Novel Antibody for the Treatment of Transthyretin Amyloidosis.

Familial amyloidotic polyneuropathy (FAP) is a systemic amyloidosis mainly caused by amyloidogenic transthyretin (ATTR). This incurable disease causes death ∼10 years after onset. Although it has been widely accepted that conformational change of the monomeric form of transthyretin (TTR) is very important for amyloid formation and deposition in the organs, no effective therapy targeting this step is available. In this study, we generated a mouse monoclonal antibody, T24, that recognized the cryptic epitope of conformationally changed TTR. T24 inhibited TTR accumulation in FAP model rats, which expressed human ATTR V30M in various tissues and exhibited non-fibrillar deposits of ATTR in the gastrointestinal tracts. Additionally, humanized T24 (RT24) inhibited TTR fibrillation and promoted macrophage phagocytosis of aggregated TTR. This antibody did not recognize normal serum TTR functioning properly in the blood. These results demonstrate that RT24 would be an effective novel therapeutic antibody for FAP.

Facial nerve reconstruction using a vascularized lateral femoral cutaneous nerve graft based on the superficial circumflex iliac artery system: an application of the inferolateral extension of the groin flap.

The use of an inferolateral extension technique of a groin flap has previously been reported. This technique involves harvesting an extended portion from the anterolateral thigh, including the lateral femoral cutaneous nerve (LFCN) and its accompanying vessels, attached to a groin flap via communications between the LFCN-accompanying vessels and the superficial circumflex iliac artery (SCIA) system. In this study, we used this technique involving a vascularized LFCN combined with a groin flap to reconstruct a facial nerve defect. The patient was a 58-year-old man with a salivary duct carcinoma in the left parotid gland. Tumor ablation resulted in a defect of the skin and soft tissue including all branches of the facial nerve. A free groin flap was harvested based on the SCIA system, composed of the LFCN and a small monitoring flap, which were nourished by the LFCN-accompanying vessels and by communication with the SCIA system. The LFCN was transplanted into the gaps in the facial nerve branches as a cable graft, and the skin flap was used to cover and fill the soft tissue defect. The postoperative course was uneventful and satisfactory facial animation was obtained. This represents a possible technique for nerve reconstruction using a vascularized nerve graft.

A novel monoclonal antibody cross-reactive with both human and mouse α9 integrin useful for therapy against rheumatoid arthritis.

This study introduces a novel monoclonal anti-α9 integrin antibody (MA9-413) with human variable regions, isolated by phage display technology. MA9-413 specifically binds to both human and mouse α9 integrin by recognizing a conserved loop region designated as L1 (amino acids 104-122 of human α9 integrin). MA9-413 inhibits human and mouse α9 integrin-dependent cell adhesion to ligands and suppresses synovial inflammation and osteoclast activation in a mouse model of arthritis. This is the first monoclonal anti-α9 integrin antibody that can react with and functionally inhibit both human and mouse α9 integrin. MA9-413 allows data acquisition both in animal and human pharmacological studies without resorting to surrogate antibodies. Since MA9-413 showed certain therapeutic effects in the mouse arthritis model, it can be considered as a useful therapy against rheumatoid arthritis and other α9 integrin-associated diseases.

Base of molecular mimicry between human ribosomal protein S19 dimer and human C5a anaphylatoxin.

The crosslinked homodimer of human ribosomal protein S19 (hRP S19) but not hRP S19 monomer shares the hC5a receptor ligation capacity with anaphylatoxin hC5a. The hRP S19 dimer engages hC5a receptor-bearing monocytes in chemotactic movement and secretion as does hC5a. Two submolecular regions essential for the receptor ligation were already identified in hRP S19 as well as in hC5a. Using the tertiary structure data base of an archaeobacterial RP S19 as template, we made a tertiary structure model of hRP S19. The obtained structure was almost entirely α-helical with two short ß-sheet regions, and folds a five α-helix bundle organized around a central amphipathic α-helix. While the secondary structure components were similar to those of hC5a, the gross tertiary structure of hRP S19 was loose and the distance between the two receptor binding regions was rather big in comparison to that of hC5a. Anti-recombinant hC5a rabbit antibodies cross-recognized not only the crosslinked hRP S19 dimer but also the guinea pig (gp) RP S19 dimer, however, these antibodies reacted hRP S19 monomer and crosslinked Gln137Asn-hRP S19 mutant dimer at significantly less extents. These antibodies neutralized the monocyte attracting capacity of the hRP S19 dimer in vitro and that of the gpRP S19 dimer in vivo. We assume that the crosslinkage between Lys122 of one hRP S19 molecule and Gln137 of the other one would assemble the hC5a-like structure probably providing one of two receptor binding regions by each hRP S19 subunit.

