Critical role of IRF1 and BATF in forming chromatin landscape during type 1 regulatory cell differentiation.

Type 1 regulatory T cells (Tr1 cells) are induced by interleukin-27 (IL-27) and have critical roles in the control of autoimmunity and resolution of inflammation. We found that the transcription factors IRF1 and BATF were induced early on after treatment with IL-27 and were required for the differentiation and function of Tr1 cells in vitro and in vivo. Epigenetic and transcriptional analyses revealed that both transcription factors influenced chromatin accessibility and expression of the genes required for Tr1 cell function. IRF1 and BATF deficiencies uniquely altered the chromatin landscape, suggesting that these factors serve a pioneering function during Tr1 cell differentiation.

Non-canonical NF-κB signaling limits the tolerogenic ß-catenin-Raldh2 axis in gut dendritic cells to exacerbate intestinal pathologies.

Dendritic cell (DC) dysfunction is known to exacerbate intestinal pathologies, but the mechanisms compromising DC-mediated immune regulation in this context remain unclear. Here, we show that intestinal dendritic cells from a mouse model of experimental colitis exhibit significant levels of noncanonical NF-κB signaling, which activates the RelB:p52 heterodimer. Genetic inactivation of this pathway in DCs alleviates intestinal pathologies in mice suffering from colitis. Deficiency of RelB:p52 diminishes transcription of Axin1, a critical component of the ß-catenin destruction complex, reinforcing ß-catenin-dependent expression of Raldh2, which imparts tolerogenic DC attributes by promoting retinoic acid synthesis. DC-specific impairment of noncanonical NF-κB signaling leads to increased colonic numbers of Tregs and IgA+ B cells, which promote luminal IgA production and foster eubiosis. Experimentally introduced ß-catenin haploinsufficiency in DCs with deficient noncanonical NF-κB signaling moderates Raldh2 activity, reinstating colitogenic sensitivity in mice. Finally, inflammatory bowel-disease patients also display a deleterious noncanonical NF-κB signaling signature in intestinal DCs. In sum, we establish how noncanonical NF-κB signaling in dendritic cells can subvert retinoic acid synthesis to fuel intestinal inflammation.

Cenicriviroc, a CCR2/CCR5 antagonist, promotes the generation of type 1 regulatory T cells.

Cenicriviroc, a dual CCR2/CCR5 antagonist, initially developed as an anti-HIV drug, has shown promising results in nonalcoholic steatohepatitis phase 2 clinical trials. It inhibits the infiltration and activation of CCR2+/CCR5+ monocytes and macrophages to the site of liver injury, preventing liver fibrosis. However, the role of Cenicriviroc in the modulation of helper T cell differentiation and functions remains to be explored. In inflamed colons of Crohn's disease patients, CCR2+ and CCR5+ CD4+ T cells are enriched. Considering the role of CCR2+ and CCR5+ T cells in IBD pathogenesis, we investigated the potential role of Cenicriviroc in colitis. Our in vitro studies revealed that Cenicriviroc inhibits Th1-, Th2-, and Th17-cell differentiation while promoting the generation of type 1 regulatory T cells (Tr1), known for preventing inflammation through induction of IL-10. This study is the first to report that Cenicriviroc promotes Tr1 cell generation by up-regulating the signature of Tr1 cell transcription factors such as c-Maf, Prdm1, Irf-1, Batf, and EGR-2. Cenicriviroc displayed a protective effect in experimental colitis models by preventing body weight loss and intestinal inflammation and preserving epithelial barrier integrity. We show that Cenicriviroc induced IL-10 and inhibited the generation of pro-inflammatory cytokines IFN-γ, IL-17, IL-6, and IL-1ß during colitis. Based on our data, we propose Cenicriviroc as a potential therapeutic in controlling tissue inflammation by inhibiting the generation and functions of effector T cells and promoting the induction of anti-inflammatory Tr1 cells.

SARS-CoV-2 infection induces thymic atrophy mediated by IFN-γ in hACE2 transgenic mice.

