Serum defensin levels in patients with systemic sclerosis

Abstract Background: Systemic sclerosis (SSc) is an autoimmune disease characterized by fibrosis of skin and lung as well as involvement of kidney, gastrointestinal system and heart. Aetiology and exact mechanism of disease is poorly understood. The association between antimicrobial peptides (AMPs) and other diseases such as idiopathic pulmonary fibrosis, diffuse panbronchiolitis, pulmoner alveolar proteinosis and psoriasis have been reported. A small number of studies have examined the role of AMPs on autoimmune diseases which has not been studied in scleroderma yet. We aimed to investigate AMP serum levels and their association with disease characteristics of SSc. Methods: Forty-two patients (40 female, mean age 42 years) and 38 healthy subjects (32 female, mean age 38 years) were enrolled. For SSc patients, the following data were recorded: disease subset (limited/diffuse), autoantibodies (antinuclear, anti-centromere (ACA), and anti-SCL-70), blood tests, erythrocyte sedimentation rate (ESR), and C-reactive protein (CRP), modified Rodnan skin score, presence and history of digital ulcers, kidney, gastrointestinal disease and lung involvement assessed by computed tomography and pulmonary function tests. Association between serum AMPs and disease characteristics were analysed. Results: Twenty-nine of the patients had diffuse (69%) and 13 of the patients had limited (31%) systemic sclerosis. Average disease duration was 5.5 years. Pulmonary involvement was detected in 20 patients (47.6%). Serum concentration of alpha defensin was higher than healthy subjects (563 ± 415 vs 377 ± 269 ng/mL, p = 0.02). However, no difference was observed for beta-1 and beta-2 defensins in SSc patients and healthy controls. In sub-group analysis patients with interstitial lung disease had higher levels of alpha defensin than those without lung involvement (684 ± 473 vs 430 ± 299 ng/ml, p = 0.04). There was also correlation between alfa defensin serum concentrations and CRP (r = 0.34). Conclusions: Alpha defensin levels are increased in scleroderma patients and correlated with lung involvement indicating a role in the pathogenesis of disease. Trial registration: This study is not a clinical trial study.(AU)

Associação entre beta-defensinas e periodontite / Association between beta-defensins and periodontitis: literature review

Objetivo: as beta-defensinas humanas (hBDs) podem ter um papel-chave na susceptibilidade às doenças na cavidade bucal. Além do efeito antimicrobiano direto, as hBDs aumentam a imunidade adaptativa. O objetivo deste estudo foi realizar uma revisão de literatura científica sobre a relação entre beta-defensinas (hBD) e periodontite. Material e métodos: foi realizada uma pesquisa bibliográfica na base de dados PubMed sobre a expressão de hBDs em indivíduos com periodontite. Os termos beta defensins e periodontitis foram utilizados nessa busca. Resultados: foram selecionados, por um revisor, sete artigos para serem incluídos nessa revisão de literatura: dois estudos de intervenção e cinco estudos transversais. Conclusão: o número de estudos sobre a expressão de beta-defensinas em indivíduos com periodontite é reduzido. O conhecimento sobre o papel das beta-defensinas na periodontite pode trazer um maior entendimento de sua etiopatogenia, além de possibilitar novos indicadores de risco e terapias. Estudos adicionais são necessários para a elucidação da relação entre esses peptídeos antimicrobianos e a periodontite.

Objective: human beta-defensins (hBDs) may play a key role in the susceptibility to diseases in the oral cavity. In addition to the direct antimicrobial effect, hBDs enhance adaptive immunity. The objective of this study was to investigate the literature on the relationship between hBD and periodontitis. Material and methods: a literature review was conducted in the PubMed database on the expression of hBDs in subjects with periodontitis. The terms "beta-defensins" and "periodontitis" were used in this search. Results: seven articles were selected being: two intervention studies and fi ve cross-sectional studies. Conclusion: the number of studies on the expression of beta-defensins in individuals with periodontitis is reduced. Knowledge about the role of beta-defensins in periodontitis may lead to a better understanding of their etiopathogenesis, in addition to providing new risk indicators and therapies. Additional studies are needed to elucidate the relationship between these antimicrobial peptides and periodontitis.

