Elevated Levels Of Th1 Cytokines Research Articles

Age-specific dynamics of neutralizing antibodies, cytokines, and chemokines in response to La Crosse virus infection in mice.

La Crosse virus (LACV) is a primary cause of pediatric arboviral encephalitis in the United States, particularly affecting children aged 16 years or younger. This age-related susceptibility extends to murine models, where weanling mice (3 weeks old) succumb to LACV infection, while adults (≥6 weeks old) demonstrate resistance. Despite its clinical relevance, the host immune response to LACV is not fully understood. In this study, we investigated the roles of neutralizing antibodies (nAbs), cytokines, and chemokines in weanling and adult mice following infection with 5 × 105 plaque-forming units (PFU) of LACV. Weanling mice demonstrated early disease onset with elevated peripheral viremia, but passive transfer of adult serum, confirmed to have nAbs, to naïve weanlings prior to infection completely rescued them from death. Moreover, adult mice had increased Th1 cytokines, Th9/Th17/Th22/Treg cytokines, and many chemokines. In contrast, weanlings had higher Th2 cytokines, correlating with symptoms onset. Flow cytometry and intracellular cytokine staining further demonstrated that weanling mice produced higher levels of IL-4 by CD4+ and CD8+ T cells compared to adults, regardless of infection status. Conversely, LACV-infected adult mice had increased IFN-γ production by CD8+ T cells compared to uninfected controls. Finally, the adoptive transfer of splenocytes from immune adult mice to naïve weanlings delayed neurological symptoms and improved survival. In conclusion, this study links nAbs and cytokine and chemokine responses to protective immunity in adult mice, contrasting with the pathogenesis seen in weanlings. These findings underscore the importance of further research into innate and adaptive immune mechanisms during LACV infection.IMPORTANCELa Crosse virus (LACV) is a primary cause of pediatric encephalitis in the United States, with an impact on children aged 16 years or younger. This age-related susceptibility is recapitulated in mouse models, where young mice succumb to LACV-induced disease, while adults demonstrate resistance. Our understanding of host responses to LACV remains underexplored. This study sheds light on the dynamics of neutralizing antibodies (nAbs), cytokines, and chemokines following LACV infection in both adult and weanling mice. Our study reveals age-specific variations in viremia, neutralizing antibody titers, survivability, and levels of cytokines and chemokines. Adult mice exhibit significantly elevated levels of Th1 cytokines, contrasting with elevated levels of Th2 cytokines observed in weanling mice, often coinciding with the onset of symptoms. These data reveal age-specific dynamics in cytokines and chemokines associated with protective versus pathogenic immunity, emphasizing the need for further studies on innate and adaptive immunity.

Comparison of serum cytokines and chemokines levels and clinical significance in patients with pemphigus vulgaris-A retrospective study.

In this study, we aimed to examine the relationship between the serum cytokine levels of patients with pemphigus vulgaris (PV) and the Pemphigus Disease Area Index (PDAI), along with the presence of anti-desmoglein (Dsg) 1 antibody, anti-Dsg3 antibody and co-infection among patients with pemphigus vulgaris. This retrospective study included 62 PV patients and 59 healthy individuals who attended the Second Affiliated Hospital of Kunming Medical University from November 2014 to November 2022. The serum concentrations of cytokines and chemokines were assessed using the Luminex 200 System (a high-throughput cytokine detection method). Additionally, anti-Dsg1 and anti-Dsg3 antibodies were determined through enzyme-linked immunosorbent assay, while disease severity was evaluated using the PDAI scoring system. The PV group exhibited elevated levels of Th1 cytokines (such as interleukin (IL)-1RA, IL-1β, IL-2, IL-12p70, GM-CSF, TNF-α, IL-18, IFN-γ), Th2 cytokines (IL-5, IL-10, IL-13) and Th17/Th22-related cytokines (IL-17A, IL-22) compared to the healthy control group (p < 0.05). Conversely, the levels of chemokines (macrophage inflammatory protein-1 alpha (MIP-1α), stromal cell-derived factor-1 alpha (SDF-1α), interferon-inducible protein-10 (IP-10), Regulated on Activation in Normal T-Cell Expressed And Secreted (RANTES), growth-regulated on-gene-alpha (GRO-α), MIP-1β) and Th2 (IL-31) were lower in the PV group compared to the healthy control group (p < 0.05). No significant differences were observed in other cytokines and chemokines (p > 0.05). Additionally, IL-7, IFN-γ, IL-18 and GRO-α showed positive correlations with PDAI, IL-6 correlated positively with anti-Dsg3 antibody levels, and IL-12p70, IL-18, and IFN-γ correlated positively with anti-Dsg1 antibody levels. Furthermore, IL-15 exhibited a positive association with skin infections. PV patients have elevated levels of various cytokines and chemokines, and there are different degrees of elevation in cytokines and chemokines associated with the activation of various T cell subsets. PDAI and the Dsg1 antibody levels are mainly related to the Th1-related cytokines.

