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Results for “Interleukin-12”

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At least 19 recordsLinked to original sources

PubMed1992

Recombinant interleukin-12 suppresses the synthesis of immunoglobulin E by interleukin-4 stimulated human lymphocytes.

Interleukin-12 is a recently discovered lymphokine displaying an array of in vitro activities suggesting a major role in protective immunity against infectious agents like viruses. This study provides evidence that IL-12 may also be implicated in the selection of the immunoglobulin isotypes. We show that picomolar concentrations of rIL-12 markedly inhibit the synthesis of IgE by IL-4-stimulated PBMC. The suppression of IgE is observed at the protein and at the mRNA levels, it is isotype specific, and it is abolished by neutralizing anti-IL-12 mAbs. IL-12 may suppress IgE synthesis by: (a) inducing the production of IFN-gamma, a known inhibitor of IgE synthesis and (b) by a novel mechanism which is IFN-gamma independent. The best evidence for this is from studies on IgE synthesis by IL-4-plus hydrocortisone-stimulated umbilical cord blood lymphocytes, which do not produce detectable amounts of IFN-gamma. In such cultures, rIL-12 inhibits IgE synthesis even in the presence of a large excess of neutralizing anti-IFN-gamma mAb.

Cells, Cultured↗

PubMed1992

Regulation of human cytolytic lymphocyte responses by interleukin-12.

IL-12 is a heterodimeric cytokine which has been shown to cause the proliferation of activated T and NK cells, to enhance the lytic activity of NK cells, and to induce IFN-gamma production by resting and activated T and NK cells. We previously reported that IL-12 could synergize with IL-2 to activate human LAK cells in the presence of hydrocortisone but that IL-12 alone was inactive. We herein show that in the absence of hydrocortisone, IL-12 by itself can activate human LAK cells. IL-12-induced LAK cell activity was mediated predominantly by CD56+ lymphocytes. Activation of LAK cells by IL-12 appeared to be independent of IL-2 since it was not inhibited by neutralizing anti-human IL-2. However, IL-12- and IL-2-induced LAK cell activation could be partially inhibited by anti-human TNF-alpha. Moreover, IL-12 produced in situ appeared to play a role in IL-2-induced LAK cell activation since rat monoclonal antibodies to human IL-12 could partially inhibit the generation of LAK cells in response to IL-2. In addition to its effects on LAK cell responses, IL-12 could facilitate specific allogeneic human CTL responses. However, IL-12-facilitated CTL responses were blocked by neutralizing anti-human IL-2 indicating a requirement for IL-2 produced in situ. The ability of IL-12 to facilitate both nonspecific LAK and specific CTL responses suggests that it may be useful as a therapeutic agent against some tumors and infectious diseases.

Cells, Cultured↗

PubMed2026

Association of IL-10 promoter and IL-12 gene polymorphisms with the risk of symptomatic Helicobacter pylori infection.

