Investigation on the monoclonal antibodies as differential markers for viral and bacterial meningitis by means of immnunohistochemistry technique / Avaliação de anticorpos monoclonais como marcadores diferenciais de meningites bacterianas e virais por meio de técnica imuno-histoquímica

Since 1996, the Laboratory of Monoclonal Antibodies Antigens and Adjuvants - Immunology Center of Adolfo Lutz Institute (IC-IAL) has been working on N. meningitidis strains antigens characterization by using a predetermined monoclonal antibodies (MoAb) panel; and the new monoclonal production has been performed for characterizing strains with unknown profiles. MoAb were obtained from different fusions performed at IAL using spleen cells and popliteal lymph nodes. Two murine hybridomas secreting MoAb anti-N. meningitidis antigens, produced and characterized in the Laboratory of IC-IAL, are presently being evaluated by immunohistochemical (IHC) technique at Immunohistochemistry Laboratory - Pathology Center, IAL. After standardizing these reactions, a protocol for performing investigation on N.meningitidis antigens by using IHQ was established. An increment in the histopathological diagnosis of meningococcal meningitis was occurred, by using MoAb specific for antigens from N. meningitidis serogroups, serotypes and subtypes, mainly in those cases without microorganisms confirmation by biomolecular techniques as PCR. The results obtained in these first tests proved to be promising, and two MoAb showed excellent results. No cross-reactivity with viral meningitis, S. pneumoniae, Rickettsia or Rubella was detected. For the further studies, it is fundamental to increase the samples size, including samples from patients with meningococcal meningitis and from individuals infected with other pathogens.

Desde 1996, o Laboratório de Anticorpos Monoclonais, Antígenos e Adjuvantes - Centro de Imunologia do Instituto Adolfo Lutz (CI-IAL) tem desenvolvido trabalhos na caracterização antigênica de cepas de Neisseria meningitidis utilizando-se painel de anticorpos monoclonais (AcMo) pré-estabelecido, e produção de novos monoclonais para a análise de cepas com perfis desconhecidos. AcMo foram obtidos das diferentes fusões realizadas no laboratório utilizando-se células esplênicas e linfonodos poplíteos. Dois hibridomas murinos secretores de AcMo anti-N. meningitidis produzidos e caracterizados no CI-IAL têm sido avaliados por meio de estudo imuno-histoquímico (IHQ) no Centro de Patologia-Laboratório de Imunohistoquímica-IAL. Com a padronização da reação, estabeleceu-se um protocolo para efetuar a pesquisa de antígenos de N. meningitidis por IHQ. Houve melhoria no diagnóstico histopatológico da meningite meningocócica, sobretudo em situações em que não há confirmação da presença do microorganismo por técnicas biomoleculares, como PCR, utilizando-se AcMo específicos para antígenos de diferentes sorogrupos, sorotipos e subtipos de N. meningitidis. O resultado obtido nos primeiros testes mostrou-se promissor, e os dois AcMo demonstraram excelentes resultados. Não houve reatividade cruzada com meningite viral, S. pneumoniae, Rickettsia ou rubéola. Nos próximos estudos, é fundamental ampliar número de amostras, incluindo-se aquelas coletadas de pacientes com meningites meningocócicas e de indivíduos infectados com outros agentes patogênicos.

Molecular characterization of Cryptosporidium spp. from HIV infected patients from an urban area of Brazil / Caracterização molecular de Cryptosporidium spp. de pacientes de área urbana do Brasil infectados por HIV

Cryptosporidium spp. are important cause of enteric disease in humans, but may also infect animals. This study describes the relative frequency of several Cryptosporidium species found in human specimens from HIV infected patients in the São Paulo municipality obtained from January to July 2007. Sequence analysis of the products of nested-PCR based on small subunit rRNA and Cryptosporidium oocyst wall protein coding genes revealed 17 (63.0 percent) isolates of C. hominis, four (14.8 percent) C. parvum, five (18.5 percent) C. felis and one (3.7 percent) C. canis. These findings suggest that, in urban environments of Brazil, the cat adapted C. felis may play a potential role in the zoonotic transmission of cryptosporidiosis whereas the anthroponotic transmission of cryptosporidiosis caused by C. hominis seems to predominate.