Adjuvant effects of TLR agonist gardiquimod admixed with Leishmania vaccine in mice model of visceral leishmaniasis.

Tropical and subtropical areas of the world are affected by leishmaniasis, which is caused by Leishmania spp. It has been categorized as an NTD (neglected tropical disease) because of its negligence. The sand fly of genus Phlebotomus acts as the vector for the transmission of the promastigote form of this protozoan parasite to the mammalian host where it converts to amastigote form in the macrophages. Visceral form of leishmaniasis (VL) is a deadly infection in the endothelial system of the human and other mammals. Only a few chemotherapeutic agents are available for the treatment of this infectious disease whereas no vaccine is available for the control of leishmanial infection. Therefore in the current study, we have tested the effects of gardiquimod (a TLR agonist) as an adjuvant in combination with the formalin-killed antigen of L. donovani as a vaccine. The mice were vaccinated thrice at an interval of 2weeks and challenged with L. donovani promastigotes after 2weeks of the last vaccination. We assessed the parasite load, delayed-type hypersensitivity (DTH) responses, humoral and cell-mediated immune response in BALB/c mice before and after challenge infection with L. donovani. Immunized mice were found to have the least parasite load, high DTH response, elevated levels of Th1 cytokines, IgG2a, and nitric oxide than non-immunized and infected control mice. The efficacy of the vaccine was boosted with the use of adjuvant gardiquimod that depicts its potential as an adjuvant in this study. Our study is reporting the adjuvant effects of gardiquimod for the first time. Further studies using other Leishmania species can be performed to signify its role.

A Lactate Fermentation Mutant of Toxoplasma Stimulates Protective Immunity Against Acute and Chronic Toxoplasmosis.

Toxoplasma gondii is an important zoonotic pathogen infecting one-third of the world’s population and numerous animals, causing significant healthcare burden and socioeconomic problems. Vaccination is an efficient way to reduce global sero-prevalence, however, ideal vaccines are not yet available. We recently discovered that the Toxoplasma mutant lacking both lactate dehydrogenases LDH1 and LDH2 (Δldh) grew well in vitro but was unable to propagate in mice, making it a good live vaccine candidate. Here, we tested the protection efficacy of ME49 Δldh using a mouse model. Vaccinated mice were efficiently protected from the lethal challenge of a variety of wild-type strains, including type 1 strain RH, type 2 strain ME49, type 3 strain VEG, and a field isolate of Chinese 1. The protection efficacies of a single vaccination were nearly 100% for most cases and it worked well against the challenges of both tachyzoites and tissue cysts. Re-challenging parasites were unable to propagate in vaccinated mice, nor did they make tissue cysts. High levels of Toxoplasma-specific IgG were produced 30 days after immunization and stayed high during the whole tests (at least 125 days). However, passive immunization of naïve mice with sera from vaccinated mice did reduce parasite propagation, but the overall protection against parasite infections was rather limited. On the other hand, Δldh immunization evoked elevated levels of Th1 cytokines like INF-γ and IL-12, at early time points. In addition, splenocytes extracted from immunized mice were able to induce quick and robust INF-γ and other pro-inflammatory cytokine production upon T. gondii antigen stimulation. Together these results suggest that cellular immune responses are the main contributors to the protective immunity elicited by Δldh vaccination, and humoral immunity also contributes partially. We also generated uracil auxotrophic mutants in ME49 and compared their immune protection efficiencies to the Δldh mutants. The results showed that these two types of mutants have similar properties as live vaccine candidates. Taken together, these results suggest that mutants lacking LDH were severely attenuated in virulence but were able to induce strong anti-toxoplasma immune responses, therefore are good candidates for live vaccines.

