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Snakebite accident treatment requires the administration of antivenoms that provide efficacy and effectiveness against several snake venoms of the same genus or family. The low number of immunogenic components in venom mixtures that allow the production of antivenoms consequently gives them partial neutralization and a suboptimal pharmacological response. This study evaluates the immunorecognition and neutralizing efficacy of the polyvalent anticoral antivenom from the Instituto Nacional de Salud (INS) of Colombia against the heterologous endemic venoms of Micrurus medemi, and M. sangilensis, and M. helleri by assessing immunoreactivity through affinity chromatography, ELISA, Western blot, and neutralization capability. Immunorecognition towards the venoms of M. medemi and M. sangilensis showed values of 62% and 68% of the protein composition according to the immunoaffinity matrix, respectively. The analysis by Western blot depicted the highest recognition patterns for M. medemi, followed by M. sangilensis, and finally by M. helleri. These findings suggest that the venom compositions are closely related and exhibit similar recognition by the antivenom. According to enzyme immunoassays, M. helleri requires a higher amount of antivenom to achieve recognition than the others. Besides reinforcing the evaluation of INS antivenom capability, this work recommends the use of M. helleri in the production of Colombian antisera. [ABSTRACT FROM AUTHOR]

Snakebite accident treatment requires the administration of antivenoms that provide efficacy and effectiveness against several snake venoms of the same genus or family. The low number of immunogenic components in venom mixtures that allow the production of antivenoms consequently gives them partial neutralization and a suboptimal pharmacological response. This study evaluates the immunorecognition and neutralizing efficacy of the polyvalent anticoral antivenom from the Instituto Nacional de Salud (INS) of Colombia against the heterologous endemic venoms of Micrurus medemi, and M. sangilensis, and M. helleri by assessing immunoreactivity through affinity chromatography, ELISA, Western blot, and neutralization capability. Immunorecognition towards the venoms of M. medemi and M. sangilensis showed values of 62% and 68% of the protein composition according to the immunoaffinity matrix, respectively. The analysis by Western blot depicted the highest recognition patterns for M. medemi, followed by M. sangilensis, and finally by M. helleri. These findings suggest that the venom compositions are closely related and exhibit similar recognition by the antivenom. According to enzyme immunoassays, M. helleri requires a higher amount of antivenom to achieve recognition than the others. Besides reinforcing the evaluation of INS antivenom capability, this work recommends the use of M. helleri in the production of Colombian antisera.

Naja nivea (Cape Cobra) is endemic to southern Africa. Envenoming by N. nivea is neurotoxic, resulting in fatal paralysis. Its venom composition, however, has not been studied in depth, and specific antivenoms against it remain limited in supply. Applying a protein decomplexation approach, this study unveiled the venom proteome of N. nivea from South Africa. The major components in the venom are cytotoxins/cardiotoxins (~75.6% of total venom proteins) and alpha-neurotoxins (~7.4%), which belong to the three-finger toxin family. Intriguingly, phospholipase A2 (PLA2) was undetected—this is a unique venom phenotype increasingly recognized in the African cobras of the Uraeus subgenus. The work further showed that VINS African Polyvalent Antivenom (VAPAV) exhibited cross-reactivity toward the venom and immunorecognized its toxin fractions. In mice, VAPAV was moderately efficacious in cross-neutralizing the venom lethality with a potency of 0.51 mg/mL (amount of venom completely neutralized per milliliter of antivenom). In the challenge-rescue model, VAPAV prevented death in 75% of experimentally envenomed mice, with slow recovery from neurotoxicity up to 24 h. The finding suggests the potential para-specific utility of VAPAV for N. nivea envenoming, although a higher dose or repeated administration of the antivenom may be required to fully reverse the neurotoxic effect of the venom. [ABSTRACT FROM AUTHOR]