BACKGROUND: The host's immune response to Helicobacter pylori (H. pylori) infection is largely determined by its cytokine profile. Genetic variations within crucial immunomodulatory genes, including those for interleukin-10 (IL-10) and interleukin-12 (IL-12), are thought to influence an individual's vulnerability to the infection and its clinical consequences by modifying cytokine production. Nonetheless, research data derived from diverse human populations continue to show inconsistent results. AIM: This case-control analysis sought to examine a potential link between symptomatic H. pylori infection susceptibility in an Iranian population and specific genetic variants in the IL-10 (-1082G > A, -819 C > T) and IL-12 (+ 1188 A > C) genes. METHODS: In this investigation, 68 individuals with confirmed symptomatic H. pylori infection diagnosed by a positive rapid urease test and elevated anti-H. pylori IgG levels exceeding 90 ng/ml via ELISA were enrolled alongside 68 healthy controls. The control group was carefully matched to the patient group based on age, sex, and ethnic background. Genotyping for the IL-10 (-1082G > A, -819 C > T) and IL-12 (+ 1188 A > C) polymorphisms was conducted using the Amplification Refractory Mutation System-PCR (ARMS-PCR) method. To evaluate associations, the distribution of genotypes and alleles between the groups was contrasted using logistic regression, applying additive, dominant, and recessive inheritance models. The strength of any association was expressed as odds ratios (ORs) accompanied by 95% confidence intervals (CIs). RESULTS: The analysis revealed no statistically significant correlations linking the investigated IL-10 and IL-12 gene variants to an increased predisposition for H. pylori infection. A notable methodological observation was the deviation from Hardy-Weinberg equilibrium (HWE) across all studied polymorphisms in the control group. Regarding the IL-10 -1082G > A locus, the AA genotype was associated with a marginally elevated risk estimate; however, this finding was not statistically significant (OR = 3.45, 95% CI: 0.29-41.36; p = 0.327). Likewise, for the IL-12 + 1188 A > C polymorphism, the CC genotype, while more prevalent in the patient cohort, also demonstrated no significant association with infection risk (OR = 1.43, 95% CI: 0.42-4.87; p = 0.567). CONCLUSION: This investigation did not establish a significant link between the specific IL-10 and IL-12 gene variants analyzed and susceptibility to symptomatic H. pylori infection in the studied population. Although minor genetic associations were noted, they lacked statistical significance. Future research with larger sample sizes is required to validate these results and to investigate additional genetic determinants that may affect infection risk.

Humans↗

PubMed1992

[Function and molecular structure of IL-12].

Natural killer cell stimulatory factor (NKSF), also called cytotoxic lymphocyte maturation factor (CLMF) or interleukin-12, is a novel cytokine of a 70 kDa heterodimer, composed of two covalently linked glycosylated chains of 40 and 35 kDa. NKSF was originally identified in the supernatant fluid of human EB virus-transformed B lymphoblastoid cell lines. NKSF has been shown to: (a) induce interferon-gamma production from both T and NK cells and synergize in this effect with interleukin-2 (IL-2), mitogens, phorbol diesters, anti-CD3 antibodies, and allogeneic antigens; (b) exert a comitogenic effect on fresh resting T cells together with lectins or phorbol diesters; (c) mediate a direct mitogenic effect on activated T or NK cell blasts; (d) enhance the cytotoxic activity of resting peripheral blood NK cells; and (e) synergize with IL-2 in the generation of lymphokine-activated killer cells.

Cell Division↗

PubMed2025

CS Ratio is an immune-related prognostic biomarker for cervical cancer.

