Tumor-Associated CD19+CD39- B Regulatory Cells Deregulate Class-Switch Recombination to Suppress Antibody Responses.

B cells are an essential component of humoral immunity. Their primary function is to mount antigen-specific antibody responses to eliminate pathogens. Despite an increase in B-cell number, we found that serum-IgG levels were low in patients with breast cancer. To solve this conundrum, we used high-dimensional flow cytometry to analyze the heterogeneity of B-cell populations and identified a tumor-specific CD19+CD24hiCD38hi IL10-producing B regulatory (Breg)-cell subset. Although IL10 is a Breg-cell marker, being an intracellular protein, it is of limited value for Breg-cell isolation. Highly expressed Breg-cell surface proteins CD24 and CD38 also impede the isolation of viable Breg cells. These are hurdles that limit understanding of Breg-cell functions. Our transcriptomic analysis identified, CD39-negativity as an exclusive, sorting-friendly surface marker for tumor-associated Breg cells. We found that the identified CD19+CD39‒IL10+ B-cell population was suppressive in nature as it limited T helper-cell proliferation, type-1 cytokine production, and T effector-cell survival, and augmented CD4+FOXP3+ regulatory T-cell generation. These tumor-associated Breg cells were also found to restrict autologous T follicular helper-cell expansion and IL21 secretion, thereby inhibiting germinal transcript formation and activation-induced cytidine deaminase expression involved in H-chain class-switch recombination (CSR). This isotype-switching abnormality was shown to hinder B-cell differentiation into class-switched memory B cells and subsequent high-affinity antibody-producing plasma B cells, which collectively led to the dampening of IgG-mediated antibody responses in patients with cancer. As low IgG is associated with poor prognosis in patients with cancer, Breg-cell depletion could be a promising future therapy for boosting plasma B cell-mediated antibody responses.

The Adroitness of Andrographolide as a Natural Weapon Against Colorectal Cancer.

The conventional carcinoma treatment generally encompasses the employment of radiotherapy, chemotherapy, surgery or use of cytotoxic drugs. However, recent advances in pharmacological research have divulged the importance of traditional treatments in cancer. The aim of the present review is to provide an overview of the importance of one such medicinal herb of Chinese and Indian origin: Andrographis paniculate on colorectal cancer with special emphasis on its principal bioactive component andrographolide (AGP) and its underlying mechanisms of action. AGP has long been known to possess medicinal properties. Studies led by numerous groups of researchers shed light on its molecular mechanism of action. AGP has been shown to act in a multi-faceted manner in context of colorectal cancer by targeting matrix metalloproteinase-9, Toll-like receptor or NFκB signaling pathways. In this review, we highlighted the recent studies that show that AGP can act as an effective immunomodulator by harnessing effective anti-tumor immune response. Recent studies strongly recommend further research on this compound and its analogues, especially under in-vivo condition to assess its actual potential as a prospective and efficient candidate against colorectal cancer. The current review deals with the roles of this phytomedicine in context of colorectal cancer and briefly describes its perspectives to emerge as an essential anti-cancer drug candidate. Finally, we also point out the drawbacks and difficulties in administration of AGP and indicate the use of nano-formulations of this phytomedicine for better therapeutic efficacy.

Molecular Insight into the Effect of a Single-Nucleotide Polymorphic Variation on the Structure and Dynamics of Methionine Synthase Reductase and Its Association with Neural Tube Defects.

