Antibodies to HTLV-I p24 in African and Portuguese populations.

Using a radioimmunoassay to detect HTLV-I protein antibodies of molecular weight 24,000, we screened populations from Algeria (140 subjects), Tunisia (442), Mali (69), Senegal (415), Uganda (135), the Central African Republic (77), the Congo (360), and Madagascar (193). Only four subjects were positive (1 from Senegal, 1 from Uganda, 2 from the Congo). This is a much lower figure than that found by others in Africa by the enzyme-linked immunosorbent assay technique. In addition, 319 Portuguese blood donors (46 of whom have lived in Angola or Mozambique) were screened using the same radioimmunoassay. All were negative.

Intrinsic expression of 20 alpha-hydroxysteroid dehydrogenase in murine myelomonocytic cell lines.

The expression of a 20 alpha-hydroxysteroid dehydrogenase (20 alpha SDH) activity was investigated in various murine hematopoietic cells. Large differences appeared between cells belonging to the same hematopoietic lineage. Normal thymocytes were positive when splenocytes, B and T lymphoma cell lines were negative. In two stromal fibroblastic cell lines, the expression of 20 alpha SDH was very high, whereas it was negative in NIH/3T3 normal fibroblasts. Among myelomonocytic cell lines, six expressed high levels and two were negative. Contaminating lymphoid subpopulations were not detectable in these cell lines. The levels of detected enzymatic activity seemed unrelated with the virus infection. The presence of 20 alpha SDH activity in factor-independent myelomonocytic cell lines, and the lack of induction of the enzymatic activity by the IL-3 containing WEHI-3B conditioned medium in negative cell lines, led us to suggest that myelomonocytic cells intrinsically express the 20 alpha SDH enzymatic activity, as well as other hemopoietic and stromal cell lines.

Abnormal sequence of expression of differentiation markers in psoriatic epidermis: inversion of two steps in the differentiation program?

This immunohistologic study was undertaken to compare epidermal differentiation in normal and psoriatic skin. Although basal cells retain a normal phenotype in this disease, suprabasal layers exhibit abnormal sets of differentiation markers. The 67-kD keratin and Bd5 antigen, which are found in normal epidermis immediately above the basal layer, appear several layers higher in involved psoriatic epidermis. On the contrary, KF2 antigen, which is found in the upper spinous layers of normal epidermis, appears more precociously in psoriatic epidermis. Paradoxically, in this disease characterized by the absence of a granular layer, some markers specific for this layer in normal skin, such as involucrin and transglutaminase, appear in lower skin cell layers, while other granular markers, such as filaggrin, are either absent or found in the parakeratotic scales. These results point out the existence in psoriasis of a suprabasal cell population characterized by a set of markers that are never coexpressed in normal epidermis. The existence of this abnormal population of cells can be explained as the result of the inversion of two steps in the differentiation program. Thus, instead of an inability to express a given differentiation marker, psoriasis seems to be characterized by an abnormal sequence of expression of these markers.

Detection of H-2Dd and H-2Kd molecules in purified Rauscher leukemia virus.

Evidence is presented that an H-2 antigenic activity is associated with Rauscher murine leukemia virions grown in vitro. Purified Rauscher MuLV grown in fibroblasts of BALB/c (H-2d), C57BL/6 (H-2b) or (BALB/c X C57BL/6)F1 (H-2d/b) were used to absorb the activity of anti-Dd, anti-Kd, anti-Db or anti-Kb antisera tested against H-2-related targets by cellular radioimmunoassay. The results show that Dd and Kd activities were associated with the virions grown in H-2d or H-2d/b fibroblasts. No H-2b antigenic activity was detected in the virions grown in C57BL/6 or F1 fibroblasts. Immunoprecipitation of surface-labelled spleen cells revealed that Rauscher MuLV grown in BALB/c or F1 fibroblasts inhibited the precipitation of the 48 000 dalton peaks characteristic of the Dd and Kd molecules whereas the precipitation of H-2b molecules was not modified by Rauscher MuLV grown in the different cell lines. Class II molecules (Ia) were not detected in Rauscher virions. Comparison of the absorbing activities of intact and disrupted viruses suggests that the H-2 activity was localized at the viral surface. Taken together, these results confirm the possible non-random association of H-2 molecules to type-C viral particles whatever the nature of this association and its possible cellular or extracellular origin. However, the H-2 antigens found in the virions being a non-restricting element of anti-viral cytolytic T lymphocytes in the same system, these results give no particular support to the "altered self" hypothesis.

Lymphoid cell surface receptor for Moloney leukemia virus envelope glycoprotein gp71. II. Isolation of the receptor.

The lymphoid cell surface receptor for Moloney leukemia virus envelope glycoprotein gp71 was isolated by using anti-gp71 antibodies to immunoprecipitate the receptor-gp71 complex from detergent extract of radiolabeled murine thymus cells. Upon sodium dodecyl sulfate gel electrophoresis, a single molecule with an apparent m.w. of 190,000 was identified as the putative gp71-receptor. Analysis in nonreducing conditions indicated that the receptor may be composed of at least 2 subunits of 190,000 daltons.

Anti HTLV-I antibodies and HLA phenotypes in the West Indies.

