Serum‐mediated adherence of feline granulocytes to microfilariae of <i>Brugia pahangi in vitro</i>: variations with parasite maturation

Johnson, Patricia R.; Cd, Mackenzie; Rr, Suswillo; Da, Denham

doi:10.1111/j.1365-3024.1981.tb00386.x

Cited by 32 publications

(16 citation statements)

References 19 publications

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“…Conditions which inactivated either the alternative pathway (zymosan, EGTA), the classical pathway (EDTA & Mg2+) or both pathways (heating, EDTA) were all equally effective at inhibiting cellular adherence and this indicates a role for both pathways. Complement alone in the absence of mf-ve sera did not promote cellular adherence, which contrasts with the results of Piessens & da Silva (1982) using B. maluyi in rodents and Johnson et al (1981) using B. pahangi in cats but is in agreement with the findings of Green et al (1981) using 0. volvulus in man. The percentage of mf involved in this reaction is lower than that reported previously by some authors (Piessens & da Silva 1982, Simonsen 1983 but this is probably due to a difference in assessing adherence (we used > 50% of mf surface covered with cells as opposed to > 5 cells/mf).…”

Section: Discussionsupporting

confidence: 74%

Antibody‐dependent cell‐mediated immune reactions to Loa loa microfilariae in amicrofilaraemic subjects

Pinder

Leclerc

Everaere

1992

Parasite Immunology

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Antibody-mediated mechanisms that could be important in controlling microfilaraemia in Loa loa infected amicrofilaraemic adults (mf-ve) were studied. These subjects were selected as having a verified ocular passage of an adult L. loa but being amicrofilaraemic and without recent diethylcarbamazine treatment. Sera from 37 mf-ve subjects were compared to 14 sera from heavily (greater than 4000 mf/ml) infected subjects (mf+ve) and 9 sera from Caucasian control subjects for their reactions with L. loa mf (mf). Many mf-ve sera (22/37) were strongly positive in immunofluorescence (IFAT) on living mf. Mf+ve sera were negative, or only weakly positive, and Caucasian sera were negative. Clinical signs were not significantly different between IFAT reactive and non-reactive mf-ve subjects. Approximately half of the IFAT positive, mf-ve sera were also able to agglutinate mf; no other sera were active in this test. Titres ranged from log2 3-6 and in most cases, 9/11, the agglutination reaction was mercaptoethanol-sensitive. Antibody-dependent cellular adherence was studied using mf and leukocytes from uninfected donors. Using cryopreserved mf many heat-inactivated mf-ve sera gave strong reactions with obvious adherence by 4 h and few motile mf remained by 16 h but when fresh mf were employed these reactions were weak. However, addition of complement to many (10/11) mf-ve sera considerably enhanced adherence to fresh mf. The effect of various treatments on the complement source indicated a role for both the classical and alternative pathways. The cells attached to mf were mainly neutrophils (83%) with some eosinophils (15%) and few mononuclear cells (2%). The common occurrence of antibodies able to mediate complement-dependent adherence of polymorphonuclear leukocytes to L. loa mf in the sera of mf-ve subjects may indicate that such a mechanism is important in controlling microfilaraemia in vivo.

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Section: Discussionsupporting

confidence: 74%

Antibody‐dependent cell‐mediated immune reactions to Loa loa microfilariae in amicrofilaraemic subjects

Pinder

Leclerc

Everaere

1992

Parasite Immunology

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“…[22][23][24][25] Apparently the anti-sheath antibodies are involved in a mechanism eliminating mf in the infected hosts, probably through mediation of leukocyte adherence to and killing of mf, as has been observed in vitro. [24][25][26][27] Anti-sheath antibodies have also been identified in sera from a proportion of humans from areas endemic for lymphatic filariasis. 8,9,28,29 It was striking in these studies, as in the present study, that individuals who were positive for anti-sheath antibodies were also negative for mf, thus suggesting the involvement of these antibodies in an mf elimination mechanism in human filariasis as well.…”

Section: Discussionmentioning

confidence: 99%

Bancroftian filariasis in Tanzania: specific antibody responses in relation to long-term observations on microfilaremia.

