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1.
PLoS One ; 17(7): e0269932, 2022.
Article in English | MEDLINE | ID: mdl-35802715

ABSTRACT

Dendritic cells (DCs) promote HIV-1 transmission by acting as Trojan horses, capturing viral particles, facilitating the infection of CD4+ T-cells. Vitamin D (VitD) has shown to decrease T cell activation, reducing susceptibility to HIV-1 infection of CD4+ T-cells in vitro; however, if VitD decreases viral transfer from DCs to CD4+ T-cells is unknown. In this study, we co-cultured HIV-1-pulsed immature and LPS mature monocytes-derived DCs (iDCs and LmDCs, respectively), differentiated in presence or absence of calcitriol (VitD active form), with PHA-activated autologous CD4+ T-cells from 16 healthy donors. In co-cultures of iDCs and LmDCs treated with calcitriol, there was a significant decrease in frequency of infected CD4+ T-cells, evaluated by flow cytometry. However, p24 levels evaluated by ELISA were not significantly reduced in culture supernatants. Moreover, calcitriol-treated iDCs exhibited decreased expression of genes involved in HIV-1 transfer compared to the control. Both, calcitriol-treated iDCs and LmDCs exhibit a similar gene expression profile, probably related to a transcriptional balance achieved after long treatment with calcitriol. Since calcitriol-differentiated DCs express on their surface a lower amount of DC-SIGN and SIGLEC-1 molecules, widely associated with HIV-1 transfer, suggesting that this mechanism contributes to a lower transfer of viral particles by the DCs.


Subject(s)
HIV Infections , HIV Seropositivity , HIV-1 , CD4-Positive T-Lymphocytes , Calcitriol/pharmacology , Cell Adhesion Molecules , Cells, Cultured , Dendritic Cells , HIV Infections/prevention & control , HIV-1/physiology , Humans , Lectins, C-Type , Monocytes , Receptors, Cell Surface , Sialic Acid Binding Ig-like Lectin 1
2.
Infect Genet Evol ; 55: 313-317, 2017 11.
Article in English | MEDLINE | ID: mdl-28964857

ABSTRACT

Siglec-1/CD169 is a sialoadhesin expressed by macrophages thought to function in cell-to-cell interactions. In the lung, the expression of Siglec-1 is specific for alveolar macrophages and single nucleotide polymorphisms (SNPs) in SIGLEC1 have been recently associated with asthma severity. Taking in account the role of alveolar macrophages in the control of M. tuberculosis and the poor literature about the contribution of SIGLEC1 genetics in M. tuberculosis susceptibility and development of pulmonary active TB, selected SNPs in SIGLEC1 were analysed in a case/control cohort from a TB endemic area of Brazil Amazon. Our findings evidenced for the first time the novel association between SIGLEC1 rs3859664 SNP and active pulmonary TB. Intriguingly, carriers of the polymorphism produced less IL-1ß than non-carriers, suggesting the possible involvement of Siglec-1 signalling pathway with inflammasome complex.


Subject(s)
Genetic Predisposition to Disease , Interleukin-1beta/metabolism , Polymorphism, Single Nucleotide , Sialic Acid Binding Ig-like Lectin 1/genetics , Tuberculosis, Pulmonary/genetics , Tuberculosis, Pulmonary/metabolism , Adult , Alleles , Brazil , Case-Control Studies , Female , Genotype , Humans , Linkage Disequilibrium , Male , Middle Aged , Mycobacterium tuberculosis , Tuberculosis, Pulmonary/microbiology , Young Adult
3.
Genet Mol Res ; 13(4): 9615-21, 2014 Nov 14.
Article in English | MEDLINE | ID: mdl-25501171