BACKGROUND: The tumor microenvironment (TME) plays a crucial role in cancer progression but its complex structure significant variability among patients present considerable challenges for research. Recent studies have demonstrated that macrophage polarization states defined by the expression levels of CXCL9 SPP1 (CS Ratio) are more prognostically relevant than traditional M1/M2 markers. The CS polarization state reflects a highly coordinated network of pro-tumor anti-tumor variables offering a simplified yet effective immune response indicator for the complex TME. The CS Ratio has been shown to correlate with the abundance of anti-tumor immune cells the gene expression programs of tumor-infiltrating cells responses to immunotherapy. Cervical cancer, one of the most common gynecological malignancies, still faces limited therapeutic options. CXCL9, a member of the CXC chemokine family, plays a critical role in immune regulation, inflammation, tumor growth, angiogenesis, and metastasis. Similarly, SPP1, a cytokine, influences immune-related pathways by regulating molecules such as interferon-γ and interleukin-12. However, no studies have systematically investigated the role of the CS Ratio in cervical cancer or its relationship with immunotherapy characteristics. Research in this area could provide critical insights into the role and clinical potential of the CS Ratio in cervical cancer and related tumors. METHODS: The expression ratio of CXCL9 to SPP1 was analyzed in cervical cancer patients using data from the Gene Expression Omnibus (GEO) database, which revealed significant differences. Data for cervical cancer patients were obtained from The Cancer Genome Atlas (TCGA) database. The optimal cutoff value for the CS Ratio was determined using the maxstat package in R, and Kaplan-Meier (KM) survival curves were constructed. Patients were categorized into High and Low groups based on the median CS Ratio. Immune scores were analyzed, and immune cell infiltration was assessed using CIBERSORT. Differences in the CS Ratio were evaluated across patients with varying pathological T stages and FIGO stages. Additionally, receiver operating characteristic (ROC) analysis was performed using the pROC package in R to calculate the area under the curve (AUC). Univariate and multivariate Cox regression analyses were performed to evaluate the potential of the CS Ratio as an independent prognostic factor in cervical cancer. A Cox regression-based nomogram integrating four key features was subsequently developed for the TCGA-CESC cohort. Nomogram performance was assessed using calibration curves and ROC analysis. RESULTS: The CS Ratio was significantly lower in cervical cancer patients compared to normal controls (P < 0.05). KM survival curves indicated that patients in the CS High group exhibited better prognoses. Immune score analysis revealed significantly higher immune scores (P < 0.05) and lower tumor purity (P < 0.05)in the CS High group compared to the Low group. CIBERSORT analysis revealed significantly higher proportions of CD8+ T cells (P < 0.05) and M1 macrophages (P < 0.05), and a significantly lower proportion of M2 macrophages (P < 0.05), in the CS High group compared to the Low group. The CS Ratio significantly decreased with advancing FIGO stage (P < 0.05). Both univariate (P < 0.05) and multivariate Cox regression analyses (P < 0.05) confirmed the CS Ratio as an independent prognostic factor. ROC analysis demonstrated that the CS Ratio had higher AUC values for predicting 1-year (AUC=0.69), 3-year (AUC=0.66), and 5-year OS (AUC=0.68) than CXCL9 or SPP1 alone. The Cox regression-based nomogram integrating four key features demonstrated predictive capability for 1-, 3-, and 5-year OS in CESC patients (Concordance Index = 0.751; 95% CI: 0.678-0.824; p = 1.50Í10-11). Significant survival differences were observed between the high-risk and low-risk groups based on the nomogram score. ROC analysis yielded high AUC values for survival prediction: 0.85 (95% CI: 0.94-0.75) at 1-year, 0.74 (95% CI:0.84-0.64) at 3-year, and 0.72 (95% CI:0.84-0.61) at 5-year. CONCLUSION: The CS Ratio may serve as a more effective prognostic biomarker for cervical cancer patients.

CXCL9↗

PubMed1992

An activated murine B cell lymphoma line (A-20) produces a factor-like activity which is functionally related to human natural killer cell stimulatory factor.

In the present article we show that supernatants derived from lipopolysaccharide (LPS) or phorbol 12-myristate 13-acetate (PMA)-stimulated A-20 B cell lymphoma are able to induce polyclonal immunoglobulin (Ig) secretion by normal B cells in a T-cell-dependent manner. This activity could be blocked by neutralizing monoclonal antibodies against interferon-gamma, but not by monoclonal antibodies against interleukin (IL)-2, IL-4, IL-5, IL-6, IL-10 and granulocyte macrophage colony-stimulating factor (GM-CSF) or even a polyclonal antibody against tumor necrosis factor (TNF)-alpha. Furthermore, A-20 supernatants induced the production of measurable amounts of interferon-gamma by normal murine spleen cells and activates natural killer (NK) cells. Fractionation of factor-rich supernatants on a Sephacryl S-200 column revealed that the factor activity is located in the fractions corresponding to a molecular mass of 160-150 kDa and 80-70 kDa. The biological activities found in the A-20 supernatant are very similar to the ones described for the recently cloned human IL-12/NK cell stimulatory factor. These results suggest the existence of a murine analogous factor for the human IL-12 produced by A-20 B cell lymphoma.

Animals↗

PubMed1992

Molecular characterization of interleukin 12.

