Chlamydia muridarum Associated Pulmonary and Urogenital Disease and Pathology in a Colony of Enzootically Infected Il12rb2 Deficient and Stat1 Knockout Mice.

Chlamydia muridarum (Cm), an intracellular bacterium of historical importance, was recently rediscovered as moderately prevalent in research mouse colonies. Cm was first reported as a causative agent of severe pneumonia in mice about 80 y ago, and while it has been used experimentally to model Chlamydia trachomatis infection of humans, there have been no further reports of clinical disease associated with natural infection. We observed clinical disease and pathology in 2 genetically engi- neered mouse (GEM) strains, Il12rb2 KO and STAT1 KO, with impaired interferon-γ signaling and Th1 CD4+ T cell responses in a colony of various GEM strains known to be colonized with and shedding Cm. Clinical signs included poor condition, hunched posture, and poor fecundity. Histopathology revealed disseminated Cm with lesions in pulmonary, gastrointestinal, and urogenital tissues. The presence of Cm was confirmed using both immunohistochemistry for Cm major outer membrane protein-1 antigen and in situ hybridization using a target probe directed against select regions of Cm strain Nigg. Cm was also found in association with a urothelial papilloma in one mouse. These cases provide additional support for excluding Cm from research mouse colonies.

Leukocytoclastic vasculitis in patients with IL12B or IL12RB1 deficiency: case report and review of the literature.

BACKGROUND: Mendelian susceptibility to mycobacterial disease (MSMD) is an inborn error of immunity, resulting in susceptibility to weakly virulent mycobacteria and other intramacrophagic pathogens. Rheumatologic manifestations and vasculitis are considered rare manifestations in MSMD patients. CASE PRESENTATION: In this study, we reported a 20-year-old female who was presented with recurrent lymphadenitis following bacillus Calmette-Guérin (BCG) vaccination and a history of recurrent disseminated rash diagnosed as leukocytoclastic vasculitis (LCV). A slight reduction in lymphocyte subsets including CD4+, CD19+, and CD 16 + 56 T-cell count, as well as an elevation in immunoglobulins level (IgG, IgA, IgM, IgE), were observed in the patient. Whole exome sequencing revealed a homozygous Indel-frameshift mutation, c.527_528delCT (p. S176Cfs*12), at the exon 5 of the IL12B gene. She experienced symptom resolution after treatment with anti-mycobacterial agents and subcutaneous IFN-γ. We conducted a manual literature search for MSMD patients reported with vasculitis in PubMed, Web of Science, and Scopus databases. A total of 18 MSMD patients were found to be affected by a variety of vasculitis phenotypes mainly including LCV and Henoch-Schönlein purpura (HSP) with often skin involvement. Patients were all involved with vasculitis at the median age of 6.8 (2.6-7.7) years, nearly 6.1 years after the initial presentations. Sixteen patients (88.9%) had IL12RB1 defects and concurrent Salmonella infection was reported in 15 (88.2%) patients. CONCLUSION: The lack of IL-12 and IL-23 signaling/activity/function and salmonella infection may be triggering factors for the development of leukocytoclastic vasculitis. IL12B or IL12RB1 deficiency and salmonellosis should be considered in MSMD patients with vasculitis.

In vivo evolution of an emerging zoonotic bacterial pathogen in an immunocompromised human host.

Zoonotic transfer of animal pathogens to human hosts can generate novel agents, but the genetic events following such host jumps are not well studied. Here we characterize the mechanisms driving adaptive evolution of the emerging zoonotic pathogen Bordetella hinzii in a patient with interleukin-12 receptor ß1 deficiency. Genomic sequencing of 24 B. hinzii isolates cultured from blood and stool over 45 months revealed a clonal lineage that had undergone extensive within-host genetic and phenotypic diversification. Twenty of 24 isolates shared an E9G substitution in the DNA polymerase III ε-subunit active site, resulting in a proofreading deficiency. Within this proofreading-deficient clade, multiple lineages with mutations in DNA repair genes and altered mutational spectra emerged and dominated clinical cultures for more than 12 months. Multiple enzymes of the tricarboxylic acid cycle and gluconeogenesis pathways were repeatedly mutated, suggesting rapid metabolic adaptation to the human environment. Furthermore, an excess of G:C > T:A transversions suggested that oxidative stress shaped genetic diversification during adaptation. We propose that inactivation of DNA proofreading activity in combination with prolonged, but sub-lethal, oxidative attack resulting from the underlying host immunodeficiency facilitated rapid genomic adaptation. These findings suggest a fundamental role for host immune phenotype in shaping pathogen evolution following zoonotic infection.

