Ixodid ticks remain attached to their hosts for several days to weeks. During this extended feeding process new proteins involved in the modulation of host immune responses are expressed in tick salivary glands. In our study a stimulatory or inhibitory effect of salivary gland extracts (SGE) of unfed and partially fed female Ixodes ricinus (Linnaeus, 1758), female and male Amblyomma variegatum ...

These studies were done to characterize the cellular requirements for B-lymphocyte responses to the haptenated polysaccharide trinitrophenyl-conjugated Ficoll. By using an in vitro microculture system, it was demonstrated that hapten-specific anti-trinitrophenyl-conjugated Ficoll plaque-forming cell responses by B lymphocytes require Ia-bearing adherent accessory cells and Thy 1+ Lyt 1+2- nylon...

We have compared the lymphocyte in vitro proliferative response induced by muscle extract, phytohaemagglutinin, and pokeweed mitogen in peripheral blood lymphocytes of patients with myasthenia gravis, polymyositis, dermatomyositis, and normal subjects. Similar mean responses to antigen and mitogen were seen in cells of all groups of patients. The proliferative responses induced by muscle did no...

Cell-mediated immune responses to chlamydial and common recall antigens were measured in 26 subjects whose clinical signs of trachoma persisted over 6 months of follow-up and in 21 subjects whose clinical signs resolved spontaneously over the same period. Seven-day lymphocyte proliferative responses to chlamydial but not common recall antigens were significantly greater in subjects whose diseas...

Young MRL/MPJ-lpr (lpr) mice 8-12 wk old challenged with alloantigen had significantly lower specific cytolytic T lymphocyte (CTL) responses than control MRL/MPJ +/+ mice. Serum from lpr mice compared with serum from ++ or normal C3H mice powerfully suppressed CTL responses in mixed lymphocyte cultures (MLC); absorbing lpr serum on protein G, adding antibody against transforming growth factor b...

Ehrlichia canis is an intracellular pathogen that causes canine monocytic ehrlichiosis. Although the role of antibody responses cannot be discounted, control of this intracellular pathogen is expected to be by cell mediated immune responses. The immune responses in dogs immunized with inactivated E. canis organisms in combination with Quil A were evaluated. Immunization provoked strong humoral ...

BACKGROUND Allergic asthma is a common childhood disease. Although T-lymphocyte activation plays a critical role in allergic asthma, the environmental factors promoting lymphocyte activation in children are not well defined. OBJECTIVE In a cohort of children at risk for asthma (n = 114), we determined whether the levels of cockroach (Bla g 1 or 2), house dust mite (Der f 1), and cat allergen ...

The leukocyte integrin LFA-1 (CD11a/CD18) plays an important role in lymphocyte recirculation and homotypic interactions. Leukocytes from mice lacking CD11a displayed defects in in vitro homotypic aggregation, in proliferation in mixed lymphocyte reactions, and in response to mitogen. Mutant mice mounted normal cytotoxic T cell (CTL) responses against systemic LCMV and VSV infections and showed...

Young MRL/MPJ-Ipr (1pr) mice 8-12 wk old challenged with alloantigen had significantly lower specific cytolytic T lymphocyte (CTL) responses than control MRL/MPJ +/+ mice. Serum from lpr mice compared with serum from + + or normal C3H mice powerfully suppressed CTL responses in mixed lymphocyte cultures (MLC); absorbing lpr serum on protein G, adding antibody against transforming growth factor ...