IOSR Journal of Pharmacy and Biological Sciences (IOSR-JPBS) e-ISSN: 2278-3008, p-ISSN:2319-7676. Volume 10, Issue 4 Ver. II (Jul - Aug. 2015), PP 33-35 www.iosrjournals.org DOI: 10.9790/3008-10423335 www.iosrjournals.org 33 | Page Evaluation of the Role of Skin Peptides Isolated from Rana tigrina in Cellular and Humoral Immunity in Normal and DL-Bearing Mice Prajapati, Raj Kumar 1 ; Ahmad, Faiyaz 2 and Acharya, Arbind 3 1 Gombe State University, Gombe, Nigeria, 2 MJK College Bettiah, West Champaran, India. 3 Banaras Hindu University, Varanasi, U.P., India. Abstract : In the present study, the peptides secreted by the dorsal skin of Rana tigrina have been isolated and its effects on cellular and humoral immunity has been studied in normal and tumor bearing mice. To evaluate the role of the peptide in cellular immunity delayed type hypersensitivity (DTH) response has been assayed in normal and DL (Dalton’s lymphoma) bearing mice and the effect of the skin peptides on humoral immunity has been evaluated by hemolytic plaque assay. The DTH response was assayed by the mice ear swelling test as described by Phanuphak et. al. (1974). The number of antibody forming cells in the spleen of SRBC (Sheep RBC) immunized mice was determined by the standard Jerne hemolytic plaque assay (Jerne, 1963) as modified by Cunningham (1968). The results show that the percentage suppression of ear swelling is significantly higher in peptide treated normal as well as DL-bearing mice. This suggests that frog peptide is a good suppressor of inflammatory response and thus a potent booster of cellular immunity. In hemolytic plaque assay a significant increase in the number of plaque forming cells (antibody producing cells) has been observed in peptide treated normal and DL-bearing mice as compared to untreated (control) mice. This suggests the potential role of peptide in antibody mediated (humoral) immune response. Keywords: Frog skin peptide, DTH response, Dalton’s lymphoma, SRBC, plaque forming cells. I. Introduction Historically, the immune system was separated into two branches: humoral immunity, for which the protective function of immunization could be found in the humor (cell-free bodily fluid or serum) and cellular immunity, for which the protective function of immunization was associated with cells. CD4 cells or helper T cells provide protection against different pathogens that survive within phagocytes or infect non-phagocytic cells. Humoral immunity refers to antibody production and the accessory processes that accompany it, including: Th2 activation and cytokine production, germinal center formation and isotype switching, affinity maturation and memory cell generation. It also refers to the effector functions of antibodies, which include pathogen and toxin neutralization, classical complement activation, and opsonin promotion of phagocytosis and pathogen elimination (Janeway, 2001). Hemolytic plaque assay as modified by Cunningham (1968) is used for the detection and study of antibody-secreting cells isolated from the spleen. Cellular immunity (CI) functions to enhance antimicrobial actions of phagocytes to eliminate microbes. Cellular immunity manifests as delayed type cellular immune responses. This T-cell–mediated activation of phagocytes depends on interferon gamma (IFN-γ); a major cytokine produced by type 1 T-helper (Th1) cells. However, anti-IFN-γ neutralizing antibodies (Abs) do not completely abrogate CI. IFN-γ or IFN-γR knock out (KO) mice do reveal attenuated cellular immunity. These results indicate that cellular immunity cannot be solely attributed to IFN-γ – mediated Th1 responses. The identification of Th17 cells, which produce interleukins (ILs): IL-17A, IL-17F, IL-21, IL-22, granulocyte-macrophage colony-stimulating factor (GM-CSF), and many other factors, shed a light on the previously observed cellular immunity in the absence of IFN-γ. IL-17 KO mice did display attenuated delayed-type hypersensitivity (DTH) against bovine serum albumin and Bacille Calmette- Guérin (BCG) (Nakae, et. al., 2002). The role of Th17 and Th1 cells in CI may vary depending on stimulants (Iwakura, et. al., 2008). DTH responses in the skin have been used to assess cellular immunity in vivo. Present findings suggest that frog peptides play crucial role in humoral as well as cellular immunity in normal as well as tumor bearing mice and thus have the potential to be used as a therapeutic immunomodulator. II. Materials And Method The DTH response was assayed by the mice ear swelling test as described by Phanuphak et. al. (1974), with slight modification. DTH was induced in these experiments by challenging the pinnae of previously sensitized mice with 2,4-dinitro-1-flourobenzene (DNFB). On the first and second days of sensitization 50 μl of DNFB was applied gradually on to the dorsal skin of mice. On day 5 th after sensitization baseline pinnae