Naja nivea (Cape Cobra) is endemic to southern Africa. Envenoming by N. nivea is neurotoxic, resulting in fatal paralysis. Its venom composition, however, has not been studied in depth, and specific antivenoms against it remain limited in supply. Applying a protein decomplexation approach, this study unveiled the venom proteome of N. nivea from South Africa. The major components in the venom are cytotoxins/cardiotoxins (~75.6% of total venom proteins) and alpha-neurotoxins (~7.4%), which belong to the three-finger toxin family. Intriguingly, phospholipase A2 (PLA2) was undetected—this is a unique venom phenotype increasingly recognized in the African cobras of the Uraeus subgenus. The work further showed that VINS African Polyvalent Antivenom (VAPAV) exhibited cross-reactivity toward the venom and immunorecognized its toxin fractions. In mice, VAPAV was moderately efficacious in cross-neutralizing the venom lethality with a potency of 0.51 mg/mL (amount of venom completely neutralized per milliliter of antivenom). In the challenge-rescue model, VAPAV prevented death in 75% of experimentally envenomed mice, with slow recovery from neurotoxicity up to 24 h. The finding suggests the potential para-specific utility of VAPAV for N. nivea envenoming, although a higher dose or repeated administration of the antivenom may be required to fully reverse the neurotoxic effect of the venom.

The relatively straightforward methods of designing and assembling various functional nucleic acids into nanoparticles offer advantages for applications in diverse diagnostic and therapeutic approaches. However, due to the novelty of this approach, nucleic acid nanoparticles (NANPs) are not yet used in the clinic. The immune recognition of NANPs is among the areas of preclinical investigation aimed at enabling the translation of these novel materials into clinical settings. NANPs’ interactions with the complement system, coagulation systems, and immune cells are essential components of their preclinical safety portfolio. It has been established that NANPs’ physicochemical properties—composition, shape, and size—determine their interactions with immune cells (primarily blood plasmacytoid dendritic cells and monocytes), enable recognition by pattern recognition receptors (PRRs) such as Toll-like receptors (TLRs) and RIG-I-like receptors (RLRs), and mediate the subsequent cytokine response. However, unlike traditional therapeutic nucleic acids (e.g., CpG oligonucleotides), NANPs do not trigger a cytokine response unless they are delivered into the cells using a carrier. Recently, it was discovered that the type of carrier provides an additional tool for regulating both the spectrum and the magnitude of the cytokine response to NANPs. Herein, we review the current knowledge of NANPs’ interactions with various components of the immune system to emphasize the unique properties of these nanomaterials and highlight opportunities for their use in vaccines and immunotherapy.

Optimal tissue preservation is critical in histotechnology to ensure quality of hematoxylin and eosin (H&E)-stained sections and enable light microscopic assessment by pathologists. Direct immersion of tissues in 10% neutral buffered formalin is the routine practice in histopathology laboratories, but whole body perfusion techniques are occasionally used, especially when high-quality tissue samples are required. The objectives of this study were to evaluate the impact four different whole body perfusion techniques have on preserving H&E tissue quality and cellular morphology using light microscopy and immunohistochemistry. Four different rat whole body perfusion techniques were conducted and compared: (1) physiological saline at pH 7; (2) physiological saline at pH 7 with heparin; (3) 4% paraformaldehyde fixative; and (4) physiological saline at pH 7 with heparin followed by 4% paraformaldehyde. All solutions were chilled prior to the start of the perfusion. Furthermore, alpha-smooth muscle actin (αSMA) immunohistochemistry was employed to investigate the effects of these techniques on tissue antigenicity. Light microscopic examination and comparison of brain, kidney, and pancreas tissues revealed no differences in cellular (nuclear or cytoplasmic) morphology among the four different perfusion techniques. In the liver, a more distinct hepatic cord pattern was noted in groups 1 and 4 compared with groups 2 and 3, with group 2 showing the least distinctive hepatic cord pattern. In addition, a noticeably more prominent vascular congestion was noted in group 3 compared with other groups. Furthermore, more artifactual vacuolation was noted in the brain in group 3 compared with other groups. No differences in αSMA immunorecognition were noted by immunohistochemistry. In conclusion, different whole body perfusion can have an impact on hepatic morphology, presence of vascular congestion, and artifactual vacuolation in the brain. The utility of any of the perfusion techniques should be considered on a case-by-case basis depending on the scientific question being answered. [ABSTRACT FROM PUBLISHER]

