Th1-type Immune Response Research Articles

The immunogenicity of Alum+CpG adjuvant SARS-CoV-2 inactivated vaccine in mice

The ongoing evolution and emergence of SARS-CoV-2 variants have raised concerns regarding the efficacy of existing vaccines and therapeutic agents. This study aimed to investigate the immunogenicity of an aluminum hydroxide (Alum) and CpG adjuvanted inactivated vaccine (IAV) candidate against SARS-CoV-2 in mice. A comparison was made between the immune response of mice vaccinated with the Alum+CpG adjuvant IAV and those vaccinated with the Alum adjuvant IAV. Mice immunized with Alum+CpG adjuvant IAV demonstrated high antibody titers and a durable humoral immune response, as well as a Th1-type cellular immune response. Notably, compared to Alum alone vaccine, the Alum+CpG adjuvant IAV induced significantly higher proportions of GC B cells in the splenocytes of immunized mice. Importantly, the changes in inflammatory cytokine levels in the sera of mice vaccinated with the Alum+CpG adjuvant IAV followed a similar trend to that of the Alum adjuvant IAV, which had been proven safe in clinical trials. Overall, our results demonstrate that Alum+CpG adjuvant has the potential to serve as a novel adjuvant, thereby providing valuable insights into the development of vaccine formulations.

Identification of broadly-conserved parasitic nematode proteins that activate immunity

IntroductionSoil transmitted nematodes are impediments to human health and agricultural production. Poor anthelmintic efficiencies, the emergence of resistant strains, and the persistence of infective stages highlight the need for more effective control strategies. Parasitic nematodes elicit a Th2-type immune response that most often is not protective. Vaccination has thus far been unsuccessful due to unrealized antigenic characters and unknown mechanisms that nematodes use to circumvent host immunity.MethodsHere, we used a genomics/proteomics approach (including immunoblot experiments from pigs infected with T. suis) to prioritize putative immunogenic excretory/secretory (E/S) proteins conserved across and specific to several gastrointestinal (GI) parasitic nematode species. A cocktail of five recombinant proteins optimized for conserved GI nematode targets was used immunize pigs and test for active antibody responses in both the serum and intestinal ileal fluid of immunized pigs. An antibody-protein array of putative immunogenic proteins was developed from a combined bioinformatic, experimental, and literature-based prioritization of homologous parasite proteins.ResultsScreening the array with sera and ileal fluid samples from immunized pigs suggested cross-reactivity among homologous proteins and a general activation of immunity. PCA clustering showed that the overall immune responses were altered by immunization, but no substantial changes were observed following direct worm challenge with either Ascaris suum or Trichuris suis.DiscussionProteins that activated immunity are potential antigens for immunization and the multi-omics phylum-spanning prioritization database that was created is a valuable resource for identifying target proteins in a wide array of different parasitic nematodes. This research strongly supports future studies using a computational, comparative genomics/proteomics approach to produce an effective parasite vaccine.

Recognition of the Subtypes Classification and Diagnostic Signature Based on RNA N6-Methyladenosine Regulators in Recurrent Spontaneous Abortion.

Recurrent spontaneous abortion (RSA) is a common reproductive disease in female patients that seriously affects the quality of life of patients. N6-methyladenosine (m6A), as the most common modification, plays an important role in various biological behaviors; however, the relationship between m6A and RSA is still unknown. In the present study, we utilized RNA sequencing data and clinical information of RSA patients and normal women in the GEO database to identify the expression profiles of m6A regulators in RSA. Based on the m6A regulators' expression profiles, we constructed a random forest model consisting of 4 genes to predict the prevalence of RSA patients, including FMR1, METTL14, LRPPRC, and RBMX. The predictive performance of the nomogram was constructed and validated. Not only that, consensus clustering was performed to divide RSA patients into 3 clusters based on the expression of m6A regulators and calculated the m6A scores and immune infiltration of patients in different clusters. It was found that the TH1-type immune response was dominant in the A cluster, the B-type immune activity was poor, and the C cluster was the strongest. In addition, on the basis of m6A typing, we further used the differentially expressed genes between clusters to perform consensus clustering verification, and the results were consistent with the previous findings. In conclusion, the m6A regulators played an indispensable role in the occurrence of RSA, and the m6A-based typing could effectively identify the immune characteristics of different RSA patients to a certain extent, providing a new direction and strategy for the diagnosis and treatment of RSA patients.