Inferolateral extension of the groin flap based on the artery accompanying the lateral femoral cutaneous nerve.

The authors reconstructed hand defects using a new type of the extended groin flap in two patients. The extended portion includes the lateral femoral cutaneous nerve (LFCN) and the artery accompanying the LFCN (LFCA). Circulation to the extended portion was maintained by the communicating branches between the LFCA and the superficial circumflex iliac artery (SCIA). The flap was used as a pedicle flap in one patient and as a free flap in the other patient. The extended portion was elevated as an island flap based on LFCA in the latter. These flaps, including the extended portion, were transferred successfully. We have already reported use of the inferior extension of the groin flap based on the descending branch of the SCIA, in 2002. However, the extension technique described here is a different type of extension, due to the use of a different nutrient vessel. We believe that this new technique increases the usefulness of the groin flap.

Anti-V3 humanized antibody KD-247 effectively suppresses ex vivo generation of human immunodeficiency virus type 1 and affords sterile protection of monkeys against a heterologous simian/human immunodeficiency virus infection.

In an accompanying report (Y. Eda, M. Takizawa, T. Murakami, H. Maeda, K. Kimachi, H. Yonemura, S. Koyanagi, K. Shiosaki, H. Higuchi, K. Makizumi, T. Nakashima, K. Osatomi, S. Tokiyoshi, S. Matsushita, N. Yamamoto, and M. Honda, J. Virol. 80:5552-5562, 2006), we discuss our production of a high-affinity humanized monoclonal antibody, KD-247, by sequential immunization with V3 peptides derived from human immunodeficiency virus type 1 (HIV-1) clade B primary isolates. Epitope mapping revealed that KD-247 recognized the Pro-Gly-Arg V3 tip sequence conserved in HIV-1 clade B isolates. In this study, we further demonstrate that in vitro, KD-247 efficiently neutralizes CXCR4- and CCR5-tropic primary HIV-1 clade B and clade B' with matching neutralization sequence motifs but does not neutralize sequence-mismatched clade B and clade E isolates. Monkeys were provided sterile protection against heterologous simian/human immunodeficiency virus challenge by the passive transfer of a single high dose (45 mg per kg of body weight) of KD-247 and afforded partial protection by lower antibody doses (30 and 15 mg per kg). Protective neutralization endpoint titers in plasma at the time of virus challenge were 1:160 in animals passively transferred with a high dose of the antibody. The antiviral efficacy of the antibody was further confirmed by its suppression of the ex vivo generation of primary HIV-1 quasispecies in peripheral blood mononuclear cell cultures from HIV-infected individuals. Therefore, KD-247 promises to be a valuable tool not only as a passive immunization antibody for the prevention of HIV infection but also as an immunotherapy for the suppression of HIV in phenotype-matched HIV-infected individuals.

Sequential immunization with V3 peptides from primary human immunodeficiency virus type 1 produces cross-neutralizing antibodies against primary isolates with a matching narrow-neutralization sequence motif.

An antibody response capable of neutralizing not only homologous but also heterologous forms of the CXCR4-tropic human immunodeficiency virus type 1 (HIV-1) MNp and CCR5-tropic primary isolate HIV-1 JR-CSF was achieved through sequential immunization with a combination of synthetic peptides representing HIV-1 Env V3 sequences from field and laboratory HIV-1 clade B isolates. In contrast, repeated immunization with a single V3 peptide generated antibodies that neutralized only type-specific laboratory-adapted homologous viruses. To determine whether the cross-neutralization response could be attributed to a cross-reactive antibody in the immunized animals, we isolated a monoclonal antibody, C25, which neutralized the heterologous primary viruses of HIV-1 clade B. Furthermore, we generated a humanized monoclonal antibody, KD-247, by transferring the genes of the complementary determining region of C25 into genes of the human V region of the antibody. KD-247 bound with high affinity to the "PGR" motif within the HIV-1 Env V3 tip region, and, among the established reference antibodies, it most effectively neutralized primary HIV-1 field isolates possessing the matching neutralization sequence motif, suggesting its promise for clinical applications involving passive immunizations. These results demonstrate that sequential immunization with B-cell epitope peptides may contribute to a humoral immune-based HIV vaccine strategy. Indeed, they help lay the groundwork for the development of HIV-1 vaccine strategies that use sequential immunization with biologically relevant peptides to overcome difficulties associated with otherwise poorly immunogenic epitopes.