically significant association with the presence of anti-Scl-70 antibody (P = 0.003, <0.0001, and 0.004, respectively). These patients had ocular fatigue, foreign body sensation, and burning sensation. No significant association was noted with the presence of SS-A/Ro and SS-B/La antibodies. CONCLUSION: This study highlights the need for an active comprehensive ophthalmic evaluation. Approximately 75% of the patients in our cohort had ocular involvement to varying extent. An isolated presence of anti-Scl70 antibody was also found to have a positive association with dry eye disease.

Clinical profile and genetic basis of Wiskott-Aldrich syndrome at Chandigarh, North India.

BACKGROUND: The Wiskott-Aldrich syndrome (WAS) is a rare X-linked immunodeficiency disorder characterized by thrombocytopenia with small sized platelets, eczema, and recurrent infections. There is paucity of information on WAS from the Indian subcontinent. We describe the clinical and molecular profile of 8 patients with WAS as seen in the Pediatric Immunodeficiency Clinic at the Advanced Pediatrics Centre, Postgraduate Institute of Medical Education and Research, Chandigarh, India. METHODS: A detailed analysis of the clinical profiles, investigations and outcome of the 8 children diagnosed with WAS during the period 2006- 2010 was performed. Confirmation of the genetic diagnosis was done at the Service d'Hématologie, d'Immunologie et de Cytogénétique, Hôpital de Bicêtre, Le Kremlin-Bicêtre, France and the National Defense Medical College, Saitama, Japan. RESULTS: 8 patients were diagnosed as WAS in 5 years. The ages at diagnosis ranged from 13 weeks to 9 years while the mean age of onset of the symptoms was 117 days +/- 136 days. The diagnosis was established within a mean period of 31 months (ranging 1-108 months) from the onset of symptoms. Recurrent infections and diarrhea were seen in 6 and 7 out of the 8 patients, respectively, while eczema was variable. Autoimmunity manifestations were observed in 2 children. Thrombocytopenia and small platelet size was the hallmark of the disease and the main clinical clue to diagnosis in our patients. Mutations in the WASP gene were seen in 8 children, out of which 2 were novel mutations. While one child successfully underwent bone marrow transplantation, two children are doing well on immunoglobulin replacement and cotrimoxazole prophylaxis. Out of 8 children 4 children in our cohort died--all had high WAS scores and could not be offered hematopoietic stem cell transplantation. CONCLUSION: WAS should be suspected clinically in any male infant with persistent unexplained thrombocytopenia and especially if the platelet size is small. Clinical presentation can be very variable and it is therefore important to recognize the entire spectrum of the disease. Understanding the molecular basis has important implications for the diagnosis, treatment, and genetic counseling of patients with WAS.

Tear IL-6 and IL-10 levels in HLA-B27-Associated Uveitis and Its clinical Implications.

Purpose: To evaluate the cytokine levels in tear samples of human leukocyte antigen B27 (HLA-B27)-associated uveitis.Methods: Twenty HLA-B27-associated uveitis patients and 10 non-HLA-B27 uveitis controls were enrolled for the estimation of interleukin-6 (IL-6) and IL-10 levels in the tear samples. The cytokine levels were determined by flow cytometry using a bead-based assay.Results: IL-6, and IL-10 levels and IL-6/IL-10 ratio were found to be higher in the tear samples of HLA-B27-associated uveitis patients as compared to controls. IL-6 levels were also elevated in the active disease as compared to the quiescent group; likewise, IL-6 levels were higher even in the quiescent phase in comparison to non-HLA-B27 disease control. Additionally, levels of IL-6 were significantly correlated with multiple disease episodes. Moreover, IL-6 showed a good area under the curve in receiver operating characteristic analysis.Conclusions: Elevated tear IL-6 levels were associated with active disease and multiple disease episodes and thus could be used as putative markers for disease episodes.

Multiple Granulomas of Ocular Toxocariasis in an Immunocompetent Male.