An investigation of human beta-defensins and cathelicidin expression in patients with pterygium / Uma investigação da expressão de beta-defensinas humanas e de catelidicina em pacientes com pterígio

ABSTRACT Purpose: To investigate human beta-defensins (HBDs) and cathelicidin LL-37 (LL-37) expressions in patients with pterygium. Methods: In this retrospective consecutive case series, 26 pterygium specimens and 15 normal conjunctival specimens of 15 control subjects were in vestigated. Expressions of HBD-1, HBD-2, HBD-3, and LL-37 were assessed using immuno histochemical staining. A brown color in the cytoplasm and/or nuclei of epithelial cells indicated positive staining for HBDs and LL-37. For each antibody, the intensity of the reaction (negative [-], weak [1+], moderate [2+], or strong [3+]) was determined to describe the immunoreactions. Results: The median age was 52 years in both groups. There were no significant differences in age and sex between the groups (p=0.583, p=0.355, respectively). Of the 26 pterygium specimens, 15 (57.7%) (14 weak, 1 moderate staining) showed HBD-2 expression, which was not observed in any of the control specimens. One (3.8%) pterygium and one (6.7%) control specimen demonstrated weak staining for HBD-3. HBD-2 expression was significantly higher in the pterygium specimens than in the controls (p=0.002). None of the tissue specimens had positive staining for HBD-1 or LL-37 in either group (both; p=1.00). Conclusions: HBD-2 expression was higher in pterygium specimens than in the controls. HBD-2 expression that might be stimulated by inflammatory cytokines may be related to inflammation and fibrovascular proliferation and may play a role in pterygium pathogenesis.

RESUMO Objetivo: Investigar as expressões beta defensinas humanas (HBD) e catelicidina em pacientes com pterígio. Métodos: Nesta série de casos retrospectivos consecutivos, 26 espécimes de pterígio e 15 espécimes conjuntivais normais de 15 indivíduos controle foram investigados. As expressões de HBD-1, HBD-2, HBD-3 e catelicidina (LL-37) foram avaliadas por coloração imuno-histoquímica. Uma cor castanha no citoplasma ou nos núcleos de células epiteliais foi definida como coloração positiva para HBDs e LL-37. Para cada anticorpo foi determinada a intensidade da reação (negativo [-], fraco [1+], moderado [2+] ou forte [3+]) para descrever as imunoreações. Resultados: A idade média foi de 52 anos em ambos os grupos. Não houve diferença significativa entre os grupos em termos de idade e sexo (p=0,583, p=0,355, respectivamente). Das 26 amostras de pterígio, 15 (57,7%) (14 fracas e 1 moderada) demonstraram a expressão de HBD-2 enquanto não foi encontrada em nenhum dos espécimes de controlo. Um dos pterígios (3,8%) e um dos espécimes de controlo (6,7%) demonstraram fraca coloração para HBD-3. A expressão de HBD-2 foi significati vamente maior nos espécimes de pterígio do que nos controles (p=0,002). Nenhum dos espécimes de tecido apresentou coloração positiva para HBD-1 ou LL-37 em ambos os grupos (ambos p=1,00). Conclusão: Encontramos aumento da expressão de HBD-2 em espécimes de pte rígio em relação aos controles. A expressão de HBD-2 que pode ser estimulada por citocinas inflamatórias pode estar relacionada com inflamação e proliferação fibrovascular e pode desempenhar um papel na patogênese do pterígio.

DEFB1 gene polymorphisms and tuberculosis in a Northeastern Brazilian population

Abstract β-Defensin-1, an antimicrobial peptide encoded by the DEFB1 gene, is known to play an important role in lung mucosal immunity. In our association study we analyzed three DEFB1 functional polymorphisms -52G>A (rs1799946), -44C>G (rs1800972) and -20G>A (rs11362) in 92 tuberculosis patients and 286 healthy controls, both from Northeast Brazil: no association was found between the studied DEFB1 polymorphisms and the disease. However we cannot exclude that this lack of association could be due to the low number of subjects analyzed, as suggested by the low statistical power achieved for the three analyzed SNPs (values between 0.16 and 0.50).

