Gizem Aytoğu

Background/Objectives: Transfusion-Related Immunomodulation (TRIM) is a complex biological phenomenon that develops following allogeneic blood transfusions. Exosomes released from stored red blood cell concentrates (RBC) may be a potential mediator of TRIM. This study aims to analyze the effects of exosomes on T cell proliferation and regulatory T cell (Treg) differentiation. Methods: RBC concentrates obtained from six healthy donors were divided into non-leukoreduced (NR) and leukoreduced (LR) units. Exosomes were isolated from these RBCs by ultracentrifugation. Allogeneic and autologous exosome pools were prepared. Peripheral blood mononuclear cells (PBMCs) were cultured with exosome pools (with 0.2, 1, or 5 μg doses) under allogeneic or autologous conditions. T-cell proliferation and Tregs were assessed by flow cytometry. Results: Total exosomal protein content increased during storage, with significantly higher levels in NR-RBC derived exosomes (NR-Exo) than LR-RBC derived exosomes (LR-Exo). NR-Exos significantly enhanced both CD4⁺ and CD8⁺ T cell proliferation, predominantly in allogeneic cultures. The proliferative effect was observed at different doses. In contrast, exosome treatment did not promote expansion of Treg populations. Instead, autologous cultures demonstrated reduced frequencies of CD8⁺ Tregs and CD39-expressing Tregs, whereas allogeneic cultures showed minimal changes. Moreover, leukoreduction attenuated exosome-mediated T-cell proliferation. Conclusions: RBC-Exos preferentially enhance effector T cell proliferation under allogeneic conditions, particularly when isolated from NR-RBC units. Tregs tended to decrease in both the autologous and leukoreduced groups. These findings suggest that RBC-Exos support both immunosuppressive effects and immune activation. However, the characteristics of the RBC and the transfusion (allogeneic/autologous and leukoreduced/non-leukoreduced) are considered the key factors in observing these effects.

Background Bovine enteroviruses (BEVs) are widely distributed among cattle worldwide and are commonly associated with subclinical infections, although their role in enteric, respiratory, and reproductive disorders remains incompletely understood. BEVs infect cattle as their natural host and are currently classified mainly within the species Enterovirus E and Enterovirus F. The advancement of virological research conducted as part of the elimination study may be affected by the concurrent circulation of enteric viruses, including BEV, in cattle populations. During a non-cytopathogenic BVDV elimination study, cytopathogenic agents unrelated to BVDV were incidentally detected and subjected to conventional virological and molecular identification. Methods and results For analysis, rectal and nasal swab samples were taken from 4 cattle showing mild respiratory symptoms on a farm, as well as blood samples from a total of 42 animals, including those that showed signs of contact. The cytopathogenic effect was detected in the Madin-Darby bovine kidney (MDBK) cell line by cultivation of fecal specimens. Two isolates were obtained and subjected to physicochemical characterization and determination of nucleic acid type. The fecal isolates were analyzed by RT-PCR using specific primers for possible key pathogens. The isolates showed resistance to chloroform and BrdU treatment, findings consistent with the characteristics of non-enveloped RNA viruses. Both isolates were positive in bovine enterovirus RT-PCR, and the molecular genetic analysis of the partial 5’UTR region of one of the isolates indicated that it belonged to the BEV-F clade. All 42 serum samples showed neutralizing activity at a dilution of ≥ 1:640 against the isolate used in the VNT. Conclusion This study, based on partial 5′UTR sequence analysis, provides preliminary molecular evidence of a bovine enterovirus associated with EV-F in Türkiye. Given the limited number of studies conducted in Türkiye, these findings could lead to more comprehensive molecular characterization and epidemiological investigations. Although BEVs are not routinely prioritized in diagnostic screening panels for cattle, the incidental detection of cytopathogenic BEV isolates, together with the high seropositivity rate observed among in-contact animals, suggests that BEVs should be considered in virological investigations.