Nucleic acid nanoparticles (NANPs) are extensively investigated as diagnostic and therapeutic tools. These innovative particles can be composed of RNA, DNA, and/or modified nucleic acids. Due to the regulatory role of nucleic acids in the cellular system, NANPs have the ability to identify target molecules and regulate expression of genes in disease pathways. However, translation of NANPs in clinical settings is hindered due to inefficient intracellular delivery, chemical instability, and off-target immunostimulatory effects following immune recognition. The composition of nucleic acids forming NANPs has been demonstrated to influence immunorecognition, subcellular compartmentalization, and physicochemical properties of NANPs. This chapter first outlines the methods used to generate a panel of NANPs with a uniform shape, size, charge, sequence, and connectivity. This includes the procedures for replacing the RNA strands with DNA or chemical analogs in the designated NANPs. Second, this chapter will also describe experiments to assess the effect of the chemical modification on enzymatic and thermodynamic stability, delivery efficiency, and subcellular compartmentalization of NANPs., (© 2023. The Author(s), under exclusive license to Springer Science+Business Media, LLC, part of Springer Nature.)

Bradykinin-potentiating peptides (BPPs) from the South American pit viper snake venom were the first natural inhibitors of the human angiotensin I-converting enzyme (ACE) described. The pioneer characterization of the BPPs precursor from the snake venom glands by our group showed for the first time the presence of the C-type natriuretic peptide (CNP) in this same viper precursor protein. The confirmation of the BPP/CNP expression in snake brain regions correlated with neuroendocrine functions stimulated us to pursue the physiological correlates of these vasoactive peptides in mammals. Notably, several snake toxins were shown to have endogenous physiological correlates in mammals. In the present work, we expressed in bacteria the BPPs domain of the snake venom gland precursor protein, and this purified recombinant protein was used to raise specific polyclonal anti-BPPs antibodies. The correspondent single protein band immune-recognized in adult rat brain cytosol was isolated by 2D-SDS/PAGE and/or HPLC, before characterization by MS fingerprint analysis, which identified this protein as superoxide dismutase (SOD, EC 1.15.1.1), a classically known enzyme with antioxidant activity and important roles in the blood pressure modulation. In silico analysis showed the exposition of the BPP-like peptide sequences on the surface of the 3D structure of rat SOD. These peptides were chemically synthesized to show the BPP-like biological activities in ex vivo and in vivo pharmacological bioassays. Taken together, our data suggest that SOD protein have the potential to be a source for putative BPP-like bioactive peptides, which once released may contribute to the blood pressure control in mammals. [ABSTRACT FROM AUTHOR]

Nucleic acid nanoparticles, or NANPs, rationally designed to communicate with the human immune system, can offer innovative therapeutic strategies to overcome the limitations of traditional nucleic acid therapies. Each set of NANPs is unique in their architectural parameters and physicochemical properties, which together with the type of delivery vehicles determine the kind and the magnitude of their immune response. Currently, there are no predictive tools that would reliably guide the design of NANPs to the desired immunological outcome, a step crucial for the success of personalized therapies. Through a systematic approach investigating physicochemical and immunological profiles of a comprehensive panel of various NANPs, the research team developes and experimentally validates a computational model based on the transformer architecture able to predict the immune activities of NANPs. It is anticipated that the freely accessible computational tool that is called an "artificial immune cell," or AI-cell, will aid in addressing the current critical public health challenges related to safety criteria of nucleic acid therapies in a timely manner and promote the development of novel biomedical tools., (© 2022 The Authors. Small published by Wiley-VCH GmbH.)

Highlights: [•] Biomimetic nanogels for the generic binding of immunoglobulins were synthesized. [•] PNIPAM-based nanoparticles were conjugated with a Protein L-mimic synthetic affinity ligand. [•] The coupled ligand represents a universal ligand for binding antibody molecules. [•] Biomimetic nanoparticles were shown to bind selectively to IgG molecules. [•] IgG-carrying particles can be used for immunorecognition of antigen proteins. [ABSTRACT FROM AUTHOR]