Cryptosporidium spp. são importantes causas de doenças entéricas em humanos, mas podem também ser encontrados em animais. O presente estudo descreve a frequência relativa de diversas espécies de Cryptosporidium em amostras de humanos da cidade de São Paulo, Brasil, obtidas de janeiro a julho de 2007. Análises de sequências de produtos de nested PCR direcionadas ao genes codificadores da menor unidade ribosomal e da proteina de parede de oocistos revelaram 17 (63,0 por cento) isolados de C. hominis, quatro (14,8 por cento) C. parvum, cinco (18,5 por cento) C. felis, e um (3,7 por cento) C. canis. Estes resultados sugerem que, em ambientes urbanos no Brasil, o genótipo adaptado ao gato pode desempenhar potencial papel na transmissão zoonótica de criptosporidiose, enquanto a transmissão antroponótica da criptosporidiose causada pelo C. hominis parece predominar.

Production of monoclonal antibody to subtype 9 of Neisseria meningitidis and the distribution of this subtype in Brazil

A new monoclonal antibody (5F81A4P1.9), which is specific for subtype 9 antigen of meningococci, was studied. The antibodies were raised against a previously non-typable (NT) serogroup B strain from Brazilian patients and were found to react with the subtype antigen of prototype reference strains for subtype 9 (M982), as well as with those of homologous strains. The subtype 9 epitope was found in 6.8 percent of serogroup B strains among 602 strains of Neisseria meningitidis case isolates, including representative isolates from Brazilian states. Subtype P1.9 was predominantly related to serogroup B in Brazil among the isolates collected during the N. meningitidis epidemic in 1992. No significant differences were observed in the occurrence of subtype P1.9 among strains isolated from several Brazilian states. Fluorescence-activated cell-sorter analysis showed that 5F81A4 MAb recognized a 46 kDa protein on the surface of a homologous strain of N. meningitidis (B:4:P1.9). These results, in association with a bactericidal activity assay for 5F81A4, and with experimental passive protection in mice, demonstrated the importance of subtype 9 class 1 proteins of N meningitidis in Brazil. Serotyping is essential for the development of vaccination strategies.

Expression of class 5 antigens by meningococcal strains obtained from patients in Brazil and evaluation of two new monoclonal antibodies

Determining the profile of antigen expression among meningococci is important for epidemiologic surveillance and vaccine development. To this end, two new mouse monoclonal antibodies (MAbs) have been derived against Neisseria meningitidis proteins (class 5). The MAbs were reactive against outer membrane antigens and were bactericidal. Selected anti-class 5 MAbs [(5.1)-3E6-2;(5.3)-3BH4-C7;(5.4)-1BG11-C7;(5.5)-3DH-F5G9 also 5FIF4-T3(5.c)], and two new monoclonal antibodies C14F10Br2 (5.8) and 7F11B5Br3 (5.9), were then tested against different meningococcal strains, (63 strains of serogroup A, 60 strains of serogroup C (from 1972 to 1974); and 136 strains of serogroup B (from 1992) meningococci). Our results demonstrated that the expression of class 5 proteins in the N. meningitidis B Brazilian strains studied is highly heterogeneous. The serotypes and subtypes of B:4:P1.15, B:4:P1.9, B:4:P1.7, B:4:P1.3, B:4:p1.14, B:4:P1.16, B:4:NT, and B:NT:NT were detected in N. meningitidis B serogroups. The strains C:2a:P1.2 and A:4.21:P1.9 were dominant in the C and A serogroups, respectively. Serogroup B organisms expressed the class 5 epitopes 5.4 (18 percent), 5.5 (22 percent), 5.8 (3.6 percent), 5.9 (8 percent) and 5c (38 percent). Serogroup C expressed class 5 epitopes 5.1(81 percent), 5.4 (35 percent), 5.5 (33 percent) and 5.9 (5 percent); and serogroup A showed reactivity directed at the class 5 protein 5c (47 percent); and reactivity was present with the new monoclonal antibody, 5.9 (5.5 percent). We conclude that the two new MAbs are useful in detecting important group B, class 5 antigens, and that a broad selection of serogroup B, class 5 proteins would be required for an effective vaccine based on the class 5 proteins.

