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L Guilherme

Publications and source records attributed to L Guilherme.

25 records · Page 2Linked to original sources
PubMed1985

[Cold lymphocytotoxins in schistosomiasis mansoni].

The serum of 134 patients infected with Schistosoma mansoni, including both acute and chronic forms of the disease, were tested for the presence of cold lymphocytotoxins. These were found in 4.5% of acute forms of the disease, in 88.4% of chronic infections and in only 9.8% of the uninfected control group (blood donors). An analysis of the results suggests a probable role for cold lymphocytotoxins in the immune response of the different phases of human schistosomiasis.

Adolescent↗
PubMed1984

Non HLA antigenic determinants expressed on activated T and B human lymphocytes.

Human antigenic determinants present on activated T and B lymphocytes and not on resting B and T cells defined by serological studies are reported. The reactivity of 13 sera against human PBM activated by various agents was tested using microlymphocytotoxicity technique. Results showed that generally similar reactions are present on B and T blasts whatever the technique of activation (PHA, ConA, PWM, TCGF, EBV and allo activation). Absorption elution studies with 5 sera on 10 alloactivated cells clearly demonstrated their independence from DR determinants. The analysis of results obtained by these 15 sera on blasts from 50 donors showed no correlation with HLA-A, -B, -C, DR and -MB antigens, neither can it be HT (Qa-like) antigens. Furthermore, 5 clusters of sera are reported. The weak correlation coefficients cannot affirm the existence of a system with an allelic distribution although each cell except one out of a panel of 50 individuals carries at most 2 specificities. The segregation of 3 of these specificities within 5 informative families showed no linkage with HLA genes.

B-Lymphocytes↗
PubMedDate not supplied

Towards a vaccine against rheumatic fever.

Rheumatic fever (RF) is an autoimmune disease which affects more than 20 million children in developing countries. It is triggered by Streptococcus pyogenes throat infection in untreated susceptible individuals. Carditis, the most serious manifestation of the disease, leads to severe and permanent valvular lesions, causing chronic rheumatic heart disease (RHD). We have been studying the mechanisms leading to pathological autoimmunity in RF/RHD for the last 15 years. Our studies allowed us a better understanding of the cellular and molecular pathogenesis of RHD, paving the way for the development of a safe vaccine for a post-infection autoimmune disease. We have focused on the search for protective T and B cell epitopes by testing 620 human blood samples against overlapping peptides spanning 99 residues of the C-terminal portion of the M protein, differing by one amino acid residue. We identified T and B cell epitopes with 22 and 25 amino acid residues, respectively. Although these epitopes were from different regions of the C-terminal portion of the M protein, they showed an identical core of 16 amino acid residues. Antibodies against the B cell epitope inhibited bacterial invasion/adhesion in vitro. Our results strongly indicated that the selected T and B cell epitopes could potentially be protective against S. pyogenes.

Animals↗