T-cell reconstitution during murine acquired immunodeficiency syndrome (MAIDS) produces neuroinflammation and mortality in animals harboring opportunistic viral brain infection

BackgroundHighly active antiretroviral therapy (HAART) restores inflammatory immune responses in AIDS patients which may unmask previous subclinical infections or paradoxically exacerbate symptoms of opportunistic infections. In resource-poor settings, 25% of patients receiving HAART may develop CNS-related immune reconstitution inflammatory syndrome (IRIS). Here we describe a reliable mouse model to study underlying immunopathological mechanisms of CNS-IRIS.MethodsUtilizing our HSV brain infection model and mice with MAIDS, we investigated the effect of immune reconstitution on MAIDS mice harboring opportunistic viral brain infection. Using multi-color flow cytometry, we quantitatively measured the cellular infiltrate and microglial activation.ResultsInfection with the LP-BM5 retroviral mixture was found to confer susceptibility to herpes simplex virus (HSV)-1 brain infection to normally-resistant C57BL/6 mice. Increased susceptibility to brain infection was due to severe immunodeficiency at 8 wks p.i. and a marked increase in programmed death-1 (PD-1) expression on CD4+ and CD8+ T-cells. Both T-cell loss and opportunistic brain infection were associated with high level PD-1 expression because PD-1-knockout mice infected with LP-BM5 did not exhibit lymphopenia and retained resistance to HSV-1. In addition, HSV-infection of MAIDS mice stimulated peripheral immune cell infiltration into the brain and its ensuing microglial activation. Interestingly, while opportunistic herpes virus brain infection of C57BL/6 MAIDS mice was not itself lethal, when T-cell immunity was reconstituted through adoptive transfer of virus-specific CD3+ T-cells, it resulted in significant mortality among recipients. This immune reconstitution-induced mortality was associated with exacerbated neuroinflammation, as determined by MHC class II expression on resident microglia and elevated levels of Th1 cytokines in the brain.ConclusionsTaken together, these results indicate development of an immune reconstitution disease within the central nervous system (CNS-IRD). Experimental immune reconstitution disease of the CNS using T-cell repopulation of lymphopenic murine hosts harboring opportunistic brain infections may help elucidate neuroimmunoregulatory networks that produce CNS-IRIS in patients initiating HAART.

Melanoma differentiation-associated gene-7 (mda-7)/interleukin (IL)-24 induces anticancer immunity in a syngeneic murine model

Previous studies have shown that the human melanoma differentiation-associated gene-7 (mda-7)/interleukin-24 (IL-24) has tumor-suppressor activity in vitro and in vivo. Additionally, in vitro studies using human peripheral blood mononuclear cells indicate that mda-7/IL-24 has TH1 cytokine-like activity. However, the individual properties of mda-7/IL-24 have been previously examined separately. Thus, there is not a single study that has examined both, antitumor and proimmune properties of mda-7/IL-24. Furthermore, the tumor suppressive activity and the cytokine activity of mda-7/IL-24 have not been previously tested in an immunocompetent setting. We therefore in the present study evaluated the antitumor and immune properties of mda-7/IL-24 in a murine syngeneic tumor model. In vitro, adenovirus-mediated mda-7 gene (Ad-mda7) transfer to murine fibrosarcoma (UV2237m; MCA16) and normal (10T1/2) cells significantly inhibited growth (P=0.001) and induced apoptosis in tumor cells but not in normal cells. In vivo, intratumoral administration of Ad-mda7 resulted in significant inhibition of tumor growth (P<0.05), with a subset of mice showing complete tumor regression. We next evaluated the immune potentiation activity of Ad-mda7 in a cancer vaccine model. UV2237m cells transfected with Ad-mda7 and injected into syngeneic immunocompetent C3H mice were unable to grow; however, they did grow in immunocompromised nude mice. These tumor-free C3H mice, when challenged with parental tumor cells experienced no tumor growth, suggesting induction of systemic immunity. Moreover, splenocytes prepared from vaccinated C3H mice demonstrated higher proliferative activity and produced elevated levels of TH1 cytokines compared with those from control mice. An in vitro subset analysis of splenocytes from vaccinated mice demonstrated a significant increase in the CD3(+)CD8(+) but not the CD3(+)CD4(+) cell population (P=0.019). Thus Ad-mda7 treatment of syngeneic tumors induces tumor cell death and promotes immune activation, leading to anticancer immunity.