Fixation and processing of tissue to paraffin blocks permit thin (4-5 µm) sections of tissues to be cut. Tissues and their subcellular components and surrounding stroma are visualized by cutting thin sections and staining them histochemically or immunohistochemically and viewing the sections using a bright field microscope. During the last century, anatomists and pathologists have used fixation with 10% neutral buffered formalin (10% NBF) as the fixative of choice. Also, both human and veterinary pathologists have trained to use fixation with 10% NBF, so these professionals are reluctant to change the familiar microscopic appearance of diagnostic tissues by using different fixatives. In addition, the effects of tissue processing on the microscopic appearance of tissue essentially has been ignored in most studies. Archives of paraffin blocks of pathological tissue contain essentially paraffin blocks fixed in 10% NBF. Therefore, if retrospective studies use archival paraffin blocks to correlate the molecular features of diseases with their outcomes, the studies must be based on tissue fixed in 10% NBF. Studies of how fixation in 10% NBF interacts with histochemical and immunohistochemical staining are limited in number and most are based on relatively long fixation times (≥36 h). Currently, fixation times in 10% NBF have been reduced to <24 h. Little is known about fixation in 10% NBF and its interaction with tissue processing for any period of fixation, especially short times. Less is known about how fixation of tissues with 10% NBF interacts with more modern assays using immunohistochemistry, real time quantitative polymerise chain reaction (PCR), and techniques that depend on analysis of proteins extracted from paraffin blocks including multiplex immunoassays or mass spectrometry. In general, multiple antibody-antigen combinations are reported not to work in tissues fixed in 10% NBF, i.e., loss of immunorecognition is nearly complete for such antibody-antigen combinations as Ki67/MIB, estrogen receptor alpha (ERα) and Progesterone receptor (PR), and partial for Bcl-2. Several models have been developed to study the interactions of tissue fixation and immunorecognition, but most have viewed the problem with immunorecognition as completely caused by fixation. Also, some of the models discussed in this special symposium do not predict the effects of fixation on frozen tissues fixed in 10% NBF and not processed to paraffin blocks. This article is a brief review of issues attending the use of 10% NBF combined with tissue processing as an interrelated process to study biomarkers identified by immunohistochemistry. [ABSTRACT FROM AUTHOR]

Abstract: Chemiluminescence immunoassay (CLIA) offers several potential advantages and has applications in clinical chemistry, bioanalysis and environmental analysis. This review covers recent developments and applications of CLIA in immunorecognition, CL markers and related techniques, and solid-phase materials. We describe automation, integration and miniaturization of CLIA. We evaluate different CLIA systems and give some pointers as to the likely directions of future developments. [Copyright &y& Elsevier]

Cancer cells’ growth in three-dimensional (3D) architectures promotes resistance to drugs, cytokines, or irradiation. We investigated effects of 3D culture as compared to monolayers (2D) on melanoma cells’ recognition by tumour-associated antigen (TAA)-specific HLA-A*0201-restricted cytotoxic T-lymphocytes (CTL). Culture of HBL, D10 (both HLA-A*0201+, TAA+) and NA8 (HLA-A*0201+, TAA−) melanoma cells on polyHEMA-coated plates, resulted in generation of 3D multicellular tumour spheroids (MCTS). Interferon-gamma (IFN-γ) production by HLA-A*0201-restricted Melan-A/MART-127–35 or gp100280–288-specific CTL clones served as immunorecognition marker. Co-culture with melanoma MCTS, resulted in defective TAA recognition by CTL as compared to 2D as witnessed by decreased IFN-γ production and decreased Fas Ligand, perforin and granzyme B gene expression. A multiplicity of mechanisms were potentially involved. First, MCTS per se limit CTL capacity of recognising HLA class I restricted antigens by reducing exposed cell surfaces. Second, expression of melanoma differentiation antigens is downregulated in MCTS. Third, expression of HLA class I molecules can be downregulated in melanoma MCTS, possibly due to decreased interferon-regulating factor-1 gene expression. Fourth, lactic acid production is increased in MCTS, as compared to 2D. These data suggest that melanoma cells growing in 3D, even in the absence of immune selection, feature characteristics capable of dramatically inhibiting TAA recognition by specific CTL.British Journal of Cancer (2007) 96, 1072–1082. doi:10.1038/sj.bjc.6603664 www.bjcancer.com Published online 6 March 2007 [ABSTRACT FROM AUTHOR]