Pathogenic infections cause thymic atrophy, perturb thymic T-cell development, and alter immunological response. Previous studies reported dysregulated T-cell function and lymphopenia in coronavirus disease-19 (COVID-19). However, immunopathological changes in the thymus associated with severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection have not been elucidated. Here, we report that SARS-CoV-2 infects thymocytes, and induces CD4+CD8+ (double positive; DP) T-cell apoptosis leading to thymic atrophy and loss of peripheral TCR repertoire in K18-hACE2 transgenic mice. Infected thymus led to increased CD44+CD25- T-cells, indicating an early arrest in the T-cell maturation pathway. Thymic atrophy was notably higher in male hACE2-Tg mice than in females and involved an upregulated de-novo synthesis pathway of thymic glucocorticoid. Further, IFN-γ was crucial for thymic atrophy, as anti-IFN-γ -antibody neutralization blunted thymic involution. Therapeutic use of Remdesivir also rescued thymic atrophy. While the Omicron variant and its sub-lineage BA.5 variant caused marginal thymic atrophy, the delta variant of SARS-CoV-2 exhibited severe thymic atrophy characterized by severely depleted DP T-cells. Recently characterized broadly SARS-CoV-2 neutralizing monoclonal antibody P4A2 was able to rescue thymic atrophy and restore the thymic maturation pathway of T-cells. Together, we report SARS-CoV-2-associated thymic atrophy resulting from impaired T-cell maturation pathway which may contribute to dyregulated T cell response during COVID-19.

Coconut Water Induces Clinical Remission in Mild to Moderate Ulcerative Colitis: Double-blind Placebo-controlled Trial.

BACKGROUND & AIMS: Coconut water (CW) is anti-inflammatory, can manipulate the gut microbiome, and is a rich source of potassium. Gut microbiome modulation improves outcomes in ulcerative colitis (UC), and potassium possesses in vitro anti-inflammatory property. We evaluated the effect of CW as an adjunct therapy for patients with mild-moderate UC. METHODS: This single-center, double-blind, placebo-controlled trial randomized patients with mild to moderate (Simple Clinical Colitis Activity Index [SCCAI]: 3-9) endoscopically active UC (Ulcerative Colitis Endoscopic Index of Severity [UCEIS] >1) in 1:1 ratio to CW + standard medical therapy (SMT) vs placebo + SMT. Four hundred mL of CW was administered for 8 weeks. Primary outcome measure was clinical remission (SCCAI ≤2), and secondary outcome measures were clinical response (SCCAI decline ≥3) and adverse events at 8 weeks. Microbiome was analyzed at baseline and 8 weeks. RESULTS: Of 121 patients screened, 95 were included for modified intention to treat analysis (CW, n = 49; placebo, n = 46) (mean age, 37.2 ± 11.2 years; males, 54.1%; disease duration, 48 months [interquartile range (IQR), 24-90 months]; pancolitis, 26.1%; SCCAI, 5 [IQR, 4-6]; UCEIS, 4 [IQR, 3-5]). Clinical response (57.1% vs 28.3%; odds ratio [OR], 3.4; 95% confidence interval [CI], 1.4-7.9; P = .01), remission (53.1% vs 28.3%; OR, 2.9; 95% CI, 1.2-6.7; P = .02), and proportion of patients with fecal calprotectin (FCP) <150 µg/g (30.6% vs 6.5%; OR, 6.3; 95% CI, 1.7-23.6; P = .003) were significantly higher in CW. The relative abundance of bacterial taxa that had a significant or trend towards negative correlation with SCCAI, UCEIS, or FCP increased at 8 weeks in CW, and this effect was independent of disease activity and dietary fiber. Adverse events were comparable, and no patient developed hyperkalemia. CONCLUSIONS: CW was more effective than placebo for induction of clinical remission in patients with mild to moderate UC. The trial was prospectively registered on Clinical Trials Registry of India (ctri.nic.in, Number: CTRI/2019/03/01827).

