To assess the prevalence of autoantibodies (Aab) to insulin (IAA), glutamic acid decarboxylase 65... more To assess the prevalence of autoantibodies (Aab) to insulin (IAA), glutamic acid decarboxylase 65 (GADA) and insulinoma antigen 2 (IA-2A), as well as human leukocyte antigen (HLA) class II alleles, in first degree relatives (FDR) of Mexican patients with type 1 diabetes (T1D), and to explore whether these parameters mirror the low incidence of T1D in the Mexican population. Aab titers were determined by ELISA in 425 FDR, 234 siblings, 40 offspring and 151 parents of 197 patients with T1D. Typing of HLA-DR and -DQ alleles was performed in 41 Aab-positive FDR using polymerase chain reaction with allele-specific oligotyping. Seventy FDR (16.47%) tested positive for Aab. The siblings (19.2%) and the offspring (25%) had significantly higher prevalence of Aab than the parents (9.9%). GADA was the most frequent Aab. Almost half of the Aab-positive FDR had two different Aab (45.7%), and none tested positive for three Aab. The highest prevalence of Aab was found among women in the 15-29 year...
AimsTo assess the prevalence of autoantibodies (Aab) to insulin (IAA), glutamic acid decarboxylas... more AimsTo assess the prevalence of autoantibodies (Aab) to insulin (IAA), glutamic acid decarboxylase 65 (GADA) and insulinoma antigen 2 (IA-2A), as well as human leukocyte antigen (HLA) class II alleles, in first degree relatives (FDR) of Mexican patients with type 1 diabetes (T1D), and to explore whether these parameters mirror the low incidence of T1D in the Mexican population.MethodsAab titers were determined by ELISA in 425 FDR, 234 siblings, 40 offspring and 151 parents of 197 patients with T1D. Typing of HLA-DR and -DQ alleles was performed in 41 Aab-positive FDR using polymerase chain reaction with allele-specific oligotyping.ResultsSeventy FDR (16.47%) tested positive for Aab. The siblings (19.2%) and the offspring (25%) had significantly higher prevalence of Aab than the parents (9.9%). GADA was the most frequent Aab. Almost half of the Aab-positive FDR had two different Aab (45.7%), and none tested positive for three Aab. The highest prevalence of Aab was found among women i...
Obesity is a chronic inflammatory disease associated with adipose tissue macrophage (ATM) activat... more Obesity is a chronic inflammatory disease associated with adipose tissue macrophage (ATM) activation. ATMs from lean mice contribute to tissue homeostasis by their M2‐oriented polarization, whereas obesity leads to an increase of M1 inflammatory ATMs that underlies obesity‐related metabolic disorders. In humans, studies characterizing ATMs and their functional status are limited. Here we investigated ATM phenotype in visceral (VAT) and subcutaneous (SAT) adipose tissue from healthy lean and obese individuals using two molecules previously identified as markers of M1‐like and M2‐like/tissue‐resident macrophages, the C‐type lectin CLEC5A and the scavenger receptor CD163L1, respectively. CD163L1 was expressed by the majority of ATMs, and CD163L1+ ATM density was greater with respect to cells expressing the pan‐macrophage markers CD68 or CD11b. ATM counts in SAT, but not in VAT, increased in obese compared to lean individuals, measured with the three markers. Accordingly, CD163L1, CD68 and ITGAM gene expression was significantly enhanced in obese with respect to control individuals only in SAT. CLEC5A+ ATMs had a proinflammatory profile and were abundant in the lean VAT, but their density diminished in obesity. The only ATM subset that increased its counts in the obese VAT had a mixed M1‐like (CD11c+CD163−CD209−) and M2‐like (CLEC5A−CD206+) phenotype. ATM expansion was dominated by a subset of M2‐like macrophages (CD11c−CLEC5A−CD163+CD206+CD209+) in the obese SAT, with a minor contribution of a CD11c+CLEC5A− ATM subpopulation. Thus, both SAT and VAT seems to limit inflammation during obesity by differentially altering their ATM subset composition.
