Inhibition of fibrin polymerization by synthetic peptides corresponding to Aα195-205 and γ69-77 sites of fibrin molecule.

Using the idea of "proline brackets" we have found four sites in fibrin amino acid sequence, and appropriate peptides were synthesized: γ69NPDESSKPN77, Bβ228QPDSSVKPY236, Bβ455RPFFPQ460 and Aα195LPSRDRQHLPL205. Turbidity and electron-microscopy analyses have demonstrated that synthetic peptide Aα195-205 specifically inhibited the stage of fibrin protofibril formation and peptide γ69-77 - the stage offibrin protofibril lateral association. The data obtained testify that there are the sites involved in these processes in the appropriate amino acid sequences of fibrin molecule.

Functional role of Bbeta-chain N-terminal fragment in the fibrin polymerization process.

Four mAbs of the IgG(1) class to the thrombin-treated N-terminal disulfide knot of fibrin, secreted by various hybridomas, have been selected. Epitopes for two mAbs, I-3C and III-10d, were situated in human fibrin fragment Bbeta15-26, and those for two other mAbs, I-5G and I-3B, were in fragment Bbeta26-36. Three of these mAbs, I-5G, I-3B and III-10D, as well as their Fab-fragments, decreased the maximum rate of fibrin desAA and desAABB polymerization up to 90-95% at a molar ratio of mAb (or Fab-fragment) to fibrin of 1 or 2.

Two monoclonal antibodies to D-dimer-specific inhibitors of fibrin polymerization.

D-dimer of human fibrin was used as antigen to obtain monoclonal antibodies (mAbs). We have obtained 16 hybridomas producing mAbs of different specificity. Only two of these mAbs inhibited fibrin polymerization.

Two-color flow cytometric analysis of natural killer and cytotoxic T-lymphocyte subsets in peripheral blood of normal human neonates.

It has been demonstrated that normal human newborns had significantly lower percentages of CD8+, CD11b+, CD16+ and CD56+, compared to adults, while no differences had been noted for the absolute numbers of these cells. Both the proportions and absolute numbers of CD57+ lymphocytes and cytotoxic T cells that mediate non-MHC-restricted cytotoxicity (CD3+CD56+) were markedly reduced in neonatal blood. Mean proportions but not absolute numbers of precursors and effectors of allocytotoxic T cells (CD8+CD11b-) significantly decreased in human neonates.

Mucosal immunity of the mammary gland and immunology of mother/newborn interrelation.

Mammary gland is assumed to function as a part of the common mucosal immune system. Lymphocytes observed in the mammary gland derived their origin from precursor immunocompetent cells presented in BALT and GALT. In relation to local immunity of the other sites of the mucosal membranes, lymphocytes homing to the mammary gland are regulated by lactogenic hormones.

Interaction of positively charged liposomes with erythrocyte membrane. An ultrastructural study.

Structural perturbations of positively charged sonicated liposomes (L) induced by incubation with human erythrocytes have been studied by thin-section electron microscopy. It has been found that just after mixing with cells L bind to cell surfaces and fuse with each other, first forming larger L and then flattened multilamellar structures. Successive fusion events occurring in the latter result in a reduced number of bilayers which gradually comes to a single one.