Monocyte function in chickens with hereditary muscular dystrophy

The influence of Spirulina extract on pathogenicity, immune response, and vaccine efficacy against H9N2 avian influenza virus in specific pathogen free chickens

Avian influenza (AI) viruses pose a risk to the worldwide poultry industry. Ultimately, improving the efficiency of the H9N2 vaccine is necessary to better control low-pathogenic avian influenza-H9N2 by using natural immunostimulant. Therefore, the goal of the present study was to examine varying doses of the cyanobacterium Spirulina extract on the effectiveness of H9N2 vaccine. Thus, a total of 150 specific pathogen-free (SPF) chickens were allocated into 6 groups, 25 birds each, as follow: G1, G2, and G6 were supplemented with 200, 400, and 400 mg Spirulina extract/kg feed, respectively, whilst the feed in G3, G4, and G5 were not supplemented with Spirulina extract. At 21-days-old, only the chickens in G1, G2, and G3 were vaccinated with the H9N2 AI vaccine. After 4 wk postvaccination, the chickens in G1, G2, G3, G4, and G6 were challenged with H9N2 AI Egyptian strain. The challenged virus was selected from a recent circulating Egyptian strain during 2022, and it was related to A/quail/Hong Kong/G1/97-like virus lineage and clustered with G1-B sub-lineage EGY-2 group. It had a high amino acids identity percentage of 92.6% with the A/chicken/Iran/av1221/1998 (Boehringer Ingelheim) vaccine. The results of real-time reverse-transcriptase polymerase-chain-reaction (rRT-PCR) revealed that no shedding of the virus was reported in G1, G2, G3, and G5. The supplementation of Spirulina extract in low (200 mg/kg of feed) and high (400 mg/kg of feed) concentration with the birds vaccinated with H9N2 AI vaccine (G1 and G2) induced prominent immuno-stimulatory effect in a dose dependent manner where it strongly enhanced the phagocytic activities of broilers' peripheral blood monocytes, and lysozyme at all days postvaccination (dpv) and days postchallenge (dpc) compared to other groups with significant differences at all day of experiment and 21st dpv, 28th dpv, 7th dpc, and 14th dpc, respectively. The supplementation with Spirulina extract in G1 and G2 induced the highest hemagglutination inhibition antibody titer in a dose-dependent manner at all-time intervals. The antibody titer postvaccination was significantly increased in G1 and G2 at 14th, and 21st dpv, in comparison with G3. Furthermore, G1 and G2 showed higher significant antibody titers at 7th and 14th dpc, compared to other groups. Furthermore, Spirulina extract (200 and 400 mg/kg feed) in G1 and G2 showed anti-inflammatory effect in a dose dependant manner by downregulating nitric oxide levels at all times postchallenge with a significant difference at 3 to 7 dpc compared to G3, G4, and G6, with improved histopathological alterations in the trachea, lung, kidney, spleen, and bursa of Fabricius.  G6 supplied with 400 mg/kg Spirulina extract feed only without vaccination had a similar effect as vaccinated groups on innate immunity. However, it delayed the production of antibodies and did not prevent viral shedding as in vaccinated groups. In conclusion, vaccination in conjunction with either dose of Spirulina extract (G1, and G2) prevents viral shedding, increases the immune response, and reduces inflammation and histopathological change caused by H9N2 AI infection in a dose dependent manner. We recommend the use of 400 mg Spirulina extract/kg feed as a natural immunostimulant in conjunction with the H9N2 vaccine to achieve the highest possible level of protection against H9N2 AI infection.

Protective effect of Echinacea purpurea (Immulant) against cisplatin-induced immunotoxicity in rats

PURPOSE

Cisplatin, one of the most effective anticancer drugs, is known to cause undesirable adverse effects, including immunotoxicity. Echinacea purpurea is an important medicinal plant with immunostimulatory and anti-inflammatory activities. We have investigated the protective effect of an herbal formulation (Immulant) containing E. purpurea extract against cisplatin-induced immunotoxicity in rats.

METHODS

Forty mature albino rats were randomized into four groups (10 rats/group). Control (group 1) animals were subjected to intraperitoneal (i.p.) injection of saline solution (0.2 ml) once every 3 days. Group 2 animals received cisplatin (3.5 mg/kg, i.p.) once every 3 days for successive 2 weeks. Group 3 rats received oral Immulant (150 mg/kg) once daily for 2 weeks. Group 4 animals received oral Immulant treatment as in group 3 in addition to cisplatin as in group 2. Serum level of total protein and albumin, total and differential leukocytic count, phagocytic activity of monocytes, humoral activity and splenic histopathology and immunohistochemistry were used as diagnostic markers of immunotoxicity.

