RESUMEN
Arabinogalactan, a microheterogeneous polysaccharide occurring in plants, is known for its allergy-protective activity, which could potentially be used for preventive allergy treatment. New treatment options are highly desirable, especially in a preventive manner, due to the constant rise of atopic diseases worldwide. The structural origin of the allergy-protective activity of arabinogalactan is, however, still unclear and isolation of the polysaccharide is not feasible for pharmaceutical applications due to a variation of the activity of the natural product and contaminations with endotoxins. Therefore, a pentasaccharide partial structure was selected for total synthesis and subsequently coupled to a carrier protein to form a neoglycoconjugate. The allergy-protective activity of arabinogalactan could be reproduced with the partial structure in subsequent in vivo experiments. This is the first example of a successful simplification of arabinogalactan with a single partial structure while retaining its allergy-preventive potential.
RESUMEN
Tetrasubstituted pyrroles can be synthesized in a one-pot procedure from isoxazoles. The process includes the photoinduced in situ formation of acylazirines combined with a subsequent cobalt(II)-catalyzed ring expansion with 1,3-diketones.
RESUMEN
Mendelian susceptibility to mycobacterial diseases (MSMD) is a rare syndrome, the known genetic etiologies of which impair the production of, or the response to interferon-gamma (IFN-γ). We report here a patient (P1) with MSMD whose cells display mildly impaired responses to IFN-γ, at levels, however, similar to those from MSMD patients with autosomal recessive (AR) partial IFN-γR2 or STAT1 deficiency. Whole-exome sequencing (WES) and Sanger sequencing revealed only one candidate variation for both MSMD-causing and IFN-γ-related genes. P1 carried a heterozygous frame-shift IFNGR2 mutation inherited from her father. We show that the mutant allele is intrinsically loss-of-function and not dominant-negative, suggesting haploinsufficiency at the IFNGR2 locus. We also show that Epstein-Barr virus transformed B lymphocyte cells from 10 heterozygous relatives of patients with AR complete IFN-γR2 deficiency respond poorly to IFN-γ, in some cases as poorly as the cells of P1. Naive CD4(+) T cells and memory IL-4-producing T cells from these individuals also responded poorly to IFN-γ, whereas monocytes and monocyte-derived macrophages (MDMs) did not. This is consistent with the lower levels of expression of IFN-γR2 in lymphoid than in myeloid cells. Overall, MSMD in this patient is probably due to autosomal dominant (AD) IFN-γR2 deficiency, resulting from haploinsufficiency, at least in lymphoid cells. The clinical penetrance of AD IFN-γR2 deficiency is incomplete, possibly due, at least partly, to the variability of cellular responses to IFN-γ in these individuals.
Asunto(s)
Haploinsuficiencia , Infecciones por Mycobacterium no Tuberculosas/genética , Receptores de Interferón/genética , Adolescente , Linfocitos B/inmunología , Linfocitos B/metabolismo , Secuencia de Bases , Estudios de Casos y Controles , Células Cultivadas , Femenino , Expresión Génica , Genes Dominantes , Estudios de Asociación Genética , Predisposición Genética a la Enfermedad , Heterocigoto , Humanos , Interferón gamma/fisiología , Infecciones por Mycobacterium/genética , Análisis de Secuencia por Matrices de Oligonucleótidos , Linaje , Fosforilación , Procesamiento Proteico-Postraduccional , Receptores de Interferón/deficiencia , Análisis de Secuencia de ADN , Eliminación de SecuenciaRESUMEN
The purpose of the immune system is not only to fight off pathogens but also to keep a tolerance to self-antigens. In central tolerance, major mechanisms include apoptosis (for T cells) and receptor editing (for B cells). Regulatory T cells appear to be the most important in peripheral tolerance. Innate immune cells also influence the maintenance of immune tolerance. We have provided an overall review of all these mechanisms. Successful restoration of the immune tolerance is the target of new strategies in autoimmune diseases therapy.
