A novel anti-inflammatory oligopeptide produced by Entamoeba histolytica.

The monocyte locomotion inhibitory factor (MLIF), a heat-stable oligopeptide found in the supernatant fluid of Entamoeba histolytica axenic cultures was isolated by ultra-filtration, gel-sieve chromatography and high powered liquid chromatography (HPLC), and its primary structure (Met-Gln-Cys-Asn-Ser) established by Edman sequencing and mass-spectrometry (MS). A synthetic peptide had the same selective anti-inflammatory features as the native material in comparable concentrations: in vitro inhibition of the locomotion in human peripheral blood monocytes, and of the respiratory burst in the same cells and in human neutrophil polymorphonuclear leucocytes; and in vivo depression of delayed hypersensitivity skin reactions to dinitrochlorobenzene in guinea pigs. This oligopeptide is apparently synthesized by the ameba as suggested by [(35)S]-Cys and Met incorporation, probably as part of a larger molecule, from which it is cleaved by proteolysis. The full sequence was not found in the 431 available E. histolytica protein sequences. The factor may contribute to the unexpected paucity of the late inflammatory reaction found in advanced invasive amebiasis and, perhaps in consequence, to the regeneration without scarring (restitutio ad integrum) of the affected organs that is observed following successful treatment of this disease

Cellular immunity in lobomycosis (keloidal blastomycosis).

The cellular immune response of twelve patients from the Brazilian Amazon basin with lobomycosis were assessed. Delayed skin reaction to bacterial and fungal antigens, skin allograft rejection, and sensitization to dinitrochlorobenzene were studied. Ninety-two percent of the patients were not reactive to dinitrochlorobenzene after sensitization; skin allograft rejection occurred in an average of 17 days. Delayed skin reaction to streptococcal, staphylococcal, trichophytin and candida antigens was negative in the majority of the patients. Reactivity to mycobacterial antigens, however, was very high. The results suggest that patients with lobomycosis are partially cellular immunodeficient.

Imunidade celular inespecífica na leishmaniose tegumentar americana / Nonspecific cellular immunity in American cutaneous leishmaniasis

Foram estudados 42 doentes de leishmaniose tegumentar americana observados na Clínica Deramtológica do Hospital das Clínicas da Faculdade de Medicina da Universidade de Säo Paulo (Serviço do Prof. Sebastiäo a. P. Sampaio) com idades entre 3 e 70 anos, compreendendo 36 homens e 6 mulheres. Tratavam-se de doentes com tempo de evoluçäo variavel de 2 meses a 47 anos e compreendiam 29 doentes brancos, 11 pardos e 2 pretos. Estes doentes distribuiram-se quanto à forma clínica em: formas cutâneas puras 21 doentes; formas cutâneos-mucosas 8 doentes; formas mucosas 13 doentes. Os doentes foram estudados imunologicamente por método "in vivo" e "in vitro. I. Metodos "in vivo": 1. Intradermorreaçöes com antigenos de Montenegro, PPD, levedurina, tricofitina e varidase. As mesmas reaçöes foram realizadas em grupo controle de 23 individuos normais. 2. Sensibilizaçäo ao DNCB. II. Métodos "in vitro": 1. determinaçäo dos linfócitos T e B no sangue periférico. 2. Transformaçäo blástica frente a fitohemaglutinina com soro autólogo e hemólogo. 3. Determinaçäo de anticorpos circulantes pela I.F.I.. Os resultados obtidos permitem as seguintes conclusöes: 1. Registraram-se baixos índices de positividade às intradermorreaçöes de leitura tardia particularmente com dois dos quatro antígenos testados, levedurina e varidase, nos doentes de leishmaniose cutâneo-mucosa comparativamente a controles normais. Verifiacaram-se: a) baixos índices de positividade à varidase no total dos doentes com formas exclusivamente cutâneas e nos doentes com lesöes mucosas, b) baixos índices de resposta à levedurina nas formas com participaçä mucosa, c) comparativamente ao grupo control, nos doentes predominaram, considerando-se o número de reaçöes positivas apresentadas, os casos co, todas as reaçöes negativas, uma das reaçöes positivas ou, no máximo duas reaçöes positivas enquanto que a positividade de três reaçöes ou quatro reaçöes predominou nitidamente entre controles. Estes resultados indicam certo grau de depressäo da imunidade celular inespecífica especialmente nos doentes com acometimento mucoso...

Immunocompetence and its modification after BCG immunotherapy in patients with colon carcinoma.

The ability to develop cutaneous response to Mantoux, phytohemagglutinin (PHA) and dinitrochlorobenzene (DNCB) was studied in patients with carcinomas in the digestive tract, with particular emphasis on cancer of the colon, in patients with benign pathology and in a control group. The patients with a malignant disease in the digestive tract, considered as a group, showed a remarkable decrease of responses to Mantoux (31%), to PHA (21%) and to DNCB (58%) compared to the control group where incidence amounted to 61%, 73% and 100% respectively. The depression in the immune cellular response is more remarkable yet in colon carcinoma (Mantoux 11%, PHA 0%, DNCB 11%) all of which suggest that the impairment of the immune response depends on the tumor localization. An increase of unresponsiveness was also observed within the group with a benign pathology although the deterioration is lower than that observed in the malignant group. The patients with adenocarcinoma of the colon received BCG immunotherapy and the changes in cellular and humoral response were studied in them. Although the improving mechanism does not seem to affect simultaneously the various expressions of cell mediated immunity, a stimulating effect in the response was observed in what refers to recall antigen, inflammatory reaction and sensitization to DNCB. These changes ranked Mantoux greater than DNCB greater than PHA. There was a direct correlation between skin test reactivity to at least one antigen and the patient survival, but is not the case with the changes observed in the immunoglobulins level. The significance of these changes in relation to the possible anti-tumor effect is discussed.

Immunological studies in onchocercosis patients.

The immunological profile of onchocercosis patients from an endemic region in Venezuela was studied. The sample was made up of patients suffering from onchocercosis and undergoing treatment, persons previously treated and apparently cured of the disease, and a group of apparently healthy individuals from the same area. The results obtained indicate that during the course of the disease the immunological apparatus suffers only slight modifications since no great variations were found in the immunoglobulin levels, the third component of the complement, the reactivity to DNCB, or the response of peripheral blood lymphocytes to mitogens. When under treatment, the levels of serum IgG and IgM are increased and there is a decrease in C3 levels. The slight modifications found can be attributed to the low severity of the disease as only one patient of those studied presented clinical manifestations ascribable to the disease (onchocercoma).