ß-defensin-2 in breast milk displays a broad antimicrobial activity against pathogenic bacteria / ß-defensina 2 no leite materno mostra uma ampla atividade antimicrobiana contra bactérias patogênicas

OBJECTIVE: To describe the antimicrobial activity of ß-defensin-2 produced in the mammary gland and secreted in human breast milk. METHODS: The peptide production was performed by DNA cloning. ß-defensin-2 levels were quantified in 61 colostrum samples and 39 mature milk samples from healthy donors, by an indirect enzyme-linked immunosorbent assay (ELISA). Using halo inhibition assay, this study assessed activity against seven clinical isolates from diarrheal feces of children between 0 and 2 years of age. The activity of ß-defensin-2 against three opportunistic pathogens that can cause nosocomial infections was determined by microdilution test. RESULTS: The peptide levels were higher in colostrum (n = 61) than in mature milk samples (n = 39), as follows: median and range, 8.52 (2.6-16.3) µg/ml versus 0.97 (0.22-3.78), p < 0.0001; Mann-Whitney test. The recombinant peptide obtained showed high antimicrobial activity against a broad range of pathogenic bacteria. Its antibacterial activity was demonstrated in a disk containing between 1-4 µg, which produced inhibition zones ranging from 18 to 30 mm against three isolates of Salmonella spp. and four of E. coli. ß-defensin-2 showed minimum inhibitory concentrations (MICs) of 0.25 µg/mL and 0.5 µg/mL for S. marcescen and P. aeruginosa, respectively, while a higher MIC (4 µg/mL) was obtained against an isolated of multidrug-resistant strain of A. baumannii. CONCLUSIONS: To the authors' knowledge, this study is the first to report ß-defensin-2 levels in Latin American women. The production and the activity of ß-defensin-2 in breast milk prove its importance as a defense molecule for intestinal health in pediatric patients. .

OBJETIVO: Descrever a atividade antimicrobiana da defensina-beta 2 na glândula mamária e secretada no leite materno humano. MÉTODOS: A produção de peptídeos foi realizada por clonagem de DNA. Os níveis de defensina-beta 2 foram quantificados em 61 amostras de colostro e 39 de leite maduro de doadoras saudáveis pelo teste ELISA indireto. Por um ensaio de halo de inibição, avaliamos a atividade contra sete isolados clínicos diarreicos de crianças entre 0 e 2 anos. A atividade da defensina 2 contra três patógenos oportunistas que podem causar infecções nosocomiais foi determinada pelo teste de microdiluição. RESULTADOS: Os níveis de peptídeos estavam significativamente maiores nas amostras de colostro (n = 61) que de leite maduro (n = 39), como segue: 8,52 (2,6-16,3 µg/mL) mediana e faixa em comparação a 0,97 (0,22-3,78), p < 0,0001; teste de Mann-Whitney. O peptídeo recombinante foi obtido da alta atividade antimicrobiana demonstrada contra uma ampla gama de bactérias patogênicas. Sua atividade antibacteriana foi demonstrada em um disco contendo entre 1-4 µg, que produziu zonas de inibição entre 18 e 30 mm contra três isolados de Salmonella spp. e quatro de E. coli. A defensina-beta 2 demonstrou concentrações inibitórias mínimas (CIMs) de 0,25 µg/mL e 0,5 µg/mL para S. marcescen and P. aeruginosa, ao passo que uma CIM maior (4 µg/mL) foi obtida contra um isolado de cepa multirresistente de A. baumannii. CONCLUSÕES: Até onde sabemos, este estudo é o primeiro a relatar níveis de defensina em mulheres da América Latina. A produção e a atividade da defensina 2 no leite materno comprovam sua importância como uma molécula de defesa para a saúde intestinal em pacientes pediátricos. .