Formation of covalently bound protein adducts with 2-arylpropionic acids (2-APAs) has been proposed as a possible explanation for hypersensitivity and toxic responses to chiral carboxylic acid drugs. To identify the cellular proteins chemically modified with optically active (S)-ibuprofen, we generate polyclonal antibodies by immunizing rabbits with immunogen coupled to bovine serum albumin (BSA) via the spacer of 4-aminobutyric acid. The resulting antibodies largely cross-reacted with N-α-(t-butoxycarbonyl)-#x03B5;-(S)-ibuprofenyl lysine as well as with the conjuguated (S)-ibuprofen with glycine and taurine and unconjugated (S)-ibuprofen, enabling enantioselective detection of (S)-ibuprofen residues anchored on ovalbumin molecules, introduced by the reaction of the ibuprofen p-nitrophenyl ester. Furthermore, immunoblotting with an antibody allows the enantioselective detection of (S)-ibuprofen-introduced glutathione-S-transferase (GST). These results indicate that the developed method will be useful for monitoring the generation and localization of protein covalently bound with (S)-ibuprofen, which may be the cause of ibuprofen-induced toxicity. [Copyright &y& Elsevier]

IgG antibodies from sera of rabbits immunized with a mixture of three synthetic peptides of highly conserved surface-exposed sequences between Schistosoma japonicum and S. mansoni cathepsin D, and a rabbit anti-bovine cathepsin D serum strongly recognized a 45 kDa molecule on immunoblots of adult S. mansoni worm saline extracts (AWSE). This recognition was abolished by immunoadsorption with two of the three selected peptides. The anti-peptide antibodies fixed onto Protein A-Sepharose specifically immunoprecipitated a S. mansoni AWSE component that was able to degrade bovine hemoglobin at pH 3.8. This reaction was inhibited by 7 μM pepstatin A, a classical aspartyl protease inhibitor, suggesting that the parasite cathepsin D was immunoprecipitated. The anti-peptide antibodies also recognized on a dot-blot assay a purified, commercially obtained bovine cathepsin D preparation but not the purified human counterpart. On the other hand, the anti-bovine cathepsin D serum recognized the two above-mentioned schistosome peptides. In addition, S. mansoni-infected patient sera recognized on immunoblots the bovine but not the human cathepsin D. These results, together with a comparative analysis of the selected peptide sequence regions between the schistosome and the two mammal enzymes, allowed us to pinpoint to one amino acid the cross-reactivity between parasite and bovine cathepsin D and the lack of it with human cathepsin D. This difference might be of relevance for immunodiagnosis. [Copyright &y& Elsevier]

Envenomation by two medically important Sundaic pit vipers, Trimeresurus wiroti (Malaysia) and Trimeresurus puniceus (Indonesia), causes hemotoxic syndrome with a potentially fatal outcome. Research on the compositions and antigenicity of these pit viper venoms is however lacking, limiting our understanding of the pathophysiology and treatment of envenomation. This study investigated the venom proteomes of both species through a protein decomplexation strategy, applying C 18 reverse-phase high-performance liquid chromatography followed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), and protein identification through nano-electrospray ionization liquid chromatography-tandem mass spectrometry (nano-ESI-LCMS/MS) of trypsin-digested peptides. The venom antigenicity was profiled against the Thai Green Pit Viper Antivenom (GPVAV, a hetero-specific antivenom), using indirect enzyme-linked immunosorbent assay (ELISA). The venom proteomes of T. wiroti and T. puniceus consisted of 10 and 12 toxin families, respectively. The major proteins were of diverse snake venom serine proteases (19–30% of total venom proteins), snake venom metalloproteinases (17–26%), disintegrins (9–16%), phospholipases A 2 (8–28%) and C-type lectins (~8%). These were putative snake toxins implicated in hemorrhage and coagulopathy, consistent with clinical hemotoxicity. GPVAV showed strong immunorecognition toward high and medium molecular weight proteins (e.g. , SVMP and PLA 2) in both venoms, while a lower binding activity was observed toward small proteins such as disintegrins. Conserved antigenicity in the major hemotoxins supported toxicity cross-neutralization by GPVAV and indicated that the immunorecognition of low molecular weight toxins may be optimized for improved binding efficacy. Taken together, the study provides insights into the pathophysiology and antivenom treatment of envenomation caused by T. wiroti and T. puniceus in the region. [Display omitted] • Venom proteomes of Trimeresurus wiroti and Trimeresurus puniceus were investigated. • Both venoms contained primarily diverse coagulopathic and hemorrhagic toxins. • Thai Green Pit Viper Antivenom immunorecognized larger proteins more effectively. • Immunorecognition was weak for small toxins and some snake venom serine proteases. • Study provides insights into pathophysiology and antivenom treatment of envenoming. [ABSTRACT FROM AUTHOR]

