Are the integrin binding motifs within SARS CoV-2 spike protein and MHC class II alleles playing the key role in COVID-19?

The previous studies on the RGD motif (aa403-405) within the SARS CoV-2 spike (S) protein receptor binding domain (RBD) suggest that the RGD motif binding integrin(s) may play an important role in infection of the host cells. We also discussed the possible role of two other integrin binding motifs that are present in S protein: LDI (aa585-587) and ECD (661-663), the motifs used by some other viruses in the course of infection. The MultiFOLD models for protein structure analysis have shown that the ECD motif is clearly accessible in the S protein, whereas the RGD and LDI motifs are partially accessible.

Reproductive immunology in viviparous mammals: evolutionary paradox of interactions among immune mechanisms and autologous or allogeneic gametes and semiallogeneic foetuses.

Literally, reproductive immunology was born in bovine on-farm reproduction where seminal experiments intended for developing methods for embryo transfer in cattle were performed. Actually, these experiments led to two of major concepts and fundamental principles of reproductive immunology using the bovine species as a model for biomedical research, namely the concept of acquired immunological tolerance and the paradox of the semiallogeneic bovine foetus whereby such organism can develop within an immunologically competent host. Peter Medawar, a scientist who together with Frank Macfarlande Burnet shared the 1960 Nobel Prize in physiology or medicine for discovery of acquired immunological tolerance, while studying dizygotic cattle twins, thereby giving birth to reproductive immunology.

Evaluation of the cellular immune responses induced by a non-adjuvanted inactivated whole virus A/H5N1/VN/1203 pandemic influenza vaccine in humans.

In the present study the homologous and heterologous type and subtype specific cellular immune response induced by a wild type inactivated whole virus H5N1 Influenza (A/Vietnam/1203/2004) vaccine was evaluated. Two immunizations with the Vero cell derived H5N1 influenza vaccine on Day 0 and Day 21 induced significant H5N1 vaccine specific and H5 haemagglutinin specific clade and cross-clade reactive CD4(+) T cell responses, which were maintained at significant levels for at least 6 months. The H5N1 vaccine specific response cross-reacted with the H1N1, but not with H3N2 or B seasonal Influenza strains.

Nonreplicating vaccinia virus vectors expressing the H5 influenza virus hemagglutinin produced in modified Vero cells induce robust protection.

The timely development of safe and effective vaccines against avian influenza virus of the H5N1 subtype will be of the utmost importance in the event of a pandemic. Our aim was first to develop a safe live vaccine which induces both humoral and cell-mediated immune responses against human H5N1 influenza viruses and second, since the supply of embryonated eggs for traditional influenza vaccine production may be endangered in a pandemic, an egg-independent production procedure based on a permanent cell line. In the present article, the generation of a complementing Vero cell line suitable for the production of safe poxviral vaccines is described.