Toxoplasma gondii Suppresses Th2-Induced by Trichinella spiralis Infection and Downregulates Serine Protease Genes Expression: A Critical Role in Vaccine Development.

Toxoplasma gondii coinfection can modify host immune responses and the severity and spread of other parasites. We investigated how T. gondii and Trichinella spiralis infections counter-regulate each other's immune responses. The parasite burden, the expression of T. gondii rhoptry kinase ROP18 and T. spiralis putative serine protease (TsSP), the IgG1 and IgG2a responses, besides histopathological and immunohistochemical staining with iNOS and arginase were used to evaluate the dynamics of coinfection. Through their effects on host immune responsiveness, coinfection with T. gondii modified the virulence of T. spiralis infection. Coinfected animals with high and low doses of T. gondii demonstrated significant reductions in the T. spiralis burden of 75.2% and 68.2%, respectively. TsSP expression was downregulated in both groups by 96.2% and 86.7%, whereasROP18 expression was downregulated by only 6% and10.6%, respectively. In coinfected mice, elevated levels of T. gondii-specific IgG2a antibodies were detected. Th1 induced by T. gondii inhibits the Th2 response to T. spiralis in coinfected animals with high iNOS expression andlow-arginine1 expression. T. gondii infection induces a shift toward a Th1-type immune response while suppressing a helminth-specific Th2 immune response, paving the way for developing novel vaccines and more efficient control strategies.

CHO-produced RBD-Fc subunit vaccines with alternative adjuvants generate immune responses against SARS-CoV-2.

Subunit vaccines feature critical advantages over other vaccine platforms such as stability, price, and minimal adverse effects. To maximize immunological protection of subunit vaccines, adjuvants are considered as main components that are formulated within the subunit vaccine. They can modulate adverse effects and enhance immune outcomes. However, the most suitable formulation providing the best immunological outcomes and safety are still under investigation. In this report, we combined recombinant RBD with human IgG1 Fc to create an RBD dimer. This fusion protein was expressed in CHO and formulated with alternative adjuvants with different immune activation including Montanide ISA51, Poly (I:C), and MPLA/Quil-A® as potential vaccine candidate formulations. Using the murine model, a potent induction of anti-RBD IgG antibodies in immunized mice sera were observed. IgG subclass analyses (IgG1/IgG2a) illustrated that all adjuvanted formulations could stimulate both Th1 and Th2-type immune responses in particular Poly (I:C) and MPLA/Quil-A®, eliciting greater balance. In addition, Montanide ISA51-formulated RBD-Fc vaccination provided a promising level of neutralizing antibodies against live wild-type SARS-CoV-2 in vitro followed by Poly (I:C) and MPLA/Quil-A®, respectively. Also, mice sera from adjuvanted formulations could strongly inhibit RBD:ACE2 interaction. This study offers immunogenicity profiles, forecasted safety based on Vaccine-associated enhanced disease (VAED) caused by Th1-skewed immunity, and neutralizing antibody analysis of candidates of RBD-Fc-based subunit vaccine formulations to obtain an alternative subunit vaccine formulation against SARS-CoV-2.

The association between rLiHyp1 protein plus adjuvant and amphotericin B is an effective immunotherapy against visceral leishmaniasis in mice

Treatment of visceral leishmaniasis (VL) is compromised by drug toxicity, high cost and/or the emergence of resistant strains. Though canine vaccines are available, there are no licensed prophylactic human vaccines. One strategy to improve clinical outcome for infected patients is immunotherapy, which associates a chemotherapy that acts directly to reduce parasitism and the administration of an immunogen-adjuvant that activates the host protective Th1-type immune response. In this study, we evaluated an immunotherapy protocol in a murine model by combining recombinant (r)LiHyp1 (a hypothetical amastigote-specific Leishmania protein protective against Leishmania infantum infection), with monophosphoryl-lipid A (MPLA) as adjuvant and amphotericin B (AmpB) as reference antileishmanial drug. We used this protocol to treat L. infantum infected-BALB/c mice, and parasitological, immunological and toxicological evaluations were performed at 1 and 30 days after treatment. Results showed that mice treated with rLiHyp1/MPLA/AmpB presented the lowest parasite burden in all organs evaluated, when both a limiting dilution technique and qPCR were used. In addition, these animals produced higher levels of IFN-γ and IL-12 cytokines and IgG2a isotype antibody, which were associated with lower production of IL-4 and IL-10 and IgG1 isotype. Furthermore, low levels of renal and hepatic damage markers were found in animals treated with rLiHyp1/MPLA/AmpB possibly reflecting the lower parasite load, as compared to the other groups. We conclude that the rLiHyp1/MPLA/AmpB combination could be considered in future studies as an immunotherapy protocol to treat against VL.