CpG oligonucleotides enhance the tumor antigen-specific immune response of an anti-idiotype antibody-based vaccine strategy in CEA transgenic mice.

A murine monoclonal anti-idiotype (Id) antibody, 3H1 has been developed and characterized previously. Anti-Id 3H1 mimics a specific epitope of carcinoembryonic antigen (CEA) and can be used as a surrogate antigen for CEA. 3H1 induced anti-CEA immunity in different species of animals as well as humans and showed promise as a potential vaccine candidate in phase I/II clinical trials for colon cancer patients. One area of interest to us has been the development of new immune adjuvants that may augment the potency of 3H1 as a tumor vaccine. Oligodeoxynucleotides containing unmethylated CpG motifs (CpG ODN) are potent immunostimulatory agents capable of enhancing the Ag-specific Th1 response when used as immune adjuvants. In this study, we have evaluated the efficacy of 3H1 as a tumor vaccine when admixed with a select CpG ODN 1826 in transgenic mice that express human CEA. The vaccine potential of 3H1 was also assessed in the presence of another widely used adjuvant, QS-21. 3H1 coupled to keyhole limpet hemocyanin (KLH) and mixed with Freund's adjuvant (FA) was used as a gold standard in this system. 3H1 vaccination with different adjuvants induced both humoral and cellular anti-3H1, as well as anti-CEA immunity in CEA transgenic mice. The immune sera could lyse CEA-transfected murine colon carcinoma cells, C15 effectively in an antibody-dependent cellular cytotoxicity assay. The anti-CEA antibody responses were somewhat comparable in each adjuvant-treated group of mice, whereas cellular immune responses were significantly greater when CpG was used as an adjuvant. Splenocytes obtained from 3H1-CpG-immunized mice showed an increased proliferative CD4(+) Th1-type T-cell response when stimulated in vitro with 3H1 or CEA and secreted elevated levels of Th1 cytokines (IL-2, IFN-gamma). This vaccine also induced MHC class I antigen-restricted CD8(+) T-cell responses. In a solid tumor model, C15 tumor growth was significantly inhibited by 3H1 vaccinations. In 3H1-CpG-vaccinated mice, the duration of survival was, however, longer compared to the 3H1-QS21-vaccinated mice. These findings suggest that 3H1-CpG vaccinations can break peripheral tolerance to CEA and induce protective antitumor immunity in this murine model transgenic for human CEA.

691. Ad-mda7/IL-24 Induces Systemic Anticancer Immunity In Vivo

The antitumor activity of human melanoma differentiation associated gene-7 (mda-7)/interleukin 24 (IL24) against human cancer cells has been well established. However, the antitumor activity of mda-7/IL-24 against tumors in immunocompetent mice has not been previously reported. In the present study, we evaluated the antitumor and immune activation of mda-7/IL-24 in murine fibrosarcoma (UV2237m; MCA16) and normal (10T1/2) cells. In vitro, adenovirus-mediated mda-7 gene (Ad-mda7) transfer significantly inhibited growth (P=0.001) and induced apoptosis in tumor cells but not in normal cells. In vivo, administration of Ad-mda7 into subcutaneous tumors resulted in significant inhibition of tumor growth (P<0.05), with a subset of mice showing complete and prolonged tumor regression. Ad-mda7 treated tumor cells had enhanced cell surface expression of major histocompatability complex class I, indicating immune enhancement. We next evaluated the immune potentiation activity of Ad-mda7 in a cancer vaccine model. Vaccination of C3H mice and nude mice with Ad-mda7 treated UV2237m cells resulted in complete tumor inhibition in C3H mice but not in nude mice. These tumor free C3H mice when treated with parental tumor cells experienced no tumor growth, suggesting induction of systemic immunity. Moreover, splenocytes prepared from vaccinated mice demonstrated higher proliferative activity and produced significantly elevated levels of TH1 cytokines compared with those from control mice. An in vitro subset analysis of splenocytes from vaccinated mice demonstrated a significant increase in the CD3+CD8+ but not the CD3+CD4+ cell population (P=0.019). Our results demonstrate that Ad-mda7 treatment of syngeneic tumor cells induces cell death via apoptosis and promotes immune activation, leading to systemic anticancer immunity.