A Syrian Refugee in Iraq Diagnosed as a Case of IL12RB1 Deficiency in Japan Using Dried Blood Spots.

Mendelian susceptibility to mycobacterial diseases (MSMD) is a rare condition of primary immunodeficiency disorder. Interleukin-12 receptor ß1 (IL12RB1) deficiency, is the most common genetic etiology of MSMD, which is characterized by the selective predisposition to clinical disease caused by weakly-virulent mycobacteria, such as Bacillus Calmette-Guérin (BCG) vaccines, and environmental non-tuberculous mycobacteria (NTM). To the best of our knowledge, this is the first case of IL12RB1 deficiency to be reported from Iraq. Our case is an 8-year-old Syrian girl, for first-cousin parents, with a refugee-status in the North of Iraq. She had a history of disseminated BCG infection 2 months after receiving BCG vaccine, in addition to repeated episodes of mild or severe illnesses, such as maculopapular skin rash, lymphadenopathy, gastroenteritis, meningitis, and clinically diagnosed tuberculosis (TB) based on local TB-prevalence setting. Because of limited medical facilities in the war-torn countries; in Syria and Iraq, no diagnosis could be reached. We used Flinders Technology Associates (FTA) cards to transfer her bone marrow aspirate to Japan. A homozygous IL12RB1 mutation was detected by whole exome sequencing in Japan, using genomic-DNA extracted from dried bone marrow sample spots on FTA filter paper. In conclusion, diagnosis of MSMD due to IL12RB1 deficiency was possible by transferring the FTA sample of the patient for genetic evaluation in Japan. Our report recalls the need of pediatricians in countries with TB-prevalence and high parental consanguinity, to consider IL12RB1 deficiency in the differential diagnosis of a child with clinical evidence of TB, especially with the history of disseminated BCG disease.

Clinical findings and genetic analysis of the patients with IL-12Rß1 deficiency from southeast Turkey.

Dogruel D, Gündeslioglu ÖÖ, Yilmaz M, Alabaz D, Altintas DU, Kocabas E. Clinical findings and genetic analysis of the patients with IL- 12Rß1 deficiency from southeast Turkey. Turk J Pediatr 2019; 61: 174-179. IL-12Rß1 deficiency is an autosomal recessive disorder characterized by predisposition to poorly pathogenic mycobacteria, salmonella and candida species. We aimed to analyze the clinical manifestations, immunological and genetic features of IL-12Rß1 deficiency in 10 Turkish patients from a single center. We retrospectively studied the clinical manifestations and genetic analysis of the IL-12Rß1 deficiency patients from 2008 to 2016. Ten patients were diagnosed and followed for eight years. The mean age at onset and diagnosis were 24.1±42.5 (med:10.5) and 52.3±6.83 (med:20) months, respectively. Parental consanguinity rate was 81.8%. All patients were BCG vaccinated. Abscess and axillary lymphadenopathy in the vaccinated area was the most common initial presentation following the BCG vaccination, six patients had recurring oral candidiasis. Active infections were treated appropriately, in addition to prophylactic therapy with IFNÉ£. We identified 6 different mutations in the IL12RB1 gene in 10 patients including 5 splice-site mutations, 3 missense, 1 frameshift, 1 premature stop codon. One of these mutations was novel. The most common mutation was IVS8+1G > A(c.783+1G > A) followed by p.R175W(c.523C > T). This study emphasizes that patients presented with abscess and axillary lymphadenopathy associated with BCG vaccination should be evaluated for IL-12Rß1 deficiency.

Impaired IL-12- and IL-23-Mediated Immunity Due to IL-12Rß1 Deficiency in Iranian Patients with Mendelian Susceptibility to Mycobacterial Disease.