Efficacy of an Immunotherapy Combining Immunogenic Chimeric Protein Plus Adjuvant and Amphotericin B against Murine Visceral Leishmaniasis.

Visceral leishmaniasis (VL) in the Americas is a chronic systemic disease caused by infection with Leishmania infantum parasites. The toxicity of antileishmanial drugs, long treatment course and limited efficacy are significant concerns that hamper adequate treatment against the disease. Studies have shown the promise of an immunotherapeutics approach, combining antileishmanial drugs to reduce the parasitism and vaccine immunogens to activate the host immune system. In the current study, we developed an immunotherapy using a recombinant T cell epitope-based chimeric protein, ChimT, previously shown to be protective against Leishmania infantum, with the adjuvant monophosphoryl lipid A (MPLA) and amphotericin B (AmpB) as the antileishmanial drug. BALB/c mice were infected with L. infantum stationary promastigotes and later they received saline or were treated with AmpB, MPLA, ChimT/Amp, ChimT/MPLA or ChimT/MPLA/AmpB. The combination of ChimT/MPLA/AmpB significantly reduced the parasite load in mouse organs (p < 0.05) and induced a Th1-type immune response, which was characterized by higher ratios of anti-ChimT and anti-parasite IgG2a:IgG1 antibodies, increased IFN-γ mRNA and IFN-γ and IL-12 cytokines and accompanied by lower levels of IL-4 and IL-10 cytokines, when compared to other treatments and controls (all p < 0.05). Organ toxicity was also lower with the ChimT/MPLA/AmpB immunotherapy, suggesting that the inclusion of the vaccine and adjuvant ameliorated the toxicity of AmpB to some degree. In addition, the ChimT vaccine alone stimulated in vitro murine macrophages to significantly kill three different internalized species of Leishmania parasites and to produce Th1-type cytokines into the culture supernatants. To conclude, our data suggest that the combination of ChimT/MPLA/AmpB could be considered for further studies as an immunotherapy for L. infantum infection.

The local skin cellular immune response determines the clinical outcome of sarcoptic mange in Iberian ibex (Capra pyrenaica).

Sarcoptic mange, caused by Sarcoptes scabiei, is a disease with implications for wildlife conservation and management. Its severity depends on the host's local skin immune response, which is largely unknown in Iberian ibex (Capra pyrenaica), a mountain ungulate dramatically affected by mange. In this species, the clinical outcome of sarcoptic mange varies among individuals, and the local immune response could be key to controlling the infestation. This study aims to characterize the local cellular immune response and its relationship with the clinical outcome. Fourteen Iberian ibexes were experimentally infested with S. scabiei and six more served as controls. Clinical signs were monitored, and skin biopsies were collected from the withers at 26, 46, and 103 days post-infection (dpi). The presence and distribution of macrophages (including M1 and M2 phenotypes), T lymphocytes, B lymphocytes, plasma cells, and interleukine 10 were quantitatively evaluated using immunohistochemical techniques. An inflammatory infiltrate that decreased significantly from 26 to 103 dpi was observed in all the infested ibexes. The predominant inflammatory cell population in the skin of the mangy ibexes was formed by macrophages (mainly the M2 phenotype) followed by T lymphocytes, with lower numbers of B lymphocytes and plasma cells. Three clinical courses were identified: total recovery, partial recovery, and terminal stage. The inflammatory infiltrates were less pronounced in the fully recovered ibexes than in those that progressed to the terminal stage throughout the study. The results suggest an exacerbated but effective Th1-type cellular immune response controlling mange in Iberian ibex. Furthermore, the local immune response appears to determine the variability of the clinical responses to S. scabiei infestation in this species. This first report on the progression of local skin immune cells is relevant not only for individuals but also for population management and conservation.