Influence of age and duration of infection on bacterial load and immune responses to Helicobacter pylori infection in a murine model

Using a murine model, we previously showed that Helicobacter pylori infects and colonizes offspring via maternal transmission during the nursing period. The aim of this study was to investigate the influence of age and duration of infection on inflammatory and immune responses to H. pylori in infant and adult mice. During the breast-feeding period, the number of bacteria was significantly suppressed in 1-week-old mice infected with H. pylori at an early stage of nursing, compared with adult mice, suggesting that breast-milk induces such low colonization. In addition, these mice had weaker gastric inflammation, especially Th1 cytokine and humoral responses than in mice infected with H. pylori after weaning in spite of elevated levels of Th1 cytokines. Although infant mice showed low inflammatory responses against H. pylori, they produced H. pylori-specific antibodies following vaccination with oral or parenteral adjuvant. Our results suggest the importance of age at the time of primary infection on bacterial load, gastric inflammation and humoral responses in a murine model of H. pylori infection.

Contrasting activity of cytosin-guanosin dinucleotide oligonucleotides in mice with experimental colitis.

Intestinal inflammation in inflammatory bowel disease (IBD) and experimental models of colitis is characterized by a dysregulated intestinal immune response with elevated levels of Th1 cytokines. The luminal flora has been implicated as a major factor contributing to the initiation and perpetuation of inflammation in experimental colitis by mechanisms not known. Bacterial DNA contains unmethylated cytosin-guanosin dinucleotides (CpG) which strongly activate Th1-mediated immune responses. To test whether these CpG-motifs modulate intestinal inflammation we treated mice with dextran sulphate sodium (DSS)-induced colitis with CpG-containing oligodeoxynucleotides (CpG-ODN). CpG-ODN given after the onset of DSS colitis aggravated the disease, as indicated by a significantly increased loss of body weight and a 30% increase of the histological score. Further, we found a severe increase of proinflammatory cytokines (interleukin (IL)-6: 40-fold; interferon (IFN)-gamma: 11-fold). In a pretreatment setting CpG-ODN reduced weight loss significantly and reduced intestinal inflammation by 45%. Colonic IFN-gamma and IL-6 mRNA levels were reduced by 75%, and IL-10 was elevated by 400% compared to controls. The prophylactic CpG-effect was not imitated by IL-12 because IL-12 pretreatment was not protective. In time-course experiments, CpG-ODN pretreatment over 5 days resulted in a tolerance effect concerning its IFN-gamma-inducing quality, and during the following days of colitis induction IL-10 secretion from mesenterial lymph node cells was elevated compared to controls. Therefore, the prophylactic effect of CpG-ODN might be explained by its tolerizing effect and/or the increased ability for IL-10 production during the consecutive intestinal inflammation.

Acute toxoplasmosis leads to lethal overproduction of Th1 cytokines.

Virulence in Toxoplasma gondii is strongly influenced by the genotype of the parasite. Type I strains uniformly cause rapid death in mice regardless of the host genotype or the challenge dose. In contrast, the outcome of infections with type II strains is highly dependent on the challenge dose and the genotype of the host. To understand the basis of acute virulence in toxoplasmosis, we compared low and high doses of the RH strain (type I) and the ME49/PTG strain (type II) of T. gondii in outbred mice. Differences in virulence were reflected in only modestly different growth rates in vivo, and both strains disseminated widely to different tissues. The key difference in the virulent RH strain was the ability to reach high tissue burdens rapidly following a low dose challenge. Lethal infections caused by type I (RH) or type II (PTG) strain infections were accompanied by extremely elevated levels of Th1 cytokines in the serum, including IFN-gamma, TNF-alpha, IL-12, and IL-18. Extensive liver damage and lymphoid degeneration accompanied the elevated levels of cytokines produced during lethal infection. Increased time of survival following lethal infection with the RH strain was provided by neutralization of IL-18, but not TNF-alpha or IFN-gamma. Nonlethal infections with a low dose of type II PTG strain parasites were characterized by a modest induction of Th1 cytokines that led to control of infection and minimal damage to host tissues. Our findings establish that overstimulation of immune responses that are normally necessary for protection is an important feature of acute toxoplasmosis.