Simonsen¹,

Meyrowitsch²

1998

Am J Trop Med Hyg

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Abstract. Following a 16-year clinical and parasitologic follow-up survey for Bancroftian filariasis in three endemic communities in northeastern Tanzania, serum antibody responses were analyzed in selected individuals in relation to the long-term observations on microfilaremia. Comparison of responses in three categories of adults (microfilaria [mf] positive at both surveys, mf positive at first but mf negative at the second survey, and mf negative at both surveys, respectively) indicated no significant differences between the mean levels of filarial-specific IgG1, IgG2, IgG3, IgG4, or IgE (measured by ELISA). However, specific IgG2 to the sheath of Wuchereria bancrofti mf (measured by an indirect fluorescence antibody test [IFAT]) was detected only in the third category. Comparison of responses in two categories of children born around the time of the first survey (to mf-positive and mf-negative mothers, respectively) showed a significantly higher mean level of filarial-specific IgG4 in the first than in the latter category, whereas the mean levels of filarial-specific IgG1, IgG2, IgG3, and IgE, and the prevalences of IgG2 IFAT positivity were similar. The overall prevalence of IgG2 IFAT positivity was considerably higher in the child study population (45.5%) than in the adult study population (16.7%). In both populations, however, a clear association between IgG2 IFAT positivity and a negative microfilarial status and negative specific circulating antigen status was seen. The study suggests that specific anti-sheath-antibodies are associated with an immunologic resistance mechanism that in the endemic community is expressed with highest prevalence in young individuals before development of patent microfilaremia.Despite the widespread occurrence of Wuchereria bancrofti infections in tropical areas, many aspects of the natural history of infection and disease in Bancroftian filariasis remain poorly understood. Basic knowledge on determinants related to host susceptibility, the longevity of infection and development of resistance, being of utmost importance for understanding the epidemiology of Bancroftian filariasis and for planning and implementation of control programs, is lacking. 1-3 A major reason for this is a scarcity of longitudinal studies.In an attempt to clarify some of these aspects, a 16-year follow-up study was carried out on Bancroftian filariasis in three endemic communities in northeastern Tanzania. All individuals were examined for microfilariae and clinical manifestations in 1975 4 and again in late 1991, 5 and as many as possible of the individuals examined in the first surveys were re-identified in the second surveys. Analyses of the parasitologic and clinical findings have already been presented. 5,6 Briefly, with respect to microfilaremia, the study showed that only few individuals had changed from a microfilaria (mf)-positive to -negative status over the 16-year period, despite the fact that the average life span of adult worms has been estimated to be much shorter. 1 In the 1991 survey...

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“…Johnson et al [62] studied in vitro cellular adherence of eosinophils and neutrophils to microfilariae of B. malayi in cat serum. They found that adherence was mediated by both, heat-labile and heat-stable factors.…”

Section: Administration To Filarial Wormsmentioning

confidence: 99%

“…Naturally occurring amicrofilaremic individuals have been documented in filarial-infected humans with O. volvulus [63], W. bancrofti [29, 64, 65], B. malayi [29, 62, 66], and B. pahangi [66], and in dogs infected with D. immitis [47, 67–70]. Wong & Suter [67] noted that when naturally amicrofilaremic D. immitis- infected dogs were treated to remove adult worms and then re-infected, the dogs were susceptible to subsequent infection, but the new infection was also amicrofilaremic.…”

Section: Administration To Filarial Wormsmentioning

confidence: 99%

Examining the role of macrolides and host immunity in combatting filarial parasites

Carithers

2017

Parasites Vectors

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Macrocyclic lactones (MLs), specifically the avermectins and milbemycins, are known for their effectiveness against a broad spectrum of disease-causing nematodes and arthropods in humans and animals. In most nematodes, drugs in this class induce paralysis, resulting in starvation, impaired ability to remain associated with their anatomical environment, and death of all life stages. Initially, this was also thought to be the ML mode of action against filarial nematodes, but researchers have not been able to validate these characteristic effects of immobilization/starvation of MLs in vitro, even at higher doses than are possible in vivo. Relatively recently, ML receptor sites exclusively located proximate to the excretory-secretory (ES) apparatus were identified in Brugia malayi microfilaria and an ML-induced suppression of secretory protein release by B. malayi microfilariae was demonstrated in vitro. It is hypothesized here that suppression of these ES proteins prevents the filarial worm from interfering with the host’s complement cascade, reducing the ability of the parasite to evade the immune system. Live microfilariae and/or larvae, thus exposed, are attacked and presented to the host’s innate immune mechanisms and are ultimately killed by the immune response, not the ML drug. These live, exposed filarial worms stimulate development of innate, cellular and humoral immune responses that when properly stimulated, are capable of clearing all larvae or microfilariae present in the host, regardless of their individual sensitivity to MLs. Additional research in this area can be expected to improve our understanding of the relationships among filarial worms, MLs, and the host immune system, which likely would have implications in filarial disease management in humans and animals.

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Serum‐mediated adherence of feline granulocytes to microfilariae of Brugia pahangi in vitro: variations with parasite maturation

Cited by 32 publications

References 19 publications

Antibody‐dependent cell‐mediated immune reactions to Loa loa microfilariae in amicrofilaraemic subjects

Antibody‐dependent cell‐mediated immune reactions to Loa loa microfilariae in amicrofilaraemic subjects

Bancroftian filariasis in Tanzania: specific antibody responses in relation to long-term observations on microfilaremia.

Examining the role of macrolides and host immunity in combatting filarial parasites

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