Sera of supposedly healthy blood donors were screened for the presence of anti HTLV-I p24 antibodies, and HLA typing for A, B, C and DR antigens was performed for 68 seropositive subjects and 92 seronegative controls. HLA phenotypes of the two groups were not significantly different but the level of the antibody response was related to the antigens of the HLA-B (P = 0.02) and -C loci (P = 0.003). Subjects with HLA-B12 or -B21 antigens had lower titres than the others. Subjects with HLA-Cw2 or -Cw7 antigens had higher titres than the others, but only the difference between HLA-B12 positive and negative subjects (P = 0.002) remained significant at the alpha = 0.10 level if the classical, although conservative, Bonferroni procedure was used to correct for the number of comparisons performed.

Lymphoid cell surface receptor for Moloney leukemia virus envelope glycoprotein gp71. I. Binding characteristics.

The characteristics of Moloney leukemia virus (M-MuLV) gp71 binding on lymphoid cells have been studied by a very sensitive assay. Analysis of the results indicated the presence of 1 class of high affinity binding sites (Ka = 1.2 X 10(9) M-1) on BALB/c thymus cells. The total number of binding sites was estimated around 1.3 X 10(4) per thymus cell. No significative differences were observed for the binding of Moloney leukemia virus gp71 on thymus cells from different inbred strains of mice, suggesting that the genetic susceptibility to Moloney leukemia virus infection does not depend on the presence of gp71 receptor on the target cells. On the other hand, it seems that M-MuLV gp71 binds preferentially on T cells, which are the final target of Moloney leukemia virus-induced transformation. Very little binding was found on Moloney, Rauscher, or x-ray-induced lymphoma cells.

[Detection of specific antibodies for HTLV in French blood donors]. / Détection d'anticorps spécifiques du HTLV chez les donneurs de sang français.

HTLV infection was detected in normal French blood donors and haemophiliac patients using HTLV p24 radio-immunoassay. No positive was found in 772 sera from continental blood donors born in continental France or in foreign countries. Among 131 donors living in continental France and born in overseas territories, 2 (1.5%) were found to possess anti-HTLV p24 antibodies. Similarly in a sample of 1 239 donors collected in Martinique, 1.5% were positive. No positive had been found in a sample of 142 continental haemophiliacs.

Sex ratio of human T-lymphotropic virus type I infection and blood transfusion.

The prevalence of human T-lymphotropic virus type I (HTLV-I) infection is higher for females than for males. Blood transfusion is a potential confounding factor which might contribute to this high female:male ratio. Two studies were performed in Martinique (French West Indies) to clarify this issue: a case-control survey comparing the experience of previous blood transfusion among 62 HTLV-I-seropositive and 88 HTLV-I-seronegative blood donors, and a retrospective study of the sex of recipients of blood. Blood transfusion was strongly associated with HTLV-I infection (odds ratio = 6.4, p less than 0.001). Females were more often given blood transfusions (57.9 percent, p less than 0.001) and received a higher percentage of blood units (53.5 percent, p less than 0.05) than could be expected from their proportion in the general population (51.6 percent). Thus, the high female:male sex ratio of HTLV-I-infected subjects might be due partially to a sex difference for blood transfusion.

Antibodies to HTLV-I p24 in sera of blood donors, elderly people and patients with hemopoietic diseases in France and in French West Indies.

Human T-cell lymphoma/leukemia virus type I (HTLV-I) is a type-C retrovirus originally isolated from patients with leukemia or lymphoma involving mature T lymphocytes. Epidemiological studies have shown that HTLV-I infection occurs not only in leukemic but also in normal people in at least two areas of the world: the Caribbean basin and the South-West of Japan. We report here the results of a large seroepidemiological study of HTLV-I infection in normal French blood donors, elderly subjects living in institutions and patients with various malignant hemopathies, obtained by the classical HTLV-I p24 radioimmunoassay. We were unable to demonstrate antibodies to HTLV-I in 510 sera from French volunteer blood donors born and living in continental France or in sera from 262 blood donors born in other countries (mainly in Europe and North Africa) and living in continental France at the time of collection. In contrast, among 131 sera from blood donors born in French overseas territories (French Guiana, French West Indies, and Reunion) but living at the time of collection in continental France, 2 (1.5%) were found to possess anti-HTLV-I antibodies. In a sample of 2,597 blood donors from Martinique, 39 (1.5%) were positive. A positive correlation with age was observed whereas no statistical relationship was found between HTLV-I antibodies and sex, red cell blood groups or the place of residence in Martinique. On the other hand, a very high level of positive values was observed in Martinique among old people living in institutions, 14% of those aged over 60 years being positive. HTLV-I-associated hematological malignancies have not been observed in patients born and living in continental France whereas a large number exist in the French West Indies. In the same area, the presence of anti-HTLV-I antibodies in 12% of patients with myeloma, a typical B-cell disease, merits attention.

Lymphoid interstitial pneumonitis in acquired immunodeficiency syndrome-related complex.

Three patients had a typical clinical, functional, and histologic pattern of lymphoid interstitial pneumonitis (LIP). All 3 also had a marked follicular and interfollicular hyperplasia of peripheral lymph nodes. A benign lymphocytic infiltration was seen in the kidneys in 2 patients, in the liver of 1 of these, and in the nasopharynx and the bone marrow in another. This LIP, associated with other diffuse benign lymphocytic infiltrates, could be part of AIDS-related manifestations. The patients originated from central Africa (2 patients) and Haiti (1 patient) where AIDS is endemic. They had several immune abnormalities frequently observed in AIDS such as a polyclonal hyperimmunoglobulinemia and, in the 2 patients studied, a decreased number of T4 lymphocytes and an inverted T4/T8 blood lymphocyte ratio. All 3 patients had serum antibodies to human T-cell leukemia viruses.