Immunomodulatory Effects of the Meretrix Meretrix Oligopeptide (QLNWD) on Immune-Deficient Mice

Abstract

The aim of this study was to explore the immunomodulatory effects of the Meretrix meretrix oligopeptide (MMO, QLNWD) in cyclophosphamide (CTX)-induced immune-deficient mice. Compared to untreated, CTX-induced immune-deficient mice, the spleen and thymus indexes of mice given moderate (100 mg/kg) and high (200 mg/kg) doses of MMO were significantly higher (p < 0.05), and body weight loss was alleviated. Hematoxylin-eosin (H&E) staining revealed that MMO reduced spleen injury, thymus injury, and liver injury induced by CTX in mice. Furthermore, MMO boosted the production of immunoglobulin G (IgG) and hemolysin in the serum and promoted the proliferation and differentiation of spleen T-lymphocytes. Taken together, our findings suggest that MMO plays a vital role in protection against immunosuppression in CTX-induced immune-deficient mice and could be a potential immunomodulatory candidate for use in functional foods or immunologic adjuvants.

Immunomodulatory Effects of Microcin C7 in Cyclophosphamide-Induced Immunosuppressed Mice

“…Wang et al reported that the antimicrobial peptide sublancin significantly improved the body weights of CTX-treated mice, which is similar to the effect of levamisole hydrochloride . Zhang et al also reported that the Meretrix meretrix oligopeptide alleviated body weight loss in CTX-treated mice …”

“…22 Zhang et al also reported that the Meretrix meretrix oligopeptide alleviated body weight loss in CTX-treated mice. 36 Hematopoietic stem cells in bone marrow have multiple potentials, including self-renewal and production of mature blood cells such as erythrocytes, leukocytes, and platelets. 37 Loss of hematopoietic stem cells and inability of bone marrow to generate new blood cells leads to leukopenia and oligocythemia, which may result in severe morbidity and mortality.…”

“…Zhang et al reported that Meretrix meretrix oligopeptide boosted the production of IgG in the serum of immune-deficient mice. 36 Yang et al reported that marine oligopeptide from Chum Salmon increased the secretion of Th1 (IL-2, IFN-γ) and Th2 (IL-5, IL-6) type cell cytokines in CTX-treated ICR mice. 48 Zhu reported that glycopeptide from Paecilomyces sinensis significantly increased serum cytokines related to immune function, including TNF-α, IL-6, and IFN-γ, in CTX-induced immunocompromised mice.…”

“…In accordance with our study, other bioactive peptides also have the ability to enhance serum hemolysin. Zhang et al reported that Meretrix meretrix oligopeptide boosted the production of serum hemolysin . Pan et al reported that milk protein hydrolysates from full-cream milk improved the level of hemolysin in serum …”

“…Zhang et al reported that Meretrix meretrix oligopeptide boosted the production of serum hemolysin. 36 Pan et al reported that milk protein hydrolysates from full-cream milk improved the level of hemolysin in serum. 52 Macrophages are specialized phagocytes of the innate immune system, together with neutrophils, constituting the first line of defense against pathogenic invasions.…”