The immunological synapse formed between a T-cell and an antigen-presenting cell is important for cell-cell communication during T-cell-mediated immune responses. Immunological synapse formation begins with stimulation of the T-cell receptor (TCR). TCR microclusters are assembled and transported to the center of the immunological synapse in an actin polymerization-dependent process. However, th...

Much evidence supports the conclusion that immunological responses to donor-specific incompatibilities are a major factor in producing "chronic" transplant rejection, including the arteriopathy (atherosclerosis) commonly present. Our experiments explored the effects of altered immunological responsiveness to these Ags on the formation of arteriopathy in transplanted mouse hearts. Specific immun...

The functional significance of some components of salivary glands and of their secretion and of haemolymph of Amblyomma hebraeum and other tick species is reviewed with respect to host responses at the attachment site, the survival of specific pathogens in the vector, the transmission of pathogens and immunological responses of the host to tick infestation.

DNAX accessory molecule 1 (DNAM-1) is expressed on all CD8(+) T cells and promotes their activation and effector function. DNAM-1 interacts with LFA-1, a critical molecule for immunological synapse formation between T cells and APCs, and for cytotoxic killing of target cells. Mice that lack DNAM-1 display abnormal T cell responses and antitumor activity; however, the mechanism involved is uncle...

The activation of biological T cell responses requires prolonged contact with APCs and sustained signaling. We investigated whether signaling must be uninterrupted to commit T cells to cytokine production or whether T cell activation may also result from summation of interrupted signals. Upon periodic addition and removal of a src kinase inhibitor, human CD4(+) T cells destroyed and re-formed i...

Functional separation of the two signals involved in stimulating immunological responses was achieved through the judicious use of two natural bacterial antigens. Native protoplasmic polysaccharide (NPP) extracted from Escherichia coli was immunochemically identical to the lipopolysaccharide (LPS) extracted from the same organism. However, NPP was not endotoxic, not mitogenic, did not fix compl...

Engineered nanomaterials promise to transform medicine at the bio-nano interface. However, it is important to elucidate how synthetic nanomaterials interact with critical biological systems before such products can be safely utilized in humans. Past evidence suggests that polyethylene glycol-functionalized (PEGylated) nanomaterials are largely biocompatible and elicit less dramatic immune respo...

Since the outbreak of a SARS epidemic last year, significant advances have been made on our understanding of the mechanisms of interaction between the SARS coronavirus (CoV) and the immune system. Strong humoral responses have been found in most patients following SARS-CoV infection, with high titers of neutralizing Abs present in their convalescent sera. The nucleocapsid (N) and spike (S) prot...

Infection of normal calves with bovine virus diarrhoea virus (BVDV) is a transient self-limiting infection that can result in a period of immunosuppression. The virus appears to be able to replicate in all of the major lymphocyte sub-populations as well as in accessory cells. This may result in the leukopenia that is often a sequel of infection and affects B-cells as well as the T-cell sub-popu...