The histomorphological studies on ontogeny of Peyer's patches in jejunum of 20 buffalo fetuses ranging from 11.5 cm CVRL (80 days) to 100 cm CVRL (299 days) were conducted. The fetuses were categorized into three groups based on their curved crown rump length (CVRL). The fetuses of gestational age from 11.5 cm CVRL (80 days) to 28 cm CVRL (136 days) were devoid of typical jejunal lymphoid patches. However, at 32 cm CVRL (145 days) aggregates of 2 to 3 lymphocytes were observed arranged linearly in submucosa of jejunum Elongated to oval lymphocytic aggregations were observed in submucosa at 54 cm CVRL (195 days) that formed primordia of lymphoid follicle. The presence of darkly stained lymphocytes was also observed in the intestinal villi above the aggregates at this stage. At 70 cm CVRL (231 days), a number of round, pear shaped developing lymphoid follicles were encountered. At 100 cm CVRL (full term), completely developed lymphoid follicles of different shapes i.e., oval, pear shaped and square shaped follicles were present that were arranged in a single row on the anti-mesenteric part of jejunum. The dome of lymphoid follicle was completely formed at this age by invading the jejunal villi that formed arcs over it. Therefore, the present study suggests that the jejunal Peyer's patches started its development at mid-gestational age and become completely developed in the fetuses that reached upto full term just before birth. Thus these jejunal Peyer's patches generates immune response by sampling foreign antigens entering the lumen and play a crucial role in terms of generating mucosal immunity.

Systematic studies on expression and characterization of toll like receptors (TLRs) in buffalo and cattle will help to understand the innate immune response specific to each species of animals. TLR4 gene is one of the most studied innate immune receptors which is mainly triggered by lipopolysaccharide. Therefore, the present study was carried out to investigate the mRNA expression and sequence analysis of TLR4 in buffalo in comparison to that of cattle. In vitro expression of TLR4 was assessed by challenging the Peripheral Blood Mononuclear Cells (PBMC) with bacterial LPS which showed significant increase of TLR4 gene expression (P LT= 0.01) in buffaloes when compared to cattle. Further the comparison of mRNA sequence of TLR4 of buffalo and cattle revealed 96 percent similarity with the cattle sequence. The primary structure of protein showed the highest percent of leucine amino acid for both the species of animals. At the same time, the number of Leucine Rich repeats (LRR) of buffalo is varied from those present in cattle TLR4. Alpha helix is the prominent secondary structure, however, there were few amino acid variations between buffalo and cattle in certain regions of TLR4 which altered the three dimensional conformation of TLR4 proteins, this in-turn possibly can influence the binding affinity and interaction with pathogens which may influence the difference in immune response in buffalo when compared to that of cattle.

The study evaluated the antibody response and interferon-gamma (IFN-gamma) messenger ribonucleic acid (mRNA) expression levels in naive bovine calves from a Foot-and-Mouth Disease virus (FMDV) potency test. Peripheral blood mononuclear cells (PBMCs) were separated from blood samples and total RNA was extracted. Two step quantitative (Real time-polymerase chain reaction (RT-PCR) method was used for measurement of IFN-gamma specific mRNA. Plasma samples were screened to detect anti-non structural proteins (NSP) antibodies for FMDV in 3AB NSP antibody enzyme linked immunosorbent assay (ELISA). Plasma samples were found free for anti- NSP antibodies for FMDV in vaccinated bovine calves as evaluated in 3AB NSP antibody ELISA test. Increase in mRNA expression level of IFN-gamma after 15 days post vaccination (DPV) was found unequivocally in all five vaccinated calves (more than two-fold increase in 4 out of 5 calves). Liquid phase blocking ELISA (LPBE) test results also revealed highest humoral antibody response on 15 DPV. Monovalent FMDV vaccination elicited highest antibody titre on 15 DPV in correlation with elevated IFN-gamma mRNA level. Humoral and cellular immunity both play important role in protection against FMDV. The study will help in further understanding the role played by both the humoral and cellular immune response against FMDV.