Interleukin 12 (IL-12), formerly known as cytotoxic lymphocyte maturation factor and natural killer cell stimulatory factor, is a cytokine secreted by a human B lymphoblastoid (NC-37) cell line when induced in culture with phorbol ester and calcium ionophore. This factor has been purified to homogeneity and shown to synergize with low concentrations of interleukin 2 in causing the induction of lymphokine-activated killer cells. In addition, purified IL-12 stimulated the proliferation of human phytohemagglutinin-activated lymphoblasts by itself and exerted additive effects when used in combination with suboptimal amounts of interleukin 2. The protein is a heterodimer composed of a 40- and a 35-kDa subunit. Amino acid sequence analysis confirmed predicted sequences from the cloned cDNAs of each subunit. Chemical and enzymatic deglycosylation of the heterodimer demonstrated that the 40- and 35-kDa subunits contain 10 and 20% carbohydrate, respectively. Structural analysis of IL-12 using site-specific chemical modification revealed that intact disulfide bonds are essential for bioactivity. The 40-kDa subunit of IL-12 was identified by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and confirmed by immunoblotting as being present in NC-37 cell supernatant solutions in relatively large amounts uncomplexed to the 35-kDa subunit. Previously it had been shown that the 40-kDa subunit alone does not cause the proliferation of activated human T lymphocytes or enhance the cytolytic activity of human natural killer cells. However, results obtained by site-specific chemical modification suggesting that a tryptophan residue is at or near the active site of IL-12 may imply a direct role of the subunit in interacting with the IL-12 receptor. These data may support the recent proposal (D.P. Gearing and D. Cosman (1991) Cell 66, 9-10) that IL-12 consists of a complex of cytokine and soluble receptor.

Amino Acid Sequence↗

PubMed1992

Role of the production of natural killer cell stimulatory factor (NKSF/IL-12) in the ability of B cell lines to stimulate T and NK cell proliferation.

We have previously used human Epstein Barr virus (EBV)-transformed B lymphoblastoid cell lines for the identification and purification of a novel cytokine, natural killer cell stimulatory factor (NKSF/IL-12), that has pleiotropic effects on human lymphocytes. B cell lines are also routinely employed as feeder cells for the culture of T and natural killer (NK) cells. In this report we describe the ability of two NKSF/IL-12 producing B cell lines (RPMI-8866 and Cess) and two nonproducing lines (Raji and Daudi) to stimulate the proliferation of T and NK cells in 8-day PBL cultures. We demonstrate, using an anti-NKSF/IL-12 neutralizing monoclonal antibody, that the endogenous production of NKSF/IL-12 in these cultures can significantly enhance the proliferation and cytotoxic activity of T and NK cells. We also report that the addition of exogenous rNKSF/IL-12 can greatly increase the number of T and NK cells obtained from the cultures following stimulation by the B cell lines. Aside from the possible practical applications, the enhanced proliferation of T and NK cells consistently observed in the presence of endogenously produced NKSF/IL-12 or exogenously added rNKSF/IL-12 in this system may further our understanding of the role of this cytokine during an in vivo immune response.

Antibodies, Monoclonal↗

PubMed2026

Immunomodulatory effects of palm-derived tocotrienol-rich fraction in healthy volunteers following influenza vaccination: A randomised clinical trial.

