Immunogenicity of variable regions of the surface envelope glycoprotein of HTLV type I and identification of new major epitopes in the 239-261 region.

The reactivity of sera of 96 individuals infected with human T-cell leukemia virus type I (HTLV-I) was tested against various synthetic peptides corresponding to the gp46 immunodominant antigenic domains: residues 86-107, 175-199, and 239-261. The frequency of reactive sera was higher for 175-199 (93%) than for 239-261 (78%) or 86-107 (24%) with some variations in geographical regions and in diseases. The region 239-261 was extensively analyzed and five (linear or conformational) epitopes were found. The reactivity of sera toward functional or immunodominant domains may depend on the sequence of the infecting virus, and the role of three frequent substitutions (asparagine by tyrosine, proline by serine, and serine by proline or leucine at positions 93, 192, and 250 respectively) was established. Finally, the role of the genetic background of the host may condition the humoral immune response as individuals infected by HTLV-Is harboring the same predicted gp46 peptide sequence may recognize one, several, or all regions examined.

[Neuromyelopathy in the population of Noir-marron of Saint-Laurent du Maroni in French Guiana]. / Neuromyélopathies dans la population de Noirs marrons de Saint-Laurent du Maroni en Guyane française.

The neurological observations have been reported at André Bouron Hospital of Saint-Laurent du Maroni and at General Hospital of Cayenne during a period of 5 years. All patients belonged to the "Noir Marron" ethnic group and lived in the area of Saint-Laurent. There were six women and four men, aged 15-35 years. Neurological symptoms were isolated or associated to other organ failure. Neurological manifestations included retrobulbar optic neuropathy, spastic paraparesis, sensitive ataxia and cerebellar ataxia, psychiatric symptoms were observed. Other organs affected were cardiovascular, digestive, cutaneous or endocrinologic (thyroid). Diet consist mainly in cassava. Thiamin deficiency has been observed several times. Improvement of neurological deficits following thiamin administration points towards Thiamin as an etiological factor. Ethnological specificity of Saint-Laurent area may explain that such neurological manifestation have not been observed in the rest of the department.

[A case of polyradiculoneuritis associated with dengue in a patient native to French Guiana]. / Un cas de polyradiculonévrite associé à une dengue chez une patiente originaire de la Guyane Française.

An acute polyradiculoneuritis in a woman native of French Guiana has been observed with serologic conversion against flaviviruses by inhibition of hemagglutination test. Dengue's diagnostic was been kept in spite of lack of causal virus isolation and non-typical clinical symptoms. Association dengue-polyradiculoneuritis appears quite uncommon and is worthy of note, in view of frequency of infection by Flaviviruses.

[HTLV1 infection and sicca syndrome]. / Infection à HTLV1 et syndrome sec.

UNLABELLED: PURPOSE OF THE STUDY AND MATERIAL: A search for sicca syndrome was performed in 54 HTLV 1 positive patients. Cases of sicca syndrome due to associated pathologies, or iatrogenic, were eliminated from this study. RESULTS: Lacrimal hyposecretion was found in 79% of the cases. Defective lacrimal quality was found in 86% of patients and a variable intensity coloration with the Fluorescine and/or with Rose Bengale was positive in 83% of cases. Histological study of the conjunctival print showed ocular dryness in 65% of the patients. Biopsy of the labial minor salivary glands showed a Gougerot-Sjögren syndrome in 71% of the cases. CONCLUSION: In our study, a sicca syndrome with varied gravity was found in 78% of cases.

HTLV-I associated sicca syndrome in Guadeloupe: lack of relation with a peculiar encoding sequence of surface envelope glycoprotein.

We previously reported a strikingly high prevalence of ocular diseases in HTLV-I infected patients in Guadeloupe (Caribbean basin). We sequenced the surface envelope encoding region of 7 HTLV-I proviruses from guadeloupean patients (5 with sicca syndrome, 2 with TSP/HAM). No relation between sequence and disease was observed. These 7 sequences are the first described from Guadeloupe.

Nucleotide sequence analysis of human T-cell lymphotropic virus type I pX and LTR regions from patients with sicca syndrome.

Human T-cell lymphotropic virus type I (HTLV-I) is associated with adult T-cell leukemia (ATL) and tropical spastic paraparesis/HTLV-I-associated myelopathy (TSP/HAM). Other inflammatory disorders may occur in HTLV-I-infected patients, such as sicca syndrome resembling Sjögren's syndrome. The sicca syndrome may be the unique clinical manifestation of HTLV-I infection, but is associated frequently with TSP/HAM, which could suggest that sicca syndrome might be an early event in disease progression to TSP/HAM in some cases. We investigated whether peculiar pX and LTR mutations could be related to sicca syndrome, or might argue the existence of clinical progression to TSP/HAM. pX, especially pX(I), pX(II), and pX(IV) ORFs corresponding to Tax cytotoxic T-lymphocyte epitopes, and LTR regions from Caribbean patients who have sicca syndrome with or without TSP/HAM, ATL patients, and healthy carriers were sequenced. The sequences were aligned and compared with ATK-1 prototype and published sequences. LTR sequences exhibited 1.5-2.4% of divergence with ATK-1. pX-sequenced regions showed a lower homology within p12(I) encoding sequences. Only few mutations were found within functionally important regions, but were not associated specifically with the clinical status. Finally, no mutations that could be related to sicca syndrome or argue the existence of clinical progression to TSP/HAM were found. It would be of interest to study the clinical evolution of HTLV-I-sicca syndrome in patients and to determine HTLV-I sequences from peripheral blood and salivary glands at different stages.

Neutralizing activity and antibody reactivity toward immunogenic regions of the human T cell leukemia virus type I surface glycoprotein in sera of infected patients with different clinical states.

The induction of specific neutralizing antibodies is an important part of vaccine strategy against human T cell leukemia virus type I (HTLV-I). A recently developed reporter gene induction assay was used to detect and quantify neutralizing antibodies in sera of HTLV-I-infected patients with different clinical states: Most sera (73/89) displayed an inhibitory activity. Neutralizing antibodies were more frequently detected in sera of patients with tropical spastic paraparesis/HTLV-associated myelopathy (TSP/HAM) or sicca syndrome (SS) (100%) than in sera of patients with adult T cell leukemia (ATL; 50%) or of asymptomatic carriers (AS; 83%). The mean titers in the different groups were significantly different (ATL < AS < TSP/HAM and SS). The antibody reactivity detected by the reporter gene inhibition assay was significantly related to the recognition of the neutralizable immunodominant domain (aa 175-199) of the surface envelope glycoprotein, indicating the importance of this region for potential vaccines.