A 25-year-old male presented with unilateral panuveitis with multiple voluminous elevated retinal lesions along with subretinal fluid and exudation. An extensive laboratory work-up was done, and a clinical suspicion of viral retinitis was considered. The patient was initiated on antiviral therapy and, subsequently, oral corticosteroids. As the corticosteroids were tapered, the patient developed worsening lesions and vitreous inflammation. Pars plana vitrectomy (diagnostic and therapeutic) was performed and cytology sample revealed a highly eosinophilic infiltrate suggestive of parasitic infection. The real-time polymerase chain reaction was positive for Toxocara cati. The diagnosis of ocular toxocariasis was made. This case highlights a highly unusual presentation where multiple retinal granulomas of ocular toxocariasis were observed in an immunocompetent male.

STAT3-Mediated Transcriptional Regulation of Osteopontin in STAT3 Loss-of-Function Related Hyper IgE Syndrome.

Background: Hyper-IgE syndrome (HIES) caused by loss-of-function (LOF) mutations in STAT3 gene (STAT3 LOF HIES) is associated with dental and facial abnormalities in addition to immunological defects. The role of STAT3 in the pathogenesis of the dental/facial features is, however, poorly elucidated. Objectives: Since mechanism of cellular resorption of mineralized tissues such as bone and teeth are similar, we attempted to study the expression of genes involved in bone homeostasis in STAT3 LOF HIES. Methods: Peripheral blood mononuclear cells from healthy controls (HCs), STAT3 LOF HIES patients, STAT3-/- PC-3 cells and STAT3+/+ LNCaP cells were stimulated with IL-6 and quantitative PCR array was performed to study the relative mRNA expression of 43 pre-selected genes. PCR array finding were further evaluated after stattic induced STAT3 inhibition. Results: Osteopontin (OPN) gene was seen to be significantly upregulated after IL-6 stimulation in HC (mean fold change 18.6, p = 0.01) compared with HIES subjects. Inhibition of STAT3 signaling by stattic followed by IL-6 stimulation abrogated the OPN response in HCs suggesting that IL-6-induced STAT3 signaling regulates OPN expression. Bioinformatics analysis predicted the presence of STAT3 response element TTCCAAGAA at position -2005 of the OPN gene. Conclusion: Regulation of OPN gene through IL-6-mediated STAT3 activation and its significant dysregulation in STAT3 LOF HIES subjects could make OPN a plausible candidate involved in the pathogenesis of dental/facial manifestations in HIES.

Role of HIV-1 subtype C envelope V3 to V5 regions in viral entry, coreceptor utilization and replication efficiency in primary T-lymphocytes and monocyte-derived macrophages.

BACKGROUND: Several subtypes of HIV-1 circulate in infected people worldwide, including subtype B in the United States and subtype C in Africa and India. To understand the biological properties of HIV-1 subtype C, including cellular tropism, virus entry, replication efficiency and cytopathic effects, we reciprocally inserted our previously characterized envelope V3-V5 regions derived from 9 subtype C infected patients from India into a subtype B molecular clone, pNL4-3. Equal amounts of the chimeric viruses were used to infect T-lymphocyte cell lines (A3.01 and MT-2), coreceptor cell lines (U373-MAGI-CCR5/CXCR4), primary blood T-lymphocytes (PBL) and monocyte-derived macrophages (MDM). RESULTS: We found that subtype C envelope V3-V5 region chimeras failed to replicate in T-lymphocyte cell lines but replicated in PBL and MDM. In addition, these chimeras were able to infect U373MAGI-CD4+-CCR5+ but not U373MAGI-CD4+-CXCR4+ cell line, suggesting CCR5 coreceptor utilization and R5 phenotypes. These subtype C chimeras were unable to induce syncytia in MT-2 cells, indicative of non-syncytium inducing (NSI) phenotypes. More importantly, the subtype C envelope chimeras replicated at higher levels in PBL and MDM compared with subtype B chimeras and isolates. Furthermore, the higher levels subtype C chimeras replication in PBL and MDM correlated with increased virus entry in U373MAGI-CD4+-CCR5+. CONCLUSION: Taken together, these results suggest that the envelope V3 to V5 regions of subtype C contributed to higher levels of HIV-1 replication compared with subtype B chimeras, which may contribute to higher viral loads and faster disease progression in subtype C infected individuals than other subtypes as well as rapid HIV-1 subtype C spread in India.