Most studies on vitamin E and immunity have focused on tocopherols, but the tocotrienol-rich fraction (TRF) from palm oil may exert stronger immunomodulatory effects. This study investigated the effect of various TRF doses on the immune response to influenza immunisation in healthy adults. We hypothesized daily supplementation with lower doses of TRF can boost immune response to the influenza vaccine in healthy Individuals. In a double-blind placebo-controlled trial, 150 participants (≥18 years) were randomised to receive placebo or TRF (50, 100, 200, or 400 mg) daily for 2 months, with vaccination on day 28. Blood samples collected on days 0, 28, and 56 were analyzed for humoral and cellular immunity, antioxidant status, and plasma concentrations of vitamin E. TRF significantly augmented anti-influenza antibody production across all doses, with the 400 mg group exhibiting the highest titers. A selective Th1-type immune response was observed, characterized by significant IFN-γ production upon restimulation in all TRF-supplemented groups compared with placebo. Plasma IL-12 was elevated in the highest dose, whereas the amount of EBI3 produced increased across a broader range of doses compared to placebo. TRF supplementation was associated with increased antioxidant enzyme activities and stable malondialdehyde activity. Elevated α-tocopherol concentrations observed, primarily at higher doses. Supplementation with TRF can enhance immune response to influenza immunisation by modulating humoral, Th1 responses and improving antioxidant status. Critically, antibody production increased similarly across all TRF doses, suggesting that lower doses may offer a cost-effective strategy for supporting humoral immunity, while higher doses provide broader immunomodulatory benefits.

Humans↗

PubMed1992

Assignment of genes encoding a unique cytokine (IL12) composed of two unrelated subunits to chromosomes 3 and 5.

IL12 (formerly NKSF or CLMF) is a unique cytokine composed of two unrelated disulfide-linked subunits. The larger 40-kDa subunit (p40) is a member of the cytokine receptor family, and the smaller 35-kDa subunit (p35) is related to IL6 and GCSF. The chromosomal localization of these two subunits was determined by PCR analysis of DNA from rodent-human hybrids. More refined mapping was obtained by PCR analysis of hybrids containing translocation chromosomes and for p40, by analysis of radiation hybrids. The subunits map to different chromosomes: p40 (IL12B) to 5q31-q33 and p35 (IL12A) to 3p12-3q13.2.

Animals↗

PubMed1992

Response of human natural killer (NK) cells to NK cell stimulatory factor (NKSF): cytolytic activity and proliferation of NK cells are differentially regulated by NKSF.

Natural killer cell stimulatory factor (NKSF) is a 70-kD heterodimeric cytokine that was initially isolated from conditioned medium of human B lymphoblastoid cell lines. The effects of recombinant NKSF on the function of human peripheral blood NK cells were examined. NKSF directly augmented the cytolytic activity of freshly isolated NK cells. Both CD56dim and CD56bright NK cells demonstrated enhanced cytotoxicity after brief exposure to NKSF. In contrast, highly purified T lymphocytes did not exhibit major histocompatibility complex-unrestricted cytotoxicity after short-term culture with NKSF. Like interleukin 2 (IL-2), NKSF augmented the lysis of NK-sensitive, NK-resistant, and antibody-coated targets. Both NKSF and IL-2 induced marked upregulation of several NK cell adhesion molecules known to participate in cytolysis, including CD2, CD11a, and CD54. However, NKSF activates NK cells through a pathway distinct from that of IL-2, since the presence of anti-IL-2 receptor (anti-IL-2R) antibodies or IL-4 did not inhibit the effects of NKSF. NKSF by itself induced very little proliferation of resting NK cells. NK cells preactivated in vitro with IL-2 demonstrated enhanced proliferation to NKSF, but the degree of proliferation was always inferior to that induced by IL-2 alone. Moreover, NKSF strongly inhibited IL-2-induced proliferation of either resting or preactivated NK cells. This inhibition was not the result of decreased IL-2R expression, because NKSF-activated NK cells expressed higher levels of both IL-2Rs p75 and p55. Furthermore, NKSF did not inhibit the proliferation of mitogen-activated T cells, indicating a selective effect on NK cell proliferation. Human NK cells expanded in vivo by prolonged continuous infusions of IL-2 remained fully responsive to NKSF. Picomolar concentrations of NKSF were as effective as nanomolar concentrations of IL-2 in augmenting the cytolytic activity of NK cells expanded in vivo by IL-2. NKSF may play an important role in the regulation of human NK cell function, and its possible use as a therapeutic cytokine deserves further investigation.