A study on ß-defensin-2 and histatin-5 as a diagnostic marker of early childhood caries progression

BACKGROUND: Recently, a continuous growth of interest has been observed in antimicrobial peptides (AMPs) in the light of an alarming increase in resistance of bacteria and fungi against antibiotics. AMPs are used as biomarkers in diagnosis and monitoring of oral cavity pathologies. Therefore, the determination of specific protein profiles in children diagnosed with early childhood caries (ECC) might be a basis for effective screening tests and specialized examinations which may enable progression of disease. METHODS: The objective of the studies was to determine the role of histatin-5 and ß-defensing-2 as a diagnostic marker of early childhood caries progression. In this work, results of concentration determination of two salivary proteins (histatin-5 and ß-defensin-2) were presented. In addition, bacterial profiles from dental plaque in various stages of ECC and control were marked. The assessment of alteration in the concentration of these two proteins in a study group of children with various stages of ECC and a control group consisting of children with no symptoms was performed by enzyme-linked immunosorbent assays. RESULTS: The statistical analysis showed a significant increase in the concentration of histatin-5 and ß-defensin-2 in the study group compared to the control group and correlated with the progression of the disease. CONCLUSIONS: The confirmation of concentration changes in these proteins during the progression of dental caries may discover valuable disease progression biomarkers.

DEFB1 polymorphisms are involved in susceptibility to human papillomavirus infection in Brazilian gynaecological patients

The human beta defensin 1 (hBD-1) antimicrobial peptide is a member of the innate immune system known to act in the first line of defence against microorganisms, including viruses such as human papillomavirus (HPV). In this study, five functional polymorphisms (namely g-52G>A, g-44C>G and g-20G>A in the 5’UTR and c.*5G>A and c.*87A>G in the 3’UTR) in the DEFB1 gene encoding for hBD-1 were analysed to investigate the possible involvement of these genetic variants in susceptibility to HPV infection and in the development of HPV-associated lesions in a population of Brazilian women. The DEFB1 g-52G>A and c.*5G>A single-nucleotide polymorphisms (SNPs) and the GCAAA haplotype showed associations with HPV-negative status; in particular, the c.*5G>A SNP was significantly associated after multiple test corrections. These findings suggest a possible role for the constitutively expressed beta defensin-1 peptide as a natural defence against HPV in the genital tract mucosa.

Human beta defensin-4 and keratinocyte growth factor gene expression in cultured keratinocyte and fibroblasts of burned patients

PURPOSE: To evaluate KGF and human beta defensin-4 (HBD-4) levels produced by dermic fibroblasts and keratinocytes cultivated from burned patients' skin samples. METHODS: Keratinocytes and fibroblasts of 10 patients (four major burns, four minor burns and two controls) were primarily cultivated according to standard methods. HBD-4 and KGF genes were analyzed by quantitative PCR. RESULTS: In fibroblasts, KGF gene expression was 220±80 and 33.33±6.67 (M±SD; N=4), respectively for major and minor burn groups. In keratinocytes, KGF gene expression was 11.2±1.9 and 3.45±0.37 (M±SD; N=4), respectively for major and minor burn groups. In fibroblasts, HBD-4 gene expression was 15.0±4.0 and 11.5±0.5 (M±SD; N=4), respectively for major and minor burn. In keratinocyte, HBD-4 gene expression was 0.0±0.0 and 13.4±4.8 (M±SD; N=4), respectively for major and minor burn. CONCLUSIONS: KGF expression was increased in burn patient fibroblasts compared to control group. In keratinocytes culture, KGF suppression is inversely proportional to burn extension; it is active and increased in major burn but decreased in minor burn. HBD-4 expression was increased in fibroblasts and decreased in keratinocytes from all burned patients. .

