Prospective uses of recombinant Lactococcus lactis expressing both listeriolysin O and mutated internalin A from Listeria monocytogenes as a tool for DNA vaccination.

In this study, Lactococcus lactis was engineered to express mutated internalin A on its surface and to secrete large amounts of listeriolysin O (LLO) in order to improve its potential as a vehicle for DNA vaccination. Western blotting experiments demonstrated that the bacterium expressed LLO in both the cytoplasmic and extracellular compartments, with higher quantities found in the culture supernatants. A hemolytic assay showed that the recombinant strain secreted 250 ng active LLO/mg total protein. This mInlA/LLO-producing strain of L. lactis may be used as an alternative tool in DNA vaccination against a number of infectious diseases or in cancer therapy.

Neonatal handling alters the structure of maternal behavior and affects mother-pup bonding.

During early life, a mother and her pups establish a very close relationship, and the olfactory learning of the nest odor is very important for the bond formation. The olfactory bulb (OB) is a structure that plays a fundamental role in the olfactory learning (OL) mechanism that also involves maternal behavior (licking and contact). We hypothesized that handling the pups would alter the structure of the maternal behavior, affect OL, and alter mother-pup relationships. Moreover, changes in the cyclic AMP-response element binding protein phosphorylation (CREB) and neurotrophic factors could be a part of the mechanism of these changes. This study aimed to analyze the effects of neonatal handling, 1 min per day from postpartum day 1 to 10 (PPD 1 to PPD 10), on the maternal behavior and pups' preference for the nest odor in a Y maze (PPD 11). We also tested CREB's phosphorylation and BDNF signaling in the OB of the pups (PPD 7) by Western blot analysis. The results showed that handling alters mother-pups interaction by decreasing mother-pups contact and changing the temporal pattern of all components of the maternal behavior especially the daily licking and nest-building. We found sex-dependent changes in the nest odor preference, CREB and BDNF levels in pups OB. Male pups were more affected by alterations in the licking pattern, and female pups were more affected by changes in the mother-pup contact (the time spent outside the nest and nursing).

Immunotherapy of allergic diseases using probiotics or recombinant probiotics.

Allergic diseases affect up to 30% of the western population, and their prevalence is increasing. Probiotics are able to modulate the mucosal immune response, and clinical trials demonstrated that specific strains, especially lactic acid bacteria (LAB) ones, reduce allergic symptoms. Moreover, the use of recombinant probiotics has been evaluated as possible strategies for the immunotherapy of allergic diseases. The production and delivery of allergens by recombinant LAB in concert with their ability to induce a Th1-type immune response have been shown to be a promising mucosal vaccination strategy in mouse model. The aim of this article is to review the applications of probiotics in allergy immunotherapy with a special focus on recombinant LAB delivering proteins or DNA.

Cytoplasmic and extracellular expression of pharmaceutical-grade mycobacterial 65-kDa heat shock protein in Lactococcus lactis.

Lactic acid bacteria (LAB) are an attractive and safe alternative for the expression of heterologous proteins, as they are nonpathogenic and endotoxin-free organisms. Lactococcus lactis, the LAB model organism, has been extensively employed in the biotechnology field for large-scale production of heterologous proteins, and its use as a "cell factory" has been widely studied. We have been particularly interested in the use of L. lactis for production of heat shock proteins (HSPs), which reportedly play important roles in the initiation of innate and adaptive immune responses. However, this activity has been questioned, as LPS contamination appears to be responsible for most, if not all, immunostimulatory activity of HSPs. In order to study the effect of pure HSPs on the immune system, we constructed recombinant L. lactis strains able to produce and properly address the Mycobacterium leprae 65-kDa HSP (Hsp65) to the cytoplasm or to the extracellular medium, using a xylose-induced expression system. Approximately 7 mg/L recombinant Hsp65 was secreted. Degradation products related to lactococcal HtrA activity were not observed, and the Limulus amebocyte lysate assay demonstrated that the amount of LPS in the recombinant Hsp65 preparations was 10-100 times lower than the permitted levels established by the U.S. Food and Drug Administration. These new L. lactis strains will allow investigation of the effects of M. leprae Hsp65 without the interference of LPS; consequently, they have potential for a variety of biotechnological, medical and therapeutic applications.

[Seroepidemiology for the hepatitis B virus (HBV) in pregnant women/parturients and its transmission to newborns in Goiânia, GO]. / Soroepidemiologia para o vírus da hepatite B (VHB) em gestantes/parturientes e sua transmissão para recém-nascidos em Goiânia-GO.

In order to detect hepatitis B virus (HBV), 1459 serum samples from pregnant/parturient women were collected at two public hospitals in Goiânia, GO. These samples were tested by enzyme linked immunosorbent assay for HBsAg and anti-HBs. 109 (7.5%) serum samples were positive. Eight (0.5%) sera were positive for HBsAg and 101 (7.0%) for anti-HBs. Viral positivity for both HBsAg and anti-HBs were observed in women which age ranged from 15 to 30 years. Four newborns from HBsAg positive mothers were submitted to the treatment with HBV vaccine (Engerix B) and with hyperimmune gammaglobulin (HBIG, Abbott Laboratories, Brazil). Cord blood from one of the newborns was positive for HBsAg. A positive association was found between hepatitis B and sexually transmitted infections and blood transfusion. These results emphasize the need for prenatal screening for HBV in pregnant women and treatment of the newborns from AgHBs-positive mothers.

[Serologic screening for hepatitis B in health professionals in the city of Goiânia-Goiás]. / Rastreamento sorológico para hepatite B em profissionais de saúde na cidade de Goiânia-Goiás.

Markers for hepatitis B virus in health care workers were analysed in 625 employees of three institutions in Goiânia city. The virus prevalence was 23.4% related to different markers (AgHBs, anit-HBs and anti-HBc). Among the positive individuals, 1.3% presented acute infection, 1.0% were virus carriers and 21.1% presented only anti-HBs and 32.6% only anti-HBc as markers. There were 19 reports of virus vaccination. Eight of them seroconverted for anti-HBs and 6 were positive for both anti-HBc and anti-HBs. Higher prevalence rates were found above 30 year of age (p < 0.05). The male and female prevalence rates were 29.5% and 21.1% (p < 0.05) respectively. The virus prevalence rates among blood and patient contacts were 25.9% (p < 0.05) and the highest prevalence was found in persons followed up for at least ten years (p < 0.05). The greatest risk section has shown to be hemodialysis unit personnel with a percentual of 77% (p < 0.05).