Neural tube defects (NTDs) are among the common and severe congenital malformations in neonates. According to a WHO report, nearly three lakh babies are affected per year worldwide by NTDs. Most studies revealed that folate deficiency is the key element to promote NTD with other oligogenic and multifactorial elements. This folate is metabolized by the FOCM (folate one-carbon metabolism) pathway. The most important step in the FOCM pathway is the conversion of methionine to homocysteine, which is guided by the enzyme MTRR. Several single-nucleotide polymorphisms (SNPs) in the MTRR gene are strongly associated with the progression of NTD. A nonsynonymous allelic variant (rs1532268) of the protein leads to a missense mutation at the 202nd position from serine to leucine (S202L) and is associated with a higher disease prevalence in different populations. In our study, this SNP indicates a 2-fold increase in the risk of disease progression (p-value of 0.03; OR 2.76; 95% CI 1.08-7.11). Here, extensive molecular dynamics simulations and interaction network analysis reveal that the change of 202nd serine to leucine alters the structures of the FAD and NAD binding domains, which restricts the ligand binding. The S202L variation alters the functional dynamics that might impede the electron transport chain along the NADP(H)→ FAD→ FMN pathway and hamper phosphorylation by kinases like GSK-3 and CaM-II during the posttranscriptional modification of the protein. The present study provides functional insights into the effect of the genetic variations of the MTRR gene on the NTD disease pathogenesis.

Curcumin as an Adjuvant to Cancer Immunotherapy.

The components of the immune system play a very sincere and crucial role in combating tumors. However, despite their firm efforts of elimination, tumor cells cleverly escape the surveillance process by adopting several immune evasion mechanisms. The conversion of immunogenicity of tumor microenvironment into tolerogenic is considered as a prime reason for tumor immune escape. Therapeutically, different immunotherapies have been adopted to block such immune escaping routes along with better clinical outcomes. Still, the therapies are haunted by several drawbacks. Over time, curcumin has been considered as a potential anti-cancer molecule. Its potentialities have been recorded against the standard hallmarks of cancer such as continuous proliferation, escaping apoptosis, continuous angiogenesis, insensitivity to growth inhibitors, tissue invasion, and metastasis. Hence, the diversity of curcumin functioning has already been established and exploration of its application with immunotherapies might open up a new avenue for scientists and clinicians. In this review, we briefly discuss the tumor's way of immune escaping, followed by various modern immunotherapies that have been used to encounter the escaping paths and their minute flaws. Finally, the conclusion has been drawn with the application of curcumin as a potential immune-adjuvant, which fearlessly could be used with immunotherapies for best outcomes.

Structural insight into the effect of polymorphic variation on the functional dynamics of methionine synthase reductase: Implications in neural tube defects.

Neural tube defects (NTDs), one of the most common birth defects, are strongly associated with the variations of several single nucleotide polymorphisms (SNPs) in the MTRR gene. The gene codes a key enzyme that is involved in the rejuvenation of methionine synthase activity. An allelic variant of the protein leads to missense mutation at 49th position from isoleucine to methionine (I49M) is associated with higher disease prevalence in different populations. Here, extensive molecular dynamics simulations and interaction network analysis reveal that the 49th isoleucine is a crucial residue that allosterically regulates the dynamics between the flavin mononucleotide (FMN) and NADP(H) binding domains. I49M variation alters the functional dynamics in a way that might impede the electron transport chain along the NADP(H) â†’ flavin adenine dinucleotide â†’ FMN pathway. The present study provides functional insights into the effect of the genetic variations of the MTRR gene on the NTDs disease pathogenesis.

Association of FOLH1, DHFR, and MTHFR gene polymorphisms with susceptibility of Neural Tube Defects: A case control study from Eastern India.