We determined the ability of tolerogenic dendritic cells (tDC) derived from type 1 diabetes melli... more We determined the ability of tolerogenic dendritic cells (tDC) derived from type 1 diabetes mellitus (T1D) patients to inactivate their autoreactive T cells recognizing the pancreatic islet antigens insulin and glutamic acid decarboxylase 65 -GAD65-. Monocyte-derived DC were generated in the absence (control, cDC) or presence of IL-10 and TGF-β1 (tDC), and loaded with insulin or GAD65. DC were cultured with effector/memory CD4+ T lymphocytes (primary culture), and then rechallenged with insulin- or GAD65-pulsed cDC (secondary culture). In the primary cultures, tDC induced lower lymphocyte proliferation and IL-2 and IFN-γ secretion than cDC, but higher IL-10 production. Lymphocytes from 60% of patients proliferated specifically against insulin or GAD65 (group 1), whereas 40% did not (group 2). Tolerance to insulin or GAD65 was induced in 14 and 10 patients, respectively. 70-80% of these patients belonged to group 1, suggesting that tDC therapy might be useful in a subset of T1D patie...
Cysts of Naegleria fowleri present an external single-layered cyst wall. To date, little informat... more Cysts of Naegleria fowleri present an external single-layered cyst wall. To date, little information exists on the biochemical components of this cyst wall. Knowledge of the cyst wall composition is important to understand its resistance capacity under adverse environmental conditions. We have used of a monoclonal antibody (B4F2 mAb) that specifically recognizes enolase in the cyst wall of Entamoeba invadens. By Western blot assays this antibody recognized in soluble extracts of N. fowleri cysts a 48-kDa protein with similar molecular weight to the enolase reported in E. invadens cysts. Immunofluorescence with the B4F2 mAb revealed positive cytoplasmic vesicles in encysting amebas, as well as a positive reaction at the cell wall of mature cysts. Immunoelectron microscopy using the same monoclonal antibody confirmed the presence of enolase in the cell wall of N. fowleri cysts and in cytoplasmic vesicular structures. In addition, the B4F2 mAb had a clear inhibitory effect on encystation of N. fowleri.
To assess the prevalence of autoantibodies (Aab) to insulin (IAA), glutamic acid decarboxylase 65... more To assess the prevalence of autoantibodies (Aab) to insulin (IAA), glutamic acid decarboxylase 65 (GADA) and insulinoma antigen 2 (IA-2A), as well as human leukocyte antigen (HLA) class II alleles, in first degree relatives (FDR) of Mexican patients with type 1 diabetes (T1D), and to explore whether these parameters mirror the low incidence of T1D in the Mexican population. Aab titers were determined by ELISA in 425 FDR, 234 siblings, 40 offspring and 151 parents of 197 patients with T1D. Typing of HLA-DR and -DQ alleles was performed in 41 Aab-positive FDR using polymerase chain reaction with allele-specific oligotyping. Seventy FDR (16.47%) tested positive for Aab. The siblings (19.2%) and the offspring (25%) had significantly higher prevalence of Aab than the parents (9.9%). GADA was the most frequent Aab. Almost half of the Aab-positive FDR had two different Aab (45.7%), and none tested positive for three Aab. The highest prevalence of Aab was found among women in the 15-29 year...
AimsTo assess the prevalence of autoantibodies (Aab) to insulin (IAA), glutamic acid decarboxylas... more AimsTo assess the prevalence of autoantibodies (Aab) to insulin (IAA), glutamic acid decarboxylase 65 (GADA) and insulinoma antigen 2 (IA-2A), as well as human leukocyte antigen (HLA) class II alleles, in first degree relatives (FDR) of Mexican patients with type 1 diabetes (T1D), and to explore whether these parameters mirror the low incidence of T1D in the Mexican population.MethodsAab titers were determined by ELISA in 425 FDR, 234 siblings, 40 offspring and 151 parents of 197 patients with T1D. Typing of HLA-DR and -DQ alleles was performed in 41 Aab-positive FDR using polymerase chain reaction with allele-specific oligotyping.ResultsSeventy FDR (16.47%) tested positive for Aab. The siblings (19.2%) and the offspring (25%) had significantly higher prevalence of Aab than the parents (9.9%). GADA was the most frequent Aab. Almost half of the Aab-positive FDR had two different Aab (45.7%), and none tested positive for three Aab. The highest prevalence of Aab was found among women i...