ABSTRACT

Porcine reproductive and respiratory syndrome (PRRS), which is caused by the PRRS virus (PRRSV), is a communicable disease. PRRS caused huge economic losses to swine breeding. The porcine alveolar macrophage (PAM) cell is the main target cell of PRRSV; therefore, it is very important to identify the specific gene promoter that controls expression in PAM cells so that the anti-PRRSV exogenous gene can be efficiently and specifically expressed in PAM cells to improve porcine resistance to PRRSV. In this study, the transcription initiation site for sialoadhesin (Siglec-1), which is a porcine alveolar macrophage-specific gene, was determined by 5' rapid amplification of cDNA end, and 88 bp of the 5'-untranslated region was cloned. Siglec-1 promoter activity was detected by a dual-luciferase reporter assay, which showed that the fragment from -173 to +81 bp had the strongest promoter activity. Additionally, the cell-specific expression of the promoter fragments was tested in a PAM cell line (CRL-2844 cells), porcine kidney 15 cell line (PK-15 cells), porcine fetal fibroblast (PEF) cells, and porcine preadipocytes. These results also showed that the fragment from -173 to +81 bp had the strongest cell-specific expression in PAM cells.


Subject(s)
Gene Expression Regulation , Macrophages, Alveolar/metabolism , Promoter Regions, Genetic , Sialic Acid Binding Ig-like Lectin 1/genetics , Sus scrofa/genetics , 5' Untranslated Regions/genetics , Animals , Base Sequence , Molecular Sequence Data , Organ Specificity/genetics , Sialic Acid Binding Ig-like Lectin 1/metabolism
4.
Asian Pac J Trop Med ; 5(8): 589-93, 2012 Aug.
Article in English | MEDLINE | ID: mdl-22840444

ABSTRACT

OBJECTIVE: To determine whether the requirements for sialic acid varies and whether several types of silaic acid independent receptors utilized for invasion mechanisms of fresh filed isolates collected around Nanay river basin, Iquitos. METHODS: The field isolates were cultured as described previously by Jensen and Trager and MR4 protocol with little modifications. The erythrocytes preparation and subsequent enzyme treatment was done as described previously by Sharma. with little modification. Invasion assay was performed as described previously by Sharma et al with little modification. RESULTS: The Nanay river basin isolates showed five types of invasion mechanisms or types of receptors-ligand interactions. Here we observed that an equal numbers of neuraminidase sensitive and resistant invasion receptor-ligand interaction profiles as the most common receptor-ligand invasion profiles. Neuraminidase resistance trypsin sensitive chymotrypsin sensitive (NM(R)T(S)CT(S)) invasion of receptor-ligand interaction profile was found in seven isolates, Five field isolates and one reference strain showed neuraminidase sensitive, trypsin sensitive and chymotrypsin resistant (NM(S)T(S)CT(R)) invasion of receptor-ligand interactions, six isolates including one reference strains dd2 showed neuraminidase sensitive, trypsin and chymotrypsin resistance (NM(S)T(R)CT(R)) indicating its dependence on sialic acids and independence of trypsin and chymotrypsin sensitive proteins. Four isolates showed neuraminidase sensitive, trypsin sensitive and chymotrypsin sensitive (NM(S)T(S)CT(S)) invasion of receptor-ligand interactions, seven isolates were neuraminidase resistant, trypsin sensitive and chymotrypsin resistance (NM(R)T(S)CT(R)) invasion of receptor-ligand interactions, indicating its dependence on trypsin sensitive proteins. CONCLUSIONS: The Nanay river basin isolates showed five types of invasion mechanisms or types of receptors-ligand interactions. A full understanding of theses invasion mechanisms may allow the development of novel prophylactic and therapeutic strategies that block erythrocyte receptor-ligand invasion mechanisms.


Subject(s)
Erythrocytes/parasitology , N-Acetylneuraminic Acid/metabolism , Plasmodium falciparum/pathogenicity , Virulence Factors/metabolism , Antigens, Protozoan/metabolism , Chymotrypsin/administration & dosage , Erythrocytes/immunology , Erythrocytes/metabolism , Hemagglutination Tests , Membrane Glycoproteins/metabolism , Neuraminidase/administration & dosage , Peru , Plasmodium falciparum/isolation & purification , Plasmodium falciparum/metabolism , Protozoan Proteins/metabolism , Receptors, Cell Surface/metabolism , Receptors, Complement/metabolism , Receptors, Immunologic/metabolism , Sialic Acid Binding Ig-like Lectin 1 , Trypsin/administration & dosage , Virulence
5.
Parasitol Res ; 97(5): 380-5, 2005 Nov.
Article in English | MEDLINE | ID: mdl-16151743