Bovine viral diarrhea virus continues to threaten animal health with serious economic losses worldwide. Various killed, live-modified, or recombinant vaccine strategies are being developed for protection and control against this virus. The most important thing discovered is the choice of local and widespread strains in the vaccine content. In this study, the effectiveness of a Montanide^® ISA 206 adjuvanted killed trivalent vaccine containing endemic local strains (TR-21 [BVDV-1l], TR-26 [BVDV-1f], and TR-15 [BVDV-2b]) isolated from Türkiye, was evaluated with a cattle challenge study. Experimental groups were designed as single dose vaccination (Group-I, n:11), two dose vaccination (Group-II, n:11), and unvaccinated (Group-III, n:6) with male calves aged about 6 months. Following the immunization, challenge virus (TR-72 [BVDV-1l], TCID₅₀ 10^6.5) was given intranasally to each group (5 animals in Group-I and II and 4 animals in Group-III), and clinical findings, hematological changes, virus shedding, side effects, and viremia were monitored for 14 days after inoculation. Serological monitoring of the remaining animals against homologous and heterologous strains was carried out at one-month intervals between the 21st and 201st days after the first vaccination. The obtained results showed that the viremia, hematological changes, and clinical findings shown in unvaccinated animals (Group-III) were significantly suppressed (p < 0.05) in the vaccinated groups (Group-I and II). In addition, it was found that serologically monitored animals maintained protective neutralizing antibody (nAb) titers ≥ 8 log₂ for vaccinal and also for all reference BVDV-1 strains, which is more than three-fold protective antibody response, lasting more than 7 months after the first vaccination, whether in single or two dose application. The rise of nAbs was also detected for heterogous BVDV strains. The detected nAb titers were significantly higher (p < 0.05) in the two dose vaccination group. Based on the results, it was concluded that this trivalent- inactivated vaccine candidate can protect cattle against acute BVDV infections.

Investigations on advance effects of boron-containing compounds have gained attention the last decade. This study was carried out to investigate the effect of hexagonal boron nitride nanoparticles (BNNPs) on Bovine Coronavirus (BCoV) and Staphylococcus aureus (S. aureus) by different methods. First, biological effects of different BNNPs concentrations lower than 0.5 mg/mL examined on HRT-18 (Human Rectal Tumor) for 5 days. Different concentrations of hBN mixed with BCoV in liquid, on membrane or directly on cells and examined for differences of titers or replications. And also Bacterial Filtration Efficiency (BFE) test of hBN powders coated on polypropylene fabric by spray method was applied against S. aureus. The compound was found slightly toxic on the HRT-18 cell line by live cell counting, while no remarkable morphological difference was observed. BNNPs treatment with 0.025 or 0.3mg/mL concentrations did not reduce the infective titer and create no inhibitory effect on in vitro replication. Stability of virus titer after treatment of BNNPs coated fabric also indicated no antiviral efficiency. But hBN applied fabric formed a barrier of ≥90.3%, while non hBN applied fabric formed ≥64.6% barrier. The present study demonstrate that, BNNPs alone is not a good candidate for disinfectant or drug for BCoVs, while it could be valuable to use as coated fabric in the areas needing easy sanitation especially for S. aureus.

Restriksiyon Parça Uzunluk Polimorfizmi (RFLP) tekniği kullanılarak tüm genomun analizinde Bovine Herpesviruses-1 (BoHV-1) suşlarını BoHV-1.1, 1.2a, 1.2b olmak üzere üç alt tipte sınıflandırılmaktadır. Bu alt tipler klinik bulgular göre de değerlendirilmektedir ancak bu yönde henüz net bir ilişkilendirme yapılmamıştır. Çoğunlukla BoHV-1.2b, genital hastalık bulgularıyla ilişkilendirilmektedir. Bu çalışmada solunum yolu hastalığından alınan nazal sürüntü örneğinde BoHV-1 izolatı elde edilmiştir. Bu çalışmada ayrıca, genomun UL44 (Glikoprotein C) bölgesini hedefleyen filogenetik analiz ve UL39 - US3 bölgelerini hedefleyen, yeni geliştirilen bir multipleks PCR analizini takiben Hind III enzimi kullanılarak uygulanan RFLP ile alt tiplendirme gerçekleştirilmiştir. Aynı zamanda izolasyon başarısı iki farklı devamlı hücre hattında karşılaştırılmıştır. SFT-R hücre hattı, BoHV-1 saha örneklerinin izolasyonunda MDBK hücre hattına nazaran daha duyarlı bulunmuştur. Elde edilen izolat (ID:8640), BoHV-1.2b olarak sınıflandırılırken, Cooper suşundan serolojik olarak ayırt edilemediği değerlendirildi. Mevcut çalışma, BoHV-1.2b'nin Türkiye'deki ilk izolasyonunu bildirmesinin yanı sıra klinik solunum yolu hastalığından nadir tespit edilen BoHV-1.2b izolasyonunu bildirmektedir. Sonuçlar ayrıca kolay ve hızlı alt tipleme için PCR tabanlı RFLP analizinin etkinliğini gösteren veriler içermektedir. Ancak BoHV-1 saha izolatlarının genetik çeşitliliğine bağlı olarak bu teknik üzerine daha fazla araştırma yapılmasına ihtiyaç duyulmaktadır.

