Proliferative Response of Hamster CD4+ T Cells after Different Mitogenic Stimulation

The measurement of effector cells involved in immune responses is an important parameter in various  fields of lymphocyte research using the Syrian Golden hamster as the experimental model. The aim of  the present study was to identify the percentage of peripheral hamster CD4+ cells that undergo proliferation  and the number of cell divisions induced by four different mitogenic compounds: phorbol-myristate  acetate plus ionomycin (PMA/ionomycin), concanavalin A (Con A), phytohaemagglutinin (PHA) and the  superantigen Staphylococcal enterotoxin B (SEB). The proliferative response was investigated by the use of  the cross-reactive mouse anti-CD4 antibody (clone H129.9) and analyzed by flow cytometry using the dye  carboxyfluorescein diacetate succinimydil ester (CFSE). PMA/ionomycin induced the highest proliferative  response of CD4+ cells. Interestingly, the down-regulation in the CD4 expression described after PMA/  ionomycin activation both in human and in mouse lymphocytes was not seen in hamster cells. Stimulation  with SEB and with Con A also induced up to 6 to 7 proliferation cycles in cells, whereas PHA induced the  lowest proliferation. These results provide useful tools for the study of CD4+ cells in the hamster model.

Oral Administration of Human Polyvalent IgG by Mouthwash as an Adjunctive Treatment of Chronic Oral Candidiasis

Candida albicans is a commensal fungus that can cause disease ranging in severity from moderate to severe mucosal infections to more serious life-threating disseminated infections in severely immunocompromised hosts. Chronic mucocutaneous candidiasis (CMC) occurs in patients with mutations in genes affecting IL-17-mediated immunity, such as STAT3, AIRE, RORC, CARD9, IL12B, and IL12RB1, or gain of function (GOF) mutations in STAT1. New strategies for the treatment of candidiasis are needed because of the increased burden of infections and the emergence of drug-resistant strains. In this study, we investigated an aspect of the role of antibodies in the control of C. albicans infection. We tested in vitro the effects of C. albicans opsonization with commercial human polyvalent intravenous IgG (IV IgG) on NADPH oxidase activity and killing of the fungi by blood leukocytes from 11 healthy donors and found a significant enhancement in both phenomena that was improved by IV IgG opsonization. Then, we hypothesized that the opsonization of Candida in vivo could help its elimination by mucosal phagocytes in human patients with mucocutaneous candidiasis. We tested a novel adjunctive treatment for oral candidiasis in humans based on topical treatment with IV IgG. For this purpose, we choose two pediatric patients with well-characterized primary immunodeficiencies who are susceptible to CMC. Two 8-year-old female patients with an autosomal recessive mutation in the IL12RB1 gene (P1, with oral candidiasis) and a GOF mutation in STAT1 (P2, with severe CMC persistent since the age of 8 months and resistant to pharmacological treatments) were treated with IV IgG administered daily three times a day as a mouthwash over the course of 2 weeks. The treatment with the IV IgG mouthwash reduced C. albicans mouth infection by 98 and 70% in P1 and P2, respectively, after 13 days, and complete fungal clearance was observed after complementary nystatin and caspofungin treatments, respectively. Therefore, treatment of oral candidiasis with human polyvalent IgG administered as a mouthwash helps eliminate mucosal infection in humans, circumventing drug resistance, and opening its potential use in patients with primary or transient immunodeficiency

The Impact of IFN-g; Receptor on SLPI Expression in Active Tuberculosis: Association with Disease Severity

Interferon (IFN)-g displays a critical role in tuberculosis (TB), modulating the innate and adaptive immune responses. Previously, we reported that secretory leukocyte protease inhibitor (SLPI) is a pattern recognition receptor with anti-mycobacterial activity against Mycobacterium tuberculosis (Mtb). Herein, we determined whether IFN-g modulated the levels of SLPI in TB patients. Plasma levels of SLPI and IFN-g were studied in healthy donors (HDs) and TB patients. Peripheral blood mononuclear cells from HDs and patients with TB or defective IFN-g receptor 1* were stimulated with Mtb antigen and SLPI, and IFN-gR expression levels were measured. Both SLPI and IFN-g were significantly enhanced in plasma from those with TB compared with HDs. A direct association between SLPI levels and the severity of TB was detected. In addition, Mtb antigen stimulation decreased the SLPI produced by peripheral blood mononuclear cells from HDs, but not from TB or IFN-gR patients. Neutralization of IFN-g reversed the inhibition of SLPI induced by Mtb antigen in HDs, but not in TB patients. Furthermore, recombinant IFN-g was unable to modify the expression of SLPI in TB patients. Finally, IFN-gR expression was lower in TB compared with HD peripheral blood mononuclear cells. These results show that Mtb-induced IFN-g down-modulated SLPI levels by signaling through the IFNgR in HDs. This inhibitory mechanism was not observed in TB, probably because of the low expression of IFN-gR detected in these individuals. (Am J Pathol 2014, 184: 1e6Fil: Tateosian, Nancy Liliana. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Centro de Estudios Farmacológicos y Botánicos; Argentina; ArgentinaFil: Pasquinelli, Virginia. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires; ArgentinaFil: Hernández Del Pino, Rodrigo Emanuel. Universidad de Buenos Aires; ArgentinaFil: Ambrosi, Nella Gabriela. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Centro de Estudios Farmacológicos y Botánicos; Argentina; ArgentinaFil: Guerrieri, Diego. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Centro de Estudios Farmacológicos y Botánicos; Argentina; ArgentinaFil: Pedraza Sánchez, Sigifredo. Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán; MéxicoFil: Santucci, Natalia Estefanía. Universidad Nacional de Rosario; ArgentinaFil: D'attilio, Luciano David. Universidad Nacional de Rosario; ArgentinaFil: Pellegrini, Joaquín Miguel. Universidad de Buenos Aires; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Araujo Solis, María A.. Instituto Mexicano del Seguro Social; MéxicoFil: Musella, Rosa M.. Hospital "F. J. Muñiz"; ArgentinaFil: Palmero, Domingo J.. Hospital "F. J. Muñiz"; ArgentinaFil: Hernandez Pando, Rogelio. Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán; MéxicoFil: Garcia, Veronica Edith. Universidad de Buenos Aires; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Chuluyan, Hector Eduardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Centro de Estudios Farmacológicos y Botánicos; Argentina; Argentin