A MnAl double adjuvant nanovaccine to induce strong humoral and cellular immune responses.

At present, the most widely used aluminum adjuvants have poor ability to induce effective Th1 type immune responses. Existing evidence suggests that manganese is a potential metal adjuvant by activating cyclic guanosine phospho-adenosine synthase (cGAS)-interferon gene stimulator protein (STING) signaling pathway to enhance humoral and cellular immune response. Hence, the effective modulation of metal components is expected to be a new strategy to improve the efficiency of vaccine immunization. Here, we constructed a manganese and aluminum dual-adjuvant antigen co-delivery system (MnO2-Al-OVA) to enhance the immune responses of subunit vaccines. Namely, the aluminum hydroxide was first fused on the surface of the pre-prepared MnO2 nanoparticles, which were synthesized by a simple redox reaction with potassium permanganate (KMnO4) and oleic acid (OA). The engineered MnO2-Al-OVA could remarkably promote cellular internalization and maturation of dendritic cells. After subcutaneous vaccination, MnO2-Al-OVA rapidly migrated into the lymph nodes (LNs) and efficiently activate the cGAS-STING pathway, greatly induced humoral and cellular immune responses. Of note, our findings underscore the importance of coordination manganese adjuvants in vaccine design by promoting the activation of the cGAS-STING-IFN-I pathway. With a good safety profile and facile preparation process, this dual-adjuvant antigen co-delivery nanovaccine has great potential for clinical translation prospects.

Depletion of Mcpip1 in murine myeloid cells results in intestinal dysbiosis followed by allergic inflammation

MCPIP1 (called also Regnase-1) is a negative regulator of inflammation. Knockout of the Zc3h12a gene, encoding Mcpip1 in cells of myeloid origin (Mcpip1MKO), has a pathological effect on many organs. The aim of this study was to comprehensively analyze pathological changes in the skin caused by Mcpip1 deficiency in phagocytes with an emphasis on its molecular mechanism associated with microbiome dysbiosis.Mcpip1MKO mice exhibited spontaneous wound formation on the skin. On a molecular level, the Th2-type immune response was predominantly characterized by an increase in Il5 and Il13 transcript levels, as well as eosinophil and mast cell infiltration. Irritation by DNFB led to a more severe skin contact allergy in Mcpip1MKO mice. Allergic reactions on the skin were strongly influenced by gut dysbiosis and enhanced systemic dissemination of bacteria. This process was followed by activation of the C/EBP pathway in peripheral macrophages, leading to local changes in the cytokine microenvironment that promoted the Th2 response. A reduced bacterial load inhibited allergic inflammation, indicating the role of intestinal dysbiosis in the development of skin diseases. Our results clearly show that MCPIP1 in phagocytes is an essential negative regulator that controls the gut-skin axis.

Eosinophil Granule Proteins Involvement in Acute Appendicitis-An Allergic Disease?