Immune responses in patients with HIV infection after vaccination with recombinant Hepatitis B virus vaccine.

BACKGROUND: Patients with HIV infection are at risk of co-infection with HBV, as the routes of transmission are shared and thus immunization with HBV vaccine could be protective in them. The aim of the present study was to assess the efficacy of recombinant vaccine in treatment-naive HIV positive patients and healthy controls, and to dissect out differences if any, in different limbs of immune response. METHODS: Forty HIV positive patients and 20 HIV negative controls, negative for HBsAg, HBsAbs and HBcAbs were vaccinated with three doses of 40 microg and 20 microg of vaccine respectively. Patients were divided into high CD4 and low CD4 group based on CD4+ lymphocytes of 200 and < 200/mm3 respectively. Group II consisted of healthy controls. Detection of phenotypic markers was done by flowcytometry. Cytokine estimation was done by sandwich ELISA. HBsAbs were estimated in serum by ELISA. RESULTS: After vaccination, CD4+, CD8+ and CD3+ cells increased significantly in all the groups. There was no increase in NK cell activity in patients with high CD4+ lymphocytes and only a marginal increase in patients with low CD4+ lymphocytes (170 to 293/mm3) whereas a marked increase was observed in controls (252 to 490/mm3). After vaccination, although an increase in memory cells was observed in HIV positive patients, yet HBsAb levels were significantly lower than controls (P < 0.05) indicating a functional defect of memory cells in HIV/AIDS patients. Basal IFN-gamma levels were also significantly lower in HIV/AIDS patients (P < 0.01). Although the levels increased after vaccination, the peak level remained lower than in controls. HBsAb titers were much lower in HIV positive patients compared to controls. (High CD4+ group: 8834 mIU/ml, low CD4+ group: 462 mIU/ml Vs. CONTROLS: 16,906 mIU/ml). IL-4 and IL-10 were low in patients. CONCLUSION: Despite a double dose in patients, IL-4 and IL-10, which regulate antibody response, were also lower in patients, and this together with low CD4+ counts and lack of T help, accounted for low HBsAb levels. Vaccination in patients with CD4+ lymphocytes < 50/mm3 was ineffective. Thus early immunization is advocated in all HIV positive patients at a stage when they are still capable of mounting an adequate immune response.

An unusual presentation of intraocular tuberculosis in a monocular patient: clinicopathological correlation.

BACKGROUND: Lack of uniform diagnostic criteria often poses a challenge in the diagnosis and management of tubercular uveitis. The index case describes an unusual presentation of tubercular panuveitis initially misdiagnosed as sympathetic ophthalmia, where the appropriate diagnosis was made using various imaging and laboratory investigations. RESULTS: A 52-year-old Indian woman underwent multimodal imaging, extensive clinical and laboratory work-up, and analysis of microbiological and histopathological specimens. At presentation, her best-corrected visual acuity (BCVA) was 20/30 in OD and no perception of light in OS. Ocular examination revealed multiple grayish-yellow choroiditis lesions resembling Dalen-Fuch's nodules, vitritis, and disc edema. Diagnosis of sympathetic ophthalmia was made and patient treated with intravenous and oral corticosteroids and immunosuppressive therapy. After an initial favorable response, the lesions progressively increased with worsening of vitritis. Due to worsening of chorioretinal lesions which were atypical for sympathetic ophthalmia, further investigations were performed that revealed positive tuberculin skin test and contrast-enhanced computerized tomography chest showed calcified mediastinal lymph nodes. Enucleation of OS confirmed acid-fast bacilli on Ziehl-Neelsen staining, tubercular granulomas on histopathology, and positive polymerase chain reaction. Anti-tubercular therapy and oral steroids were started with good healing response. CONCLUSIONS: Tubercular uveitis may have protean clinical manifestations. Thorough clinical evaluation and molecular/histopathological evaluation helps in establishing the diagnosis and the institution of appropriate therapy.