Inhibition of early RNA replication in Chikungunya and Dengue virus by lycorine: In vitro and in silico studies.

Arboviruses such as chikungunya virus (CHIKV) and dengue virus (DENV) collectively afflict millions of individuals worldwide particularly in endemic countries like India, leading to substantial morbidity and mortality. With the lack of effective vaccines for both CHIKV and DENV in India, the search for antiviral compounds becomes paramount to control these viral infections. In line with this, our investigation was focused on screening natural compounds for their potential antiviral activity against CHIKV and DENV. Using different assays, including plaque assay, immunofluorescence, and reverse transcription-quantitative real-time PCR (qRT-PCR), out of 109 natural compounds tested, we confirmed lycorine's in vitro antiviral activity against CHIKV and DENV at low micromolar concentrations in different cell types. Time of addition assays indicated that lycorine does not impede viral entry. Additionally, qRT-PCR results along with time of addition assay suggested that lycorine interferes with the synthesis of negative strand viral RNA. Molecular docking analysis was done to understand the mode of inhibition of viral replication. The results revealed that the most likely binding site with the highest binding affinity of lycorine, was at the palm and finger domains, in the vicinity of the catalytic site of CHIKV and DENV RNA-dependent RNA polymerase (RdRp). Collectively, our data underscores the potential of lycorine to be developed as a direct acting inhibitor for DENV and CHIKV, addressing the critical need of requirement of an antiviral in regions where these viruses pose significant public health threats.

A combination of potently neutralizing monoclonal antibodies isolated from an Indian convalescent donor protects against the SARS-CoV-2 Delta variant.

Although efficacious vaccines have significantly reduced the morbidity and mortality of COVID-19, there remains an unmet medical need for treatment options, which monoclonal antibodies (mAbs) can potentially fill. This unmet need is exacerbated by the emergence and spread of SARS-CoV-2 variants of concern (VOCs) that have shown some resistance to vaccine responses. Here we report the isolation of five neutralizing mAbs from an Indian convalescent donor, out of which two (THSC20.HVTR04 and THSC20.HVTR26) showed potent neutralization of SARS-CoV-2 VOCs at picomolar concentrations, including the Delta variant (B.1.617.2). One of these (THSC20.HVTR26) also retained activity against the Omicron variant. These two mAbs target non-overlapping epitopes on the receptor-binding domain (RBD) of the spike protein and prevent virus attachment to its host receptor, human angiotensin converting enzyme-2 (hACE2). Furthermore, the mAb cocktail demonstrated protection against the Delta variant at low antibody doses when passively administered in the K18 hACE2 transgenic mice model, highlighting their potential as a cocktail for prophylactic and therapeutic applications. Developing the capacity to rapidly discover and develop mAbs effective against highly transmissible pathogens like coronaviruses at a local level, especially in a low- and middle-income country (LMIC) such as India, will enable prompt responses to future pandemics as an important component of global pandemic preparedness.

A broadly neutralizing monoclonal antibody overcomes the mutational landscape of emerging SARS-CoV-2 variants of concern.

The emergence of new variants of SARS-CoV-2 necessitates unremitting efforts to discover novel therapeutic monoclonal antibodies (mAbs). Here, we report an extremely potent mAb named P4A2 that can neutralize all the circulating variants of concern (VOCs) with high efficiency, including the highly transmissible Omicron. The crystal structure of the P4A2 Fab:RBD complex revealed that the residues of the RBD that interact with P4A2 are a part of the ACE2-receptor-binding motif and are not mutated in any of the VOCs. The pan coronavirus pseudotyped neutralization assay confirmed that the P4A2 mAb is specific for SARS-CoV-2 and its VOCs. Passive administration of P4A2 to K18-hACE2 transgenic mice conferred protection, both prophylactically and therapeutically, against challenge with VOCs. Overall, our data shows that, the P4A2 mAb has immense therapeutic potential to neutralize the current circulating VOCs. Due to the overlap between the P4A2 epitope and ACE2 binding site on spike-RBD, P4A2 may also be highly effective against a number of future variants.