Several pieces of evidence point to an allergic component as a trigger of acute appendicitis. As the Th2 immune response is characterized by eosinophil mobilization to the target organ and release of their cationic granule proteins, it is reasonable to investigate if the degranulation of eosinophils could be associated with the local injury. The primary aim of this study is to evaluate the participation of eosinophils granules proteins in acute appendicitis, both at local and systemic levels and the secondary aim is to evaluate the diagnostic accuracy of eosinophils granules proteins for the detection of acute appendicitis, as well as for distinguishing between complicated and uncomplicated acute appendicitis. Eosinophil-derived neurotoxin (EDN), eosinophil cationic protein (ECP) and eosinophil peroxidase (EP) are the most well-known eosinophil granule proteins. From August 2021 to April 2022, we present a prospective single-center study to evaluate the EDN, ECP, and EP concentrations simultaneously in appendicular lavage fluid (ALF) and the serum of 22 patients with acute phlegmonous appendicitis (APA), 24 with acute gangrenous appendicitis (AGA), and 14 normal controls. Concerning EDN, no differences were found between groups. ECP concentrations in ALF and serum were significantly higher in the histologically confirmed acute appendicitis compared to the control groups (p < 0.0001 and p < 0.0001, respectively). In ALF, no differences were found between ECP levels in APA: 38.85 ng/mL (IQR 26.50-51.77) and AGA 51.55 ng/mL (IQR 39.55-70.09) groups (p = 0.176). In the serum, no difference was found between ECP levels at APA: 39 ng/mL (IQR 21.30-56.90) and AGA: 51.30 ng/mL (IQR 20.25-62.59) (p = 0.100). For EP, the concentrations in ALF (p < 0.001) and serum (p < 0.001) were both higher in acute appendicitis compared to the control. In ALF, no difference was found between APA: 240.28 ng/mL (IQR 191.2-341.3) and AGA: 302.5 (IQR 227.7-535.85) (p = 0.236). In the serum, no differences were found between APA: 158.4 ng/mL (IQR 111.09-222.1) and AGA: 235.27 (IQR 192.33-262.51) (p = 0.179). Globally, the ALF concentrations were higher than serum concentrations, reflecting an intense inflammatory local reaction in AA. The optimal ECP cut-off for discriminating between acute appendicitis and the controls was >11.41 ng/mL, with a sensitivity of 93.5%, but with a specificity for identifying appendicitis of 21.4%, good discriminative power (AUC = 0.880). For EP, the optimal cut-off was >93.20 ng/mL, with a sensitivity of 87%, but with a specificity of 14.3% (AUC = 0.901), excellent discriminative power. For the diagnosis of perforated AA, the discriminative power of ECP and EP serum concentrations are weak (AUC = 0.562 and AUC = 0.664, respectively). Concerning the presence of peritonitis, the discriminative power of ECP and EP serum concentrations is acceptable, respectively: AUC = 0.724 and AUC = 0.735. Serum levels of EDN (p = 0.119), ECP (p = 0.586) and EP (p = 0.08) in complicated appendicitis were similar to uncomplicated appendicitis. Serum concentrations of ECP and EP can be added to decision-making AA diagnosis. A Th2-type immune response is present in AA. These data bring forward the role of an allergic reaction in the pathogenesis of acute appendicitis.

A candidate subunit vaccine induces protective immunity against Mycobacterium avium subspecies paratuberculosis in mice

Mycobacterium avium subspecies paratuberculosis (MAP) causes paratuberculosis (PTB), which is a granulomatous enteritis in ruminants that threatens the dairy industry’s healthy development and public health safety worldwide. Because the commercial inactivated vaccines are not completely protective and interfere with bovine tuberculosis diagnostics, we tested four fusion proteins, namely 66NC, 66CN, 90NC, and 90CN, which were constructed with MAP3527, Ag85B, and Hsp70 of MAP in different tandem combinations. Notably, 66NC, which encodes a 66 kDa fusion protein that combines in linear order MAP3527N40–232, Ag85B41–330, and MAP3527C231–361, induced a powerful and specific IFN-γ response. Immunization of C57BL/6 mice with the 66NC fusion protein formulated in Montanide ISA 61 VG adjuvant generated robust Th1, Th2, and Th17 type immune responses and strong antibody responses. The 66NC vaccine protected C57BL/6 mice against virulent MAP K-10 infection. This resulted in a reduction of bacterial load and improvement of pathological damage in the liver and intestine, in addition to a reduction of body weight loss; significantly better protection than the reported 74 F vaccine was also induced. Furthermore, vaccine efficacy correlated with the levels of IFN-γ-, TNF-α-, and IL-17A-secreting antigen-specific CD4+ and CD8+ T lymphocytes as well as with serum IFN-γ and TNF-α levels after vaccination. These results demonstrate that recombinant protein 66NC is an efficient candidate for further development into a protective vaccine in terms of inducing specific protection against MAP.

Global inhibition of Ly-49/MHC-I interactions by anti-MHC-I augments innate and adaptive immunity against cancer metastasis.