Exosome-mediated delivery of NANPs and/or other functional moieties. After isolation and purification of exosomes, cargos of interest are loaded into the exosome lumen and used for the delivery to target cells. [Display omitted] With recent advances in nanotechnology and therapeutic nucleic acids (TNAs), various nucleic acid nanoparticles (NANPs) have demonstrated great promise in diagnostics and therapeutics. However, the full realization of NANPs' potential necessitates the development of a safe, efficient, biocompatible, stable, tissue-specific, and non-immunogenic delivery system. Exosomes, the smallest extracellular vesicles and an endogenous source of nanocarriers, offer these advantages while avoiding complications associated with manufactured agents. The lipid membranes of exosomes surround a hydrophilic core, allowing for the simultaneous incorporation of hydrophobic and hydrophilic drugs, nucleic acids, and proteins. Additional capabilities for post-isolation exosome surface modifications with imaging agents, targeting ligands, and covalent linkages also pave the way for their diverse biomedical applications. This review focuses on exosomes: their biogenesis, intracellular trafficking, transportation capacities, and applications with emphasis on the delivery of TNAs and programmable NANPs. We also highlight some of the current challenges and discuss opportunities related to the development of therapeutic exosome-based formulations and their clinical translation. [ABSTRACT FROM AUTHOR]

The relatively straightforward methods of designing and assembling various functional nucleic acids into nanoparticles offer advantages for applications in diverse diagnostic and therapeutic approaches. However, due to the novelty of this approach, nucleic acid nanoparticles (NANPs) are not yet used in the clinic. The immune recognition of NANPs is among the areas of preclinical investigation aimed at enabling the translation of these novel materials into clinical settings. NANPs' interactions with the complement system, coagulation systems, and immune cells are essential components of their preclinical safety portfolio. It has been established that NANPs' physicochemical properties—composition, shape, and size—determine their interactions with immune cells (primarily blood plasmacytoid dendritic cells and monocytes), enable recognition by pattern recognition receptors (PRRs) such as Toll-like receptors (TLRs) and RIG-I-like receptors (RLRs), and mediate the subsequent cytokine response. However, unlike traditional therapeutic nucleic acids (e.g., CpG oligonucleotides), NANPs do not trigger a cytokine response unless they are delivered into the cells using a carrier. Recently, it was discovered that the type of carrier provides an additional tool for regulating both the spectrum and the magnitude of the cytokine response to NANPs. Herein, we review the current knowledge of NANPs' interactions with various components of the immune system to emphasize the unique properties of these nanomaterials and highlight opportunities for their use in vaccines and immunotherapy. [ABSTRACT FROM AUTHOR]

For almost a century self-nonself discrimination has been considered the driving force of the immune system and the dogma of self-tolerance ( horror autotoxicus) the essential issue for understanding protective immunity and pathologic autoreactivity. This classical picture has been recently challenged by the discovery that the immune system is influenced by internal activation ( amor autocognitus) and autoreactive clones are both present and activated in healthy individuals. Central to the concepts of reactivity and tolerance, in other terms, to physiology and pathology, is the analysis of structures involved in immunorecognition and as they contribute to the outcome of the immune response. The capacity of the immune system to recognize nonself structures and eventually react to them developed during evolution probably before the generation of clonally distributed antigen receptors. The high level of autoreactivity that characterizes the immune system seems to suggest that immunocompetent cells never learned to ignore the self, but rather that, sometime during evolution, they specialized in the function of self-identification, one of the most basic activities of all living cells. Autoimmune diseases would result from a pathologic deviation of a physiologic function, just as many other diseases do. [ABSTRACT FROM AUTHOR]