Induction and molecular signature of pathogenic TH17 cells.

Interleukin 17 (IL-17)-producing helper T cells (T(H)17 cells) are often present at the sites of tissue inflammation in autoimmune diseases, which has led to the conclusion that T(H)17 cells are main drivers of autoimmune tissue injury. However, not all T(H)17 cells are pathogenic; in fact, T(H)17 cells generated with transforming growth factor-ß1 (TGF-ß1) and IL-6 produce IL-17 but do not readily induce autoimmune disease without further exposure to IL-23. Here we found that the production of TGF-ß3 by developing T(H)17 cells was dependent on IL-23, which together with IL-6 induced very pathogenic T(H)17 cells. Moreover, TGF-ß3-induced T(H)17 cells were functionally and molecularly distinct from TGF-ß1-induced T(H)17 cells and had a molecular signature that defined pathogenic effector T(H)17 cells in autoimmune disease.

Understanding the landscape of the SARS-CoV-2-specific T cells post-omicron surge.

Emerging evidence shows increased humoral response post-omicron surge, but research on T cell responses is limited. This study investigated the durability, magnitude, and breadth of SARS-CoV-2-spike-specific T cell responses in 216 two-dose vaccinated individuals pre- and post-omicron surge. Post-surge samples showed enhanced T cell responses, indicating widespread asymptomatic exposure to omicron. Further analysis of 105 individuals with multiple exposures to SARS-CoV-2 through boosters or infections showed that post-omicron, two-dose vaccinated individuals had T cell responses comparable to those of COVID-19 convalescents or boosted individuals. Additionally, we report cross-reactive T cell responses against omicron sub-variants, including BA2.86, remained strong, with preserved frequencies of spike-specific stem-cell-like memory T cells. In silico prediction indicates that mutated epitopes of JN.1 and KP.2 retain over 95.6% of their HLA binding capability. Overall, our data suggests that T cell responses are sustained, enhanced, and cross-reactive against emerging SARS-CoV-2 variants following symptomatic or asymptomatic omicron infection.

To be remembered: B cell memory response against SARS-CoV-2 and its variants in vaccinated and unvaccinated individuals.

COVID-19 disease has plagued the world economy and affected the overall well-being and life of most of the people. Natural infection as well as vaccination leads to the development of an immune response against the pathogen. This involves the production of antibodies, which can neutralize the virus during future challenges. In addition, the development of cellular immune memory with memory B and T cells provides long-lasting protection. The longevity of the immune response has been a subject of intensive research in this field. The extent of immunity conferred by different forms of vaccination or natural infections remained debatable for long. Hence, understanding the effectiveness of these responses among different groups of people can assist government organizations in making informed policy decisions. In this article, based on the publicly available data, we have reviewed the memory response generated by some of the vaccines against SARS-CoV-2 and its variants, particularly B cell memory in different groups of individuals.

Plant lectins and their usage in preparing targeted nanovaccines for cancer immunotherapy.

Plant lectins, a natural source of glycans with a therapeutic potential may lead to the discovery of new targeted therapies. Glycans extracted from plant lectins are known to act as ligands for C-type lectin receptors (CLRs) that are primarily present on immune cells. Plant-derived glycosylated lectins offer diversity in their N-linked oligosaccharide structures that can serve as a unique source of homogenous and heterogenous glycans. Among the plant lectins-derived glycan motifs, Man9GlcNAc2Asn exhibits high-affinity interactions with CLRs that may resemble glycan motifs of pathogens. Thus, such glycan domains when presented along with antigens complexed with a nanocarrier of choice may bewilder the immune cells and direct antigen cross-presentation - a cytotoxic T lymphocyte immune response mediated by CD8+ T cells. Glycan structure analysis has attracted considerable interest as glycans are looked upon as better therapeutic alternatives than monoclonal antibodies due to their cost-effectiveness, reduced toxicity and side effects, and high specificity. Furthermore, this approach will be useful to understand whether the multivalent glycan presentation on the surface of nanocarriers can overcome the low-affinity lectin-ligand interaction and thereby modulation of CLR-dependent immune response. Besides this, understanding how the heterogeneity of glycan structure impacts the antigen cross-presentation is pivotal to develop alternative targeted therapies. In the present review, we discuss the findings on structural analysis of glycans from natural lectins performed using GlycanBuilder2 - a software tool based on a thorough literature review of natural lectins. Additionally, we discuss how multiple parameters like the orientation of glycan ligands, ligand density, simultaneous targeting of multiple CLRs and design of antigen delivery nanocarriers may influence the CLR targeting efficacy. Integrating this information will eventually set the ground for new generation immunotherapeutic vaccine design for the treatment of various human malignancies.

