Peptide immunization excludes antigen-specific T cells from splenic lymphoid compartments.

Using adoptive transfer of TCR-transgenic T cells, we examined the homing of transgenic T cells to splenic compartments in situ. After systemic immunization with peptide or protein antigen, the location of clonotypic T cells, cytokine production, cell surface markers, and apoptosis were assessed. There were distinct differences in the splenic homing of CD4(+) TCR-transgenic T cells in mice immunized with peptide as compared to mice immunized with whole-protein antigen.

Organ-specific cytokine polarization induced by adoptive transfer of transgenic T cells.

There are two distinct phenotypes of T cell cytokine responses that lead to different effector functions and different outcomes in disease processes. Although evidence suggests a possible role of the local microenvironment in the differentiation or localization of T cells with these phenotypes, there are no examples of divergent T cell cytokine phenotypes with the same Ag specificity concurrently existing in different tissue compartments. Using a CD8(+) T cell adoptive transfer model for graft-vs-host disease, we demonstrate that a potent type 2 cytokine response develops in the spleen while a potent type 1 cytokine response simultaneously develops in the testis.

CD43 polarization in unprimed T cells can be dissociated from raft coalescence by inhibition of HMG CoA reductase.

Movement of T-lymphocyte cell surface CD43 is associated with both antigen activation of T-cell clones and chemokine induction of T-lymphocyte motility. Here, we demonstrate that CD43 movement away from the site of T-cell receptor ligation occurs in unprimed CD4(+) T cells as well as T-cell clones. The T-cell receptor (TCR)-dependent movement of CD43 in unprimed T cells is associated with a polarized morphology and CD43 accumulation at the uropods of the cells, unlike that reported for primed T cells.

Use of a quantitative product-enhanced reverse transcriptase assay to monitor retrovirus levels in mAb cell-culture and downstream processing.

Murine hybridoma cells used in the production of monoclonal antibodies (mAb's) produce endogenous type C retrovirus particles. Regulatory agencies require a demonstration that mAb's intended for human use are free of retrovirus with an adequate margin of safety. This is usually achieved by validation studies, performed at small scale, to demonstrate that the manufacturing process is capable of removing or inactivating several different model viruses, including a murine retrovirus.

Synthetic peptides representing T-cell epitopes act as carriers in pneumococcal polysaccharide conjugate vaccines.

Improvement of antibody responses to polysaccharides through their linkage to proteins is thought to be mediated by protein-specific T helper (Th) cells. To investigate whether the carrier protein of a conjugate could be substituted by a Th epitope, Streptococcus pneumoniae type 17F polysaccharide (PS) was bromoacetylated and coupled to different peptides via their carboxy-terminal cysteines. Two peptides, one from the mycobacterial 65-kDa heat shock protein (hsp65) and the other from influenza virus hemagglutinin, are well-known Th epitopes.