Carbopol improves the early cellular immune responses induced by the modified-life vaccine Ingelvac PRRS® MLV

Abstract

Adjuvants enhance both the magnitude and duration of immune responses, therefore representing a central component of vaccines. The nature of the adjuvant can determine the particular type of immune response, which may be skewed toward cytotoxic T cell (CTL) responses, antibody responses, or particular classes of T helper (Th) responses and antibody isotypes. Traditionally, adjuvants have been added to intrinsically poor immunogenic vaccines, such as those using whole killed organisms or subunit vaccines. Here, we have compared cellular immune responses induced by the immunogenic modified life-attenuated vaccine Ingelvac PRRS® MLV when administered alone or in combination with carbopol, a widely used adjuvant in veterinary medicine. Using functional readouts (IFN-γ ELISpot and cell proliferation) and analyzing phenotypical hallmarks of CD4T cell differentiation, we show that carbopol improves cellular immunity by inducing early IFN-γ-producing cells and by preferentially driving T cell differentiation to effector phenotypes. Our data suggest that adjuvants may enhance and modulate life-attenuated--not only subunit/inactivated--vaccines.

Innate and adaptive immunity against Porcine Reproductive and Respiratory Syndrome Virus

“…The observation that the inclusion of either IL-12 or IFN-␣ during immunization increased the intensity of the IFN-␥ response to PRRSV validates the proposed role of these two innate cytokines in directing the in vivo differentiation of swine Th1 cells, and helps explain the poor virus-specific IFN-␥ response that develops as a result of the exposure of pigs to PRRSV (Meier et al, 2003;Xiao et al, 2004a). Co-administration of adjuvant with modified-live PRRSV has also been shown to enhance the early IFN-␥ cellular immunity, though the connection to innate immune activation was not made (Mair et al, 2015). The plausible role of IFN-␥ in mediating protective immunity against PRRSV is supported by the ability of this cytokine to inhibit PRRSV replication in the simian MARC-145 cell line as well as in porcine AM .…”

Assessment of safety and reproductive performance after vaccination with a modified live-virus PRRS genotype 1 vaccine in pregnant sows at various stages of gestation

“…Vaccination of ponies with carbomer adjuvated equine influenza vaccines increased the duration and the level of antibody response and did not provoke local or system reactions [41]. Additionally, results from a recent study have shown that the addition of carbopol to PRRSV MLV vaccine enhances cellular immunity and therefore has beneficial effects on modified life-attenuated vaccines [42]. The absence of abortions for at least four weeks after vaccination as well as reduced systemic and local reactions in the IVP group indicated that the new PRRS MLV vaccine causes relatively minimal adverse effects in pregnant sows/gilts.…”

Distinct functional enrichment of transcriptional signatures in pigs with high and low IFN-gamma responses after vaccination with a porcine reproductive and respiratory syndrome virus (PRRSV)

“…It is thought that this partial lack of efficacy may be attributable to the genetic and antigenic diversity of the virus. However, several studies have highlighted that there is high inter-individual variability in the development of the immune response and protection after vaccination with a PRRSV vaccine [ 12 , 44 , 45 ] which may account for some lack of efficacy. Therefore one of the challenges of PRRS control is the development of tools to predict the efficacy of vaccines with greater accuracy.…”