Haemocytes of the gastropod mollusc, Helix pomatia, possess on their surface a membrane-integrated GalNac-specific lectin which binds to and stimulates phagocytosis of GalNac-bearing target cells (human A erythrocytes) only in the presence of extracellular calcium ions. Target cells without GalNac moieties on their surface (human B and bovine erythrocytes) are not recognised. Helix haemocytes also possess a Ca-independent mannose-6-phosphate-specific lectin on their surface which, in the absence of extracellular calcium ions, enables recognition and phagocytosis of A rbc opsonised with agglutinins isolated from either the snail's albumin gland or serum. These opsonins, however, bind to host haemocytes only after binding to GalNac moieties on the surface of test particles. Our results indicate that such a ligand-specific opsonin/target cell interaction apparently induces a conformational change in the opsonin, resulting in exposure of mannose 6-phosphate moieties that are recognised by the Ca-independent lectin on the surface of the haemocytes. [ABSTRACT FROM AUTHOR]

• King cobra (Ophiophagus hannah) venoms (KCV) exhibit geographical variation. • Indonesian and Chinese KCV are more lethal than Malaysian and Thai KCV. • Thai Ophiophagus hannah monovalent antivenom (OHMAV) is the most potent. • OHMAV showed different efficacy toward KCV from different geographical locales. • Heterospecific antivenoms have limited or negligible efficacy toward KCV. The wide distribution of king cobra (Ophiophagus hannah), a medically important venomous snake in Asia could be associated with geographical variation in the toxicity and antigenicity of the venom. This study investigated the lethality of king cobra venoms (KCV) from four geographical locales (Malaysia, Thailand, Indonesia, China), and the immunological binding as well as in vivo neutralization activities of three antivenom products (Thai Ophiophagus hannah monovalent antivenom, OHMAV; Indonesian Serum Anti Bisa Ular, SABU; Chinese Naja atra monovalent antivenom, NAMAV) toward the venoms. The Indonesian and Chinese KCV were more lethal (median lethal dose, LD 50 ~0.5 μg/g) than those from Malaysia and Thailand (LD 50 ~1.0 μg/g). The antivenoms, composed of F(ab)' 2 , were variably immunoreactive toward the KCV from all locales, with OHMAV exhibited the highest immunological binding activity. In mice, OHMAV neutralized the neurotoxic lethality of Thai KCV most effectively (normalized potency = 118 mg venom neutralized per g antivenom) followed by Malaysian, Indonesian and Chinese KCV. In comparison, the hetero-specific SABU was remarkably less potent by at least 6 to10 folds, whereas NAMAV appeared to be non-effective. The finding supports that a specific king cobra antivenom is needed for the effective treatment of king cobra envenomation in each region. Image, graphical abstract [ABSTRACT FROM AUTHOR]

Nucleic acid nanoparticles (NANPs) have evolved as a new class of therapeutics with the potential to detect and treat diseases. Despite tremendous advancements in NANP development, their immunotoxicity, one of the major impediments in clinical translation of traditional therapeutic nucleic acids (TNAs), has never been fully characterized. Here, we describe the first systematically studied immunological recognition of 25 representative RNA and DNA NANPs selected to have different design principles and physicochemical properties. We discover that, unlike traditional TNAs, NANPs used without a delivery carrier are immunoquiescent. We show that interferons (IFNs) are the key cytokines triggered by NANPs after their internalization by phagocytic cells, which agrees with predictions based on the experiences with TNAs. However, in addition to type I IFNs, type III IFNs also serve as reliable biomarkers of NANPs, which is usually not characteristic of TNAs. We show that overall immunostimulation relies on NANP shapes, connectivities, and compositions. We demonstrate that, like with traditional TNAs, plasmacytoid dendritic cells serve as the primary interferon producers among all peripheral blood mononuclear cells treated with NANPs, and scavenger receptor-mediated uptake and endosomal Toll-like receptor signaling are essential for NANP immunorecognition. The TLR involvement, however, is different from that expected for traditional TNA recognition. Based on these results, we suggest that NANP technology may serve as a prototype of auxiliary molecular language for communication with the immune system and the modulation of immune responses.