Humans↗

PubMed1992

Natural killer (NK) cell stimulatory factor increases the cytotoxic activity of NK cells from both healthy donors and human immunodeficiency virus-infected patients.

Natural killer cell stimulatory factor (NKSF), or interleukin 12 (IL-12), is a heterodimeric lymphokine produced by B cells that has multiple effects on T and NK cell functions. NKSF at concentrations as low as 0.4 pM enhances the spontaneous cytotoxic activity of peripheral blood lymphocytes (PBL) against a variety of tumor-derived target cell lines and virus-infected target cells. The combined treatment of PBL with NKSF and IL-2 results in a less than additive enhancement of cytotoxicity. NKSF enhances the cytotoxic activity of spontaneously cytotoxic CD16+CD5- NK cells and does not confer cytotoxic activity to CD16-CD5+ T cells. PBL from patients infected with human immunodeficiency virus (HIV) have significantly lower cytotoxic activity against tumor-derived target cells and virus-infected target cells than PBL from control healthy donors. Treatment of PBL from HIV-infected patients with NKSF and/or IL-2 results in an increase of NK cell cytotoxicity against both types of target cells to levels similar to or higher than those of untreated PBL from healthy donors. PBL from HIV-infected patients produce interferon gamma in response to NKSF and/or IL-2, although at levels 5- or 10-fold lower than those produced by PBL from healthy donors. The multiple biological effects of NKSF, its activity at very low molar concentrations, and its ability to synergize with other physiological stimuli suggest that NKSF/IL-12 is a lymphokine likely to have physiological importance and considerable therapeutic potential.

Adult↗

PubMed1992

Production of natural killer cell stimulatory factor (interleukin 12) by peripheral blood mononuclear cells.

Natural killer cell stimulatory factor (NKSF), or interleukin 12 (IL-12), is a 70-kD heterodimeric cytokine composed of two covalently linked chains, p40 and p35. NKSF/IL-12 has multiple effects on T and NK cells and was originally identified and purified from the supernatant fluid of Epstein-Barr virus (EBV)-transformed human B lymphoblastoid cell lines. We have produced a panel of monoclonal antibodies against both chains of NKSF/IL-12. Some of these antibodies have neutralizing activity, and several combinations of them have been used to establish sensitive radioimmunoassays detecting the free p40 chain, the free p35 chain, or the p70 heterodimer. Using these reagents, we have determined that most EBV-transformed human B lymphoblastoid cell lines constitutively produce low levels of the p70 heterodimer and an excess of the free p40 chain, whereas Burkitt lymphoma-derived, T, myeloid, and many solid tumor-derived cell lines produce neither. Production of both p40 and p70 is increased several-fold upon stimulation of the EBV-transformed cell lines with phorbol diesters. The ability of supernatant fluids from unstimulated and phorbol diester-stimulated cell lines to induce interferon gamma (IFN-gamma) production from T and NK cells, one of the effects of NKSF/IL-12, parallels the levels of production of the p70 heterodimer, known to be the biologically active form of NKSF/IL-12. Staphylococcus aureus Cowan I strain (SAC) and other stimuli induce accumulation of p40 mRNA and production of both p40 and p70 by peripheral blood mononuclear cells (PBMC). The producer cells appear to include both adherent cells and nonadherent lymphocytes, possibly B cells. The supernatant fluids from SAC-stimulated PBMC mediate the typical functions of NKSF/IL-12 (i.e., IFN-gamma induction, mitogenic effects on T/NK blasts, enhancement of NK cell cytotoxicity) at concentrations of p70 similar to those at which recombinant NKSF/IL-12 mediates the same functions. Moreover, these activities are significantly inhibited by anti-NKSF/IL-12 antibodies. The neutralizing anti-NKSF/IL-12 antibodies also inhibit 85% of the IFN-gamma production in response to SAC, an NKSF/IL-12 inducer, and approximately 50% of the IFN-gamma production in response to non-NKSF/IL-12-inducers such as IL-2, phytohemagglutinin, and anti-CD3 antibodies. These results indicate that induced or constitutively produced NKSF/IL-12 has a major role in facilitating IFN-gamma production by peripheral blood lymphocytes.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗

PubMed1992

Use of T-cell growth factors (interleukins 2, 4, 7, 10, and 12) in the evaluation of T-cell reactivity to melanoma.

