In vitro effect of anti-inflammatory agents on phagocytosis and bacterial killing by human neutrophilic leukocytes

Immunotherapeutic potential of Crotoxin: anti-inflammatory and immunosuppressive properties

For the past 80 years, Crotoxin has become one of the most investigated isolated toxins from snake venoms, partially due to its major role as the main toxic component in the venom of the South American rattlesnake Crotalus durissus terrificus. However, in the past decades, progressive studies have led researchers to shift their focus on Crotoxin, opening novel perspectives and applications as a therapeutic approach. Although this toxin acts on a wide variety of biological events, the modulation of immune responses is considered as one of its most relevant behaviors. Therefore, the present review describes the scientific investigations on the capacity of Crotoxin to modulate anti-inflammatory and immunosuppressive responses, and its application as a medicinal immunopharmacological approach. In addition, this review will also discuss its mechanisms, involving cellular and molecular pathways, capable of improving pathological alterations related to immune-associated disorders.

The association of serum IgM and IgG levels with the number of X chromosomes in patients with abnormal number of X chromosomes

The following attributes of the immune response were studied from nine patients with different numbers of X chromosomes: serum immunoglobulin levels, C3 and C4 concentrations, the presence of autoantibodies, phagocytosis, killing of bacteria, the chemotactic response of neutrophils, the in vitro response of lymphocytes to PHA, ConA, PwM, PPD and oidiomycin; and the proportion of T lymphocytes was determined. The number of X chromosomes varied from one (45,X) to four (48,XXXX). No evidence of severe dysfunction in the immune system was found in any of the patients. The correlation coefficients between the serum concentration of IgM and IgG and the number of X chromosomes present were statistically significant (r = 0.691, P less than 0.05, and r = 0.714, P less than 0.05, respectively). The serum IgA concentration showed a tendency towards a negative correlation. The concentrations of neither IgD nor IgE correlated to the number of X chromosomes. It seems obvious that the number of X chromosomes is positively associated with the concentration of serum IgG and IgM. The results support the hypothesis that antibody production is at least partially controlled by genes located in the X chromosome.

Effect of methotrexate on phagocytosis and killing of Staphylococcus aureus by human granulocytes

The effect of methotrexate on the phagocytosis and killing of Staphylococcus aureus by granulocytes from healthy blood donors was investigated in vitro. A concentration of methotrexate of 2.2 x 10(-4) mol/1 (100 micrograms/ml), which is readily obtained on high dose intravenous administration did not decrease the phagocytosis and intracellular killing of Staph. aureus. In addition, granulocytes isolated from patients after termination of 6 h and 24 h high-dose methotrexate infusions showed normal phagocytic activity.

Influence of hydrocortisone on granulocyte function and glucose metabolism

Examination has been made of the influence of hydrocortisone on the in vitro phagocytosis and intracellular killing of Staphylococcus aureus by human neutrophils and the production of lactate and CO2 during phagocytosis of latex particles. In high concentrations, 0.5-2 mg per ml, hydrocortisone caused a significant reduction in the phagocytosis and the production of lactate. Neither the bactericidal activity nor the production of 14CO2 from (U-14C) glucose in phagocytizing leukocytes was influenced by these hydrocortisone concentrations.

Influence of hydrocortisone on uptake and elimination of 32P-labelled E. coli by rat polymorphonuclear neutrophils (PMN) in vitro

Hydrocortisone was tested for inhibition of uptake and of elimination of E. coli by monolayers of rat peritoneal PMN. 32P was used as label of the bacteria and their degradation products eliminated from the phagocytes. The cellular uptake was reduced by hydrocortisone (1-2 mg per ml) both in the presence and absence of serum, while the elimination of bacterial label was reduced by 0.5 mg per ml and higher concentrations of the drug.

The effect of cytotoxic drugs on neutrophil phagocytosis in vitro and in patients with acute myelogenous leukaemia

The in vitro effects of a range of concentrations of cyclophosphamide, doxorubicin, actinomycin D, cytarabine and methotrexate on neutrophil phagocytosis of C. albicans was studied. The reduction in phagocytic index (PI) was inversely proportional to the dilution of the drug and there was some inhibition of phagocytosis at all dilutions of all drugs. In patients with acute myelogenous leukaemia (AML), in vivo experiments showed that remission chemotherapy of doxorubicin or daunorubicin together with cytosine arabinoside increasingly inhibited phagocytosis over the period studied. The importance of these findings in the chemotherapy of malignant disease and the possible mode of action of cytotoxic drugs are discussed.

The effect of cytotoxic and anti-inflammatory drugs on the phagocytosis of neutrophil leucocytes

The phagocytosis of heat-killed Candida albicans by neutrophil leucocytes was inhibited in vitro by phenylbutazone and acetylsalicylic acid and by the cytotoxic drugs vincristine, vinblastine, cytosine arabinoside, daunorubicin and busulphan, but not by mustine hydrochloride or procarbazine. In vivo studies in man have shown a significant reduction in phagocytosis after phenylbutazone ingestion, but not following an oral dose of aspirin. Possible explanatory mechanisms of drug action on neutrophil phagocytosis are discussed.