Oleuropein activates autophagy to circumvent anti-plasmodial defense.

Antimalarial drug resistance and unavailability of effective vaccine warrant for newer drugs and drug targets. Hence, anti-inflammatory activity of phyto-compound (oleuropein; OLP) was determined in antigen (LPS)-stimulated human THP-1 macrophages (macrophage model of inflammation; MMI). Reduction in the inflammation was controlled by the PI3K-Akt1 signaling to establish the "immune-homeostasis." Also, OLP treatment influenced the cell death/autophagy axis leading to the modulated inflammation for extended cell survival. The findings with MII prompted us to detect the antimalarial activity of OLP in the wild type (3D7), D10-expressing GFP-Atg18 parasite, and chloroquine-resistant (Dd2) parasite. OLP did not show the parasite inhibition in the routine in vitro culture of P. falciparum whereas OLP increased the antimalarial activity of artesunate. The molecular docking of autophagy-related proteins, investigations with MMI, and parasite inhibition assays indicated that the host activated the autophagy to survive OLP pressure. The challenge model of P. berghei infection showed to induce autophagy for circumventing anti-plasmodial defenses.

Co-Delivery of Aceclofenac and Methotrexate Nanoparticles Presents an Effective Treatment for Rheumatoid Arthritis.

Background: Rheumatoid arthritis (RA) is a common acute inflammatory autoimmune connective tissue arthropathy. The genetic studies, tissue analyses, experimental animal models, and clinical investigations have confirmed that stromal tissue damage and pathology driven by RA mounts the chronic inflammation and dysregulated immune events. Methods: We developed methotrexate (MTX)-loaded lipid-polymer hybrid nanoparticles (MTX-LPHNPs) and aceclofenac (ACE)-loaded nanostructured lipid carriers (ACE-NLCs) for the efficient co-delivery of MTX and ACE via intravenous and transdermal routes, respectively. Bio-assays were performed using ex-vivo skin permeation and transport, macrophage model of inflammation (MMI) (LPS-stimulated THP-1 macrophages), Wistar rats with experimental RA (induction of arthritis with Complete Freund's adjuvant; CFA and BCG), and programmed death of RA affected cells. In addition, gene transcription profiling and serum estimation of inflammatory, signaling, and cell death markers were performed on the blood samples collected from patients with RA. Results: Higher permeation of ACE-NLCs/CE across skin layers confirming the greater "therapeutic index" of ACE. The systemic delivery of MTX-loaded LPHNPs via the parenteral (intravenous) route is shown to modulate the RA-induced inflammation and other immune events. The regulated immunological and signaling pathway(s) influence the immunological axis to program the death of inflamed cells in the MMI and the animals with the experimental RA. Our data suggested the CD40-mediated and Akt1 controlled cell death along with the inhibited autophagy in vitro. Moreover, the ex vivo gene transcription profiling in drug-treated PBMCs and serum analysis of immune/signalling markers confirmed the therapeutic role co-delivery of drug nanoparticles to treat RA. The animals with experimental RA receiving drug treatment were shown to regain the structure of paw bones and joints similar to the control and were comparable with the market formulations. Conclusion: Our findings confirmed the use of co-delivery of drug nanoformulations as the "combination drug regimen" to treat RA.

Aceclofenac and methotrexate combination therapy could influence Th1/Th17 axis to modulate rheumatoid-arthritis-induced inflammation.

Rheumatoid arthritis (RA) is an inflammatory, autoimmune and connective-tissue arthropathy. The methotrexate (MTX) and aceclofenac (ACL) combination drug regimen is known to regulate the immunological pathways. Also, RA-elicited inflammation is decreased by the combination drug treatment. ACL and MTX combination treatment has been shown to regulate the signaling pathway controlled by NF-κB and FOXO1. The present manuscript reviews the importance of the combination drug regimen to treat and/or manage RA. The combination drug regimen could affect the Th1/Th17 axis to switch the balance toward the immunoregulatory (Th1) phenotype for establishing immune homeostasis. In conclusion, we propose the study of the immunological signaling pathways in experimental humanized RA mice.

Role of natural killer and B cell interaction in inducing pathogen specific immune responses.

The innate lymphoid cell (ILC) system comprising of the circulating and tissue-resident cells is known to clear infectious pathogens, establish immune homeostasis as well as confer antitumor immunity. Human natural killer cells (hNKs) and other ILCs carry out mopping of the infectious pathogens and perform cytolytic activity regulated by the non-adaptive immune system. The NK cells generate immunological memory and rapid recall response tightly regulated by the adaptive immunity. The interaction of NK and B cell, and its role to induce the pathogen specific immunity is not fully understood. Hence, present article sheds light on the interaction between NK and B cells and resulting immune responses in the infectious diseases. The immune responses elicited by the NK-B cell interaction is of particular importance for developing therapeutic vaccines against the infectious pathogens. Further, experimental evidences suggest the immune-response driven by NK cell population elicits the host-specific antibodies and memory B cells. Also, recently developed humanized immune system (HIS) mice and their importance in to understanding the NK-B cell interaction and resulting pathogen specific immunity has been discussed.