BACKGROUND: Worldwide, Neural tube defects (NTDs) are considered as major clinical problems imposing a huge socio-economic burden for both affected individuals and their families. In India, the prevalence of Neural tube defects is significantly high. This study aims to evaluate the association between genetic defects in folate metabolism pathway genes, mainly: Folate hydrolase 1 (FOLH1), Dihydrofolate reductase (DHFR) and Methylenetetrahydrofolate reductase (MTHFR) and neural tube defects from eastern India. METHODS: We enrolled 62 consecutive mothers with NTDs foetuses as cases and their corresponding age matched 73 mothers with healthy babies as controls (genetic power has been calculated). Four single nucleotide polymorphisms (FOLH1: rs202676, DHFR: rs70991108, MTHFR: rs1801133 and rs1801131) have been amplified by polymerase chain reaction (PCR) and sequenced. Statistical analysis has been undertaken to find out association with NTDs. RESULTS: Genotype and allele frequency analysis of these SNPs revealed that, rs1801133 (p.Ala222Val) was significantly associated with NTDs risk (p value = 0.028; odds ratio-2.31; 95% CI 1.08-4.93), whereas rs202676 (p.Tyr60His) showed protective role (p value = 0.0066; odds ratio-0.11; 95% CI 0.01-0.86). Serum homocysteine (Hcy) concentration was respectively higher in subjects carrying 222Ala/Val and 222Val/Val alleles (p value = 0.009; p value ≤ 0.0001). CONCLUSION: In conclusion, it can be stated that, rs1801133 was associated with neural tube defects risk in patients from the eastern part of India and it might be counted as a molecular marker for evaluating the susceptibility of NTDs.

Absence of KCNQ4 mutation in Bengali families with ADNSHL originated from West Bengal, India.

OBJECTIVE: Autosomal Dominant Non-Syndromic Hearing Loss (ADNSHL) is extremely heterogeneous in nature. More than 60 loci with 30 different genes have been identified linked to ADNSHL. Mutation in KCNQ4 is considered as one of the most common causative factor responsible for ADNSHL. No study focused on the genetic alteration of KCNQ4 gene among hearing loss patients in India. The present study for the first time was carried out to determine the mutation spectrum of KCNQ4 gene in ADNSHL patients of West Bengal state, India. METHOD: Twenty nine individuals from 10 independent ADNSHL family (with two or more generation affected) were studied both clinically and genetically. Most of the patients showed moderate progressive sensorineural hearing loss. Mutation analysis was conducted for KCNQ4 gene using polymerase chain reaction followed by direct sequencing. RESULTS: Neither any reported nor a novel pathogenic mutation in KCNQ4was detected in our studied group, in contrast to the findings among East Asians. CONCLUSION: The result of the present study suggests that mutations in KCNQ4 gene are unlikely to be a major causative factor of ADNSHL in our studied patients from West Bengal, India, pointing to other genes might be responsible for ADNSHL in our studied patients.

Spectrum and frequency of GJB2, GJB6 and SLC26A4 gene mutations among nonsyndromic hearing loss patients in eastern part of India.

Genetically caused nonsyndromic hearing loss is highly heterogeneous. Inspite of this large heterogeneity, mutations in the genes GJB2, GJB6 and SLC26A4 are major contributors. The mutation spectrum of these genes varies among different ethnic groups. Only a handful of studies focused on the altered genetic signature of these genes in different demographic regions of India but never focused on the eastern part of the country. Our study for the first time aimed to characterize the mutation profile of these genes in hearing loss patients of West Bengal state, India. Mutations in GJB2, GJB6 and SLC26A4 genes were screened by bidirectional sequencing from 215 congenital nonsyndromic hearing loss patients. Radiological diagnosis was performed in patients with SLC26A4 mutations by temporal bone CT scan. The study revealed that 4.65% and 6.97% patients had monoallelic and biallelic GJB2 mutations respectively. Six mutations were identified, p.W24X being the most frequent one accounting for 71.05% of the mutated alleles. Mutations in GJB6 including the previously identified deletion mutation (GJB6-D13S1830) were not identified in our study. Further, no patients harbored biallelic mutations in the SLC26A4 gene or the common inner ear malformation Enlarged Vestibular Aqueduct (EVA). The mutation profile of GJB2 in our study is distinct from other parts of India, suggesting that the mutation spectrum of this gene varies with ethnicity and geographical origin. The absence of GJB6 mutations and low frequency of SLC26A4 mutations suggest that additional genetic factors may also contribute to this disease.