Activation of Dendritic Cells in Tonsils Is Associated with CD8 T Cell Responses following Vaccination with Live Attenuated Classical Swine Fever Virus

Abstract

Classical swine fever (CSF) is a highly contagious disease caused by the classical swine fever virus (CSFV). The live attenuated C-strain vaccine is highly efficacious, initiating protection within several days of delivery. The vaccine strain is detected in the tonsil early after inoculation, yet little is known of the role that tonsillar immune cells might play in initiating protection. Comparing the C-strain vaccine with the pathogenic CSFV Alfort-187 strain, changes in the myeloid cell compartment of the tonsil were observed. CSFV infection led to the emergence of an additional CD163+CD14+ cell population, which showed the highest levels of Alfort-187 and C-strain infection. There was also an increase in both the frequency and activation status (as shown by increased MHC-II expression) of the tonsillar conventional dendritic cells 1 (cDC1) in pigs inoculated with the C-strain. Notably, the activation of cDC1 cells coincided in time with the induction of a local CSFV-specific IFN-γ+ CD8 T cell response in C-strain vaccinated pigs, but not in pigs that received Alfort-187. Moreover, the frequency of CSFV-specific IFN-γ+ CD8 T cells was inversely correlated to the viral load in the tonsils of individual animals. Accordingly, we hypothesise that the activation of cDC1 is key in initiating local CSFV-specific CD8 T cell responses which curtail early virus replication and dissemination.

Nano-adjuvanted dry powder vaccine for the mucosal immunization against airways pathogens

“…Peripheral blood samples in Li-heparin were collected at 0, 14, 21, 28, 35, and 47 days PV to evaluate the systemic immune responsiveness of T cells and B cells by means of an IFN-γ ELISPOT assay and flow cytometry, respectively. In line with the results reported by Soldevila et al (17) regarding the quantification of immune cell frequencies, the mean value of the mock-vaccinated control group at 0 days PV was used as the reference value for group comparisons throughout the study period.…”

A Genetically Engineered Bivalent Vaccine Coexpressing a Molecular Adjuvant against Classical Swine Fever and Porcine Epidemic Diarrhea

“…N pro is an autoprotease located at the N-terminus of the polyprotein and disrupts type I IFN (IFN-α/β) synthesis by inducing IRF3 degradation, which endows CSFVs with high antivirus immune escape abilities [10][11][12][13][14]. To control this Class-A infectious disease classified by the World Organization for Animal Health (OIE), the CSFV C-strain vaccine has been regarded as one of the safest and most effective attenuated vaccines for CSF prevention [15][16][17]. Furthermore, the C-strain has been used to successfully express foreign proteins [18,19], indicating that it is a potential vaccine vector.…”