Differential expression of chemokine receptors and chemotactic responsiveness of type 1 T helper cells (Th1s) and Th2s

Abstract

T helper cells type 1 (Th1s) that produce interferon-gamma predominantly mediate cellular immune responses and are involved in the development of chronic inflammatory conditions, whereas Th2s which produce large amounts of IL-4 and IL-5 upregulate IgE production and are prominent in the pathogenesis of allergic diseases. The precise factors determining whether Th1- or Th2-mediated immune responses preferentially occur at a peripheral site of antigen exposure are largely unknown. Chemokines, a superfamily of polypeptide mediators, are a key component of the leukocyte recruitment process. Here we report that among four CXC (CXCR1-4) and five CC (CCR1-5) chemokine receptors analyzed, CXCR3 and CCR5 are preferentially expressed in human Th1s. In contrast, Th2s preferentially express CCR4 and, to a lesser extent, CCR3. In agreement with the differential chemokine receptor expression, Th1s and Th2s selectively migrate in response to the corresponding chemokines. The differential expression of chemokine receptors may dictate, to a large extent, the migration and tissue homing of Th1s and Th2s. It may also determine different susceptibility of Th1s and Th2s to human immunodeficiency virus strains using different fusion coreceptors.

Figure 1

Intracellular cytokine production of Th1 and Th2 lines and clones. Neonatal T cells were stimulated as described in Materials and Methods with PHA in the presence of IL-12 and neutralizing anti–IL-4 antibodies for Th1 cultures or IL-4 and neutralizing anti–IL-12 antibodies for Th2 cultures, respectively. Cells were washed on day 3 and expanded in a medium containing 100 U/ml IL-2. After 10 d, cells were washed, stimulated with PMA and ionomycin, and stained for intracellular IFN-γ and IL-4. Cells were then analyzed by FACS^® analysis. The staining of two representative Th1 and Th2 lines (a and b, respectively) and Th1 (ET3.20) and Th2 (E4.1) clones (c and d, respectively) is shown.

Figure 2

Differential expression of chemokine receptors in Th1s versus Th2s. 10 μg of total mRNA purified from Th1s and Th2s were used in Northern blots analysis. Autoradiographies were obtained after 12 h of exposure, except for CCR3 which required 7 d. Lane to lane variation in RNA loading was <15%, as assessed by densitometric analysis of β-actin expression. Results are representative of three experiments. (A) CCR1 through 5. (B) CXCR1 through 4.

Figure 2

Differential expression of chemokine receptors in Th1s versus Th2s. 10 μg of total mRNA purified from Th1s and Th2s were used in Northern blots analysis. Autoradiographies were obtained after 12 h of exposure, except for CCR3 which required 7 d. Lane to lane variation in RNA loading was <15%, as assessed by densitometric analysis of β-actin expression. Results are representative of three experiments. (A) CCR1 through 5. (B) CXCR1 through 4.

Figure 3

Differential expression of chemokine receptors in Th1 versus Th2 T cell clones. (Top) Expression of CCR4, CCR5, and CXCR3 was examined on four antigen-specific Th1 clones derived from three different donors and on two antigen-specific Th2 clones derived from two different donors with similar results. Northern analysis from one representative Th1 (ET3.20) and one Th2 (E4.1) clone is shown. (Bottom) Chemotactic responsiveness to MDC and MIP-1β of T cell clones ET3.20 (Th1) and E4.1 (Th2). For IP-10, see Fig. 4.

Figure 4

Migratory response of Th1s and Th2s to chemokines. Migration was assessed in nitrocellulose filters as described (26). Spontaneous migration was subtracted. Results are the mean of three (MDC, MCP-1), two (eotaxin, IP-10), or one (MIP-1α, MIP-1β) experiment. The IP-10 dose response was obtained with one Th1 (ET3.20) and one Th2 (E4.1) clone; bulk Th1 and Th2 lines were only tested at one concentration, with similar results.