Intrinsic D614G and P681R/H mutations in SARS-CoV-2 VoCs Alpha, Delta, Omicron and viruses with D614G plus key signature mutations in spike protein alters fusogenicity and infectivity.

The SARS-CoV-2 virus has been rapidly evolving over the time and the genetic variation has led to the generation of Variants of Concerns (VoC), which have shown increased fitness. These VoC viruses contain the key mutations in the spike protein which have allowed better survival and evasion of host defense mechanisms. The D614G mutation in the spike domain is found in the majority of VoC; additionally, the P681R/H mutation at the S1/S2 furin cleavage site junction is also found to be highly conserved in major VoCs; Alpha, Delta, Omicron, and its' current variants. The impact of these genetic alterations of the SARS-CoV-2 VoCs on the host cell entry, transmissibility, and infectivity has not been clearly identified. In our study, Delta and D614G + P681R synthetic double mutant pseudoviruses showed a significant increase in the cell entry, cell-to-cell fusion and infectivity. In contrast, the Omicron and P681H synthetic single mutant pseudoviruses showed TMPRSS2 independent cell entry, less fusion and infectivity as compared to Delta and D614G + P681R double mutants. Addition of exogenous trypsin further enhanced fusion in Delta viruses as compared to Omicron. Furthermore, Delta viruses showed susceptibility to both E64d and Camostat mesylate inhibitors suggesting, that the Delta virus could exploit both endosomal and TMPRSS2 dependent entry pathways as compared to the Omicron virus. Taken together, these results indicate that the D614G and P681R/H mutations in the spike protein are pivotal which might be favoring the VoC replication in different host compartments, and thus allowing a balance of mutation vs selection for better long-term adaptation.

Nrf2 through Aryl Hydrocarbon Receptor Regulates IL-22 Response in CD4+ T Cells.

IL-17A and IL-22 derived from Th17 cells play a significant role in mucosal immunity and inflammation. TGF-ß and IL-6 promote Th17 differentiation; however, these cytokines have multiple targets. The identification and screening of additional molecules that regulate IL-17A and IL-22 responses in certain inflammatory conditions is of great clinical significance. In this study, we show that CDDO-Im, a specific Nrf2 activator, promotes IL-17A and IL-22 responses in murine Th17 cells. In contrast, CDDO-Im inhibits IL-17A response in multiple sclerosis patient-derived PBMCs. However, Nrf2 specifically regulates IL-22 response in vivo. Nrf2 acts through the regulation of antioxidant response element (ARE) binding motifs in target genes to induce or repress transcription. Promoter analysis revealed that Il17a, Rorc, and Ahr genes have several ARE motifs. We showed that Nrf2 bound to ARE repressor (ARE-R2) of Rorc and inhibited Rorc-dependent IL-17A transactivation. The luciferase reporter assay data showed that CDDO-Im regulated Ahr promoter activity. Chromatin immunoprecipitation quantitative PCR data showed that Nrf2 bound to ARE of AhR. Finally, we confirmed that the CDDO-Im-mediated induction of IL-22 production in CD4+ T cells was abrogated in CD4-specific Ahr knockout mice (AhrCD4 ). CH-223191, a specific AhR antagonist, inhibits CDDO-Im-induced IL-22 production in CD4+ T cells, which further confirmed the AhR-dependent regulation. Collectively, our data showed that Nrf2 via AhR pathways regulated IL-22 response in CD4+ T cells.