PURPOSE: Inborn errors of IFN-γ-mediated immunity underlie Mendelian Susceptibility to Mycobacterial Disease (MSMD), which is characterized by an increased susceptibility to severe and recurrent infections caused by weakly virulent mycobacteria, such as Bacillus Calmette-Guérin (BCG) vaccines and environmental, nontuberculous mycobacteria (NTM). METHODS: In this study, we investigated four patients from four unrelated consanguineous families from Isfahan, Iran, with disseminated BCG disease. We evaluated the patients' whole blood cell response to IL-12 and IFN-γ, IL-12Rß1 expression on T cell blasts, and sequenced candidate genes. RESULTS: We report four patients from Isfahan, Iran, ranging from 3 months to 26 years old, with impaired IL-12 signaling. All patients suffered from BCG disease. One of them presented mycobacterial osteomyelitis. By Sanger sequencing, we identified three different types of homozygous mutations in IL12RB1. Expression of IL-12Rß1 was completely abolished in the four patients with IL12RB1 mutations. CONCLUSIONS: IL-12Rß1 deficiency was found in the four MSMD Iranian families tested. It is the first report of an Iranian case with S321* mutant IL-12Rß1 protein. Mycobacterial osteomyelitis is another type of location of BCG infection in an IL-12Rß1-deficient patient, notified for the first time in this study.

Severe BCG-osis Misdiagnosed as Multidrug-Resistant Tuberculosis in an IL-12Rß1-Deficient Peruvian Girl.

PURPOSE: Mendelian suceptibility to mycobacterial disease (MSMD) is a rare primary immunodeficiency predisposing to severe disease caused by mycobacteria and other intracellular pathogens. Delay in diagnosis can have an impact on the patient's prognosis. METHODS: We evaluated the IFN-γ circuit by studying IFN-γ production after mycobacterial challenge as well as IL-12Rß1 expression and STAT4 phosphorylation in response to IL-12p70 stimulation in whole blood of a 6-year-old Peruvian girl with disseminated recurrent mycobacterial infection diagnosed as multidrug-resistant tuberculosis. Genetic studies with Sanger sequencing were used to identify the causative mutation. Microbiological studies based on PCR reactions were used to diagnose the specific mycobacterial species. RESULTS: We identified a homozygous mutation in the IL12RB1 gene (p. Arg211*) causing abolished expression of IL-12Rß1 and IL-12 response. MSMD diagnosis led to a microbiological reevaluation of the patient, revealing a BCG vaccine-related infection instead of tuberculosis. Treatment was then adjusted, with good response. CONCLUSIONS: We report the first Peruvian patient with IL-12Rß1 deficiency. Specific mycobacterial species diagnosis within Mycobacterium tuberculosis complex is still challenging in countries with limited access to PCR-based microbiological diagnostic techniques. Awareness of MSMD warning signs and accurate microbiological diagnosis of mycobacterial infections are of the utmost importance for optimal diagnosis and management of affected patients.

Interferon-γ-dependent protection against Neospora caninum infection conferred by mucosal immunization in IL-12/IL-23 p40-deficient mice.

We have recently demonstrated the effectiveness of an intranasal immunization approach against Neospora caninum infection in immunosufficient mice. Generated evidence indicated that antibodies could be mediating the observed protection. We similarly immunized IL-12/IL-23 p40 chain-deficient (Il12b-/-) mice, which have impaired cellular immunity, to further explore the host protective mechanism conferred by the used immunization strategy. The immunized mice presented lower parasitic burdens after intraperitoneal infection with N. caninum and also had elevated levels of parasite-specific antibodies. However, passive immunization with antibodies purified from immunized donors conferred only limited protection to infected Il12b-/- recipients. Despite their intrinsic IL-12 deficiency, the immunized Il12b-/- mice mounted a parasite-specific immune response that was mediated by interferon-γ (IFN-γ). Neutralization of IFN-γ in the immunized mice abrogated the observed protective effect of the immunization. These results show altogether that the used immunization strategy overcome the cellular immunity defect of Il12b-/- mice and conferred protection from N. caninum infection. The observed protective effect was predominantly mediated by IFN-γ and to a lesser extent but non-negligibly by IgG antibodies. These results also highlight that in a host with compromised cellular immunity, the immune response against intracellular pathogens could be markedly boosted by immunization.

Inhibition of interleukin-12 and/or interleukin-23 for the treatment of psoriasis: What is the evidence for an effect on malignancy?

Immune cells and cytokines play an important role in the pathogenesis of psoriasis. Interleukin-12 (IL-12) and IL-23 promote cellular responses mediated by T cells, which contribute to an inflammatory loop responsible for the induction and maintenance of psoriatic plaques. Antibodies that inhibit IL-12/23 or IL-23 are key treatment options for patients with psoriasis. IL-12 and IL-23 also play a key role in immune responses to infections and tumors. A growing body of information from clinical trials, cohort studies, postmarketing reports, genetic studies and animal models provides insights into the potential biological relationships between IL-12/23 inhibition and malignancies. We summarize this information in tables and provide some context for the interpretation of these data with the goal of informing dermatologists who are using IL-12/23 or IL-23 inhibitors to treat patients with psoriasis.

