This study investigated the effect of caffeine on antigen-stimulated lymphocyte activation. Six males rested for 3.5 h after ingesting 0 (PLA), 2, or 6 (6CAF) mg·kg(-1) body mass of caffeine. The number of antigen-stimulated NK CD69(+) cells increased in 6CAF at 1 h compared with PLA (P = 0.021). Caffeine did not influence the number of antigen-stimulated CD69(+) T cells or the geometric mean f...

The peripheral blood lymphocyte response and hemagglutination inhibition antibody titers were measured in nine adults before and after immunization with a killed split influenza virus vaccine. Cord blood lymphocytes were tested with the influenza antigen to exclude a nonspecific mitogenic effect. All of the subjects demonstrated preexisting antibody titers and antigen recognition by lymphocytes...

Gamma interferon (IFN-gamma)-activated macrophages are believed to play a key role in resistance to Babesia bovis through parasite suppression by macrophage secretory products. However, relatively little is known about interactions between this intraerythrocytic parasite and the macrophages of its bovine host. In this study, we examined the in vitro effect of intact and fractionated B. bovis me...

CD4(+) lymphocyte count and human immunodeficiency virus (HIV) type 1 RNA level are useful for determining when to initiate antiretroviral therapy but are not used widely in developing countries due to the high cost. Heat-denatured protein 24 (p24) antigen is an inexpensive assay that predicts disease progression among persons with advanced disease but has not been assessed among persons with e...

Antigen presentation to T lymphocytes has been characterized extensively in terms of T lymphocyte activation and eventual cell death. In contrast, little is known about the consequences of antigen presentation for the antigen-presenting cell (APC). We have determined the outcome of major histocompatibility complex class II-restricted peptide presentation to a specific T cell. We demonstrate tha...

PURPOSE This study was designed to investigate an animal model of uveitis that resembles anterior uveitis in humans after immunization with iris-ciliary body antigen. METHODS Male Lewis rats 6 to 8 weeks of age were immunized with the buffer- and detergent-insoluble bovine iris-ciliary body antigen mixed with complete Freund's adjuvant and pertussis toxin. Antigen was digested with various pr...

Hepatitis B surface antigen is the first genetically engineered vaccine licensed for human use. Various strategies have been proposed to obtain a vaccine that would bypass the need for injection. In this study, a non-toxic portion of heat-stable enterotoxin of Escherichia coli that is capable of adhering to epithelial cells was inserted at amino acid position 112 of hepatitis surface antigen. T...

Lymphocyte function in vivo is dictated by multiple external cues, but the integration of different signals is not well understood. Here, we show that competition for the axis of polarization dictates functional outcomes. We investigated the effect of ligation of the immunoregulatory cell surface receptor, CD46, on lymphocyte polarity during antigen presentation and cytotoxic effector function....

Selected populations of thymus-derived (T) rat lymphocytes having specific immunological reactivity to chosen histocompatibility (H) alloantigens are found among the cellular products of the mixed lymphocyte interaction (MLI). Such specific selection seems to depend on (a) the antigen-induced proliferation of specific H antigen reactive cells (HARC), and (b) the disappearance of nonreactive cel...