Tetramerizing tGCN4 domain facilitates production of Influenza A H1N1 M2e higher order soluble oligomers that show enhanced immunogenicity in vivo.

One strategy for the development of a next generation influenza vaccine centers upon using conserved domains of the virus to induce broader and long-lasting immune responses. The production of artificial proteins by mimicking native-like structures has shown to be a promising approach for vaccine design against diverse enveloped viruses. The amino terminus of influenza A virus matrix 2 ectodomain (M2e) is highly conserved among influenza subtypes, and previous studies have shown M2e-based vaccines are strongly immunogenic, making it an attractive target for further exploration. We hypothesized that stabilizing M2e protein in the mammalian system might influence the immunogenicity of M2e with the added advantage to robustly produce the large scale of proteins with native-like fold and hence can act as an efficient vaccine candidate. In this study, we created an engineered construct in which the amino terminus of M2e is linked to the tetramerizing domain tGCN4, expressed the construct in a mammalian system, and tested for immunogenicity in BALB/c mice. We have also constructed a stand-alone M2e construct (without tGCN4) and compared the protein expressed in mammalian cells and in Escherichia coli using in vitro and in vivo methods. The mammalian-expressed protein was found to be more stable, more antigenic than the E. coli protein, and form higher-order oligomers. In an intramuscular protein priming and boosting regimen in mice, these proteins induced high titers of antibodies and elicited a mixed Th1/Th2 response. These results highlight the mammalian-expressed M2e soluble proteins as a promising vaccine development platform.

Targeting cryptic-orthosteric site of PD-L1 for inhibitor identification using structure-guided approach.

Approved mAbs that block the protein-protein interaction (PPI) interface of the PD-1/PD-L1 immune checkpoint axis have led to significant improvements in cancer treatment. Despite having drawbacks of mAbs only few a compounds are reported till date against this axis. Inhibiting PPIs using small molecules has emerged as a significant therapeutic opportunity, demanding for the identification of drug-like molecules at an accelerated pace under the hit-to-lead campaigns. Due to the PD-L1's cross-talk with PD-1/CD80 and its overexpression on cancer cells, as well as the availability of its crystal structures with small molecules, it is an enticing therapeutic target for structure-assisted small molecule design. Furthermore, the selection of chemical databases enriched with focused designing for PPI interfaces is crucial. Therefore, in this study we have utilized the Asinex signature library for structure-assisted virtual screening to find the potential PD-L1 inhibitors by targeting the cryptic PD-L1 interface, followed by induced fit docking for pose refinements in the pocket. The obtained hits were then subjected to interaction fingerprinting and ligand-based drug-likeness investigations in order to evaluate and analyze their drug-like qualities (ADME). Twelve compounds qualified for molecular dynamics simulations, followed by thermodynamic calculations for evaluation of their stability and energetics inside the pocket. Two novel compounds with different chemical moieties have been identified that are consistent throughout the simulation, mimicking the interactions and binding energies with BMS-1166. These compounds appear as potential therapeutic candidates to be explored experimentally, thereby paving the way for the development of novel leads as immunomodulators.

Interplay among Structural Stability, Plasticity, and Energetics Determined by Conformational Attuning of Flexible Loops in PD-1.