Evaluation of hbeta;D-1 and hbeta; D-2 levels in saliva of patients with oral mucosal diseases / Evaluación de los niveles de hbeta; D-1 y hbeta;D-2 en la Saliva de pacientes con enfermedades de la mucosa oral

OBJECTIVE: This study aimed to determine a possible correlation between oral mucosal disease and salivary concentrations of the antimicrobial peptides human beta-defensin-1 (hβD-1) and human betadefensin- 2 (hβD-2). METHOD: The present work focussed on the establishment of a reversed phase-high performance liquid chromatography (RP-HPLC) procedure to quantify human beta-defensins (hβD-1 and hβD-2) in saliva samples of patients with oral diseases such as lichen planus (n = 10), Behçet (n = 10) and recurrent apthous stomatitis (n = 10). RESULTS: Linear calibration range for hβD-1 and hβD-2 defensins was 1.67−200 µg mL-1 and 3.13− 100 µg mL-1 with R2 values of 0.9998 and 0.996, correspondingly. The concentration of beta-defensins in saliva was determined by comparing the peak areas of eluted hβD-1 and hβD-2 with that of their standards. The variation of the amount of beta-defensins was evaluated by comparisons of the results obtained from the patients with oral mucosal diseases before and after treatments and the control subjects. The limit of detection (LOD) and limit of quantification (LOQ) were found to be 1.62 µg mL- 1 and 5.39 µg mL-1 for hβD-1 and 0.94 µg mL-1 and 3.13 µg mL-1 for hβD-2, respectively. CONCLUSION: The salivary beta-defensin concentration was significantly higher in patients with oral mucosal diseases than in healthy volunteers; furthermore, in patients with oral mucosal diseases, the concentration was significantly higher before treatment than after treatment.

OBJETIVO: Este estudio tuvo por objeto determinar una posible correlación entre la enfermedad de la mucosa oral y las concentraciones salivales de la beta-defensina humana 1 (hβD-1) y la beta-defensina humana 2 (hβD-2) de los péptidos antimicrobianos. MÉTODO: El presente trabajo estuvo encaminado al establecimiento de un procedimiento de cromatografía líquida de alta eficacia de fase reversa (RP-HPLC) para cuantificar las beta-defensinas humanas (hβD-1 y hβD-2) en muestras de saliva de pacientes con enfermedades orales como el liquen plano (n = 10), Behçet (n = 10), y la estomatitis aftosa recurrente (n = 10). RESULTADOS: El rango de calibración lineal de las defensinas hβD-1 y hβD-2 fue 1.67-200 µg mL-1 y 3.13-100 µg mL-1 con valores R2 de 0.9998 y 996, respectivamente. La concentración de beta-defensinas en la saliva se determinó utilizando el área de sus estándares. La variación de la cantidad de beta defensinas fue evaluada por comparaciones de los resultados obtenidos de los pacientes con enfermedades de la mucosa oral, antes y después de los tratamientos y los sujetos de control. Se halló que el límite de detección (LDD) y el límite de cuantificación (LDC) fueron 1.62 µg mL-1 y 5.39 µg mL- 1 para hβD-1 y 0.94 µg mL-1 y 3.13 µg mL-1 hβD-2, respectivamente. CONCLUSIÓN: La concentración de beta-defensina salival fue significativamente mayor en los pacientes con enfermedades de la mucosa oral que en los voluntarios sanos. Además, en pacientes con enfermedades de la mucosa oral, la concentración fue significativamente mayor antes del tratamiento que después del tratamiento.

β Defensinas em membranas corioamnióticas de gestações complicadas por prematuridade: expressão gênica e imunolocalização / Human Beta defensis in chorioamniotic membranes of pregnancies complicated by preterm birth: gene expression and immunolocalization