Coexistence of 2 rare autosomal recessively inherited disorders manifesting with immune deficiency; IL-12 receptor ß1 and biotinidase deficiencies.

Dogruel D, Bulut FD, Yilmaz M, Önenli-Mungan N, Altintas DU. Coexistence of 2 rare autosomal recessively inherited disorders manifesting with immune deficiency; IL-12 receptor ß1 and biotinidase deficiencies. Turk J Pediatr 2018; 60: 584-587. In this report, we described an infant with both partial biotinidase and IL-12Rß1 deficiencies as these two entities are rare and unrelated inherited disorders. One-month-old girl was diagnosed as partial biotinidase deficiency with newborn screening programme. Mutation analysis revealed a compound heterozygous mutation BTD: c.1330G > C (p.Val444Leu) / c.196_197dupCATC (p.Leu69HisfsTer24). At the age of 6 months, a nodule on her left axilla with purulent discharge was noticed which was related to BCG vaccination. A mutational analysis revealed a homozygous c.783+1G > A mutation on IL-12Rß1 gene. Interferon-gamma and anti-tuberculosis treatment were initiated together and the nodule with purulent discharge regressed dramatically. Here, we want to emphasize consideration of coexistence of two rare autosomal recessively inherited diseases in a patient due to the high rate of consanguinity in our country.

Inherited IL-12Rß1 Deficiency in a Child With BCG Adenitis and Oral Candidiasis: A Case Report.

Tuberculosis is a major worldwide problem, and protection from it is achieved mainly by live attenuated bacille Calmette-Guérin vaccine, which is capable of causing disease in immunocompromised host. Oral thrush is abnormal in healthy children, which suggests an underlying immunodeficiency. Mendelian susceptibility to mycobacterial disease is a rare primary immunodeficiency characterized by a selective predisposition to weakly virulent Mycobacteria and Salmonella and also predisposition to chronic mucocutaneous candidiasis. Interleukin 12 receptor ß1 (IL-12Rß1) deficiency is the most common disease of Mendelian susceptibility to mycobacterial disease, and to date only 50 IL-12Rß1 deficient patients with clinical signs of chronic mucocutaneous candidiasis have been reported. We report a 2.5-year-old daughter of consanguineous parents with both regional bacille Calmette-Guérin lymphadenitis and recurrent oral candidiasis carrying biallelic R175W mutation in the IL12RB1 gene, resulting in complete loss of expression of IL-12Rß1. To our knowledge, this is the first report of bacille Calmette-Guérin lymphadenitis with concurrent oral candidiasis displaying such a mutation. New mutations and wide clinical diversities are the indisputable fact of populations with a high rate of consanguineous marriages.

Severe Enteropathy and Hypogammaglobulinemia Complicating Refractory Mycobacterium tuberculosis Complex Disseminated Disease in a Child with IL-12Rß1 Deficiency.

PURPOSE: Mendelian susceptibility to mycobacterial disease is a rare clinical condition characterized by a predisposition to infectious diseases caused by poorly virulent mycobacteria. Other infections such as salmonellosis and candidiasis are also reported. The purpose of this article is to describe a young boy affected with various infectious diseases caused by Mycobacterium tuberculosis complex, Salmonella sp, Klebsiella pneumonie, Citrobacter sp., and Candida sp, complicated with severe enteropathy and transient hypogammaglobulinemia. METHODS: We reviewed medical records and performed flow cytometry staining for lymphocyte populations, lymphocyte proliferation in response to PHA, and intracellular IFN-γ production in T cell PHA blasts in the patient and a healthy control. Sanger sequencing was used to confirm the genetic variants in the patient and relatives. RESULTS: Genetic analysis revealed a bi-allelic mutation in IL12RB1 (C291Y) resulting in complete IL-12Rß1 deficiency. Functional analysis demonstrated the lack of intracellular production of IFN-γ in CD3+ T lymphocytes from the patient in response to rhIL-12p70. CONCLUSIONS: To our knowledge, this is the third patient with MSMD due to IL-12Rß1 deficiency complicated with enteropathy and hypogammaglobulinemia and the first case of this disease to be described in Colombia.