Asunto(s)
Linfocitos B/inmunología , Tolerancia Inmunológica , Linfocitos T/inmunología , Enfermedades Autoinmunes/inmunología , HumanosRESUMEN
Common variable immunodeficiency (CVID) is a primary immunodeficiency of humoral immunity with heterogeneous clinical features. Diagnosis of CVID is based on hypogammaglobulinaemia, low production of specific antibodies, and disorders of cellular immunity. The standard therapy includes replacement of specific antibodies with human immunoglobulin, prophylaxis, and symptomatic therapy of infections. High prevalence of autoimmunity is characteristic for CVID, most commonly: thrombocytopaenia and neutropaenia, celiac disease, and systemic autoimmune diseases. The study included seven children diagnosed with CVID and treated with immunoglobulin substitution from 2 to 12 years. Thrombocytopenia was diagnosed prior to CVID in four children, developed during immunoglobulin substitution in three children. In one boy with CVID and thrombocytopaenia, haemolytic anaemia occurred, so a diagnosis of Evans syndrome was established. Therapy of thrombocytopaenia previous to CVID included steroids and/or immunoglobulins in high dose, and azathioprine. In children with CVID on regular immunoglobulin substitution, episodes of acute thrombocytopaenia were associated with infections and were treated with high doses of immunoglobulins and steroids. In two patients only chronic thrombocytopaenia was noted. Splenectomy was necessary in one patient because of severe course of thrombocytopaenia. The results of the study indicated a supportive role of regular immunoglobulin substitution in patients with CVID and chronic thrombocytopaenia. However, regular substitution of immunoglobulins in CVID patients did not prevent the occurrence of autoimmune thrombocytopaenia episodes or exacerbations of chronic form. In episodes of acute thrombocytopaenia or exacerbations of chronic thrombocytopaenia, infusions of immunoglobulins in high dose are effective, despite previous regular substitution in the replacing dose.
RESUMEN
Immunoglobulin M is a pentamer found in the intravascular compartment and on the surface of B lymphocytes. It is the antibody isotype produced initially in the immune response, and the first immunoglobulin class to be synthesized by a fetus or newborn. IgM antibodies do not cross the placenta. Decreased levels of IgM have been associated with autoimmune disease, several primary immunodeficiency but exist also as selected primary immunodeficiency.
Asunto(s)
Enfermedades Autoinmunes/inmunología , Disgammaglobulinemia/inmunología , Inmunoglobulina M/deficiencia , Síndromes de Inmunodeficiencia/inmunología , HumanosRESUMEN
Seven boys with diagnosis of X-linked agammaglobulinemia on regular substitution of immunoglobulins were included into study. The patients showed episodes of infections but the clinical course was mild with good response to antibiotics. All patients developed, with time, the chronic sinusitis with proliferation of mucous membrane, two patients showed bronchiectases. The number of T lymphocytes, ratio of CD4:CD8 subpopulations, response to stimulation and NK number were assayed with flow cytometry and cell culture. Results showed CD4:CD8 ratio within normal value in majority of patients, reverse ratio in 2 boys, increased number of activated T cells (CD3/HLA-DR) in one of them. The number of NK cells was different from lack of these cells to high number. Response of T cells to stimulation (mitogens and CD3) were normal in majority of assays. There were no associations between clinical course and observed changes in T or NK cell populations. Further studies on number and function of NK cells are needed.
Asunto(s)
Agammaglobulinemia/inmunología , Enfermedades Genéticas Ligadas al Cromosoma X/inmunología , Células Asesinas Naturales/inmunología , Linfocitos T/inmunología , Agammaglobulinemia/complicaciones , Recuento de Linfocito CD4 , Niño , Preescolar , Enfermedades Genéticas Ligadas al Cromosoma X/complicaciones , Humanos , Lactante , Recién Nacido , Activación de Linfocitos/inmunología , Masculino , Sinusitis/complicaciones , Sinusitis/inmunologíaRESUMEN
We have studied the effect of intravenous immunoglobulins (IVIG) on monocyte subpopulations and cytokine production in patients with CVID. The absolute number of CD14(+)CD16(++) monocytes decreased on average 2.5-fold 4h after IVIG and after 20h returned to the baseline. The cytokine level in the supernatants of peripheral blood mononuclear cells (PBMC) after ex vivo LPS stimulation demonstrated the >2-fold decrease in TNF production 4h after IVIG. The TNF expression, which is higher in the CD14(+)CD16(++) monocytes, was decreased in these cells by IVIG in 4/7 CVID cases. In vitro exposure of the healthy individuals' monocytes to the IVIG preparation resulted in reduced TNF production, which was overcome by blockade of the FcγRIIB in the CD14(+)CD16(++) CD32B(high) monocytes. Our data suggest that reduction in the number of CD14(+)CD16(++) monocytes and the blockade of their cytokine production via triggering CD32B can contribute to the anti-inflammatory action of IVIG.