This study reports the high prevalence and molecular characterization of BoHV-1 infection in imported cattle with respiratory system disease after international transport. A high mortality rate of 14.16% (51/360) was reported in a group of animals imported from Hungary to Turkey in 2019. A total of 17 samples were evaluated (3 lung tissue and 14 nasal swab samples) from 15 cattle aged 6 to 9 months not vaccinated against BoHV-1. Virus isolation, polymerase chain reaction (PCR) and restriction endonuclease analysis (REA) procedures were performed within the scope of this study. By virus isolation in MDBK cells, cytopathologic effects was detected in 8 samples (3 lung tissue and 5 nasal swabs samples). The same eight samples were also found positive by BoHV-1 PCR targeting gC (UL44) gene region. According to the sequencing result, the sample (ID: 10054) dropped into a cluster of BoHV-1.1. The REA was applied to the samples to confirm the results of phylogenetic analysis. All of the isolates were identified in the subgroup BoHV-1.1 by REA. These results showed a high mortality risk for imported animals and the possibility for BoHV-1 entering the receiving country via imported animals after transport. This event is a serious problem both for the control of BoHV-1 as well as for animal health and welfare.

Pigs are the main host species for the pseudorabies virus, while it causes fatal encephalitis in many species including human being. The objective of this article is to report the first clinical case of pseudorabies as well as isolation and molecular characterization of the virus from a hunting dog in Bursa province, Turkey. The dog showing clinical signs including pruritus and neurological signs as stumbling and inability to stand up compatible with pseudorabies. The virus isolate was obtained from supernatant of fresh tissue samples from cerebellum, cornu ammonis, spleen, salivary gland, and conjunctival swab, as well as serum, and buffy coat samples. The glycoprotein C region is targeted for viral DNA amplification. Pseudorabies virus genome was detected both in fresh tissues and supernatants of 3^rd passage on Vero cells. Number of PCR positive samples were dramatically increased after having cell culture inoculations. Genome sequencing revealed that the strain (Bursa-10303) isolated in Turkey where a non-endemic area is for the virus is dropped into clade A. This study confirms the presence of psedorabies infection in the wild life reservoirs in Turkey. Future studies may clarify the importance of the infection for Turkey where there is no common pig production.

Bovine viral diarrhea virus (BVDV) is a globally-distributed agent responsible for numerous clinical syndromes that lead to major economic losses. Two species, BVDV-1 and BVDV-2, discriminated on the basis of genetic and antigenic differences, are classified in the genus Pestivirus within the Flaviviridae family and distributed on all of the continents. BVDV-1 can be segregated into at least twenty-one subgenotypes (1a–1u), while four subgenotypes have been described for BVDV-2 (2a–2d). With respect to published sequences, the number of virus isolates described for BVDV-1 (88.2%) is considerably higher than for BVDV-2 (11.8%). The most frequently-reported BVDV-1 subgenotype are 1b, followed by 1a and 1c. The highest number of various BVDV subgenotypes has been documented in European countries, indicating greater genetic diversity of the virus on this continent. Current segregation of BVDV field isolates and the designation of subgenotypes are not harmonized. While the species BVDV-1 and BVDV-2 can be clearly differentiated independently from the portion of the genome being compared, analysis of different genomic regions can result in inconsistent assignment of some BVDV isolates to defined subgenotypes. To avoid non-conformities the authors recommend the development of a harmonized system for subdivision of BVDV isolates into defined subgenotypes.