Melanoma represents the single best example of a human tumor that has been shown to elicit specific T-cell reactivity. The responsiveness of some patients with metastatic melanoma to treatment with the prototypic T-cell growth factor (TCGF), interleukin-2 (IL-2), indicates that T cells play a role in antitumor immunity. Interleukin-4 (IL-4), another TCGF that has been administered clinically to humans, was not associated with tumor response in our trials conducted at the Surgery Branch of the National Cancer Institute. Combination trials of IL-2 with IL-4 have shown no increase in responsiveness of melanoma or other tumors when compared to IL-2 alone. However, enhanced expansion of tumor-infiltrating lymphocytes (TILs) in vitro has been observed with combinations of low-dose IL-2 and IL-4. We have begun a study evaluating the trafficking of such expanded lymphocytes following their adoptive transfer in association with systemic administration of IL-2 and IL-4. We have established several TIL cultures from fresh tumor samples, maintained them in long-term culture, and marked them with the neomycin phosphotransferase gene using the LNL6 retroviral vector. Such TILs appear to demonstrate no notable alterations in phenotype or cytolytic activity when compared to their nontransduced counterparts. In addition to IL-2 and IL-4, there are a variety of other novel TCGFs that are now available for evaluation in preclinical and clinical trials. IL-7 induces proliferation and lymphokine-activated killer (LAK) cell activity from human peripheral blood mononuclear cells.(ABSTRACT TRUNCATED AT 250 WORDS)

Cell Division↗

PubMed2026

Exploring Causal Links Between 91 Circulating Inflammatory Proteins and Hashimoto's Thyroiditis: A Bidirectional Mendelian Randomization Study.

BACKGROUND: Increasing evidence has linked inflammation to Hashimoto's thyroiditis (HT) etiology. However, the causal role of circulating inflammatory proteins in HT remains uncertain. To investigate this, we conducted a bidirectional Mendelian randomization (MR) study. METHODS: Genetic data for 91 inflammatory proteins and HT were sourced from publicly available GWAS databases. The PhenoScanner database was then searched for pleiotropic SNPs associated with potential confounders. Inverse variance weighted (IVW) analysis was used as the primary analysis, simultaneously supplemented by five sensitivity analyses to strengthen the results. RESULTS: The results revealed that, after false discovery rate (FDR) correction, interleukin (IL)-12p40 was causally associated with increased risk of HT (OR [95% CI] = 1.295 [1.172, 1.431], p = 3.66 × 10-7, PFDR = 3.33×10-5). Conversely, none of the inflammatory proteins was a consequence of HT. CONCLUSION: This study suggests that IL-12p40 is probably one of the factors correlated with HT etiology, contributing to a better understanding of the pathogenesis of HT and underscoring the potential for therapeutic interventions targeting inflammatory proteins.

Humans↗

PubMed2026

Th2 skewing in patients with disseminated coccidioidomycosis.