ABSTRACT

Trypanosoma cruzi is a parasite with large amounts of sialic acid (SA) residues exposed at its surface that seems to be involved in macrophages infection. Some macrophages, present in T. cruzi infected tissues, expresses sialoadhesin (Sn), a receptor that recognizes SA. Thus, the involvement of Sn in the association of T. cruzi to macrophages was investigated. Sn was induced in mice peritoneal macrophages by homologous serum (HS) cultivation. Epimastigotes and trypomastigotes associated more to HS cultured macrophages than to fetal bovine serum (FBS). Blocking of Sn with antibodies reduced the association of trypomastigotes to similar level as for FBS cultured macrophages. Desialylation reduced the association of parasites to HS cultured macrophages indicating the Sn importance. Furthermore, the entrance mechanism of trypomastigotes to Sn positive macrophages has a phagocytic nature as demonstrated by scanning electron microscopy and cytochalasin D treatment. Sn positive macrophages may important in the initial trypomastigote infection, thus in the establishment of Chagas disease.


Subject(s)
Macrophages, Peritoneal/parasitology , Membrane Glycoproteins/metabolism , Receptors, Immunologic/metabolism , Trypanosoma cruzi/pathogenicity , Animals , Cells, Cultured , Chagas Disease/parasitology , Erythrocytes/metabolism , Macrophages, Peritoneal/metabolism , Male , Mice , Microscopy, Electron, Scanning , N-Acetylneuraminic Acid/metabolism , Sialic Acid Binding Ig-like Lectin 1 , Trypanosoma cruzi/growth & development
6.
Medicina (B Aires) ; 51(2): 133-6, 1991.
Article in English | MEDLINE | ID: mdl-1820499

ABSTRACT

Human T lymphocytes carry a membrane receptor for sheep erythrocytes (E) which is responsible for the well-known phenomenon of E-rosette formation. This receptor has been related to CD2 molecules; it is present in a soluble form (Rs) in normal serum and may play an immunoregulatory role. In this study we quantitated soluble E-receptor in serum samples of 43 normal controls, 32 patients with tuberculoid leprosy and 53 with lepromatous leprosy, using rocket electrophoresis and an anti E receptor serum (anti-Rs) obtained from an adult sheep immunized with autologous E treated with Rs. In the 3 groups studied, the rocket means were respectively 5.0, 7.5 and 10.9 mm (p less than 0.001). We found abnormally high levels of Rs in the serum of various diseases associated with a depression of cell-mediated immunity. The increase of Rs levels in the serum may be one of the mechanisms responsible for the depression of cellular immunity in leprosy.


Subject(s)
Leprosy, Lepromatous/immunology , Leprosy, Tuberculoid/immunology , Membrane Glycoproteins , Receptors, Immunologic/analysis , T-Lymphocytes/immunology , Adult , Electrophoresis , Humans , Immunity, Cellular , Receptors, Immunologic/metabolism , Sialic Acid Binding Ig-like Lectin 1
7.
Arch Invest Med (Mex) ; 21(4): 381-4, 1990.
Article in Spanish | MEDLINE | ID: mdl-1669228

ABSTRACT

Nude homozygote nu/nu mice show a deficiency in their cellular immune response, due to the fact that their thymic tissue is very scarce. The purpose of this paper has been to determine whether nu/nu mice, in the presence of T lymphocytes, have the capacity of forming E rosettes with sheep erythrocytes. These mice do present them, although in significantly lower quantities when compared to the nu/+ and normal ones of Balb/c strain. This result confirms previous information which point towards the existence of other types of markers on the surface of T lymphocytes in nu/nu mice.


Subject(s)
Membrane Glycoproteins , Mice, Nude/immunology , Rosette Formation , T-Lymphocytes/immunology , Animals , Antigens, Differentiation, T-Lymphocyte/analysis , Erythrocytes/immunology , Erythrocytes/metabolism , Heterozygote , Homozygote , Male , Mice , Mice, Inbred BALB C/immunology , Mice, Nude/genetics , Receptors, Immunologic/metabolism , Sheep/blood , Sialic Acid Binding Ig-like Lectin 1 , T-Lymphocytes/metabolism
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