Eventos inflamatórios na interface mateno-fetal estão pronunciados em gestações complicadas por prematuridade e a corioamnionite é reconhecida como a principal causa de morbimortalidade perinatal. As membranas corioamnióticas desempenham papel fundamental na imunidade inata local e inibem o crescimento de micro-organismos, em parte, pela expressão de β defensinas humanas (HBDs). Essas moléculas são antimicrobianos naturais que apresentam atividade antibatcteriana, antifúngica e antiviral e são produzidas por células epiteliais. Quantificar a expressão gênica e avaliar a imunolocalização de HBD-1, HBD-2 e HBD-3 em membranas corioamnióticas de gestações complicadas por prematuridade. Trata-se de um estudo prospectivo e transversal. Fragmentos das membranas corioamnióticas foram coletadas de gestantes atendidas no Serviço de Obstetrícia do Hospital das Clínicas da Faculdade de Medicina de Botucatu, UNESP, Botucatu, São Paulo, Brasil. O grupo estudo foi constituído por 25 membranas corioamnióticas de gestantes em Trabalho de Parto Prematuro na presença ou não de Rotura Prematura de Membranas Pré-Termo que tiveram parto prematuro como desfecho gestacional. Como grupo controle, 27 membranas corioamnióticas de gestações de termo em trabalho de parto foram analisadas. Fragmentos das membranas corioamnióticas foram fixadas em formalina a 10%, embebidas em parafina e seccionadas para análise da imunolocalização de HBD-1, HBD-2 e HBD-3 pela técnica de imunoistoquímica. Outros fragmentos das membranas corioamnióticas foram congelados em nitrogênio líquido e submetidos à extração do RNA total para posterior quantificação da expressão de RNAm de HBD-1, HBD-2 e HBD-3 empregando-se a técnica de PCR em tempo real utilizando o sistema TaqMan Gene Expression Assays (Applied Biosystems)...

nflammatory events can be pronounced in the maternal-fetal interface in pregnancies complicated by prematurity and chorioamnionitis is a major cause of perinatal morbidity and mortality. The chorioamniotic membranes play fundamental role in the local innate immunity and inhibit the microorganisms growth, partly by the expression of human β defensins (HBDs). These molecules are natural antimicrobials that present antibacterial, antifungal and antiviral activities and are produced by epithelial cells. To quantify the expression and to evaluate the immunolocalization of HBD-1, HBD-2 and HBD-3 in chorioamniotic membranes from pregnancies complicated by prematurity. This was a prospective controlled study. Fragments of chorioamniotic membranes were collected from pregnant women admitted at the Obstetrics Unit of the Clinical Hospital of the Botucatu Medical School, São Paulo State University, Botucatu, São Paulo, Brazil. The study group consisted of 25 chorioamniotic membranes samples from pregnant women with preterm labor, in the presence or not of Preterm Premature Rupture of Membranes (PPROM), who delivery prematurely. In the control group, 27 chorioamniotic membranes from pregnancies at term in the presence at labor were analysed. Samples of the chorioamniotic membranes were fixed in 10% formalin, embedded in paraffin and sectioned for immunolocalization of HBD-1, HBD-2 and HBD-3 by immunohistochemistry technique. Other chorioamniotic membranes samples were collected in liquid nitrogen and total RNA was extracted to quantify mRNA expression of HBD-1, HBD-2 and HBD-3 using real time quantitative PCR employing the TaqMan Gene Expression Assays (Applied Biosystems). Statistical analyses were performed using z and Mann Whitney tests in SigmaStat Software and the level of significance adopted was of 5%...

Expression of mouse beta defensin 2 in Escherichia coli and its broad-spectrum antimicrobial activity

Mature mouse beta defensin 2 (mBD2) is a small cationic peptide with antimicrobial activity. Here we established a prokaryotic expression vector containing the cDNA of mature mBD2 fused with thioredoxin (TrxA), pET32a-mBD2. The vector was transformed into Escherichia Coli (E. coli) Rosseta-gami (2) for expression fusion protein. Under the optimization of fermentation parameters: induce with 0.6 mM isopropylthiogalactoside (IPTG) at 34ºC in 2×YT medium and harvest at 6 h postinduction, fusion protein TrxA-mBD2 was high expressed in the soluble fraction (>95 percent). After cleaved fusion protein by enterokinase, soluble mature mBD2 was achieved 6 mg/L with a volumetric productivity. Purified recombinant mBD2 demonstrated clear broad-spectrum antimicrobial activity for fungi, bacteria and virus. The MIC of antibacterial activity of against Staphylococcus aureus was 50 µg/ml. The MIC of against Candida albicans (C. albicans) and Cryptococcus neoformans (C. neoformans) was 12.5µg/ml and 25µg/ml, respectively. Also, the antimicrobial activity of mBD2 was effected by NaCl concentration. Additionally, mBD2 showed antiviral activity against influenza A virus (IAV), the protective rate for Madin-Darby canine kidney cells (MDCK) was 93.86 percent at the mBD2 concentration of 100 µg/ml. These works might provide a foundation for the following research on the mBD2 as therapeutic agent for medical microbes.