The dynamics and plasticity of the PD-1/PD-L1 axis are the bottlenecks for the discovery of small-molecule antagonists to perturb this interaction interface significantly. Understanding the process of this protein-protein interaction (PPI) is of fundamental biological interest in structure-based drug designing. Food and Drug Administration (FDA)-approved anti-PD-1 monoclonal antibodies (mAbs) are the first-in-class with distinct binding modes to access this axis clinically; however, their mechanistic aspects remain elusive. Here, we have unveiled the interactive interfaces with PD-L1 and mAbs to investigate the native plasticity of PD-1 at global (structural and dynamical) and local (residue side-chain orientations) levels. We found that the structural stability and coordinated Cα movements are increased in the presence of PD-1's binding partners. The rigorous analysis of these PPIs using computational biophysical approaches revealed PD-1's intrinsic plasticity, its concerted loops' movement (BC, FG, and CC'), distal side-chain motions, and the thermodynamic landscape, which are perturbed remarkably from its unbound to bound states. Based on intra-/inter-residues' contact networks and energetics, the hot-spots have been identified that were found to be essential to arrest the dynamical motions of PD-1 significantly for the rational design of therapeutic agents by mimicking the mAbs mechanism.

Advanced strategies for development of vaccines against human bacterial pathogens.

Infectious diseases are one of the main grounds of death and disabilities in human beings globally. Lack of effective treatment and immunization for many deadly infectious diseases and emerging drug resistance in pathogens underlines the need to either develop new vaccines or sufficiently improve the effectiveness of currently available drugs and vaccines. In this review, we discuss the application of advanced tools like bioinformatics, genomics, proteomics and associated techniques for a rational vaccine design.

Statistical interpretation of environmental influencing parameters on COVID-19 during the lockdown in Delhi, India.

The novel coronavirus disease is known as COVID-19, which is declared as a pandemic by the World Health Organization during March 2020. In this study, the COVID-19 connection with various weather parameters like temperature, wind speed, and relative humidity is investigated and the future scenario of COVID-19 is predicted based on the Gaussian model (GM). This study is conducted in Delhi, the capital city of India, during the lowest mobility rate due to strict lockdown nationwide for about two months from March 15 to May 17, 2020. Spearman correlation is applied to obtain the interconnection of COVID-19 cases with weather parameters. Based on statistical analysis, this has been observed that the temperature parameter shows a significant positive trend during the period of study. The number of confirmed cases of COVID-19 is fitted with respect to the number of days by using the Gaussian curve and it is estimated on the basis of the model that maximum cases will go up to 123,886 in number. The maximum number of cases will be observed during the range of 166 ± 36 days. It is also estimated by using the width of the fitted GM that it will take minimum of 10 months for the complete recovery from COVID-19. Additionally, the linear regression technique is used to find the trend of COVID-19 cases with temperature and it is estimated that with an increase in temperature by 1 °C, 30 new COVID-19 cases on daily basis will be expected to observe. This study is believed to be a preliminary study and to better understand the concrete relationship of coronavirus, at least one complete cycle is essential to investigate. The laboratory-based study is essential to be done to support the present field-based study. Henceforth, based on preliminary studies, significant inputs are put forth to the research community and government to formulate thoughtful strategies like medical facilities such as ventilators, beds, testing centers, quarantine centers, etc., to curb the effects of COVID-19.

IL-4 inhibits TGF-beta-induced Foxp3+ T cells and, together with TGF-beta, generates IL-9+ IL-10+ Foxp3(-) effector T cells.

Transcription factor Foxp3 is critical for generating regulatory T cells (T(reg) cells). Transforming growth factor-beta (TGF-beta) induces Foxp3 and suppressive T(reg) cells from naive T cells, whereas interleukin 6 (IL-6) inhibits the generation of inducible T(reg) cells. Here we show that IL-4 blocked the generation of TGF-beta-induced Foxp3(+) T(reg) cells and instead induced a population of T helper cells that produced IL-9 and IL-10. The IL-9(+)IL-10(+) T cells demonstrated no regulatory properties despite producing abundant IL-10. Adoptive transfer of IL-9(+)IL-10(+) T cells into recombination-activating gene 1-deficient mice induced colitis and peripheral neuritis, the severity of which was aggravated if the IL-9(+)IL-10(+) T cells were transferred with CD45RB(hi) CD4(+) effector T cells. Thus IL-9(+)IL-10(+) T cells lack suppressive function and constitute a distinct population of helper-effector T cells that promote tissue inflammation.