Gene Expression Analysis of Swine Leukocyte Antigen (SLA-1 and SLA-2) Involved in Porcine Pre-Weaning and Post-Weaning Diarrhea in Nueva Ecija, Philippines.

The immune responses of two breeds of piglets to diarrhea at pre-weaning and post-weaning were evaluated in terms of the relative quantification of Major Histocompatibility Complex (MHC) glycoproteins represented by the swine leukocyte antigen (SLA) class I. The expression of SLA-1 and SLA-2 genes of diarrheic and non-diarrheic Native and Large White piglets were measured using real time polymerase chain reaction (qPCR). Blood samples from 20 Native and 20 Large White piglets were used in this study. It is comprised of 5 Native piglets with clinical signs of diarrhea and 5 Native piglets with no diarrhea at pre-weaning. Same number of piglets were used for Native piglets at post-weaning and Large White piglets at pre-and post-weaning periods. The cDNA samples were amplified using primers for SLA-1 and SLA-1 alleles having amplicon sizes of 217 bp and 126 bp, respectively. Factors that were considered in the study include breed and status of piglets. Relative quantification was done using comparative threshold cycle (C_T) method. Significantly higher levels of SLA-1 were noted in diarrheic pigs compared to those of non-diarrheic piglets (P=0.040) of the Native and Large White breeds at pre-weaning period. This observation was not analogous with the non-significant differences in SLA-2 expression, deduced as SLA-linked immune responses of piglets from the Native and Large White breeds with and without diarrhea observed at pre-weaning and post-weaning stages. The upregulation of SLA-1 in piglets with diarrhea at pre-weaning in the two breeds of swine examined the potential role of SLA-1 in the host's response to diarrhea. These data associate the significance of the SLA-1 gene as a marker for diarrhea in pre-weaning piglets. [ABSTRACT FROM AUTHOR]