RESULTS

Cisplatin induced marked inhibition of cellular immunity as exhibited by significant decrease of leukocytic count, lymphocyte percentage and phagocytic activity with marked increase in neutrophil percentage. Humoral immunity represented by marked inhibition in total protein and γ-globulin concentration and significant inhibition in antibody titer against Mycoplasma gallisepticum were recorded. Histopathological and immunohistochemical observation of the spleen of cisplatin-treated rats revealed obvious pathological findings of marked depletion and degeneration of lymphoid tissue. Co-oral administration of Immulant resulted in substantial improvement of various immunotoxicological indices compared to cisplatin control.

CONCLUSION

The herbal medicine Immulant is an immunostimulant which could be used to treat the immunotoxic effects of cisplatin. Graphical abstract Cisplatin (CP) is a highly effective antineoplastic DNA alkylating agent. CP induces free radical production causing an oxidative damage.Cisplatin induced marked inhibition in cellular and humoral immunityEchinacea purpurea (Immulant) is a powerful anticytotoxic agent against cisplatin toxicity.

Cell-mediated and humoral immunity and phagocytic ability in chicken Lines divergently selected for serum immunoglobulin M and G levels

Humoral and cell-mediated immunities and phagocytic ability were examined at the third and fourth generations of selection in two pairs of chicken lines (at 10 wk of age) that were divergently selected for levels of high serum Ig M (HIM), low serum Ig M (LIM), high serum Ig G (HIG), and low serum Ig G (LIG). Cell-mediated immunity was examined by splenomegaly assay at 12 wk of age. At 20 and 23 wk of age, 20 birds from the respective lines were injected Brucella abortus (BA), and blood samples were collected at 7 and 14 d postprimary immunization (PPI) and postsecondary immunization (PSI). Phagocytic ability was measured by carbon clearance assay at 25 and 30 wk of age. The results showed that the LIG line had higher degree of splenomegaly indices than the HIG line in both generations. The HIM and HIG lines had significantly (P < 0.05) higher total antibody titers to BA than their low counterparts. Similarly, mercaptoethanol-resistant (MER) antibody titers to BA, as measured only in the fourth generation, were significantly (P < 0.05) higher in the HIM and HIG lines than their low counterparts. In both generations, the HIM and HIG lines had significantly (P < 0.01) faster carbon clearance ability than the LIM and LIG lines. The results suggest that both pairs of selected lines exhibited divergence in immunocompetence, although they had been selected for serum Ig isotypes.

T lymphocyte reactivity to glutamic acid-alanine-tyrosine in vitro does not reflect antibody response in vivo

Mechanisms responsible for the differences in humoral immune response to GAT (a random linear amino acid polymer) were investigated in a line of chickens consisting of four sublines homozygous for Ea-B (B1 or B19) and high or low antibody response to GAT (Ir-GATH or Ir-GATL). Previous research provided evidence of chromosomal recombination between the serologically determined regions of the MHC (encoded by B-F and B-G genes) and the gene or genes that control immune response to GAT, but immune response to GAT did not seem to be mediated through differences in B-L gene products. In the present study, proliferation of GAT-primed T lymphocytes indicated that reactivity in vitro was not associated with antibody levels produced in the animal. Cell surface markers were identified by flow cytometry. Lymphocytes from Ea-B19 chickens that were Ir-GATL had a higher percentage of suppressor T (CD8)-positive cells than did lymphocytes from Ir-GATH chickens. The Ea-B1 chickens that were Ir-GATL had a higher percentage of CD4-positive lymphocytes than did chickens that were Ir-GATH. This may indicate that low response to GAT in the Ea-B19 chickens, but not in Ea-B1 chickens, is mediated by CD8-positive cells. The ability of antigen-presenting cells (APC) to process and present GAT to antigen-primed T lymphocytes was tested in vitro. Measurements of lymphocyte proliferation indicated that, within the Ea-B1 blood type, APC from Ir-GATL chickens produced higher (P < .05) stimulation of both GAT low- and GAT high-responder lymphocytes.(ABSTRACT TRUNCATED AT 250 WORDS)

Genetic control of cell-mediated immunity in chickens

The present review briefly outlines the effector cells and molecules influencing cell-mediated immunity. Emphasis is placed on the genes determining these molecules in mammals and in the chicken, including genes for cytokines and cytokine receptors. The review concludes with a tabular presentation containing examples of specific genetic influences on cell-mediated immunity in chickens and mammals.