NKB cells: A double-edged sword against inflammatory diseases.

Interferon-γ (IFN-γ)-producing natural killer (NK) cells and innate lymphoid cells (ILCs) activate the adaptive system's B and T cells in response to pathogenic invasion; however, how these cells are activated during infections is not yet fully understood. In recent years, a new lymphocyte population referred to as "natural killer-like B (NKB) cells", expressing the characteristic markers of innate NK cells and adaptive B cells, has been identified in both the spleen and mesenteric lymph nodes during infectious and inflammatory pathologies. NKB cells produce IL-18 and IL-12 cytokines during the early phases of microbial infection, differentiating them from conventional NK and B cells. Emerging evidence indicates that NKB cells play key roles in clearing microbial infections. In addition, NKB cells contribute to inflammatory responses during infectious and inflammatory diseases. Hence, the role of NKB cells in disease pathogenesis merits further study. An in-depth understanding of the phenotypic, effector, and functional properties of NKB cells may pave the way for the development of improved vaccines and therapeutics for infectious and inflammatory diseases.

Translating Treg Therapy for Inflammatory Bowel Disease in Humanized Mice.

Crohn's disease and ulcerative colitis, two major forms of inflammatory bowel disease (IBD) in humans, afflicted in genetically predisposed individuals due to dysregulated immune response directed against constituents of gut flora. The defective immune responses mounted against the regulatory mechanisms amplify and maintain the IBD-induced mucosal inflammation. Therefore, restoring the balance between inflammatory and anti-inflammatory immunepathways in the gut may contribute to halting the IBD-associated tissue-damaging immune response. Phenotypic and functional characterization of various immune-suppressive T cells (regulatory T cells; Tregs) over the last decade has been used to optimize the procedures for in vitro expansion of these cells for developing therapeutic interventional strategies. In this paper, we review the mechanisms of action and functional importance of Tregs during the pathogenesis of IBD and modulating the disease induced inflammation as well as role of mouse models including humanized mice repopulated with the human immune system (HIS) to study the IBD. "Humanized" mouse models provide new tools to analyze human Treg ontogeny, immunobiology, and therapy and the role of Tregs in developing interventional strategies against IBD. Overall, humanized mouse models replicate the human conditions and prove a viable tool to study molecular functions of human Tregs to harness their therapeutic potential.

Transdermal Immunization of Elastic Liposome-Laden Recombinant Chimeric Fusion Protein of P. falciparum (PfMSP-Fu24) Mounts Protective Immune Response.

Transdermal immunization exhibits poor immunogenic responses due to poor permeability of antigens through the skin. Elastic liposomes, the ultradeformable nanoscale lipid vesicles, overcome the permeability issues and prove a versatile nanocarrier for transcutaneous delivery of protein, peptide, and nucleic acid antigens. Elastic liposome-mediated subcutaneous delivery of chimeric fusion protein (PfMSP-Fu24) of Plasmodium falciparum exhibited improved immunogenic responses. Elastic liposomes-mediated immunization of PfMSP-Fu24 conferred immunity to the asexual blood-stage infection. Present study is an attempt to compare the protective immune response mounted by the PfMSP-Fu24 upon administered through transdermal and intramuscular routes. Humoral and cell-mediated immune (CMI) response elicited by topical and intramuscularly administered PfMSP-Fu24-laden elastic liposomes (EL-PfMSP-Fu24) were compared and normalized with the vehicle control. Sizeable immune responses were seen with the transcutaneously immunized EL-PfMSP-Fu24 and compared with those elicited with intramuscularly administered antigen. Our results show significant IgG isotype subclass (IgG1and IgG3) response of specific antibody levels as well as cell-mediated immunity (CMI) activating factor (IFN-γ), a crucial player in conferring resistance to blood-stage malaria in mice receiving EL-PfMSP-Fu24 through transdermal route as compared to the intramuscularly administered formulation. Heightened immune response obtained by the vaccination of EL-PfMSP-Fu24 was complemented by the quantification of the transcript (mRNA) levels cell-mediated (IFN-γ, IL-4), and regulatory immune response (IL-10) in the lymph nodes and spleen. Collectively, elastic liposomes prove their immune-adjuvant property as they evoke sizeable and perdurable immune response against PfMSP-Fu24 and justify its potential for the improved vaccine delivery to inducing both humoral and CM immune response.