Most Japanese individuals are genetically predisposed to recognize an immunogenic protein fragment shared between COVID-19 and common cold coronaviruses

In the spring of 2020, we and others hypothesized that T cells in COVID-19 patients may recognize identical protein fragments shared between the coronaviruses of the common cold and COVID-19 and thereby confer cross-virus immune memory. Here, we look at this issue by screening studies that, since that time, have experimentally addressed COVID-19 associated T cell specificities. Currently, the identical T cell epitope shared between COVID-19 and common cold coronaviruses most convincingly identified as immunogenic is the CD8+ T cell epitope VYIGDPAQL if presented by the MHC class I allele HLA-A*24:02. The HLA-A*24:02 allele is found in the majority of Japanese individuals and several indigenous populations in Asia, Oceania, and the Americas. In combination with histories of common cold infections, HLA-A*24:02 may affect their protection from COVID-19.

Effect of β-alanine on humoral immune response in low-dose allergy model

At the present time, the efforts of many research groups around the world are aimed at finding new factors triggering the allergic sensitization process linked with IgE synthesis to harmless allergens. According to the recent data, production of tissue cytokines is induced in tissue cells by alarmins, thus, in turn, eliciting pro-allergic immune response. Previously we have shown that β-alanine could be a potential alarmin capable to stimulate production of tissue cytokines. The aim of this work was to determine the impact of β-alanine on humoral immune response in low-dose allergy model. BALB/c mice were immunized by recombinant Asp f 2 protein or commercial ovalbumin (OVA) in the withers 3 times a week with or without β-alanine supplementation. To determine the mechanism of β-alanine effect, α-L-alanine, an isomer which is not MrgD receptor ligand, and β-aminoisobutyrate with β-alanine-like affinity to MrgD ligand, were compared. According to our data, β-alanine stimulated specific IgE and IgG1 production in a short-term course (7 immunizations) and enhanced antibody affinity after long-term (14 immunizations) protocol in the case of low-immunogenic protein Asp f 2. In the case of high-immunogenic OVA protein, the impact of β-alanine was significant only upon antibody affinity. Hence, β-alanine accelerates specific IgE production in the case of low-immunogenic protein. The impact of β-alanine on specific IgE production was not linked to specific MrgD receptor activation, because β-aminoisobutyrate, which is the other ligand of this receptor, did not have a similar effect upon humoral immune response. The effect of β-alanine on IgG1 production seems also independent of MrgD receptor, since the common proteinogenic amino acid α-L-alanine also enhanced specific IgG1 production. The effect of β-alanine on humoral immune response could be linked to its non-specific action, e.g., due to its ability to induce oxidative stress through blocking taurine transporter, or due to its ability to stimulate cellular metabolism.

PURIFIKASI PROTEIN IMUNOGENIK 31 DAN 56 kDa DARI KELENJAR SALIVA Aedes aegypti

Purification of 31 and 56 kDa Immunogenic Proteins from the Salivary Glands of Aedes aegyptiThe salivary gland of arthropod vector contains various bioactive compounds and plays a role in the transmission of pathogens to the host. The host develops anti-salivary antibodies against vector saliva exposure. Our previous research has identified two immunogenic proteins with molecular weights of 31 and 56 kDa from the Aedes aegypti salivary gland protein extract. However, the role of the 31 and 56 kDa immunogenic proteins from saliva Ae. aegypti is not fully known, so it is necessary to purify two immunogenic protein fractions to better specify the target of developing a dengue vaccine. This study aimed to purify the 31 and 56 kDa immunogenic protein fractions by electroelution and dialysis methods. The purification of the two protein fractions has been successful which were confirmed by the SDS-PAGE by the existence of single-band parallel to the positive control. These results were further supported by the dot blot analysis which showed a positive reaction in the form of dark spots in the two protein fractions which were reacted with dengue patients' serum, endemic healthy people, and neonates. These results indicated that the purified 31 and 56 kDa immunogenic protein fraction can be identified by specific antibodies.Keywords: dialysis, electroelution, immunogenic, purification, saliva  ABSTRAKKelenjar saliva vektor arthropoda mengandung berbagai senyawa bioaktif dan berperan dalam transmisi patogen ke tubuh inang. Tubuh inang mengembangkan antibodi anti-saliva terhadap paparan saliva vektor. Penelitian kami sebelumnya telah mengidentifikasi dua protein imunogenik dengan berat molekul 31 dan 56 kDa dari ekstrak protein kelenjar saliva Aedes aegypti. Namun demikian, peranan protein imunogenik 31 dan 56 kDa dari saliva Ae. aegypti belum diketahui sepenuhnya sehingga perlu dilakukan purifikasi dua fraksi protein imunogenik untuk lebih menspesifikkan target pengembangan vaksin dengue. Tujuan penelitian ini untuk melakukan purifikasi fraksi protein imunogenik 31 dan 56 kDa melalui metode elektroelusi dan dialisis. Keberhasilan purifikasi dua fraksi protein 31 dan 56 kDa terbukti dari hasil konfirmasi SDS-PAGE dengan terbentuknya pita tunggal sejajar dengan kontrol positif. Hasil tersebut diperkuat dengan analisis dot blot yang menunjukkan reaksi positif dengan munculnya noktah gelap pada dua fraksi protein tersebut ketika direaksikan dengan serum pasien DBD, penduduk sehat endemik dan neonatus. Hasil ini mengindikasikan bahwa fraksi protein imunogenik 31 dan 56 kDa hasil purifikasi dapat dikenali oleh antibodi spesifik.

Mating with immunised male mice affects the phenotype of adult progeny

The life-history theory suggests that parental experience of the environment is passed to offspring, which allows them to adapt to prevailing conditions. This idea is supported from the mother’s side, but to a much less extent from the father’s side. Here, we investigated the effect of immunising fathers on pre- and neonatal development and on immune and neuroendocrine phenotypes of their offspring in C57BL/6J mice. Nine days before mating, fathers were intraperitoneally injected with the immunogenic protein keyhole limpet hemocyanin (KLH). Females mated with immunised males had less pre-weaning mortality of newborns compared to those mated with control males. Although the antibody response to KLH was similar for the male offspring of control and immunised fathers, the mass indexes of their main immune organs and their androgen response differed significantly. The mass indexes of the thymus and spleen in adult male offspring of immunised fathers were higher compared with the control offspring. The plasma testosterone levels were significantly decreased after KLH administration in the male offspring of control but not of immunised fathers. This was correlated with changes in sperm average path and straight-line velocities. Finally, excitatory neurotransmitters prevailed over inhibitory ones in the amygdala of the progeny of immunised fathers, while in control offspring, the opposite occurred. This is indicative of complex behavioural changes in the offspring of immunised fathers, including sexual ones. Therefore, the paternal experience of foreign antigens modulates the immune and neuroendocrine systems of their progeny, suggesting possible survival and reproductive adaptations to parasitic pressure.