Production of monoclonal antibodies anti-Taenia crassiceps cysticerci with cross-reactivity with Taenia solium antigens

We describe the production of the potential monoclonal antibodies (MoAbs) using BALB/c mice immunized with vesicular fluid (VF)-Tcra (T. crassiceps) antigen. Immune sera presented anti-VF-Tcra (<20kD) IgG and IgM antibodies with cross-reactivity with T. solium (Tso) antigen (8-12, 14, and 18 kD). After cell fusion, we selected 33 anti-Tcra and anti-Tso reactive IgM-clones and 53 anti-Tcra specific IgG-clones, 5 of them also recognizing Tso antigens. Two clones identified the 8-14 and 18kD peptides of VF-Tcra.

Conservaçäo de bactérias do gênero Haemophilus / Preservation of genera Haemophilus bacteria

Há vários métodos de preservação de microrganismos e nem sempre é fácil a escolha do método mais adequado. Descrevemos neste trabalho um estudo comparativo com FHaemophilus influenzae (biogrupo aegyptius) e Haemophilus influenzae b preservados por liofilização e conservação em miçangas (pérolas de vidro). Conservamos, com sucesso, estes microrganismos por um ano em miçangas de forma semelhante a liofilização, porém com as seguintes vantagens: o método é simples de ser executado; centenas de raças podem ser armazenadas por longos períodos em pequeno espaço; a recuperação das culturas é rápida com pouca ou nenhuma perturbação de outras culturas estocadas; somente uma porção de cultura é removida e descongelada ao passo que as demais permanecem congeladas; as miçangas descongelam rapidamente quando colocadas em meio sólido e a recuperação é imediata.

Trypanosoma cruzi: serum antibody reactivity to the parasite antigens in susceptible and resistant mice

The specific antibody responses were compared among susceptible (A/Sn), moderately susceptible (Balb/c) and resistant (C57 BL/lOJ) mice infected with Trypanosoma cruzi (Y strain). Sera obtained during the second week of infection recognized a surface trypomastigote antigen of apparent Mr 80 kDa while displaying complex reactivity to surface epimastigote antigens. Complex trypomastigote antigens recognition was detected around the middle of the third week of infection. No major differences were observed along the infection, among the three strains of mice, neither in the patterns of surface antigen recognition by sera, nor in the titres of antibodies against blood trypomastigotes (lytic antibodies), tissue culture trypomastigotes or epimastigotes. On immunoblot analysis, however, IgG of the resistant strain displayed the most complex array of specificities against both trypo and epimastigote antigens, followed by the susceptible strain. IgM antibodies exhibited a more restricted antigen reactivity, in the three mouse strains studied. Balb/c sera (IgG and IgM) showed the least complex patterns of reactivity to antigens in the range of 30 kDa to 80 kDa. The onset of reactivity in the serum to trypomastigote surface antigens was also dependent on the parasite load to which the experimental animal was subjected

Enhanced sensitivity of dor-immunobinding assays for the detection of antibodies in mice by the use of mild detergent extracted Trypanosoma Cruzi antigens

A method for a rapid and accurate demonstrations of antibodies to Trypanosoma Cruzy by using nitrocellulose paper strips with antigens of the parasite was developed and evaluated. We report herein additional advantages of its use for the detection of specific antibody to Trypanosoma Cruzi in the sera of mice. Increased sensibility without increase in the background was achieved using parasite antigens obtained by mild non-ionic detergent extraction as compared to antigens extracted by alkaline digestion.