Dysfunction of hepatic regulatory T cells in experimental sclerosing cholangitis is related to IL-12 signaling.

BACKGROUND & AIMS: Reduced numbers of regulatory T cells (Treg) have been reported in patients with primary sclerosing cholangitis (PSC); therefore, Treg expansion might serve as a therapeutic approach. Here, we explored whether treatment with IL-2/IL-2 monoclonal antibody complex (IL-2/IL-2Ab complex) could provide in vivo Treg expansion and treatment of experimental sclerosing cholangitis. METHODS: Treg were expanded by repeated injection of IL-2/IL-2Ab complex in mouse models of cholangitis (Mdr2-/-, DDC) or colitis (dextran sulfate sodium [DSS]) as control. In vitro suppressive capacity and gene expression were analyzed in isolated hepatic and splenic Treg. RESULTS: In vivo expansion resulted in a 5-fold increase in hepatic Treg, which localized within the inflamed portal tracts. However, although Treg expansion was associated with reduced pro-inflammatory IL-17 and increased anti-inflammatory IL-10 production by hepatic lymphocytes, the severity of cholangitis was not reduced. In contrast, DSS-induced colitis could be improved by Treg expansion, suggesting a selectively reduced functionality of intrahepatic Treg. Indeed, hepatic Treg manifested reduced Foxp3 expression and reduced suppressive capacity compared to splenic Treg. Hepatic Treg dysfunction could be linked to increased IL-12 signaling due to an upregulation of the IL-12 receptor. Accordingly, IL-12 receptor beta 2 knockout mice (IL-12rb2-/-) were able to maintain hepatic Treg functionality. CONCLUSIONS: Hepatic Treg expanded in vivo failed to improve the course of cholangitis, which was related to the effects of hepatic IL-12 on Treg. Therefore, neutralization of IL-12 should be considered as part of treatment strategies targeting Treg in sclerosing cholangitis. LAY SUMMARY: Primary sclerosing cholangitis (PSC) is associated with a paucity of regulatory T cells (Treg) that have a particular ability to control immune responses; therefore, in vivo expansion of Treg might serve as a treatment of cholangitis. However, in a mouse model of PSC, we show that Treg enrichment in the liver was not sufficient to provide effective control of cholangitis, as the suppressive functionality of hepatic Treg was significantly limited by IL-12 signals. Thus, neutralization of IL-12 should be considered as part of treatment strategies to improve the efficacy of Treg-based treatments for liver diseases. Data accession number: GSE 87898.

IL12Rß1 defect presenting with massive intra-abdominal lymphadenopathy due to Mycobacterium intracellulare infection.

Infections due to non-tuberculous mycobacteria species are problematic for immunodeficient individuals. Mendelian susceptibility to mycobacterial diseases (MSMD) defines a group of genetic defects affecting cellular interactions and the interferon (IFN)-γ pathway. Patients with MSMD may present with a disseminated infection resulting from the Bacillus Calmette-Guerin vaccine, Mycobacterium tuberculosis complex, environmental nontuberculous mycobacteria or Salmonella species. Atypical mycobacterial infections and deficient granuloma or giant cell formation are important indicators for MSMD, especially in patients with a family history of parental consanguineous marriage. Herein we report the case of a boy with an IL-12Rß1 defect who presented with massive intraabdominal lymphadenopathy due to Mycobacterium intracellulare infection. The patient was born to consanguineous parents, both heterozygous for the IL-12Rß1 defect mutation. Debulking surgery was planned in order to decrease the abdominal mass, but could not be performed due to a high risk of fatal outcomes. He has been receiving linezolid, levofloxacin, azithromycin, rifabutin and IFN-γ therapy for the past 14 months. At follow-up, the patient showed significant clinical improvement and weight gain.

Visceral leishmaniasis in two patients with IL-12p40 and IL-12Rß1 deficiencies.

Mutations of the IL12B and IL12RB1 genes underlie the development of IL-12 p40 and IL-12Rß1 deficiencies, respectively, both of which cause predisposition to infection with weakly virulent mycobacteria and Salmonella. Infections with other intramacrophagic organisms have only been rarely observed. We identified two patients with visceral leishmaniasis who had autosomal recessive IL-12 p40 and IL-12Rß1 deficiencies, respectively. This finding demonstrates the importance of IFN-γ immunity in the control of leishmaniasis. We also searched the literature for similar reports in patients with these and other primary immunodeficiencies.