Obesity is a chronic inflammatory disease associated with adipose tissue macrophage (ATM) activat... more Obesity is a chronic inflammatory disease associated with adipose tissue macrophage (ATM) activation. ATMs from lean mice contribute to tissue homeostasis by their M2‐oriented polarization, whereas obesity leads to an increase of M1 inflammatory ATMs that underlies obesity‐related metabolic disorders. In humans, studies characterizing ATMs and their functional status are limited. Here we investigated ATM phenotype in visceral (VAT) and subcutaneous (SAT) adipose tissue from healthy lean and obese individuals using two molecules previously identified as markers of M1‐like and M2‐like/tissue‐resident macrophages, the C‐type lectin CLEC5A and the scavenger receptor CD163L1, respectively. CD163L1 was expressed by the majority of ATMs, and CD163L1+ ATM density was greater with respect to cells expressing the pan‐macrophage markers CD68 or CD11b. ATM counts in SAT, but not in VAT, increased in obese compared to lean individuals, measured with the three markers. Accordingly, CD163L1, CD68 and ITGAM gene expression was significantly enhanced in obese with respect to control individuals only in SAT. CLEC5A+ ATMs had a proinflammatory profile and were abundant in the lean VAT, but their density diminished in obesity. The only ATM subset that increased its counts in the obese VAT had a mixed M1‐like (CD11c+CD163−CD209−) and M2‐like (CLEC5A−CD206+) phenotype. ATM expansion was dominated by a subset of M2‐like macrophages (CD11c−CLEC5A−CD163+CD206+CD209+) in the obese SAT, with a minor contribution of a CD11c+CLEC5A− ATM subpopulation. Thus, both SAT and VAT seems to limit inflammation during obesity by differentially altering their ATM subset composition.
We determined the ability of tolerogenic dendritic cells (tDC) derived from type 1 diabetes melli... more We determined the ability of tolerogenic dendritic cells (tDC) derived from type 1 diabetes mellitus (T1D) patients to inactivate their autoreactive T cells recognizing the pancreatic islet antigens insulin and glutamic acid decarboxylase 65 -GAD65-. Monocyte-derived DC were generated in the absence (control, cDC) or presence of IL-10 and TGF-β1 (tDC), and loaded with insulin or GAD65. DC were cultured with effector/memory CD4+ T lymphocytes (primary culture), and then rechallenged with insulin- or GAD65-pulsed cDC (secondary culture). In the primary cultures, tDC induced lower lymphocyte proliferation and IL-2 and IFN-γ secretion than cDC, but higher IL-10 production. Lymphocytes from 60% of patients proliferated specifically against insulin or GAD65 (group 1), whereas 40% did not (group 2). Tolerance to insulin or GAD65 was induced in 14 and 10 patients, respectively. 70-80% of these patients belonged to group 1, suggesting that tDC therapy might be useful in a subset of T1D patie...
Cysts of Naegleria fowleri present an external single-layered cyst wall. To date, little informat... more Cysts of Naegleria fowleri present an external single-layered cyst wall. To date, little information exists on the biochemical components of this cyst wall. Knowledge of the cyst wall composition is important to understand its resistance capacity under adverse environmental conditions. We have used of a monoclonal antibody (B4F2 mAb) that specifically recognizes enolase in the cyst wall of Entamoeba invadens. By Western blot assays this antibody recognized in soluble extracts of N. fowleri cysts a 48-kDa protein with similar molecular weight to the enolase reported in E. invadens cysts. Immunofluorescence with the B4F2 mAb revealed positive cytoplasmic vesicles in encysting amebas, as well as a positive reaction at the cell wall of mature cysts. Immunoelectron microscopy using the same monoclonal antibody confirmed the presence of enolase in the cell wall of N. fowleri cysts and in cytoplasmic vesicular structures. In addition, the B4F2 mAb had a clear inhibitory effect on encystation of N. fowleri.
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Papers by Norma Segovia-gamboa