Asunto(s)
Inmunodeficiencia Variable Común/terapia , Inmunoglobulinas Intravenosas/farmacología , Receptores de Lipopolisacáridos/metabolismo , Monocitos/efectos de los fármacos , Receptores de IgG/metabolismo , Adulto , Anticuerpos Monoclonales/farmacología , Antígenos CD/metabolismo , Femenino , Proteínas Ligadas a GPI/metabolismo , Antígenos HLA-DR/metabolismo , Humanos , Inmunoglobulinas Intravenosas/uso terapéutico , Inmunofenotipificación , Interleucina-10/metabolismo , Interleucina-12/metabolismo , Cinética , Recuento de Leucocitos , Leucocitos Mononucleares/efectos de los fármacos , Leucocitos Mononucleares/metabolismo , Lipopolisacáridos/farmacología , Masculino , Persona de Mediana Edad , Monocitos/citología , Monocitos/inmunología , Monocitos/metabolismo , Receptores de IgG/inmunología , Factor de Necrosis Tumoral alfa/metabolismo , Adulto JovenRESUMEN
Intravenous immunoglobulin (IVIG) products are derived from plasma pools of thousands of healthy donors. These immunoglobulin concentrates contain large number of antibodies as well trace levels various other immunologically active molecules. Therapeutic Ig formulations contain intact IgG molecules, with variable amounts of monomeric and dimeric form existing in a dynamic equilibrium. Paradoxically, IgG can exert both pro-and anti-inflammatory activities, depending on its concentration. IVIG have been used for the treatment of primary immunodeficiency disorders for more than 25 years. IVIG products are also effective in the treatment of autoimmune and inflammatory disorders; however, the precise mechanism (s) of action is not known. Clinical and laboratory studies have documented various mechanisms of action of IVIG. The complex network of immunological reactions resulting from the infusion of IVIG includes changes in several cytokines, interactions with dendritic cells, T-and B-cell effects, macrophage effects, mediated by distinct Fc-gamma receptors. IVIG is also a recently recognized modifier of complement activation and injury. The complement--scavenging ability of Ig implies expansion of the use of IVIG to all disease in which generation of complement fragments plays a crucial role in pathogenesis. Recent studies showed that the anti-inflammatory activity of IVIG result from a minor population of the pooled IgG molecules that contains terminal a-2,6 sialic acid linkages on their Fc-linked glycans. This fully processed glycan is found in 1-3% of IgG in IVIG, which may explain the requirement for a high dose of IVIG. Recent data demonstrate, that the anti-inflammatory properties of IVIG can be recapitulated with fully recombinant preparation of appropriately sialylated IgG Fc fragments. This recombinant preparation had a 35 fold enhanced activity and potentially could be used at much lower doses than IVIG preparation in the treatment of autoimmune disorders.
Asunto(s)
Antiinflamatorios/administración & dosificación , Inmunoglobulinas Intravenosas/administración & dosificación , Enfermedades Autoinmunes/tratamiento farmacológico , Humanos , Síndromes de Inmunodeficiencia/tratamiento farmacológicoRESUMEN
A shot in the arm for cancer treatment: two MUC1 tetanus toxoid vaccines were synthesized and induced a strong immune response in mice. The antibodies elicited by the vaccines show a high selectivity for the tumor cells in mammary carcinoma tissues and also distinguish between tumor tissues at different stages.