Abstract We have identified an pan-anti-MHC-I mAb (M1/42), which blocks the interaction of NK cell inhibitory receptors (Ly-49 antigens) with MHC-I, but does not inhibit antigen presentation by MHC-I. Administration of M1/42 in vivo markedly activated IFNg-producing NK cells. NK cell-derived IFNg stimulated APC to produce IL-12/-15/-18 cytokine cascades that further drove the proliferation of NK cells and memory phenotype (MP) T cells. M1/42 treatments profoundly augmented innate and adaptive immunity against PD-1-sensitive and -resistant transplanted tumors. Given that NK cells are critical to control of cancer metastases, we evaluated the effects of M1/42 therapy in several metastatic cancer models. M1/42 treatments successfully constrained B16F10 lung metastasis by enhancing CD8 +T cell infiltration and inducing melanoma-specific MP CD8 +T cell expansion and activation. In contrast, treatment with conventional checkpoint inhibitors (anti-PD-1/PD-L1, anti-CTLA-4 and anti-NKG2A) had no therapeutic effect. scRNAseq analysis of B16F10 lung melanoma tumor infiltrating lymphocytes revealed that M1/42 treatment significantly enhanced the expression of multiple genes associated with NK cell proliferation and activation. M1/42 also enhanced Th1-type innate and adaptive immune responses, and greatly restricted liver and lung metastasis produced by pancreatic adenocarcinoma cell line via intrasplenic or intravenous injection. Thus, the global inhibition of Ly-49/MHC-I interactions by M1/42 results in activation of a potent innate and adaptive immune response that restrains the growth of both transplanted tumors and cancer metastasis produced by intrasplenic or intravenous injection of tumor cells. This work was supported by the Intramural Research Program of NIAID, NIH.

Preparation and Evaluation of Polyacrylate Microgels and Their Adjuvant Activities Using Ovalbumin as a Model Antigen.

As vaccine adjuvants, polyacrylate materials can induce a specific immune response in the body and have been widely studied in recent years due to their advantages, such as their safety, effectiveness, and low required dosage. In this study, a series of polyacrylates with hydrophobic physical crosslinking and chemical crosslinking were prepared using precipitation polymerization, and their structures were characterized by nuclear magnetic resonance spectroscopy and Fourier-transform infrared spectroscopy. The optimal reaction conditions were determined according to the effect of reaction time, azodiisobutyronitrile, Span 60, allyl pentaerythritol, and octadecyl methacrylate (OMA) contents on the viscosity of the polyacrylate microgel, combined with the effects of allyl pentaerythritol and OMA contents on the subcutaneous immune safety of the polyacrylate microgel in BALB/c mice. The polyacrylate microgels with different OMA contents showed good biological safety. In addition, in vivo immunity experiments were carried out in mice to analyze the adjuvant properties of ovalbumin as a model antigen. Based on the titer results of the IgG1 and IgG2a antibodies, with 1 wt % OMA content, the polyacrylate microgel vaccine could optimally induce the body to produce an immune response type dominated by Th2-type humoral immune response and supplemented by Th1-type cellular immune response.

Toll-like Receptor-Mediated Immunomodulation of Th1-Type Response Stimulated by Recombinant Antigen of Type 2 Porcine Reproductive and Respiratory Syndrome Virus (PRRSV-2).

PRRSV infects CD163-positive macrophages and skews their polarization toward an M2 phenotype, followed by T-cell inactivation. In our previous study, we found that recombinant protein A1 antigen derived from PRRSV-2 was a potential vaccine or adjuvant for immunization against PRRSV-2 infection due to its ability to repolarize macrophages into M1 subtype, thereby reducing CD163 expression for viral entry and promoting immunomodulation for Th1-type responses, except for stimulating Toll-like receptor (TLR) activation. The aim of our current study was to evaluate the effects of another two recombinant antigens, A3 (ORF6L5) and A4 (NLNsp10L11), for their ability to trigger innate immune responses including TLR activation. We isolated pulmonary alveolar macrophages (PAMs) from 8- to 12-week-old specific pathogen free (SPF) piglets and stimulated them with PRRSV (0.01 MOI and 0.05 MOI) or antigens. We also investigated the T-cell differentiation by immunological synapse activation of PAMs and CD4+ T-cells in the cocultured system. To confirm the infection of PRRSV in PAMs, we checked the expression of TLR3, 7, 8, and 9. Our results showed that the expression of TLR3, 7, and 9 were significantly upregulated in PAMs by A3 antigen induction, similar to the extent of PRRSV infection. Gene profile results showed that A3 repolarizes macrophages into the M1 subtype potently, in parallel with A1, as indicated by significant upregulation of proinflammatory genes (TNF-α, IL-6, IL-1β and IL-12). Upon immunological synapse activation, A3 potentially differentiated CD4 T cells into Th1 cells, determined by the expression of IL-12 and IFN-γ secretion. On the contrary, antigen A4 promoted regulatory T cell (T-reg) differentiation by significant upregulation of IL-10 expression. Finally, we concluded that the PRRSV-2 recombinant protein A3 provided better protection against PRRSV infection, suggested by its capability to reeducate immunosuppressive M2 macrophages into proinflammatory M1 cells. As M1 macrophages are prone to be functional antigen-presenting cells (APCs), they can call for TLR activation and Th1-type immune response within the immunological synapse.

