The identity of the measles virus receptor has been controversial. Several years ago CD46 was identified as a cellular receptor for the Edmonston strain of measles virus, but most clinical isolates of measles virus, which are most efficiently isolated in the marmoset B cell line B95a, cannot grow in many CD46+ cell lines. Although some researchers attributed it to post-entry block in viral replication, others believed that there is a receptor other than CD46 for wild-type measles viruses. A new study showed that human signalling lymphocytic activation molecule (SLAM; also known as CDw150) is a cellular receptor for measles virus, including the Edmonston strain. SLAM is expressed on lymphocytes and dendritic cells, and plays an important role in lymphocyte activation. The identification of SLAM as a measles virus receptor nicely explains the pathogenesis of measles virus infection.

Antigens, CD↗

PubMedDate not supplied

Studies on the synthesis of sesquiterpene lactones, 12. Synthesis of (+)-colartin, (+)-arbusculin A, and their C-4 epimers and their biological activities.

Colartin [9] and arbusculin A [11] have been synthesized from alpha-santonin [1] in 14.5% (11 steps) and 9.3% (13 steps) overall yields, respectively. Arbusculin A [11] and compounds 20, 21, and 22, which were derived from intermediate 2, showed significant cell growth inhibitory activity against murine lymphocytic leukemia (P-388) in vitro. Plant growth regulating activity of 11 and its synthetic intermediates 4, 5, 8, and 9 was also studied.

Animals↗

PubMedDate not supplied

A human T cell-specific cDNA clone encodes a protein having extensive homology to immunoglobulin chains.

We have cloned and sequenced a human mRNA specific for mammalian T-lymphoid cells. The message was found to be expressed in human and murine T lymphoblasts, thymocytes and phytohaemagglutinin-stimulated T lymphocytes. The protein deduced from the cDNA sequence has a molecular weight of 34,938 and shows extensive similarity to the entire length of the variable, joining and constant regions of mammalian immunoglobulin light chains. In addition, the relative positions of the cysteine residues are similar to those of the light chains of murine and human immunoglobulin molecules. These properties suggest that the cDNA clone may correspond to a message that specifies part of the human T-cell receptor.

Amino Acid Sequence↗

PubMedDate not supplied

Presence of T-cell receptor mRNA in functionally distinct T cells and elevation during intrathymic differentiation.

Understanding the differentiation of functionally distinct subsets of T lymphocytes is essential to unravel their crucial role in the immune response and awaits knowledge of the assembly and expression of genes encoding the T-cell receptor. Recently, we have cloned and sequenced complementary DNA that may specify part of the human T-cell receptor. The deduced protein sequence showed extensive similarity to the entire length of mammalian immunoglobulin light chains. In addition, sequences corresponding to this message undergo somatic rearrangements and are assembled from non-contiguous genomic sequences into a single mRNA molecule, a mechanism similar to those found in the generation of immunoglobulin messages. A related molecule from the mouse was also isolated independently by Hedrick et al. Here we show that the putative T-cell receptor mRNA is expressed at a relatively high level during intrathymic differentiation before decreasing about 10-20-fold in normal, mature peripheral blood T cells and that it can also be detected in T-cell clones with helper and cytotoxic functions, as well as in at least one clone with suppressor properties.

Cell Differentiation↗

PubMedDate not supplied

Rearrangements of T-cell receptor gene YT35 in human DNA from thymic leukaemia T-cell lines and functional T-cell clones.

An essential property of the immune response is its ability to distinguish between self and non-self and to generate enormous diversity in antibody and T-cell immune responses. Although the genetic and molecular mechanisms responsible for antibody diversity have now largely been elucidated, the structure of the T-cell receptor and the diversification of the receptor repertoire have only recently become amenable to study. One approach has involved immunochemical studies of the protein precipitated by monoclonal antibodies which react specifically with the immunizing T-cell clones. Another approach has been to clone and sequence a human or a murine T-cell specific message that may specify part of the T-cell receptor. We present here results of Southern blot analysis of non-T, immature T, and mature T-cell genomic DNA, and provide evidence that rearrangements of the YT35 sequences do occur in the DNA of thymic leukaemia T cells. This suggests that YT35 codes for at least part of the T-cell receptor and that rearrangements occur at this early stage of thymic ontogeny. Furthermore, DNA rearrangements are present in lymphocytes with phenotypic and functional characteristics of helper, killer, or suppressor T cells. We conclude that the three subpopulations of T cells operate via receptor molecules encoded by the same gene family.

Cell Line↗

PubMedDate not supplied

Sequence and expression of transcripts of the human T-cell receptor beta-chain genes.

T lymphocytes can produce mRNAs from the first or second constant region of the T-cell antigen receptor beta-chain. A 1.3-kilobase (kb) transcript encoding the mature protein contains V, J and one of the two C region sequences, but does not always contain D sequences. A 1.0-kb mRNA, found mainly in immature T cells, does not contain V sequences and can result from transcription that initiates upstream from an unrearranged J element.

Base Sequence↗

PubMedDate not supplied

Gene rearrangement in cells with natural killer activity and expression of the beta-chain of the T-cell antigen receptor.

The mammalian host defence system can be divided broadly into adaptive and non-adaptive immunity. Adaptive immunity is acquired and is mediated by B and T lymphocytes. Non-adaptive immunity is mediated in part by a small subclass of heterogeneous peripheral blood mononuclear cells. This population, termed null cells, consists of haematopoietic precursors and cells mediating natural killer (NK) activity and antibody-dependent cellular cytotoxicity (ADCC). NK cells are a class of non-adherent, non-phagocytic, rapidly cytotoxic lymphocytes which can efficiently lyse a wide variety of tumour cells, virally infected cells and immature cell types of normal origin. Despite the broad range of targets, only a limited number of specificities are thought to be involved in target-cell recognition. Morphologically, NK cells are large granular lymphocytes, but they have been shown to exhibit cell-surface markers characteristic of both T cells and monocytes, raising doubt over their lineage. The recent cloning of the beta-chain of the T-cell antigen receptor has now allowed us to investigate whether some NK cells are T-cell-related. We have examined rearrangement and expression of the beta-chain of the T-cell receptor in cloned murine NK cell lines and fresh murine NK cell populations, and our results support the hypothesis that a subpopulation of NK cells is related to T cells and provide basis for examining whether some NK activity is mediated by a small number of T-cell receptors.

Animals↗

PubMedDate not supplied

Reconstitution of an active surface T3/T-cell antigen receptor by DNA transfer.

We have introduced a full-length complementary DNA of the T-cell antigen receptor beta-chain into a mutant human T-cell line that lacked a complete beta-chain messenger RNA, had a diminished level of alpha-chain transcript and did not express surface T3- or antigen receptor. Expression of the transfected beta-chain led to a normal level of alpha-chain transcript and a structurally and functionally active T3 T-cell antigen receptor complex on the cell surface.

Cell Line↗

PubMedDate not supplied

Psychiatry of diencephalon damages. A case report.

The diencephalon syndrome due to head injury in a 60-year-old woman is reported. The dicenphalon syndrome of the patient offered a variety of productive psychic and somatopsychic symptoms without reduction of intelligence; these included optic and acoustic hallucinations, delusions, cenesthesic hallucinations, disturbances of body schema and distinct functional disorders of the vegetative system. Autopsy findings of the brain were obtained in the 1.5 years up to her death. The problems of diencephalon syndrome related with suspected organic bases of schizophrenia and rhythmicity of diencephalogenic impulse reduction are discussed.

Accidents, Traffic↗