Expresión diferencial en placenta de beta-defensinas humanas y detección de variantes alélicas en el gen DEFB1 de madres positivas para VIH-1 / Differential expression of human beta defensins in placenta and detection of allelic variants in the DEFB1 gene from HIV-1 positive mothers

Introduction. Low infection rates in neonates born to HIV-1-seropositive mothers highlight the existence of natural defense mechanisms in the maternal-fetal interface. Human beta defensins (HBDs) inhibit HIV-1 replication in vitro and their variants are associated with HIV-1 resistance/susceptibility. Objective. Levels of HBD mRNA expression in placentas were obtained from seropositive and healthy mothers to determine whether HIV-1 infection induces anti-viral factors. Materials and methods. HBD-1, -2 and -3 transcripts were quantified by real time RT-PCR, and A692G/G1654A/A1836G variants in the DEFB1 gene were evaluated by sequencing. Results. Transcript levels of HBD-1 were significantly higher, and those of HBD-3 were lower in placenta from seropositive mothers compared to controls. Additionally, simultaneous presence of the A692G A/G and A1836G G/G genotypes was associated with high expression of HBD-1 in all populations and the A692G variant in babies born to seropositive mothers was in Hardy-Weinberg disequilibrium. Conclusion. Contrasting results in levels of HBDs were probably due to viral stimuli and suggest that HIV-1 induce a differential expression of HBDs in placenta and these proteins could be involved in protecting against HIV-1 at least early in pregnancy. However, it was not possible to associate these findings directly with protection against HIV-1 vertical transmission since none of the newborn infants became infected.

Introducción. Las bajas tasas de infección en neonatos nacidos de madres seropositivas para el VIH-1 resaltan la existencia de mecanismos de defensa natural en la interfase materno-fetal. Las beta-defensinas humanas inhiben la replicación del VIH-1 in vitro y sus polimorfismos están asociados con la resistencia o susceptibilidad al VIH-1. Objetivo. Comparar los niveles de expresión de ARNm de beta-defensinas humanas en placentas de madres seropositivas y en seronegativas para determinar si la infección por VIH-1 induce factores antivirales que pudieran proteger a los bebés de la transmisión del VIH-1. Materiales y métodos. Los transcritos de HBD-1, 2 y 3 se cuantificaron por PCR en tiempo real y las variantes A692G/G1654A/A1836G del gen DEFB1 se evaluaron por secuenciación. Resultados. Los niveles de transcritos de HBD-1 fueron significativamente mayores, y los de HBD-3 fueron menores en placentas de madres seropositivas en comparación con los controles. Además, la presencia simultánea de los genotipos A692G A/G y A1836G G/G se asoció con alta expresión de HBD-1 en toda la población estudiada y la variante A692G estuvo en desequilibrio de Hardy-Weinberg en los bebés nacidos de madres seropositivas. Conclusión. Los resultados contrastantes de los niveles de HBD se deben, probablemente, a estímulos virales y sugieren que el VIH-1 induce una expresión diferencial de beta-defensinas humanas en placenta y que estas proteínas podrían estar involucradas en la protección contra el VIH-1, al menos, en las etapas tempranas del embarazo. Sin embargo, no fue posible asociar estos hallazgos con la protección contra la transmisión vertical del VIH-1, puesto que ninguno de los bebés adquirió la infección.