BACKGROUNDDisseminated coccidioidomycosis (DCM) is an often fatal and otherwise intractable condition requiring lifelong antifungal treatment. We have previously shown that a deranged polarization of CD4+ T cells toward a Th2 phenotype can exist in the context of DCM. Here, we studied a large population to determine the frequency of abnormal Th2 skewing of CD4+ T cells in patients with coccidioidomycosis and to identify underlying genetic mechanisms supporting this phenotype.METHODSWe collected PBMCs from 204 patients with coccidioidomycosis, including 96 patients with disseminated disease. We measured immune phenotypes and cytokine production by CD4+ T cells from patients and healthy controls, and comparisons between groups were made based on disease severity and demographics. Whole-genome sequencing was conducted on 180 individuals who also had cytokine profiling.RESULTSWe found that approximately 25% of patients with DCM had a CD4+ T cell compartment that was abnormally skewed toward a Th2 phenotype, and Th2 skewing was highly correlated with male sex. Coculture of T cells with the IL-4R/IL-13R-blocking antibody dupilumab reduced Th2 skewing. Sequencing revealed rare variants in genes involved in the IL-12/IFN-γ axis in several Th2-skewed patients, and we validated one such variant in IFNGR1 as hypomorphic.CONCLUSIONPatients with DCM, especially males, should be screened for Th2 skewing of CD4+ T cells. Patients with Th2 skewing should be additionally screened for genetic defects in the IL-12/IFN-γ axis. Our findings give a mechanistic rationale for blockade of IL-4R in Th2-skewed patients with refractory coccidioidomycosis.FUNDINGNational Institute of Allergy and Infectious Diseases/NIH grants R21 AI149654 and U19 AI166059 and University of California Office of the President grant VFR-19-633386.

Humans↗

PubMed1992

Mechanisms of IFN-gamma induction by natural killer cell stimulatory factor (NKSF/IL-12). Role of transcription and mRNA stability in the synergistic interaction between NKSF and IL-2.

We have investigated the molecular mechanisms regulating IFN-gamma production in human T lymphocytes stimulated by NK cell stimulatory factor (NKSF/IL-12). We show that NKSF synergizes with IL-2 and phorbol diesters inducing the accumulation of IFN-gamma mRNA in PHA-activated T cell blasts. NKSF regulates IFN-gamma mRNA expression in PHA blasts and the T leukemia cell line, TALL-103/2, at both the transcriptional and posttranscriptional levels. NKSF increases the transcriptional rate for IFN-gamma in both these cell types, as determined by nuclear run-on analysis. However, synergy between NKSF and IL-2 can be demonstrated only at the level of mRNA stability, and both cytokines are required to increase IFN-gamma mRNA half-life.

Blotting, Northern↗

PubMed1992

Cloning and expression of murine IL-12.

Human IL-12 (NK cell stimulatory factor, cytotoxic lymphocyte maturation factor) is a heterodimeric cytokine that can act as a growth factor for activated human T and NK cells, enhance the lytic activity of human NK/lymphokine-activated killer cells, and stimulate the production of IFN-gamma by resting human PBMC. Because in our hands, human IL-12 did not elicit similar responses in murine lymphocytes, we have cloned and expressed the murine IL-12 subunit cDNA in order to obtain recombinant protein for murine studies. Comparison of the predicted amino acid sequences of the murine subunits with their human counterparts revealed that the p40 subunits are more highly conserved than the p35 subunits (70% vs 60% identity, respectively). The sizes of the p35 and p40 subunit mRNA were estimated to be 1.5 kb and 2.6 kb, respectively. RNA blot analysis showed that p35 mRNA was expressed in lymphoid tissues (spleen, thymus) and nonlymphoid tissues (lung, brain), whereas p40 mRNA expression was only detected in lymphoid cells. Incubation of splenocytes with pokeweed mitogen did not significantly affect p35 mRNA levels, however, it resulted in a decrease of p40 mRNA. Coexpression of the murine p35 and p40 cDNA clones in COS cells resulted in the secretion of IL-12, which was active in human and mouse T cell proliferation, murine NK cell activation, and murine IFN-gamma induction assays. Transfection of each subunit cDNA alone did not result in measurable secreted IL-12 activity. A hybrid heterodimer consisting of murine p35 and human p40 subunits retained bioactivity on murine cells; however, the combination of human p35 and murine p40 was completely inactive on murine cells. These results indicate that the observed inability of human IL-12 to act on murine cells is largely determined by the p35 subunit.

Amino Acid Sequence↗