Single-Cell Analysis in Blood Reveals Distinct Immune Cell Profiles in Gouty Arthritis.

Gout is a chronic disease caused by monosodium urate crystal deposition. Previous studies have focused on the resident macrophage, infiltrating monocyte, and neutrophil responses to monosodium urate crystal, yet the mechanisms of the potential involvement of other immune cells remain largely unknown. In this study, we enrolled seven gout patients and five age-matched healthy individuals and applied single-cell mass cytometry to study the distribution of immune cell subsets in peripheral blood. To our knowledge, our study reveals the immune cell profiles of gout at different stages for the first time. We identified many immune cell subsets that are dysregulated in gout and promote gouty inflammation, especially those highly expressing CCR4 and OX40 (TNFR superfamily member 4), including CCR4+OX40+ monocytes, CCR4+OX40+CD56high NK cells, CCR4+OX40+CD4+ NK T cells, and CCR4+CD38+CD4+ naïve T cells. Notably, the plasma levels of CCL17 and CCL22, measured by ELISA, increased in the acute phase of gout and declined in the interval. We also found a clue that Th2-type immune responses may participate in gout pathology. Moreover, the subset of granzyme B+ (GZMB+) CD38+ NK cells is positively correlated with serum urea acid level, and another two γδT subsets, GZMB+CD161+ γδT cells and GZMB+CCR5+ γδT cells, are negatively correlated with erythrocyte sedimentation rate. In sum, gouty arthritis is not a disease simply mediated by macrophages; multiple types of immune cell may be involved in the pathogenesis of the disease. Future research needs to shift attention to other immune cell subsets, such as NK cells and T cells, which will facilitate the identification of novel therapeutic targets.

Safety and immunogenicity of a thermostable ID93 + GLA-SE tuberculosis vaccine candidate in healthy adults

Adjuvant-containing subunit vaccines represent a promising approach for protection against tuberculosis (TB), but current candidates require refrigerated storage. Here we present results from a randomized, double-blinded Phase 1 clinical trial (NCT03722472) evaluating the safety, tolerability, and immunogenicity of a thermostable lyophilized single-vial presentation of the ID93 + GLA-SE vaccine candidate compared to the non-thermostable two-vial vaccine presentation in healthy adults. Participants were monitored for primary, secondary, and exploratory endpoints following intramuscular administration of two vaccine doses 56 days apart. Primary endpoints included local and systemic reactogenicity and adverse events. Secondary endpoints included antigen-specific antibody (IgG) and cellular immune responses (cytokine-producing peripheral blood mononuclear cells and T cells). Both vaccine presentations are safe and well tolerated and elicit robust antigen-specific serum antibody and Th1-type cellular immune responses. Compared to the non-thermostable presentation, the thermostable vaccine formulation generates greater serum antibody responses (p < 0.05) and more antibody-secreting cells (p < 0.05). In this work, we show the thermostable ID93 + GLA-SE vaccine candidate is safe and immunogenic in healthy adults.

Nocardia rubra cell-wall skeleton activates an immune response in cervical tissue via stimulating FPR3 to enhance dendritic cell-mediated Th1 differentiation.

