Shifts in bovine CD4+ subpopulations increase T-helper-2 compared with T-helper-1 effector cells during the postpartum period

J Dairy Sci. 1999 Aug;82(8):1696-706. doi: 10.3168/jds.S0022-0302(99)75399-3.

Abstract

This study determined the cytokine profile of CD4+ T-helper cells to elucidate the specific CD4+ T-helper phenotype during the postpartum period. Peripheral blood mononuclear cells were isolated from cows during periods of increased susceptibility (3 d postpartum, n = 7) and decreased susceptibility (mid- to late lactation, n = 6) to mastitis. Isolated mononuclear cells were magnetically separated into CD4(+)-enriched or CD4(+)-depleted populations using specific bovine monoclonal antibodies and were confirmed to be enriched or depleted by flow cytometric analysis. T-helper-1 and T-helper-2 subpopulations were distinguished by cytokine profiles, at both the molecular and protein level, by competitive quantitative reverse transcriptase-polymerase chain reaction and specific bioassays, respectively. The CD4(+)-enriched cultures isolated postpartum had enhanced interleukin-4 and interleukin-10 mRNA transcript expression; cultures isolated during the mid- to late lactating period had enhanced interleukin-2 mRNA transcripts. Depletion of CD4+ lymphocytes decreased, and enrichment of CD4+ lymphocytes increased interferon-gamma transcripts in cultures isolated from mid- to late lactation cows. Interferon-gamma and interleukin-2 bioassays revealed that cytokine secretion paralleled mRNA transcript levels. These data suggest that CD4+ lymphocytes act predominantly as T-helper-2 compared with T-helper-1 within 3 d after calving. Alterations in the T-helper-1 and T-helper-2 responses, and therefore the repertoire of cytokines produced, may be an underlying reason for diminished host immune response during the postpartum period.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Animals
  • CD4 Lymphocyte Count*
  • Cattle / immunology*
  • Female
  • Immunomagnetic Separation
  • Interferon-gamma / genetics
  • Interleukin-10 / genetics
  • Interleukin-2 / genetics
  • Interleukin-4 / genetics
  • Postpartum Period*
  • RNA, Messenger / blood
  • Reverse Transcriptase Polymerase Chain Reaction
  • Th1 Cells / immunology*
  • Th2 Cells / immunology*

Substances

  • Interleukin-2
  • RNA, Messenger
  • Interleukin-10
  • Interleukin-4
  • Interferon-gamma