Un<em> In Vitro</em> Modello per la misurazione Risposte immunitarie Malaria nel contesto della coinfezione da HIV
Summary
Human co-infection is difficult to replicate in vitro. However, human malaria parasites can readily be cultured in vitro, as can freshly isolated human peripheral blood mononuclear cells naturally infected with HIV. This provides an excellent model for studying early immune responses to malaria parasites in the context of HIV co-infection.
Abstract
Malaria and HIV co-infection is a growing health priority. However, most research on malaria or HIV currently focuses on each infection individually. Although understanding the disease dynamics for each of these pathogens independently is vital, it is also important that the interactions between these pathogens are investigated and understood.
We have developed a versatile in vitro model of HIV-malaria co-infection to study host immune responses to malaria in the context of HIV infection. Our model allows the study of secreted factors in cellular supernatants, cell surface and intracellular protein markers, as well as RNA expression levels. The experimental design and methods used limit variability and promote data reliability and reproducibility.
All pathogens used in this model are natural human pathogens (Plasmodium falciparum and HIV-1), and all infected cells are naturally infected and used fresh. We use human erythrocytes parasitized with P. falciparum and maintained in continuous in vitro culture. We obtain freshly isolated peripheral blood mononuclear cells from chronically HIV-infected volunteers. Every condition used has an appropriate control (P. falciparum parasitized vs. normal erythrocytes), and every HIV-infected donor has an HIV uninfected control, from which cells are harvested on the same day. This model provides a realistic environment to study the interactions between malaria parasites and human immune cells in the context of HIV infection.
Introduction
Co-infezione, infezione da infezioni multiple concomitanti, è la norma in ambienti naturali. Co-infezione può avere un grande impatto sulla patologia della malattia e sulla gestione clinica di ogni infezione. Nel contesto di co-infezione, il vaccino e l'efficacia dei farmaci, così come test diagnostico, può essere influenzato negativamente (rivisto in 1). Tuttavia, nonostante la sua importanza, la maggior parte delle ricerche patogeno ritiene infezioni solo singoli.
La malaria e HIV-1 (HIV) sono le principali cause di morbilità e mortalità a livello mondiale. Aree di malaria e l'HIV endemicità condividono una vasta sovrapposizione geografica, mettendo a milioni di persone a rischio di co-infezione e di conseguenza a rischio di più grave malattia clinica 2-10. Le due malattie interagiscono negativamente. Negli individui affetti da HIV, la carica virale HIV più alti e le diminuzioni temporanee CD4 + T-cellule può essere visto nel corso di una infezione della malaria, mentremalaria oneri parassita e il rischio di malaria clinica e grave sono più alti in co-infettati individui 2,3,5,7,8,10. I meccanismi attraverso i quali l'HIV aumenta la malaria gravità non sono pienamente compresi e meritano ulteriori indagini.
Qui si descrive un metodo con cui la malaria e la co-infezione HIV possono essere studiati in vitro. In particolare, questo metodo consente per l'esame delle risposte immunitarie specifiche per malaria nel contesto dell'infezione da HIV. Il nostro protocollo descrive un sistema versatile di co-coltura con cellule mononucleate del sangue periferico appena isolate (PBMC) isolati da donatori infetti cronicamente da HIV e in vitro colta P. falciparum parassitati eritrociti (PfRBC). L'impatto dell'HIV terapia antiretrovirale nelle risposte può essere esaminata usando PBMC prospetticamente raccolti da HIV (+) i donatori pre e post-terapia.
Abbiamo usato questo sistema per studiare l'impatto dell'infezione da HIVsulle risposte immunitarie innate specifiche malaria 11,12, e sono stati in grado di determinare che IFNγ e TNF risposte specifiche per malaria sono alterate nelle cellule NK, cellule NKT, γδ cellule T da HIV (+) i donatori pre e post-HIV terapia antiretrovirale . Inoltre, siamo stati in grado di utilizzare questo sistema per determinare che le funzioni monocitiche sono anche compromesse HIV (+) i donatori, ma recuperare post-HIV terapia antiretrovirale.
Protocol
Representative Results
Discussion
Il nostro protocollo è stato ottimizzato al fine di studiare più realisticamente la co-infezione HIV-malaria in vitro. In primo luogo, i globuli rossi umani freschi e siero sono necessari per la cultura parassita della malaria. Questo è fondamentale per ottenere una popolazione sana di parassiti della malaria. Lisati parassiti non possono essere sostituiti per i parassiti dal vivo come la produzione di citochine è molto più rapido e intenso quando si utilizza dal vivo P. falciparum infett…
Disclosures
The authors have nothing to disclose.
Acknowledgements
C.A.M.F. and L.S. participated in protocol design, acquisition and analysis of data, and drafting of the article.
The authors wish to thank Dr. Kain, Dr. Loutfy, Dr. Wasmuth, and Dr. Ayi for their contributions.
C.F. was supported by a CTN/Ontario HIV Treatment Network (OHTN) postdoctoral fellowship. L.S. is supported by an OHTN Junior Investigator Development Award. The present work was supported by a Canadian Institutes of Health Research (CIHR) operating grant (MOP-13721 and 115160), and a CIHR New Investigator Catalyst grant.
Materials
| alanine | Sigma | A7377 | |
| antibodies (see other table) | |||
| BD Cytofix/Cytoperm with BD GolgiPlug | BD | 555028 | includes brefeldin A, cytofix/cytoperm buffer and perm/wash buffer |
| BD Vacutainer ACD Solution A | BD | 364506 | |
| BD Vacutainer Sodium Heparin | BD | 17-1440-02 | |
| DPBS (no calcium, no magnesium) | Corning | 21-031-CV | |
| Fetal Bovine Serum | Sigma | F1051 | heat inactivate before use |
| Ficoll-Paque PLUS | GE Healthcare | 17-1440-02 | |
| gentamycin (10mg/ml) | Gibco | 15710-064 | |
| Hema3 Staining Set | Fisher | 122-911 | |
| HEPES | Fisher | BP310-500 | |
| hypoxanthine | Sigma | H9636 | |
| Ionomycin | Sigma | I3909 | |
| MEM non-essential amino acids (10mM) | Gibco | 11140 | |
| PMA | Sigma | P8139 | |
| RPMI-1640 powder | Life-Technologies | 31800-022 | |
| RPMI-1640 with L-glutamine and HEPES | Thermo Scientific | SH30255.01 | |
| sodium bicarbonate (powder, cell culture) | Sigma | S5761 | |
| Sodium Pyruvate (100mM) | Gibco | 11360 | |
| Tris (Trizma base) | Sigma | T6066 | |
| Trizol | Ambion | 15596018 | |
| Trypan Blue (0.4%) | Gibco | 15250-061 | |
| BD CompBead | BD | 552843, 552845 | depends on antibodies used |
| Parasite Gas Mixture | By special order | 3% CO2, 1% O2, balance N2 |
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