Human milk lymphocytes (ML) can be partially purified and propagated in vitro as a means of assessing their immunological function. When exposed to a variety of stimuli known to activate T lymphocytes, ML respond in a unique manner that indicates a selected population of immunocompetent cells. ML are hyporesponsive to to nonspecific mitogens and respond in a reduced manner to histocompatibility...

The existence of four subpopulations in resting porcine T lymphocytes is documented. In addition to the two known subpopulations which are typified by a mutually exclusive expression of either the CD8 or the CD4 differentiation antigen, CD4-CD8+ and CD4+CD8- T lymphocytes, respectively, two unusual subpopulations were prominent not only in peripheral blood, but also in lymphoid tissues: CD4-CD8...

Peripheral blood lymphocytes from 14 cattle infected with the bovine leukemia virus (BLV) and 14 BLV-free cattle were examined by the membrane immunofluorescent antibody technique to detect surface immunoglobulin (S-Ig) and by the erythrocyte-antibody-complement (EAC) rosette test for the detection of complement receptors. Direct comparisons of the percentages of S-Ig-bearing cells and EAC rose...

It is well known that the lymphocytes of the rat thoracic duct consist of two populations, namely about 5% large lymphocytes and 95% small ones. The two populations differ not only in morphological but also in biological respects (1, 2). Furthermore, we have evidence that the small lymphocytes themselves also consist of two populations. This is particularly so in rodents, but it is also found i...

We have identified two populations of human lymphocytes differing in responsiveness to the plant mitogen concanavalin A (Con-A). When peripheral blood lymphocytes are passed through a nylon column a population of lymphocytes highly responsive to Con-A adheres to the fibers while a second population of cells relatively unresponsive to Con-A emerges from the column. The untreated peripheral blood...

Production of nerve growth factor (NGF) was assessed in cultures of human T and B lymphocytes and macrophages. NGF was constitutively produced by B cells only, which also expressed surface p140trk-A and p75NGFR molecules and hence efficiently bound and internalized the cytokine. Neutralization of endogenous NGF caused disappearance of Bcl-2 protein and apoptotic death of resting lymphocytes bea...

The extent and nature of lymphocyte activation in the circulation in rheumatoid arthritis (RA) was investigated. Peripheral blood lymphocytes (PBL) from RA patients and healthy controls were separated into a number of discrete fractions by density in discontinuous Ficoll density gradients. Low density (activated) lymphocytes were found at significantly higher levels in RA, particularly in patie...

Human immunodeficiency virus (HIV) has been isolated from cervicovaginal secretions from infected women and is thought to be cell associated. To identify which cells harbour viral antigen, we used monoclonal antibodies to OKT4 and a monoclonal antibody directed against HIV p17 core antigen to perform indirect immunofluorescence assays of genital secretions from 17 HIV seropositive and 17 HIV se...

The relationship between the concentration of cell-free DNA (cfDNA) and the number of proliferating/apoptotic lymphocytes in peripheral blood of premature newborns of different gestation age and full-term newborns was determined. The experiments were performed using fluorescent spectrophotometry (with Hoechst 33342), flow cytometry, and microscopy (Feulgen staining of lymphocytes). It was deter...

Atypical lymphocytes from nine young adults with acute infectious mononucleosis (IM) were studied for morphologic, ultrastructural, cytochemical, and membrane surface marker characteristics. There was an absolute increase in T lymphocytes in the patients. Atypical lymphocytes accounted for 83%-96% of the lymphocyte population. These lymphocytes contained cytoplasmic inclusions which ranged in s...