In vitro proliferation of lymphocytes from cyclophosphamide-pretreated mice immunized with antigen mixed with dimethyl dioctadecyl ammonium bromide

Induction of T-cell immunity to oligosaccharide antigens immobilized on crystalline bacterial surface layers (S-layers)

Immunization of Balb/c mice with conjugates of oligosaccharide haptens and crystalline bacterial surface-layer proteins (S-layers) primed the mice for a strong, hapten-specific, delayed-type hypersensitivity (DTH) response. Conjugates of haptens with bovine serum albumin produced only weak DTH responses but, when mixed with aluminium hydroxide, elicited DTH responses comparable to those against S-layer conjugates. Surface-layer conjugates also elicited strong anti-hapten DTH responses when administered by an oral/nasal route. Apparently, the natural assembly of S-layer proteins into large, two-dimensional arrays endows them with intrinsic adjuvant properties.

Generation of monoclonal antibodies against a nematode peptide extract: another approach for identifying unknown neuropeptides

Monoclonal antibodies that cross-react with Ascaris neural antigens were generated in mice immunized with a conjugate made with keyhole limpet hemocyanin (KLH) linked to a crude peptide extract from Caenorhabditis elegans. The response to KLH was suppressed by injection of cyclophosphamide 3 days after immunization with a gamma-aminobutyric acid (GABA)-KLH conjugate. Screening of hybridomas was carried out by enzyme-linked immunosorbent assay and whole mount immunocytochemistry. Two similar clones produced antibodies that recognized a small subset of Ascaris neurons. This result suggests that the monoclonal antibody technique might be useful for identifying new neuropeptides since the antibodies can be used for localization of the neuropeptidelike substances and, potentially, for immunoaffinity chromatography. As a by-product of this experiment, monoclonal antibodies that recognize GABA-like immunoreactivity in whole mounts and plastic sections were also obtained.

T-cell recognition of measles virus haemagglutinin studied in a mouse model

BALB/c mice were pretreated with cyclophosphamide and immunized 2 days later with inactivated, purified measles virus (MV) mixed with dimethyl dioctadecyl ammonium bromide (DDA). Seven days later, lymph nodes (LN) were removed and lymphocytes cultured in the presence of purified MV antigens. MV haemagglutinin (H) was found to be a major antigen responsible for proliferation of the lymphocytes. Incorporation of purified H into liposomes significantly enhanced the proliferative response compared with purified H alone. Response to MV nucleocapsid protein was only moderate, and insertion of this protein into liposomes did not improve the response. As an attempt to analyse T-cell epitopes of MV H, three synthetic peptides previously found to elicit a strong antibody response were used both as priming and stimulating antigens. None of the peptides was able to elicit a secondary response when MV-primed LN cells were stimulated in vitro. However, each peptide primed T cells for a secondary challenge with purified, inactivated MV, which was demonstrated by proliferation and a delayed-type hypersensitivity assay and also by transfer experiments with peptide-primed cells.

T cell cross-reactivity among viruses of the paramyxoviridae

Blastogenesis and delayed-type hypersensitivity assays were used to examine mouse T cell responses to five viruses representing the three genera of the Paramyxoviridae. Cross-reactive T cell responses were observed in a lympho-proliferative assay for measles, mumps, respiratory syncytial, canine distemper and parainfluenza type 3 virus. Confirmation of T cell cross-reactivity among measles, mumps and respiratory syncytial virus was obtained with a delayed-type hypersensitivity test. These results show that T cell cross-reactivity is common for Paramyxoviridae viruses, even though these viruses show virtually no inter-genus antibody cross-reactivity. The cross-reactivity among respiratory syncytial, measles and mumps virus at the T cell level may have implications for usage of the attenuated measles/mumps/rubella (MMR) vaccine. Respiratory syncytial virus is contacted by many children before they receive the MMR vaccine and T cells induced by respiratory syncytial virus may influence subsequent development of immunity to measles and/or mumps virus.