Nocardia rubra cell wall skeleton (Nr-CWS) has proven to be a successful medicine for therapy of cervical human papillomavirus infection. The mechanism of action of Nr-CWS is unclear but may involve a stimulatory effect on the host immune system. We previously found that CD4+ T cells were increased in cervical tissue after Nr-CWS treatment. Microarray data from these cervical tissues revealed the significant upregulation of formylated peptide receptor 3 (FPR3). This study aimed to explore the role of Nr-CWS in immunomodulatory based on these findings. Examination of CD4+ T cell subsets in cervical tissue from patients who received Nr-CWS revealed substantial increases in Th1 cytokines and transcription factors. The regulatory effects of Nr-CWS on the function and phenotype of dendritic cells (DCs) were assessed in comparison with the traditional DC maturation inducer lipopolysaccharide (LPS). Similar to LPS, Nr-CWS potently induced DC maturation and interleukin-12 (IL-12) secretion. Differentiation of T cells induced by Nr-CWS stimulated DCs was assessed using the mixed lymphocyte reaction assay. Significant differentiation towards Th1 was evident. Finally, FPR3 expression in DCs in response to Nr-CWS and LPS was measured. Nr-CWS potently upregulated FPR3 expression, while the LPS did not. Silencing FPR3 in DCs reduced Nr-CWS-induced IL-12 production and Th1 cell polarization in co-cultured T cells. The collective findings indicate that Nr-CWS may target FPR3 on the surface of DC cells and activate a Th1-type immune response. The findings clarify the basis of the antiviral immune effects of Nr-CWS on human papillomavirus.

Recombinant endonuclease III protein from Leishmania infantum associated with Th1-type adjuvants is immunogenic and induces protection against visceral leishmaniasis.

Vaccination against visceral leishmaniasis (VL) should be considered as a safe and effective measure to disease control; however, few vaccines are available against canine VL and there is no an approved human vaccine. In this context, in the present study, we evaluated the endonuclease III (ENDO) protein, which was recently showed to be antigenic for human disease, as a vaccine candidate against Leishmania infantum infection. The recombinant protein (rENDO) was administered in BALB/c mice alone or associated with saponin (rENDO/Sap) or micelles (rENDO/Mic) as adjuvants. Controls received saline, saponin or empty micelles. Results showed that both rENDO/Sap and rENDO/Mic compositions induced higher levels of IFN-γ, IL-12, TNF-α, and GM-CSF cytokines, besides nitrite and IgG2a isotype antibodies, before and after challenge infection, which were related to both CD4+ and CD8+ T cell subtypes. The immunological results contributed to significant reductions in the parasite load found in the spleens, livers, bone marrows and draining lymph nodes of the vaccinated animals. In general, mice immunized with rENDO/Mic presented a slightly higher Th1-type cellular and humoral immune response, as compared to those receiving rENDO/Sap. In addition, saponin caused a slight to moderate inflammatory edema in their vaccinated footpads, which was not observed when micelles were used with rENDO. In addition, a preliminary analysis showed that the recombinant protein was immunogenic to human cells cultures, since PBMCs from treated VL patients and healthy subjects showed higher lymphoproliferation and IFN-γ production in the culture supernatants. In conclusion, data suggest that rENDO could be considered as a candidate to be evaluated in future studies as vaccine to protect against VL.

Full-length transcriptome sequencing of lymphocytes respond to IFN-γ reveals a Th1-skewed immune response in flounder (Paralichthys olivaceus)

Interferon gamma (IFN-γ), the member of type II interferons, is a major driver and effector cytokine for Th1 cells and plays broad roles in regulating the function of immune cells. Teleost fish represents the oldest living bony vertebrates containing T-lymphocyte subsets. However, whether or how the regulatory mechanisms of IFN-γ on Th1 cells occur in teleost fish remain unknown. In this study, full-length transcriptome sequencing was performed to analyze the differentially expressed genes (DEGs) and signaling pathways in the IFN-γ stimulated lymphocytes of flounder (Paralichthys olivaceus), the data showed 811 genes were upregulated and 1107 genes were downregulated, Th1 and Th2 cell differentiation pathway was remarkably enriched from DEGs, and the genes in the Th1 cell differentiation pathway were upregulated and verified. Accordingly, variations on Th1 cell differentiation marker genes and CD4+ cells were investigated after IFN-γ stimulation, the results confirmed that CD4+ T lymphocytes proliferated significantly after IFN-γ stimulation, accompanied by eight genes significant upregulation and increased T-bet expression in lymphocytes. In conclusion, the results revealed an induction of IFN-γ on Th1-type immune response, providing novel perspectives into the differentiation of CD4+ T lymphocytes in teleost.