Calcitriol Inhibits the Proliferation of Triple-Negative Breast Cancer Cells through a Mechanism Involving the Proinflammatory Cytokines IL-1β and TNF-α

Triple-negative breast cancer (TNBC) is one of the most aggressive tumors, with poor prognosis and high metastatic capacity. The aggressive behavior may involve inflammatory processes characterized by deregulation of molecules related to the immunological responses in which interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α) are involved. It is known that calcitriol, the active vitamin D metabolite, modulates the synthesis of immunological mediators; however, its role in the regulation of IL-1β and TNF-α in TNBC has been scarcely studied. In the present study, we showed that TNBC cell lines SUM-229PE and HCC1806 expressed vitamin D, IL-1β, and TNF-α receptors. Moreover, calcitriol, its analogue EB1089, IL-1β, and TNF-α inhibited cell proliferation. In addition, we showed that synthesis of both IL-1β and TNF-α was stimulated by calcitriol and its analogue. Interestingly, the antiproliferative activity of calcitriol was significantly abrogated when the cells were treated with anti-IL-1β receptor 1 (IL-1R1) and anti-TNF-α receptor type 1 (TNFR1) antibodies. Furthermore, the combination of calcitriol with TNF-α resulted in a greater antiproliferative effect than either agent alone, in the two TNBC cell lines and an estrogen receptor-positive cell line. In summary, this study demonstrated that calcitriol exerted its antiproliferative effects in part by inducing the synthesis of IL-1β and TNF-α through IL-1R1 and TNFR1, respectively, in TNBC cells, highlighting immunomodulatory and antiproliferative functions of calcitriol in TNBC tumors

Disseminated Tuberculosis and Chronic Mucocutaneous Candidiasis in a Patient with a Gain-of-Function Mutation in Signal Transduction and Activator of Transcription 1

In humans, recessive loss-of-function mutations in STAT1 are associated with mycobacterial and viral infections, whereas gain-of-function (GOF) mutations in STAT1 are associated with a type of primary immunodeficiency related mainly, but not exclusively, to chronic mucocutaneous candidiasis (CMC). We studied and established a molecular diagnosis in a pediatric patient with mycobacterial infections, associated with CMC. The patient, daughter of a non-consanguineous mestizo Mexican family, had axillary adenitis secondary to BCG vaccination and was cured with resection of the abscess at 1-year old. At the age of 4 years, she had a supraclavicular abscess with acid-fast-staining bacilli identified in the soft tissue and bone, with clinical signs of disseminated infection and a positive Gene-X-pert test, which responded to anti-mycobacterial drugs. Laboratory tests of the IL-12/interferon gamma (IFN-γ) circuit showed a higher production of IL-12p70 in the whole blood from the patient compared to healthy controls, when stimulated with BCG and BCG + IFN-γ. The whole blood of the patient produced 35% less IFN-γ compared to controls assessed by ELISA and flow cytometry, but IL-17 producing T cells from patient were almost absent in PBMC stimulated with PMA plus ionomycin. Signal transduction and activator of transcription 1 (STAT1) was hyperphosphorylated at tyrosine 701 in response to IFN-γ and -α, as demonstrated by flow cytometry and Western blotting in fresh blood mononuclear cells and in Epstein-Barr virus lymphoblastoid cell lines (EBV-LCLs); phosphorylation of STAT1 in EBV-LCLs from the patient was resistant to inhibition by staurosporine but sensitive to ruxolitinib, a Jak phosphorylation inhibitor. Genomic DNA sequencing showed a de novo mutation in STAT1 in cells from the patient, absent in her parents and brother; a known T385M missense mutation in the DNA-binding domain of the transcription factor was identified, and it is a GOF mutation. Therefore, GOF mutations in STAT1 can induce susceptibility not only to fungal but also to mycobacterial infections by mechanisms to be determined