Enhanced cytokine production by milk macrophages following infection with respiratory syncytial virus.
Paired samples of milk and serum collected 3 days postpartum from 20 women were tested for the presence and level of interleukin (IL)-1, IL-6, IL-12, tumor necrosis factor alpha (TNF-alpha), and interferon-gamma (IFN-gamma) by enzyme immunoassay. The expression of these cytokine mRNAs in milk macrophages from eight donors were semiquantitatively analyzed by reverse transcriptase-polymerase chain reaction. The effects of respiratory syncytial virus (RSV) infection on cytokine production were determined in five samples of milk macrophages. Over 90% of the milk samples tested exhibited detectable levels of IL-1beta, IL-6, and TNF-alpha. No IL-12 or IFN-gamma activity was detected in the milk. IL-6 activity was weakly detected in about 45%, and TNF-alpha activity in about 10% of the serum samples tested. However, no IL-1beta, IL-12, or IFN-gamma activity was demonstrated in any of the serum samples. Milk macrophages from eight subjects all exhibited mRNA for IL-1beta, TNF-alpha, and IL-6, and IFN-gamma mRNA in six of eight subjects, although no IFN-gamma was detected in any of the 20 samples of milk tested. RSV exposure resulted in a 2- to 100-fold increase in the expression of IL-1beta, IL-6, and TNF-alpha mRNA as well as cytokine protein. Although RSV infection enhanced the expression of IFN-gamma mRNA, no detectable IFN-gamma was produced by the milk macrophages. These observations suggest that the milk macrophages are actively engaged in the physiological production of IL-1beta, IL-6, TNF-alpha, and IFN-gamma in the mammary gland and continue to possess the capacity to increase production of these cytokines in response to RSV and possibly other viral infections.
Sone
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Department of Pediatrics, Sapporo Medical University School of Medicine, Japan.
Tsutsumi
H
H
Takeuchi
R
R
Matsuda
K
K
Imai
S
S
Ogra
P L
PL
Chiba
S
S
D016207:Cytokines / Q000096:biosynthesis* / Q000378:metabolism; D005260:Female; D006801:Humans; D007124:Immunoenzyme Techniques; D008264:Macrophages / Q000378:metabolism* / Q000821:virology*; D008895:Milk, Human / Q000166:cytology* / Q000821:virology*; D012333:RNA, Messenger / Q000378:metabolism; D018357:Respiratory Syncytial Virus Infections / Q000378:metabolism; D018113:Respiratory Syncytial Virus, Human; D012680:Sensitivity and Specificity
D016207:Cytokines; D012333:RNA, Messenger