Anti-CD4 monoclonal antibody, clone C597B2

The identification of cross-reactive monoclonal antibodies (mAbs) that recognize orthologous leukocyte differentiation molecules (LDM) in buffaloes has overcome a major impediment limiting research on the immune response to pathogens and development of vaccines. As reported, two pilot trials were conducted to accomplish two objectives: (1) demonstrate that multiparameter flow cytometry can be conducted equally well in buffalo with mAbs directly and indirectly labeled with fluorochromes in research and (2) flow cytometry can be used to compare and extend studies on diseases of economic importance to buffalo using bovine viral diarrhea virus (BVDV) as a model pathogen. Pregnant buffalo cows were infected with BVDV-1 at 81 (trial 1) and 203 (trial 2) days post artificial insemination and flow cytometric evaluations were performed at 0, 3, 4, and 14 days after infection (dpi). Fluorochrome conjugated mAbs were used in trial 1, and fluorochrome conjugated goat isotype specific anti-mouse antibodies were used to label mAbs in trial 2. Flow cytometric analysis revealed a transient lymphopenia occurs during the 1st days following infection similar to lymphopenia reported in cattle. In particular, significant differences were observed between pre- and post-infection absolute values of T lymphocytes (-56%, P < 0.01). CD21(+) B lymphocytes (-65%, P = 0.04), and Natural Killer cells (-72%, P < 0.001). No significant differences were observed in monocytes and neutrophil absolute values, or the CD4:CD8 ratio. Animal health status was followed until 15 days after calving. No clinical signs of infection were observed during the evaluation period, however, animals in trial 1 developed complications later the infection. One cow aborted at 57 days post-infection, the second cow developed a prolapse a day after calving and died. These two animals also showed a more pronounced lymphopenia in comparison with animals infected at 203 days of pregnancy (e.g., -77 vs. -22% T lymphocytes at 3 dpi, respectively). The pilot studies have demonstrated that it is possible to use multicolour multiparameter flow cytometry to study the immune response to pathogens affecting the health of buffalo.

This study isolated and characterized a novel polysaccharide (PNPS-0.3) from the residue of Panax notoginseng by gradient elution. PNPS-0.3 mainly consisted of a backbone of -> 4)alpha-D-GalAp-(1 -> 4-beta-L-Rhap-1 -> 4)-beta-DGalp-(1 -> residues, with an alpha-L-Araf-1 -> 5)-alpha-L-Araf-(1 -> branch connecting to the backbone at O-3 of -> 4-beta-L-Rhap-1 -> and a molecular weight of 76,655 Da. Furthermore, the adjuvant potential of PNPS-0.3 with bone marrow dendritic cells (BMDCs) was investigated. The results suggested that PNPS-0.3 could induce maturation of BMDCs by reshaping the morphology, upregulating the CD40, CD80, CD86 and MHC II membrane phenotypic markers, and by promoting the secretion of TNF-alpha and IL-12 proinflammatory cytokines. Moreover, PNPS-0.3 can trigger the DC-induced T-cell immune response, as indicated by the higher expressions of CD4, CD8, CD69, and MHC II in T cells with increased secretion of INF-beta. Furthermore, PNPS-0.3 can bind to the pattern recognition receptors (PRR) of Toll-like receptor 4 (TLR 4), Toll-like receptor 2 (TLR 2), and mannose receptor (MR) on BMDCs. PNPS-0.3 also upregulated the expressions of Myd88, IKK beta, P-P65, T-P65, and NF-kappa B, suggesting that the TLR4/TLR2-NF-kappa B signaling pathway was involved in the immunomodulatory mechanism. In conclusion, the immunoadjuvant potential of novel PNPS-0.3 was characterized, which is beneficial for the future utilization and development of P. notoginseng. (c) 2020 Published by Elsevier B.V.